HANARO Symposium 2010 15th Anniversary of HANARO Operation and Inauguration of the Cold Neutron Research Facility November 1-2, 2010 Daejeon Convention Center (DCC), Daejeon, Korea Organizer: The Ministry of Education Science and Technology Hosts: Korea Atomic Energy Research Institute, Korean Nuclear Society URL: http://hanarosymposium.kaeri.re.kr
KOREA ATOMIC ENERGY RESEARCH INSTITUTE
HANARO Symposium 2010
CONTENTS l Message from the Organizer
01
l Program and Schedule
02
l Invited Speakers
05
l Organization
07
l Introduction to the HANARO
10
l Venue
12
l Visiting Information
14
l Plenary Session
23
l Technical Session - Source / Reactor
30
- Energy / Engineering
88
- Soft Matter
116
- Magnetism
134
- Activation Analysis
158
- Irradiation Tests
186
- Radioisotopes
220
l Author Index
243
Message from the Organizer Korea Atomic Energy Research Institute
The High-flux Advanced Neutron Application Reactor, HANARO, reached the first criticality in February and started the normal operation in April, 1995. With the 30 MW thermal power and the peak neutron flux of 5x10 14 (neutrons/cm 2路sec) HANARO has become one of the most powerful research reactors in the world. The year 2010 marks the reactor's 15th anniversary of operation. KAERI would like to host an international symposium to celebrate the successful launching of the Cold Neutron Research Facility.
The symposium will be held at Daejeon Convention Center on November 1st and 2nd, 2010. In the spirit of celebrating the occasion, the following meetings are embedded in the symposium: International Advisory Committee Meeting and IAEA Research Reactor Networking in the field of Neutron Scattering within the PacificAsian region. The symposium covers a board range of subjects from research reactors in general to spin dynamics utilizing inelastic neutron scattering techniques. There will be invited speakers along with the local scientists and engineers to exchange information on research reactor and neutron science.
This symposium will provide an opportunity to look back the past 15 years and to plan the future of the research reactor utilization in Korea. The organizer would like to welcome everyone, who is interested in the research reactor and its applications for the peaceful use of nuclear technology. Every attendant will make a valuable contribution to the success of the symposium and the future of HANARO.
Thank you very much,
November, 2010 President, KAERI Dr. Myung-Seung Yang
Korea Atomic Energy Research Institute
Program and Schedule
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Korea Atomic Energy Research Institute
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Invited Speakers
Plenary Session Dr. Jae Joo Ha (KAERI, Republic of Korea) Dr. Yury Sokolov (IAEA, Austria) Dr. Ferenc Mezei (ESS, Sweden) Prof. Amares Chatt (Int. Committee on Activation Analysis, Canada) Dr. Masahiro Ishihara (JAEA, Japan) Prof. J. Harvey Turner (School of Medical and Pharmacology Department of Nuclear Medicine, Australia)
Cold Neutron Source Dr. Ken Holst Andersen (ILL, France) Dr. Juergen Peter Duppich (PSI, Switzerland) Dr. Alexander V. Belushkin (Frank Laboratory of Neutron Physics Joint Institute for Nuclear Research, Russia) Prof. Michael James (ANSTO, Australia)
Neutron Diffraction Dr. Takashi Kamiyama (KEK, Japan) Dr. Xun-Li Wang (OakRidge National Laboratory, USA) Dr. Hahn Choo (The University of Tennessee, USA) Dr. Yo Tomota (Ibaraki University, Japan) Prof. Yang Mo Koo (POSTECH, Republic of Korea)
Inelastic Neutron Scattering Dr. T.J. Sato (The University of Tokyo, Japan) Dr. Craig Brown (NIST, USA) Dr. Jason Stewart Gardner (NIST, USA) Prof. Wen-Hsien Li (Neutron Beam Research Center, Taiwan)
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Korea Atomic Energy Research Institute
Neutron Reflectrometry and Small Angle Neutron Scattering Prof. Sung Min Choi (KAIST, Republic of Korea) Prof. Kook Heon Char (Seoul National University, Republic of Korea) Prof. Kwan Woo Shin (Sogang University, Republic of Korea) Prof. Sung Kyun Park (Pusan National University, Republic of Korea) Dr. Albrecht Wiedenmann (ILL, France) Dr. Hideki Matsuoka (Kyoto University, Japan) Dr. Jun-ichi Suzuki (JAEA, Japan)
Neutron Activation Analysis Dr. R. G. Downing (NIST, USA) Prof. Ok Hee Lee (Yong In University, Republic of Korea)
Radioisotopes Dr. George F. Vandegrift (Argonne National Laboratory, USA) Prof. Shantanu Roy (IIT, India)
Irradiation Tests Dr. Wolfgang Wiesenack (Institute for Energiteknikk, Norway) Prof. Kwang Hun Park (Kyung Hee University, Republic of Korea) Prof. Kyu Tae Kim (Hanyang University, Republic of Korea)
Research Reactor Dr. Somporn Chongkum (Thailand Institute of Nuclear Technology, Thailand) Dr. Alim Tarigan (Center for Multipurpose Reactor, Indonesia)
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Organization
Advisory Committee Jong Kyung Kim (Hanyang University, Republic of Korea) Mahn Won Kim (KAIST, Republic of Korea) Yasuhiko Fujii (Comprehensive Research Organization for Science and Society, Japan) Ferenc Mezei (European Spallation Source, Sweden) John William White (Australian National University, Australia) John Michael Rowe (USA) Hiroshi Kawamura (Japan Atomic Energy Agency, Japan) Young Jin Kim (KAERI, Republic of Korea) Se Ki Oh (Ajou University, Republic of Korea) Se Jung Oh (Seoul National University, Republic of Korea) Myung Chul Lee (Korea Radioisotope Association, Republic of Korea) Ki Hak Kim (KEPCO NF, Republic of Korea) Moon Hee Chang (KAERI, Republic of Korea)
Organizing Committee Jae Joo Ha (KAERI, Republic of Korea) Kyeong Lak Jeon (KEPCO NF, Republic of Korea) Kye Hong Lee (KAERI, Republic of Korea) In Cheol Lim (KAERI, Republic of Korea) Sun Ju Choi (KAERI, Republic of Korea) Young Ki Kim (KAERI, Republic of Korea) Ki Bong Lee (Pohang University of Science and Technology, Republic of Korea) Sung Min Choi (KAIST, Republic of Korea) Gyu Seong Cho (KAIST, Republic of Korea) Jin Hong Lee (Chungnam National University, Republic of Korea) Myung Hyun Kim (Kyung Hee University, Republic of Korea) Hee Seung Bom (Chonnam National University, Republic of Korea) Yong Kyun Kim (Hanyang University, Republic of Korea) Kwang Heon Park (Kyung Hee University, Republic of Korea)
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Korea Atomic Energy Research Institute
Technical Committee Kye Hong Lee (KAERI, Republic of Korea) Seung Wook Lee (KAERI, Republic of Korea) Gyu Seong Cho (KAIST, Republic of Korea) Sang Jin Cho (KAERI, Republic of Korea) Sang Ik Wu (KAERI, Republic of Korea) Il Kyoung Jeong (Pusan National University, Republic of Korea) Chang Hee Lee (KAERI, Republic of Korea) Jae Ho Chung (Korea University, Republic of Korea) Je Geun Park (Seoul National University, Republic of Korea) Sungil Park (KAERI, Republic of Korea) Sung Min Choi (KAIST, Republic of Korea) Kwan Woo Shin (Sogang University, Republic of Korea) Man Ho Kim (Seoul National University, Republic of Korea) Jeong Soo Lee (KAERI, Republic of Korea) Baek Seok Seong (KAERI, Republic of Korea) Jin Hong Lee (Chungnam National University, Republic of Korea) Jong Hwa Moon (KAERI, Republic of Korea) Yong Kyun Kim (Hanyang University, Republic of Korea) Jun Sig Lee (KAERI, Republic of Korea) Kwang Hun Park (Kyung Hee University, Republic of Korea) Kyu Tae Kim (Dongguk University, Republic of Korea) Sung Ho Ahn (KAERI, Republic of Korea) Kee Nam Choo (KAERI, Republic of Korea) Cheol Park (KAERI, Republic of Korea) Myung Hyun Kim (Kyung Hee University, Republic of Korea)
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Sponsors Korean Nuclear Society The Korean Hydrogen & New Energy Society The Korean Institute of Metals Materials The Korean Society of Analytical Sciences The Korean Magnetics Society Korea Radioisotope Association The Korean Society of Nuclear Medicine The Korean Society for Nondestructive Testing The Korean Vacuum Society Innovative Technology Center for Radiation Safety The Korea Institute of applied superconductivity and cryogenics Korea Neutron Beam User Association Korea Industrial Testing MFT-Korea Nano Technology Research Association The Polymer Society of Korea Samyoung Unitech Co., LTD Hojin Industrial Co., Ltd Nam Il Optical Components Corp. Korean Physical Society Hyundai Engineering & Construction AONSA (The Asia-Oceania Neutron Scattering Association) SURYUK EN’G CO., LTD
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Korea Atomic Energy Research Institute
Introduction to the HANARO HANARO, the National User Facilities HANARO is a 30 MW open-pool type multi-purpose research reactor which is operated by the Korea Atomic Energy Research Institute. Its initial criticality was achieved in Feb. 1995 and has been utilized for various purposes. The HANARO composed of the HANARO reactor building, the RIPF (Radio-Isotope Production Facility), the IMEF (Irradiated Material Examination Facility), and the CNL (Cold Neutron Laboratory). HANARO has been utilized for neutron science, reactor material and fuel irradiation tests, radioisotope production, neutron transmutation doping, neutron activation analysis, and neutron radiography.
HANARO Characteristics Reactor The reactor is in the pool that is 4m in diameter and 13.4m deep and filled with demineralized water. The reactor structure consists of five components: inlet plenum supporting the reactor tank and distributing inlet coolant the lower grid plate holding the fuel assemblies and experimental facilities reflector tank the outlet chimney where coolant passed through individual flow tubes and bypass flow are mixed flow tube channels HANARO fuel is a rod type unlike the plate type used in the conventional MTRs. The rods are clustered to form a fuel assembly. The two types of fuel assemblies are used in the HANARO.
Experimental Holes and Beam tubes HANARO has 32 vertical holes for irradiation test and 7 horizontal tubes for beam research. 3 vertical holes are locates in the inner core, high thermal and fast flux region. The inner core is surrounded by the inner shell of zircaloy, which separates the inner core and the reflector.4 vertical holes in the outer core in the reflector adjacent to the inner shell, high thermal and epi-thermal flux region. The other 25 vertical holes and 7 horizontal tubes are located in the reflector tank. 17 small holes in the reflector tank are used to produce the radiation isotopes and two NTD (Neutron Transmutation Doping) holes are used for irradiation of silicon ingots.
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HANARO Core
Under-development
Horizontal Tubes Installed ST2 High Resolution Powder Diffractometer, Four Circle Diffractometer NR Neutron Radiography Facility CN Cold Neutron Guide IR Ex-core Neutron-irradiation Facility for BNCT & DNR ST1 PGAA and RSI ST3 Vertical Reflectometer ST3 Horizontal Reflectometer ST3 High Intensity Powder Diffractometer
ST4 Triple Axis Spectrometer
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Korea Atomic Energy Research Institute
Venue Symposium Site Daejeon Convention Center Address: 4-19 Doryong-dong, Yousung-gu, Daejeon, Republic of Korea URL: http://www.dcckorea.or.kr/ Tel: +82-42-821-0114 Fax: +82-42-821-0119
CNRF Inauguration Site Date: November 1st, 2010 Place: INTEC at KAERI KAERI (URL: http://www.kaeri.re.kr/) Nuclear Training & Education Center (URL: http://www.kntc.re.kr/English) Address: Nuclear Training and Education Center, KAERI, 1045 Daedeokdaero, Yousung-gu, Daejeon, 305-353, Republic of Korea Tel: +82-42-868-2678 Fax: +82-42-861-5018
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1st Floor
2nd Floor
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Korea Atomic Energy Research Institute
Visiting Information The symposium will be held from 1 November to 2 November, at Daejeon Convention Center (DCC), which is center of Daejeon in Republic of Korea. In the first day of the symposium, there will be CNRF (Cold Neutron Research Facility) Inauguration Ceremony at INTEC KAERI. People, who want to participate in the CNRF ceremony, can apply to the HANARO Symposium Secretariat (hanaro@kaeri.re.kr). After the ceremony, the bus bound for DCC will be served in front of the KAERI entrance gate to go to the symposium site (Daejeon Convention Center). Please see the time table in the symposium program.
How to go to your hotel at Daejeon from the INCHEON international airport Step 1) Find the bus stop (9D) at the Incheon international airport You can use the convenient limousine bus from Incheon international airport to Daejeon city. The limousine bus takes about 2.5 hours depends on traffic along the high way and the limousine fare is 22,100 Korean won (~$20).
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Step 2) Buy a ticket and put your baggage into the luggage cabinet Step 3) Drop off at the government complex (2nd stop) and please take a taxi to go for your hotel. You can use the convenient limousine bus from Incheon international airport to Daejeon city. The limousine bus takes about 2.5 hours depends on traffic along the high way and the limousine fare is 22,100 Korean won (~$20). Bus Stops at Daejeon : 1) Daedeok Culture Center(Daedeok Lotte Hotel) 2) Government Complex at Daejeon (Usually several taxis are waiting for the passenger) 3) Dongbu Inter-city Bus terminal Taxi information It will take 15 minutes from the bus stop (Gov. Complex) to your hotel. Taxi fee is about 5000~10000 Korean Won (less than $10) from the bus stop to your hotel. Current initial charge is 2,300 Korean won. The total fare is calculated by both the distance and time of travel. It is advisable to show the driver map in order to ensure you get to your destination. Overnight charge is added by 20 percent between midnight and 4 a.m. Taxis are available 24/7.
Step 4) Drop off in front of your hotel Hotel Spapia (at Yousung) 545-5 Bongmyung-dong, Yousung-gu, Daejeon, Republic of Korea Website: http://www.hotelspapia.com/ Tel: +82-42-600-6000 Yousung Hotel 480 Bongmyung-dong, Yousung-gu, Daejeon, Republic of Korea Website: http://www.yousunghotel.com/ Tel:+82-42-820-0100 Please mention when you check-in the hotel that you will attend the HANARO symposium organized by KAERI to get a reduced rate on hotel fees. If you have any difficulty to reach your hotel, please call to the symposium secretariat (Cell. 010-7712-2036)
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Korea Atomic Energy Research Institute
Symposium Information Registration The registration desk will be located in the first floor at DCC during Nov. 1-2. People who have pre-registered, please visit the registration desk. We will prepare your registration receipt, proceeding book, souvenir, and name tag and so on. People who want to register on site should fill out registration form first, and then come to the registration desk. A notice board for the message will be set up in next to the registration desk. Only credit card payment is acceptable on site. In any question or emergency state, please visit registration desk (Daejeon Convention Center, Project Manager +82-42-821-0131)
*Registration Fee General
Student
Pre-Registration thru. Web
100,000 Korean Won / USD100
30,000 Korean Won / USD30
On-Site Registration
150,000 Korean Won / USD150
50,000 Korean Won / USD50
Opening ceremony and Plenary lectures The Opening ceremony will be held on Nov. 1st from 14:00 for 20 minutes at room 201 (2nd floor) in the DCC. Dr. Jae-Joo Ha (Vice president of KAERI) will address the welcome message. Dr. Nam Pyo Hong (Director General of Atomic Energy Bureau) and Dr. Yury Sokolov (Deputy Director General, IAEA) will address the congratulatory remarks. Plenary lecture 1 will start after the opening ceremony. The plenary lecture 2 will be in the 2nd day of the symposium.
Coffee Breaks Coffee and tea will be served designated breaks. Throughout the symposium, coffee, tea, water and some refreshments are available in the exhibition area of the symposium.
Banquet and Luncheon Banquet and luncheon are included in your symposium registration fee. The symposium banquet will be held at the Grand ball room (201) on the first day of the symposium (on Nov. 1) starting at P.M. 6:30. On banquet, there will be a Korean traditional music performance by Seoul National University Korean Music Team for about 30 minutes. Luncheon will be prepared in the second day of the symposium (on Nov. 2) at noon at room 202.
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Parallel Technical Sessions The parallel technical sessions will be held at 101-105 and 201 rooms during the symposium.
Instructions to Oral Speakers (a) Check your presentation and upload before starting each session begins. You can check your presentation can be checked at the preview room. (b) Arrive at the symposium site 20 minutes prior each session and make you known to the chair person. (c) Time of the parallel session can be tight. Chairs may ask you to follow kindly the published schedule. (d) Chair persons will indicate with a chair bell on 3 minutes before your presentation time. (e) All the general speakers can make a presentation for 20 minutes including 5 minutes for questions and discussion (Invited speakers are allowed to make a presentation for 30 minutes)
Poster Presentation The Poster Sessions will be located at the lobby in the first floor. The available size for each poster will be 90 cm (width) x 120 cm (length). The poster session will start on the second day of the symposium from PM 1:00 to PM 3:30. You can present your poster at your assigned poster area (1st floor lobby) in the second the day of the symposium. Push pins will be provided. Please remove your poster after the poster session on Tuesday by PM 6:00. As the poster sessions are excellent occasions for discussions, we would like the presenters to be present at their posters. Schedule for the peer group general meetings Day
Time
Meeting
Venue
Nov. 2. Tue.
12:20 - 13:30
IC (‘Fuel/Material Irradiation’ Section)
102
Nov. 2. Tue.
17:00 - 18:00
RI (Radioisotopes Section)
102
Nov. 2. Tue.
17:00 - 18:00
NAA (Neutron Activation Analysis Section)
103
Nov. 2. Tue.
13:00 - 15:00
KAERI-JAEA Promote Program
203
Internet Access The PC Room will be located in the second floor at DCC. In addition, wireless internet access will be available throughout the symposium site for your laptop.
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Korea Atomic Energy Research Institute
Publications / Conference Proceedings Among the full papers, the publication committee will review and select several papers to publish on the NET (Nuclear Engineering and Technology) journal. Nuclear Engineering and Technology (NET) is an international journal issued by the Korean Nuclear Society. The society was founded on March 9, 1969 to contribute to the development of nuclear science and technology, pursue the academic and technical progress, and promote cooperation between members. The society has been publishing this journal since September 25, 1969 under the title of the Journal of the Korean Nuclear Society until December 2004 and under the title of Nuclear Engineering and Technology since then. The journal provides an international medium (SCIE journal) for the communication of original research, ideas and developments in all aspects of the theory and application of nuclear science and technology and related fields.
Tour Information Subway and Bus at Daejeon City The major hubs for passenger transportation in Daejeon are subway station and the city bus station. Daejeon has a very extensive network of city buses, which are easily identified by their colors each: red, blue, green. Red buses (express) covers 2 routes and they stop at major bus stops, ensuring a rapid transit service. Blue buses (regular) connect the downtown areas with the suburbs. There are 2 types of green-colored buses: one is connects all districts within Daejeon, and the other connects Daejeon with its neighboring areas. Detailed travel information and timetables are found on (http://traffic.metro.daejeon.kr/) and then select internet pages in English. Tickets for subway can be bought at the station and bus fares vary depending on the age group: children, middle and high school students, and adults. Traffic card is recommended as it offers discounts and free transfer.
Tourist Attractions EXPO Park EXPO Science Park is a theme park opened to commemorate the Daejeon International Exposition Korea in 1993. With the neighboring Daedeok Research and Development district, National Science Museum and Currency Museum, it is a de facto science Mecca. (http://www.expopark.co.kr)
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National Science Museum National Science Museum exhibits a diverse science and technology collection and provides educational programs. This museum features the largest observatory in the nation with the 23meter-wide dome. The museum is a place where youth can see, feel, and experience the developments of science for themselves and cultivate their own science-tech interests and creativity. (http://www.science.go.kr)
Daejeon Observatory Daejeon Observatory offers opportunities to observe celestial bodies. This observatory is the first of its kind in terms of accessibility for ordinary people to enjoy astronomy. Observation of the sun can be made during the day, and the observation of other celestial bodies such as planets, nebulas, and clusters of stars at night. (http://star.metro.daejeon.kr/)
Uam Historical Park The park, nestled under Mt. Gyejoksan in Gayang-dong, is a time-honored structure, where famous Joseon-era Confucian scholar Song Si-yeol (1607-1689) lived. Uam was his pen name. The ruins of the buildings were restored as a historical park. Among the cultural assets and properties are Namganjeongsa (old structure), Gigukjeong and Songja Daejeon-pan. (Wooden Printing Blocks of the Books by Song Si-yeol) (Tel: +82-42-673-9286)
Hanbat Museum of Education The Hanbat Museum of Education located at Samseong-dong, Dong-gu, has a collection of 6,000 educational materials. One can view the history of Korean education at a glance here. (http://www.hbem.or.kr)
The Museum of Daejeon History The Museum of Daejeon History was established in 1991 to hand down the historical tradition of the Daejeon area, and to increase residents awareness of history and culture. Along these establishment objectives, it conducts research of cultural relics, and organizes the history of Daejeon according to ensuing research activities. Moreover, it introduces and displays cultural heritages and excavation data. Also, diverse scientific preservation method that is meant to prevent damage to traditional cultural assets is carried on as well. (http://museum.daejeon.go.kr)
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Korea Atomic Energy Research Institute
Restaurants [Korean] Gyeonghoeru In this restaurant, various traditional dishes can be tasted in a beautiful, antique and unique Korean atmosphere. Four type of food servings composed of nine varieties of side dishes including soup, gimchi soup, tangpyeongchae and gujeolpan, along with twenty-nine kinds of dishes including bukeotang (dried pollack soup), bulgogi, boiled sea foods, and chilcheop-bansang (rice meal with seven different side dishes) are served here. (Address: 538-5 Bongmyung-dong, Yousung-gu, Daejeon, Tel: +82-42-822-8416)
Myeongmunga This is a traditional Hanjeongsik (Korean set meal) restaurant. Truly Korean foods including pickled fish, various kind of hot seafood soups, grilled foods, doenjang-jjigae, doenjangguk, and 30 types of side dishes. (Address: 540-13 Bongmyung-dong, Yousung-gu, Daejeon, Tel: +82-42- 822-8000)
Yongsusan More than 30 kinds of seasonal dishes can be tasted in the cozy and comfortable mood created in this eatery. There are three types of set meals, known as Yongjeongsik, Sujengsik and Sanjeongsik. The Yongjeongsik consists of cooked potherbs and gimchi, pickled fish, sinseonro, gujeolpan, galbi, and susamcho. In Sujeongsik, fish is added to the dishes of Yongjeongsik. Sanjeongsik is a simple set meal served at lunchtime. (Address: 546-9 Bongmyung-dong, Yousung-gu, Daejeon, Tel: +8242-822-9421)
[Western or Japanese style]
Arizona Log Cabin This restaurant has a distinctive Mexican style interior. Original Mexican foods are slightly adjusted through use of various spices and sauces for Korean taste buds. As such, foods are neither spicy nor greasy and can be enjoyed by everyone. (Address: 14-11 Yongjeon-dong, Dong-gu, Daejeon, Tel: +82-42- 622-6940)
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Soya Dongaseu (Pork Cuttlet) Meal times here can be enjoyed with family or friends in a comfortable atmosphere and at an affordable price. The specially developed sauce, vegetables and fruits that are served with the tender pork cutlets help create a flavorful meal. (Address: 326-13 Yucheon-dong, Jung-gu, Daejeon, Tel: +82-42-537-7667) Cocos This family restaurant specializes in original California foods. Its interior is decorated based on California tradition creating a clean and imaginative atmosphere. Fifty types of dishes including such tasty delights as various chicken foods, sirloin beefsteak, salads, buffalo wings, nachos, cream soup and french fries are served in this restaurant. (Address: 552-13 Bongmyung-dong, Yousunggu, Daejeon, Tel: +82-42-822-4608) Hanjunggwan The interior design of cleanliness and comfortability in this establishment is impressive. Kind service and various seasonal Japanese foods prepared by a highly skilled head chef continue attract a wide customer base. Businessmen often bring their clients here to them to its fine cuisine. (Address: 40-2 Songchon-dong, Daedeok-gu, Daejeon, Tel: +82-42-621-2501) Onnuri The unique tastes found at this restaurant are created from natural seasonings such as tangleweed and gatsuobusi (dried slices of bonito), shabushabu and sukiyaki can both be enjoyed here. (Address: 1474 Dunsan 1(il)-dong, Seo-gu, Daejeon, Tel: +82-42-472-8242)
[Shopping] Galleria Timeworld Galleria Time world is a tourist and a shopper attraction located in the center of Daejeon. Since there is a cultural center, sports center, and a theater, people can enjoy spending their free time and shopping in this shopping center. Located in the center of the Daejeon, Time World store has various facilities, such as a wedding shop, clinic, beauty shop, and travel agency, and several cultural center for kids. At the same time, there is a sports center with various programs, such as squash, swimming, workout, golf, and aquarobics. Since it plays a role as a large-scale complex for cultural things, leisure, and shopping, people can enjoy all of them simultaneously. (Address: 1036, Dunsan 2-dong, Seo-gu, Daejeon, Tel: +82-42 480-5000, Open Hours: 10:30-20:00, Parking: Over 1,300 vehicles, Website: http://www.timeworld.co.kr)
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Korea Atomic Energy Research Institute
Lotte Department Store The Lotte department store in Daejeon with 12 floors, gives you the opportunity to conveniently do your shopping and enjoy a fruitful cultural life. Lotte Department Store in Daejeon, which is composed of a department store and a discount store, has based their strategy on good service. It has earned its popularity by offering customers various high quality goods at reasonable prices. It also has various facilities including a movie theater with all of the latest technologies and a cultural center. For this reason, though it is a department store, it is also called a discount store or even a movie theater. There is Magnet, a discount store, on the first basement floor and a multiplex movie theater on the tenth floor. Besides these, there is almost everything you need including restaurants, coffee shops, and game rooms on from the eighth to the eleventh floor. Lotte Department Store, opened in the year 2000, plays a large role as a complex cultural center and has become the basis of another commercial area in Daejeon. (Address: 423-1 Goejeong-dong, Seo-gu, Daejeon, Tel: +82-42-601-2500, Open Hours: 10:0020:00, Parking: Over 1,650 vehicles, Web Site: www.lotteshopping.com/depart/branch)
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Plenary Session
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Monday, 1 Nov. 14:20 – 14:50 (Room 201)
Current Status and Future of Research Reactor Technology in Korea Jae Joo Ha a*, Kye Hong Lee a, Sun Ju Choi a, In Cheol Lim a, Jong Man Park a, Young Ki Kim a, Soo Yeol Oh a, Doo-Jeong Leea Korea Atomic Energy Research Institute, 1045 Daedeok-daero Yuseong-gu,Daejeon, Korea305-353 *Corresponding author: jjha@kaeri.re.kr
a
It took 15 years for HANARO to become a total multi-purpose research reactor in every utilization area of neutron beam research, fuel and material irradiation tests, radioisotope development and production, and neutron transmutation doping. Seven horizontal beam ports have been all taken by neutron instruments and neutron radiography facility, one of which is for cold neutron guides to the cold neutron guide hall. Two of seven cold neutron beam lines and the space for the thermal neutron guides are reserved for the next stage of neutron instrument installation, while the cold neutron activation station is already in design stage. The irradiation technologies are under development for qualification test of advanced fuels, high temperature structure material test, and material test for new reactors. The development of radiopharmaceuticals for cancer therapy, fission moly production technology, and multi-phase fluid flow radioactive particle tracking technology are in progress. Every effort should be made for the success of Jordan Research and Training Reactor construction and for the launch of new domestic research reactor project. Consistent marketing for the export of new research reactors will be maintained to replace the old reactors or introduce advanced reactors in the world. The research reactor fuel development and fabrication is one of the key technologies that are in progress and essential for the research reactor construction.
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Enhanced Utilization and Sustainability of Research Reactors Yury Sokolov International Atomic Energy Agency, Wagramer strasse 5, PO Box 100, 1400 Vienna, Austria *Corresponding author: Y.Sokolov@iaea.org
For more than 60 years, research reactors (RRs) have been centres of innovation and productivity for nuclear science and technology. Although historically research reactors (RRs) have supported the initiation and fulfilment of national nuclear power programmes, the multidisciplinary research that RRs support has equally spawned new developments in other areas as radioisotope production and nuclear medicine, neutron beam research and applications, materials characterization and testing, computer code validation, various elemental analyses, including nuclear education and training [1]. To date, some 670 RRs have been built, and of these, 246 reactors in 56 countries continued to operate in 2010 [2]. However, half of the world's operational RRs are now over 40 years old. Many of them are being refurbished to meet today's technological standards and safety requirements, including core conversion from high enriched to low enriched uranium fuel. However, the challenges associated with RR underutilization, ageing, fuel cycle and safety aspects, along with the maintenance of staff and funding for these facilities, continue to be important issues and challenges in many countries. On the other hand, recently a considerable number of IAEA Member States have approached the IAEA for advice and assistance in building their first RR and to develop their technical and safety infrastructures as a valuable first step towards a nuclear power programme. If the benefits from RRs are to be realized, then the premises upon which they are built and operated must be reconsidered and updated to fit today’s technical, economic and social situation. In this respect, all aspects of research reactor utilization, strategy and life cycle management should be re-examined. Given the projected decrease in RRs from 246 today to between 100 and 150 by 2020, greater international cooperation will be required to assure broad access to such facilities and their efficient use. These networks will also contribute to upgrading existing facilities, developing new facilities and improving access to countries without RRs. Although significant results have been obtained so far in initiating and supporting RR coalitions, extensive work is still needed to achieve the objective to improve all aspects of the utilization, modernization and sustainability of individual RRs through involvement in collaborative efforts like networks or coalitions. In this regard, countries without RRs are encouraged to join these coalitions as a first step in developing their national capabilities, either as a partner or as an end user of RR products and services. The IAEA has also continued to support a number of initiatives and assist Member States in core conversion and fuel repatriation projects, organizing topical meetings and workshops, encouraging collaboration through coordinated research projects, as well as supporting the enhanced utilization and safety culture of research reactors through national and regional technical cooperation projects. In addition, the IAEA continues to encourage the application of the Code of Conduct on the Safety of Research Reactors and relevant Safety Standards. Upon the request of Member States, the IAEA conducts safety review and expert missions to assist in enhancing the safe utilization of these facilities. Research reactors are extremely valuable training, research and technological tools, and it is important that their use remains viable. The IAEA is assisting its Member States in attaining these goals, thus helping to fulfil the promise that nuclear science and technology offer for the good of humanity.
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Plenary Session
Monday, 1 Nov. 14:50 – 15:20 (Room 201)
Monday, 1 Nov. 15:20 – 15:50 (Room 201)
Neutron Sources for the Next Generation: New Capabilities and Complementarities F. Mezei a,b ESS AB, PO BOX 117, SE-22100 Lund, Sweden HAS Research Institute for Solid State Physics, Pf. 49, 1525 Budapest, Hungary *Corresponding author: mezei@esshungary.eu a
b
In the past half a century the exploration of condensed matter by neutron scattering methods underwent a huge progress, primarily driven by the development of neutron instrumentation methods – such as advanced neutron guides – and neutron moderators – such as cold sources. The recent implementation of these modern developments has also vastly enhanced the capabilities of the Hanaro facility over the past decade. At the same time, until most recently, the brightness of the neutron sources themselves essentially remained at the level first achieved in 1958 at Chalk River, Canada. In the last years, for the first time in a half of a century, a huge leap of an order of magnitude in neutron source brightness has been also mastered with SNS at Oak Ridge, USA having achieved the milestone of 1 MW power for a pulsed spallation source. This jump in performance actually concerns the instantaneous peak flux, while the time average brightness remained below that of powerful continuous reactor sources. Correspondingly, the new opportunities brought to life by the enhanced sensitivity of SNS and of the newer similar source at J-PARC at Tokai, Japan concentrate on part of the broad spectrum of neutron scattering research. By refining the source technology developed at this latest generation neutron facilities, primarily by better exploiting the interplay between accelerator design and instrumentation approaches, the next generation of pulsed spallation sources will offer both highest peak and time average brightness for both thermal and cold neutrons. These so called long pulse spallation sources will combine features of reactor sources and conventional short pulse spallation sources, and the European Spallation Source (ESS) project is on track to achieve this second breakthrough in neutron source power within a decade, rather than in another half a century. The hugely enhanced sensitivity brought about by these advances lend to neutron scattering research new capabilities in investigating new phenomena by accessing smaller signals, smaller samples or scanning the volume of larger objects, samples rapidly changing in time, parametric studies, etc. Most of the new scientific challenges are related to the advent of new materials to be explored and understood. The next generation of researchers will have at its disposal a worldwide network of modern neutron source facilities with, on the one hand, comparable high performance instruments and beam devices and, on the other hand, sheer source neutron brightness varying by up to 2 orders of magnitude between 10 MW reactors and 5 MW pulsed spallation sources. By modern instrumentation at sources at the lower end of this brightness scale one can most efficiently and flexibly explore novel samples which are available in quantities on the scale of cubic centimeters. The most intense sources need substantially higher resources to build and operate and they can be most efficiently used by focusing on cases of low signal, such as samples only available in small quantities, real time and space resolved studies, etc. The complementary set of a couple of dozens of most economical and a few highest flux neutron sources worldwide will best make available the powerful multidisciplinary opportunities of neutron scattering research to the broadest research community.
- 26 -
Studies of Total, Bioavailable, Proteic, Lipidic, and Ionic Species of Trace Elements in Biological Materials by Neutron Activation Analysis Amares Chatt* SLOWPOKE-2 Facility, Trace Analysis Research Centre, Department of Chemistry Dalhousie University, Halifax, Nova Scotia, B3H 4J3, Canada *Corresponding author: a.chatt@dal.ca
Neutron activation analysis (NAA) is a well-established analytical technique for the simultaneous measurement of multielement concentrations at percentage to parts per trillion levels in a variety of materials. We have developed several types of NAA methods for the determination of a number of elements in individual food items and duplicate diets. These methods include: instrumental NAA (INAA), cyclic NAA (CINAA) and pseudo-cyclic INAA (PCINAA), epithermal INAA (EINAA), preconcentration NAA (PNAA), radiochemical NAA (RNAA), derivative NAA (DNAA), and indirect INAA (IINAA) employing thermal, epithermal and fast neutrons in conjunction with conventional and Compton suppression gamma-ray spectrometry. We have used the Dalhousie University SLOWPOKE-2 reactor with a neutron flux of 1-10 x 1011 cm-2 s-1 for all irradiations. Although NAA has traditionally been applied to measuring the total concentrations of elements, we have extended the scope of NAA in conjunction with chemical separations prior to irradiations to determine the species of an element. This technique is termed speciation NAA (SNAA). We have further extended SNAA to simultaneously determine several species and called it simultaneous SNAA (SSNAA). Since the toxicity of an element depends significantly on its physico-chemical forms, there is an increasing interest in studying its speciation. In SSNAA we have advantageously exploited a number of characteristic features of NAA, which other techniques normally do not possess. For example, we have used SSNAA for: (i) simultaneous multielement speciation with high specificity, (ii) speciation of elements which are not chemically similar such as Cd, Mn and Se, (iii) speciation of elements such as Cl, Br and I which are rather difficult to determine by most other techniques, etc. The SSNAA technique also has some unique and enhanced quality assurance features which other techniques lack. We have developed SNAA methods for assaying inorganic and organic arsenic species in water and in foods of marine origin. We then extended these methods to include simultaneous speciation of As, Sb and Se in water and studied their interconversions. We have developed SNAA methods to determine iodine species in milk. We have applied an in vitro enzymolysis method to estimate bioavailable species of several elements in duplicate diets. We have employed NAA in conjunction with bioanalytical methods to investigate several metalloproteins and protein-bound trace elements in the cytosol fraction of bovine kidneys. The techniques used to separate, purify and characterize metalloproteins in bovine kidneys include dialysis, ammonium sulphate precipitation, gel filtration, ionexchange and hydroxyl apatite chromatography, high-performance liquid chromatography, chromatofocusing, isoelectrofocusing, isotachophoresis, sedimentation equilibrium and enzymatic assay. We studied proteins containing As, Br, Ca, Cl, Cu, Fe, I, K, Mg, Mn, Mo, Na, Rb, S, Se, V, and Zn in bovine kidneys. Recently we have concentrated our efforts to develop SSNAA methods in conjunction with GC, LC, NMR and MS for the simultaneous separation and characterization of extractable organochlorine, organobromine and organoiodine proteic and lipidic species in fisheries samples. Details of the above methods with results will be presented to focus on the recent trends in NAA.
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Plenary Session
Tuesday, 2 Nov. 08:50 – 09:20 (Room 201)
Tuesday, 2 Nov. 09:20 – 09:50 (Room 201)
STATUS OF REFURBISHMENT PROJECT AND FUTURE PROGRAM OF THE JMTR Hiroshi Kawamura1, * 1
Neutron Irradiation and Testing Reactor Center, Japan Atomic Energy Agency 4002 Narita Oarai-machi, Higashiibaraki-gun, Ibaraki, 311-1393, Japan tel: (81) + 81-266-5001, fax: (81) + 81-266-7471 , *Corresponding author : kawamura.hiroshi@jaea.go.jp
The Japan Materials Testing Reactor (JMTR) in Japan Atomic Energy Agency is a light water cooling tank typed reactor having first criticality in March, 1968. The JMTR have a hot laboratory to which the irradiated samples can be transported safely and quickly from the reactor to the hot laboratory by a water canal. The JMTR has been applied to irradiation tests of fuel and materials for LWRs, HTGR, fusion reactor, RI production, human education, etc. This JMTR operation was once stopped at August 2006. Then, the refurbishment has been started. The renewed JMTR will be started from FY 2011 and operated for a period of about 20 years until about FY 2030. The usability improvement of the JMTR, e. g. higher reactor available factor, shortening turnaround time to get irradiation results, attractive irradiation cost, business confidence, is also discussing with users as the preparations for re-operation. The expected main roles of re-operated JMTR are "lifetime extension of LWRs”, “progress of science and technologies”, “expansion of industrial use" and "education and training of nuclear scientists and engineers". In June of this year, Japanese Government announced 14 specialized projects of advanced research infrastructure in order to promote basic as well as applied researches. In the program, development of user-friendly environment especially for young and female researchers is highlighted.°°One of these 14 projects, “birth of the nuclear technopark with the JMTR” is selected, then new irradiation facilities and PIE equipments will be installed up to FY 2013 at least. In this presentation, the status of the refurbishment of reactor facilities is introduced and the future program of the JMTR will be explained.
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Trend of Therapeutic Radioisotopes in Nuclear Medicine Professor J. Harvey Turner* The University of Western Australia *Corresponding author: Turner@health.wa.gov.au
In the beginning, there were the elements, Iodine-131, Phosphorus-32 and Strontium-89 and upon these therapeutic radionuclides was founded the speciality of Nuclear Medicine 70 years ago. Therapeutic nuclear oncology has developed exponentially in the past decade with the advent of targeted radiopharmaceuticals achieving selective cancer cell kill to control disseminated malignancies which express the specific tumour receptor. Such targets may be tumour cell antigens or designated up-regulated and over-expressed receptors which bind particular peptides, or molecular biomarker localising agents, which may be radiolabelled with therapeutic radionuclides. Whilst the pure beta emitter Yttrium-90 has been used for targeted radionuclide therapy, tumour uptake cannot be measured in-vivo and critical normal organ dosimetry estimation cannot be performed in patients. The preferred therapeutic radionuclides have beta emission of effective median range 0.5-5 mm together with gamma emission energies comparable with that of the ubiquitous diagnostic radionuclide Technetium-99m (140 keV). Such therapeutic radioisotopes may be imaged, as whole body and on SPECT/CT, quantitatively, on standard gamma camera systems, to permit calculation of individual patient dosimetry, preferably prospectively prior to administration of the radionuclide therapy, Iodine-131 remains the mainstay of targeted radionuclide therapy, but newer radionuclides such as Rhenium-188 and Lutetium-177 with a more favourable radiation safety profile are providing the basis for the resurgence of radionuclide therapy in clinical management of patients with disseminated malignancy, such as prostate cancer, hepatocellular carcinoma, lymphoma and neuroendocrine tumours. The presentation reviews recent clinical experience of 131I-rituximab anti CD-20 monoclonal antibody radioimmunotherapy of non-Hodgkin lymphoma, radiopeptide therapy of neuroendocrine tumours with the somatostatin analogue 177Lu-octreotate, palliative treatment of bone cancer with 188Re-HEDP and hepatocellular carcinoma therapy with 188Re-lipiodol, all of which, could be practically applied in developing countries. The advent of new alpha emitting radionuclides for targeted therapy will also be contemplated particularly in relation to potential cancer stem cell targeting. The future of radionuclide therapy will embrace the concepts of combination of radiosensitizing chemotherapy and molecular signalling pathway modifiers with specific targeted therapeutic radiopharmaceuticals to enhance efficacy whilst minimizing toxicity. Prescription of an accurate radiation absorbed dose to tumour and critical normal organs by individual patient dosimetry, ideally prospectively, will be imperative to achieve optimal therapeutic outcomes. The objective of therapeutic nuclear oncology is serial radiopharmaceutical therapy to control cancer, with durable progression-free survival and preservation of quality of life. Radiopharmaceutical therapy should be safe, effective, affordable, practical and available to all.
- 29 -
Plenary Session
Tuesday, 2 Nov. 09:50 – 10:20 (Room 201)
Source / Reactor
- 30 Source / Reactor
- 32 Source / Reactor
- 33 -
- 34 Source / Reactor
SR-O-01
Monday, 1 Nov. 16:10 – 16:40 (Room 101)
The Swiss Spallation Neutron Source SINQ: Operational History, Status and Developments Jürgen Duppich*, Werner Wagner Paul Scherrer Institute, 5232 Villigen PSI, Switzerland *Corresponding author: juergen.duppich@psi.ch
The continuous spallation neutron source SINQ – the only one of its kind worldwide – is located at the Paul Scherrer Institute, Villigen/Switzerland. The source started operation in 1997 (first beam - 3. December 1996) and is driven by the vertical proton beam from the PSI 590 MeV ring cyclotron with a DC beam power in the MW range. The 1.5 mA proton beam hits the heavy metal spallation target and releases neutrons into the D2O moderator and the D2 cold moderator, making SINQ a source for users with characteristics similar to a research reactor. The cold neutron source is located in the flux maximum resulting in an optimized neutron flux. SINQ is fully equipped with supermirror coated neutron guides and state of the art instrumentation. The primary dedication of SINQ is the user facility, operating at present with 18 instruments for neutron diffraction, spectroscopy and imaging. The current thermal neutron flux close to the target is 1.5 x 1014 n/cm2/s. This paper outlines the most recent efforts towards an improved SINQ spallation source, describing, for example, the newly developed concept of the solid “cannelloni” target. This target was ready for operation in spring 2009. The paper further gives a brief summary of 12 years of operational history. The year 2009 showed the highest neutron production since its commissioning in 1997. This record is the result of evolutionary development of its solid target, interrupted by the experimental operation of the MEGAPIE liquid metal target in 2006. Some results from this experiment led to further improvements of the present solid target, resulting in a 300% higher neutron production compared to the first years of operation. A significant contribution to this result was brought by the 75 % increase in the proton beam during this period. Last not least, we will present the results of our periodical neutron flux measurements using gold foil activation. At several reference positions along the neutron guide system, we mounted Al-supports which hold the gold foils in the neutron beam. Except for the annual shutdown of the ring cyclotron in winter, the operational beam time schedule is 24 hours per day, with 2 to 4 days of service, beam set-up and beam development shifts, every four weeks. During each restart period, neutron flux measurements are made at the reference positions to monitor and compare the beam flux results from the gold foil activation.
- 35 -
SR-O-02
Monday, 1 Nov. 16:40 – 17:10 (Room 101)
K.H. Andersen1,2, *, P.M. Bentley1,3, M. Kreuz1, M. BĂśhm1 1
Institut Laue-Langevin, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9, France 2 European Spallation Source, Lund University P.O. Box 117, SE-221 00 Lund, Sweden (from 1/10/2010) 3 Bragg Institute, Australian Nuclear Science and Technology Organisation, Menai NSW 2234, Australia (from 1/4/2010) *Corresponding author: Andersen@ill.fr
The H5 guide system extracts neutrons from the horizontal cold source at the ILL and distributes them to seven instruments at the ILL, of which six are in the second guide hall. The installation of new instruments there in the coming years, coupled with the required rebuild of the horizontal cold source, has prompted us to redesign the entire guide system. The redesign must not adversely affect the instruments already on the guide system which are not being changed, while maximising the useful flux on the new and upgraded instruments. The optimisation must also take into account the engineering constraints imposed by the neutron-optical components of the instruments other layout issues. We describe the optimisation process leading up to the presently-envisaged design. Implications for pulsed neutron sources, such as the ESS, are briefly discussed.
- 36 -
Source / Reactor
Cold Neutron Beam Extraction: The H5 Project at the ILL and Implications for the ESS
SR-O-03
Monday, 1 Nov. 17:10 – 17:30 (Room 101)
Maintenance, Reliability and Operational Status of the OPAL Cold Neutron Source Russell Thiering*, David Taylor, Weijian Lu Australian Nuclear Science and Technology Organization, Lucas Heights, NSW 2234 *Corresponding author: rct@ansto.gov.au
Australia’s first Cold Neutron Source (CNS) is a major asset to OPAL’s nuclear research program. The CNS was commissioned in early 2007 and since that time has been in full power operation at the OPAL research reactor. The 20-litre single phase liquid deuterium source delivers a 109 n/cm2 ·s cold flux at the end of the neutron guides. As OPAL is a multipurpose research reactor, used for beam research as well as silicon (NTD) andradiopharmaceutical production, the cryogenic system of the OPAL CNS has a unique design feature that allows for some system maintenance without interrupting the reactor operation. This feature has required a review of the typical maintenance and operating plans used by helium refrigerators. In this report the unique operating, condition monitoring and maintenance experience gained from the utilization of the OPAL CNS is discussed. This paper was cancelled as the request of the author and is replaced by the paper(SR-P-08) of Mr. Y.G.Cho
- 37 -
SR-O-04
Monday, 1 Nov. 17:30 – 18:00 (Room 101)
A.V.Belushkin* Frank Laboratory of Neutron Physics, Joint Inst. Nucl. Res., Dubna, 141980, Russian Federation *Corresponding author:belushk@nf.jinr.ru
IBR-2 reactor operated by Frank Laboratory of Neutron Physics is the main basic facility at JINR dedicated to condensed matter research. The IBR-2 is a fast pulsed reactor. Its main distinctive property, which makes it differ from other nuclear reactors, is the mechanical modulation of the reactivity by means of a movable reflector. IBR-2 is the most intense pulsed neutron source in the world (IAEA-TECDOC-1439, February 2005). Producing a record neutron flux of 1016 n/cm2 /s in the pulse, the IBR-2 reactor is also an economical and relatively inexpensive facility. The IBR-2 reactor is mainly used for investigations in the fields of condensed matter physics (solids and liquids), biology, chemistry, Earth and materials science. Some recent highlights from IBR-2 research will be presented. Last year the Laboratory put into operation the IREN facility – power electron linac which is used to produce very short neutron pulses from heavy metal target. This facility is already in use for some applied research and education and is planned to be upgraded for basic research in nuclear physics in near future. Some results from this facility will be presented. Laboratory has a long and fruitful collaboration with Russian Space Research Institute. Common experiments aimed for searching water on Mars, Moon have been realized and results will be reported. Last, but not least, information on the applied research activities in the fields of ecology, biotechnology, and engineering research will be outlined.
- 38 -
Source / Reactor
Neutron Research at the Frank Laboratory of Neutron Physics
SR-O-05
Tuesday, 2 Nov. 10:40 – 11:00 (Room 101)
Key Issues and Challenges in Utilization and Sustainability of Research Reactors Danas Ridikas a*, Pablo Adelfangb, Kevin Alldredb, Ed Bradleyb, Guenter Mank a, Nathan Pelda,b Division of Physical and Chemical Sciences (NAPC) Division of Nuclear Fuel Cycle and Waste Technology (NEFW) International Atomic Energy Agency Wagramer strasse 5, PO Box 100, 1400 Vienna, Austria *Corresponding author: D.Ridikas@iaea.org a
b
Research reactors (RRs) have played and continue to play an extremely important role in the development of nuclear science and technology. They are used to produce medical and industrial isotopes, for research in physics, biology and materials science, and for scientific education and training. They also occupy an indispensible place in nuclear power programmes. Given the projected decrease in RRs from 245 today [1] to between 100 and 150 in 2020, greater international cooperation will be required to assure broad access to such facilities and their efficient use. These networks will also contribute to upgrading existing facilities, developing new facilities and improving access to countries without RRs. Although significant results have been obtained so far in initiating and supporting RR coalitions [2], extensive work is still needed to achieve the objective of increased utilization of individual RRs through involvement in collaborative efforts like networks or coalitions. Today the decreasing and rather old fleet of RRs world-wide (more than 50 % of the operating RRs in the world are over 40 years old) faces a number of critical issues and important challenges such as underutilization, inexistent or inappropriate strategic business plans, aging and needs for modernization-refurbishment, the presence of fresh or spent HEU fuel, unavailability of qualified high-density LEU fuels, accumulation of spent nuclear fuel, needs for advanced decommissioning planning and implementation stages, and, in some cases, safety and security issues. In addition to this non-exhaustive list of issues are the plans to build new RRs by Member States (MS) with little experience in this domain. In response to these challenges, the IAEA is taking action and designing activities to tackle these issues and make sure that promotion, support, and assistance to Member States in the development and uninterrupted operation of strong, dynamic, sustainable, safe, and secure RRs dedicated to peaceful uses of atomic energy and nuclear techniques is preserved. The IAEA has taken the initiative in this direction by organising expert meetings and workshops, encouraging collaboration through coordinated research projects, publishing state-of-the-art technical documents as well as assisting MS through national and regional Technical Cooperation projects. In addition, through strategic planning and allied support, the IAEA is assisting MS without RRs to become part of RR coalitions or networks as a first step to develop their national capabilities and at the same time improve all aspects of utilization and modernisation of existing RRs, and therefore, sustainability and innovation. Although IAEA has been playing a lead role in all these areas, this paper will concentrate on the ongoing IAEA project D2.01 titled, Enhanced Utilization and Applications of RRs [3]. Both recent achievements and future planed actions will be reported with the major emphasis on RR utilization related issues, specific applications of RRs, networks and coalitions, and assistance to the MS planning their 1st RR. References 1. The IAEA Research Reactor Data Base (RRDB), http://nucleus.iaea.org/RRDB/ 2. D. Ridikas, et al., The IAEA Activities Towards Enhanced Utilization, Sustainability and Applications of Research Reactors, Proceedings of the 14th International Topical Meeting on Research Reactor Fuel Management (RRFM2010), 21-25 March 2010, IAEA, Marrakesh, Morocco; available at http://www.euronuclear.org/meetings/rrfm2010/. 3. IAEA Project D2.01: Enhanced Utilization and Applications of Research Reactors: http://wwwnaweb.iaea.org/napc/physics/research_reactors/index.html
- 39 -
SR-O-06
Tuesday, 2 Nov. 11:00 – 11:30 (Room 101)
S.Chongkum*, S. Chue-inta, N. Klaysuban and C. Tippayakul Thailand Institute of Nuclear Technology, 9/9 Moo7, Tambol Saimoon, Amphur Ongkharak, Nakornnayok 26120, Thailand. *Corresponding author:somporn@tint.or.th
Abstract. The 2 MW Thai Research Reactor type TRIGA Mark III has reached 18th core configuration in 2010 after more than thirty years of service since 1977. The recent hexagonal core comprises mixed 107 fuel elements of 8.5-20% U wt. and five control rods and with maximum neutron flux of 3x1013 neutron/cm2/seconds at 1.2MW. Core calculation is carried out by Neutronics Computer Codes (3D Deterministic method- SRAC and 3D Monte Carlo method- MVP) and Thermal Hydraulics Codes (Steady-state Calculation- COOLODN2 and Reactivity Insertion AnalysisEUREKA2/RR). There are 10 in-core tubes and 12 out-core tubes and facilities. The reactor serves research and development on neutron activation analysis, neutron radiography, plant mutation, as well as services on medical radioisotope production (I-131, P-32 and Sm-153), gems quality enhancement and elemental analysis. The reactor also serves education, training and technology transfer including university reactor experiments and technical tours for the public.
1. Introduction The Thai Research Reactor-1/Modification 1 (TRR-1/M1) is currently under the responsibility of Thailand Institute of Nuclear Technology (TINT). After its first criticality in October 1977, the reactor has been utilized for a wide variety of applications. It is also the only research reactor in Thailand and has served as the largest neutron source for many users. This paper provides information on the descriptions of the TRR-1/M1, its operation, maintenance, fuel management program and current utilization.
2. Description of TRR-1/M1 [1] The TRR-1/M1 is an open pool-type TRIGA – Mark III with concrete biological shield and four neutron beam tubes. Historically, the reactor was built as an MTR type research reactor and it was named as Thailand Research Reactor 1 (TRR-1). The reactor had been operated since 1962 until 1975 when it was converted to the TRIGA type research reactor. In the conversion, the high-enriched uranium fuel plate was replaced by the low-enriched uranium fuel rod designed and supplied by General Atomics (GA). In addition, the control system and the safety features were also replaced so that TRR-1 became essentially a TRIGA reactor. The reactor was then renamed as Thai Research Reactor-1/Modification 1 (TRR-1/M1) to reflect this conversion. After successfully achieving its first criticality in October 1977, the routine operation of TRR-1/M1 has begun since November 1977. The TRR-1/M1 is licensed for 2 MW and the core cooling is provided by natural circulation of pool water, which is in turn cooled and purified in external coolant circuits. FIG.1. presents the perspective and top views of the TRR-1/M1 structures.
- 40 -
Source / Reactor
Utilization of the Thai Research Reactor (TRR-1/M1)
Auxiliary bridge Reactor pool
Reactor Bridge
Reactor core Thermal Colum
Beam ports
FIG.1. Perspective view of TRR-1/M1 structures
As of 2010, TRR-1/M1 has gone through 18 core configurations. The current core configuration uses two types of 20% enriched UZrH fuel elements; namely 8.5% wt. and 20% wt. uranium. Both fuel element types are identical in size and have the same cladding material (SS304). The 8.5% wt fuel element contains approximately 38 g of uranium while the 20% wt fuel element contains approximately 98 g of uranium. The fuel elements are positioned in a grid plate forming hexagonal configuration. Five control rods are used in the reactor core, i.e., a safety rod, a regulating rod, two shim rods and a transient rod. The regulating, shim and safety rods are fuel follower control rods (FFCRs) containing B4C as the neutron absorber in the upper part of the rod while the lower part contains 20% wt. fuel. These fuel follower control rods are sealed in 304 stainless steel tubes. On the other hand, the transient rod is an air follower control rod (AFCR) containing B4C as the neutron absorber in the upper part of the rod while the lower part is simply air-filled. The air follower control rod has aluminum clad. In the current core configuration, there are 107 fuel elements in total. There are numbers of neutron irradiation facilities including 10 in-core tubes (CT, C8, C12, F3, F12, F22, F29, G5, G22 and G33) and 12 out-core tubes and facilities (A1, A4, CA2, CA3, TA, TC, wet tube, SNIF, Rotary specimen rack, void tank and beam tubes and thermal column). The maximum flux of TRR1/M1 (at CT-Central Thimble position) is in the magnitude of 3x1013ncm-2s-1 at the nominal power of 1.2 MW. FIG.2. presents the current core configuration describing the locations of fuel elements, control rods and also the incore irradiation facilities. FIG.3. also presents the diagram of the TRR-1/M1 out core irradiation facilities. Neutron flux at each irradiation facility is presented in table 1.
- 41 -
Source / Reactor FIG2. Current TRR-1/M1 core configuration (core loading no. 18)
FIG.3. Location diagram of the TRR-1/M1 out-core irradiation facilities
- 42 -
No.
Neutron Flux( ncm-2sec-1)
Detail
Thermal
Epithermal
Fast
Cd Ratio (Au)
Thermal per Fast Neutron
2.89E+13
2.27E+12
1.63E+13
2.65
1.77
In Core Facilities 1
CT-1-3/4” wet tube
2
C8-1-3/4” wet tube
2.01E+13
2.14E+12
1.38E+13
2.38
1.46
3
C12-1-3/4” wet tube
2.15E+13
2.60E+12
1.53E+13
2.35
1.41
4
F3-1-3/4” wet tube
1.20E+13
7.90E+11
7.31E+12
3.57
1.64
5
F12-1-3/4” wet tube
1.05E+13
9.13E+11
6.86E+12
3.05
1.53
6
F22-1-3/4 “ wet tube
1.07E+13
7.60E+11
6.16E+12
3.21
1.74
7
F29-1-3/4” wet tube
1.25E+13
8.16E+11
5.04E+12
3.08
2.48
8
G5-1-3/4” wet tube
9.07E+12
6.21E+11
4.44E+12
3.77
2.04
9
G33-1-3/4” wet tube
9.28E+12
3.95E+11
3.64E+12
4.16
2.55
10
G22-1-3/4” dry tube
5.81E+12
5.01E+11
3.35E+12
2.87
1.73
11
A1-1-3/8” dry tube
2.06E+11
2.35E+10
8.95E+10
2.28
2.31
12
CA2-1-3/8” dry tube
1.62E+11
2.73E+09
7.18E+10
10.83
2.26
13
CA3-1-3/4” dry tube
1.49E+11
1.81E+09
5.50E+10
12.68
2.71
14
A4-1-1/2” dry tube
5.15E+10
1.83E+09
4.45E+10
5.53
1.16
15
TA-1-3/4” dry tube
4.47E+10
3.57E+09
2.56E+10
2.96
1.75
16
Lazy Susan 41 dry tubes
2.55E+11
7.88E+09
4.80E+10
7.49
5.31
17
SNIF dry tube
1E+6
18
Thermal Column
1E+9
19
Beams-6” and 8” dry tubes
20
WT-13 wet tubes
5.55
2.44
Out core facilities
1E+6 1E+6
8.09E+11
3.10E+10
3.32E+11
Table 1 neutron flux of the irradiation facilities in the TRR-1/M1 at 1.2MW
3. TRR-1/M1 operation, maintenance and fuel management program The philosophy of the operation, maintenance and fuel management program of TRR-1/M1 is to endeavor its best performance and hence enhances the utilization of TRR-1/M1. Assurance of the stable reactor operation, high reliability and ultimate safety are provided for all reactor users. The operation, maintenance and fuel management of TRR-1/M1 is under the responsibility of the reactor management section, Division of Nuclear Technology Operation. There are currently 18 staffs in this section. Routine operation is scheduled on Tuesday to Thursday between 8:30-20:30 and on Friday between 8:30-18:30 while Monday is reserved for weekly inspection and minor maintenance as well as special experiments and training. Major maintenance shutdown is annually scheduled for 45days during February – March each year. In conclusion, the reactor is nominally operated at the power of 1.2 MW for 10.5 months to reach the burn up target of 90 MWD. Fuel reloading is mostly performed biennially. The fuel management utilizes advanced 3D neutronics calculations to determine the core loading pattern. These 3D neutronics calculations are performed by such computer codes as SRAC [2] and MVP [3]. The computational methodology implemented in SRAC is similar to the typical fuel management methodology adopted by commercial nuclear power reactors. This methodology is to
- 43 -
Top view
Axial View FIG.4. MVP model of TRR-1/M1
Safety analysis is performed to ensure the safety of the reactor management program. A steady-state thermal hydraulics COOLODN2 computer code [4] has been adopted to assess the thermal safety margin for TRR-1/M1. The code has also been validated against the experimental data and measurement. Mostly, the model is slightly overestimating thus its resulted is considered applicable for steady-state safety assessment of TRR-1/M1. Reactivity insertion analysis is also performed by using EUREKA-2/RR computer code [5] to verify that, even in case of transient accident the reactor is still under safety limits.
3.1 Instrumentation and Control Upgrade Project Under the memorandum of understanding for technical cooperation between Korea Atomic Energy Research Institute (KAERI) and Thailand Institute of Nuclear Technology (TINT), the important fields of cooperation are design, construction, safe operation and utilization technology of research reactor. Both parties are agree to establish instrumentation and control upgrade project for the TRR-1/M1 reactor; with two main objectives, as followings, (1) to refurbish the current I&C system, and (2) to gain knowledge in design of I&C system. The project was approved by the Board of TINT already, are could be started at begin of the year 2011, within 18 months period.
4. Current utilization of TRR-1/M1 [7] TRR-1/M1 is currently the largest neutron source in Thailand. The reactor attracts quite a number of reactor users for different purposes. The applications of TRR-1/M1 can be broadly categorized as irradiation services (Isotopes production, analytical services and gems colorization), experimental researches, education and training and public relation. List of irradiation facility utilization in 2009 is summarized in table 2.
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Source / Reactor
generate the few-group cross sections by detailed transport calculation and subsequently performs the whole core calculation by a diffusion calculation with the generated few-group cross section. On the contrary, MVP is a Monte Carlo method code which simulates a whole core with less approximation comparing to SRAC. Both SRAC and MVP codes are used in conjunction to evaluate a new core loading pattern. The reactor core model of TRR-1/M1 by 3D Monte Carlo MVP computer code is shown in FIG. 4 as the example.
In core Facility
Main proposes
Targets
Products
Samples
CT
Isotope production
TeO2, Sm2O3
I131, Sm153
17
C8, C12, F29
Isotope production
TeO2
F3
Isotope production
Lu2O3, TeO2
G5, G33
Isotope production
NH4HPO4, TeO2
F12, F22
Experiments
Gems
Colourization
13
G22
R&D
Foods, ores, particulate
Short live isotopes
560
Out core facility
Main proposes
Targets
Products
No.
A1, CA2, TA
R&D
Food, environmental
Medium live isotopes
246
A4, CA3
Service
Alloy, Ore, sludge
Medium live isotopes
61
LZ
R&D
Food, environmental
Long love isotopes
77
WT
Services
Gems
Colourization
55
Column & Beams
Experiments
Antiques
Radiography
11
SNIFFS
Experiments
Seeds
Mutation
17
131
I
9
Lu177, I131
8
P ,I 32
131
65
Table2. Utilization of TRR-1/M1 irradiation facilities in 2009
More explanation is described in the following:
4.1. Isotope production Isotope production is one of the main uses for TRR-1/M1. The target for isotope production is irradiated at the relatively high neutron flux regions of the reactor core, that is, the in-core irradiation facilities. The in-core irradiation facilities, CT, C8, C12, F3, F29, G5 and G33 are normally reserved for isotope production. Typical irradiation time per batch is approximately 8 weeks. After irradiation, the irradiated target is processed in a hot cell in the isotope center close to the reactor building. The total capacity with all the in-core irradiation facilities is approximately 4.5 Ci/week. This production capacity suffices roughly half of the domestic demand. The special service, Isotope Production Center of TINT dedicated to radio-isotope production and sale. The main radio-isotope produced by TRR-1/M1 is I-131 from TeO2 target, in solution and many labeled forms, mostly for medical applications. The production of other isotopes, though on occasional basis, includes Sm-153 for medical applications and P-32 for agricultural applications. Table 3 summarizes radioisotope products, and number medical diagnostic and treatment cases in 2009.
- 45 -
1 2
Product
Unit
I131-solution 131
I -Diagnostic Capsule 131
total
Cases
mCi
173,963
1,150
mCi
93
93
3
I -Therapeutic Capsule(1-10mCi)
Capsules
1,218
1,175
4
I131-Therapeutic Capsule(11-20mCi)
Capsules
214
209
Capsules
5,359
1,954
5
131
I -Therapeutic Capsule(21-50mCi) 131
6
I -MIBG Diagnostic Dose
mCi
133
138
7
I131-MIBG Therapeutic Dose
mCi
560
4
mCi
144
144 34
8
131
I -Hippuran 153
9
Sm -EDTMP
mCi
2,255
10
P32
mCi
18
Total Income and cases
4,90
(Income from RR products) Table 3 Radioisotope products, income and medical application cases in 2009
4.2. Gemstone irradiation The Gemstone Irradiation Center of TINT is responsible for the gemstone irradiation operation. Topaz is the most common gemstone being irradiation by TRR-1/M1. The neutron irradiation transforms the naturally occurring colorless Topaz into blue Topaz which enhances its values up to 30 times. The gemstone irradiation typically requires fast neutrons; therefore, it is usually irradiated in the relatively high fast flux region. The in-core irradiation facilities in the outer rings of the core are suitable for the gemstone irradiation since they have high fast flux. The incore irradiation facilities, F12 and F22, are normally reserved for gemstone irradiation. It should be noted that, although the in-core irradiation facilities of the inner rings generally have higher fast flux, they are probably more valuable for applications requiring high thermal flux such as isotope production. Gemstone to be irradiated in the incore facilities is restrained by its size due to limited space in the core. TRR-1/M1 has also out core irradiation facilities which are currently used for gemstone irradiation. Gemstone with larger size can be irradiated in these outcore irradiation facilities. Out-core irradiation facilities (VS, VN, wet tubes) are normally reserved for gemstone irradiation. The typical gemstone irradiation time per batch is 2 weeks for in-core positions and 3 - 6 months for outcore positions. The current gemstone irradiation capacity by TRR-1/M1 is approximate 150 kg annually.
4.3. Neutron Activation Analysis (NAA) Nuclear Service Center renders services on NAA of ore from mining and elemental analysis in sludge, along with other techniques such as X-ray Fluorescence. However, the income from NAA service is still limited to 4 percent of the total analytical services income of 3,063,517 Baht in 2009. NAA is also a prominent technique of Research and Development Group for trace elemental analysis of agricultural products, foods and air particulates etc. Most irradiation facilities available for NAA are the in core G22 pneumatic dry tube and other out core dry tubes such as A1, CA2, CA3, A4, TA, TC and the rotary specimen rack with 41 irradiation positions. There are 6 publications in 2009.
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Source / Reactor
Number
4.4. Research and Development Few research and development based on neutron experiments conducted at the TRR-1/M1 include neutron radiography of antiques, neutron tomography, neutron scattering, prompt gamma NAA and plant mutation. Both incore and out-core irradiation facilities are available upon request by the users. There are two publications in 2009.
4.5. Education and Public Relation technology transfer Critical approach along with other reactor experiments conducted for university students in nuclear technology and engineering. Reactor operator training and refreshment scheduled biannually. Reactor visit is also part of public relation program. The averaged number of visitor is 2,000 per annum.
5. Future utilization plan To support promotion and enhancement of the TRR-1M1 utilization, a working group has been assigned to identify needs, opportunities, problem, and to formulate the proper utilization plan for this coming year. More collaboration with university, laboratory and research institute and end users will be encouraged. Neutron radiography and forensic sciences are the main topics of interests. The reactor would also be used as the educational platform for human development program in nuclear engineering, nuclear and radiation safety, safe guards, etc toward nuclear power development.
6. Conclusion The Thai Research Reactor TRR-1/M1 mainly supports research & development, education and public relation technology transfer and partly provides commercial radioisotope products and analytical services to the public. TINT will try to promote and enhance the TRR-1/M1 utilization through collaboration with end users.
REFERENCE [1] TINT, TRR-1/M1 Safety Analysis Report [2] K. Okumura, T. Kugo, K Kaneko and K. Tsuchihashi, 2002, SRAC (Ver. 2002); The comprehensive neutronics calculation system [3] MVP/GMVP II : General Purpose Monte Carlo Codes for Neutron and Photon Transport Calculations based on Continuous Energy and Multigroup Methods (JAERI 1348) Japan Atomic Energy Research Institute 2005 [4] M. Kaminaga, 1994, COOLOD-N2: A computer code for the analyses of stead-state thermal-hydraulics in research reactors [5] M. Kaminaga, 1996, EUREKA-2/RR: A Computer Code for the reactivity accident analyses in the research reactor [6] C. Tippayakul, D. Saengchantr, “Fuel management methodology upgrade of Thai Research Reactor (TRR-1/M1) using SRAC computer code�, 2nd International Conference on Research Reactor: Safe Management and Effective Utilization, Australia 2007 [7] TINT Annual Report 2009, p 44-48
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SR-O-07
Tuesday, 2 Nov. 11:30 – 12:00 (Room 101)
Ned Xoubi a P.O.Box 70, Shafa Badran, 11934 Amman, Jordan *Corresponding author : Ned @Xoubi.com , Drxoubi@yahoo.com a
Jordan Research Reactor is a 5 MW light water open pool multipurpose reactor that serves as the focal point for Jordan national nuclear centre, and is designed to be utilized in three main areas; education & training, nuclear research, and radioisotopes production and other commercial & industrial services. The research reactor is the only new build in 2010 worldwide, and is a gigantic step towards establishing a nuclear power program in Jordan, and a landmark of its nuclear technology infrastructure. Jordan Atomic Energy Commission (JAEC) is the owner and operator of the reactor that is being designed and constructed by a Korean consortium of KAERI and Daewoo E&C. The project which started earlier this year will take 56 months to complete making the reactor ready for operation in 2015. The reactor is located in Ramtha approximately 70 Km north of Amman, within Jordan University of Science and Technology (JUST) campus, one of the largest universities in Jordan with about 20,000 students from more than 50 nations, the university is home to the only Nuclear Engineering Department (NED) in Jordan. Currently, Jordan serves as a regional educational center, a medical hub for the Middle East and a supplier of know-how in the various areas of education, engineering and science. It is anticipated that the established nuclear center will support these efforts and complement/solidify the objective of instituting nuclear energy as a viable option for fulfilling the Jordanian electricity and water needs in the 21st century The compact reactor core design is optimized to produce the highest thermal neutron flux to power ratio of 3x1013 n/cm2s/MW, with a maximum incore thermal flux of 1.5x1014 n/cm2s. The core is composed of 18 fuel assemblies, MTR plate type 19.75% enriched uranium silicide (U3Si2) in aluminum matrix, and is reflected on all sides by beryllium and graphite, and is controlled by Hafnium control absorber rod and B4C shutdown rod. The reactor power is upgradable to 10 MW. The reactor is designed to include laboratories and classrooms that will support the establishment of a Nuclear Reactor School for educating and training students in disciplines like nuclear engineering, reactor physics, radiochemistry, nuclear technology, radiation protection, and other related scientific fields where classroom instruction and laboratory experiments will be related in a very practical and realistic manner to the actual operation of the reactor. Nuclear Engineering problems of shielding, criticality, control rod aspects, temperature feedback, and reactivity will be demonstrated using the reactor, providing students with an enormously valuable experience. The reactor is designed to support advanced nuclear research as well as commercial and industrial services, which can be preformed utilizing any of its 35 experimental facilities; three incore facilities for radioisotope production and potentially material test, 10 facilities in the inner region (IR) with a flux greater than 6x1013, 10 outer region (OR) facilities for irradiation experiment and radioisotope production, 1 large facility (LH) for irradiation of bulky objects, 3 facilities are dedicated for neutron activation analysis, 3 facilities for neutron transmutation doping of up to 8�. One horizontal facility (ST4) is dedicated for cold neutron source (CNS), 2 horizontal facilities (ST1 & ST2) can be used for neutron sciences elastic scattering instruments, inelastic scattering instruments, prompt gamma NAA, one facility (ST3) is for Neutron Radiography. The thermal column will be used for irradiation of bulky objects and potentially boron neutron capture therapy (BNCT)
- 48 -
Source / Reactor
Current Status and Prospective of Jordan Research Reactor Project
SR-O-08
Tuesday, 2 Nov. 14:00 – 14:30 (Room 101)
Neutron Powder Diffraction for Materials Science Takashi Kamiyamaa*, Shuki Toriia, Masano Yonemuraa, Ryoko Oishi-Tomiyasua, Junrong Zhanga, Toru Ishigakib, Akinori Hoshikawab, Kazuhiro Moric, Toshiharu Fukunagac High Energy Accelerator Research Organization, Tsukuba, Ibaraki, Japan b Ibaraki University, Hitachi, Ibaraki, Japan c Kyoto University, Kumatori, Osaka, Japan *Corresponding author: takashi.kamiyama@kek.jp
a
Neutron powder diffraction, as well as synchrotron radiation X-ray powder diffraction has been increasingly recognized as a powerful technique to clarify the relationship between the structures and the function of materials. Their application fields have been expanding in materials science. Here we report on the present status of powder diffractometers at J-PARC (the proton accelerator research complex) and describe materials science using powder diffraction. In MLF (the materials and life science experimental facility) of J-PARC, 12 neutron instruments are carrying out scattering experiments at 120kW operation (1/10 of goal), among which 8 of them accepts general users. In 2010, about 200 proposals were accepted. Four powder (polycrystalline) diffractometers started operation: a super high resolution powder diffractometer (SuperHRPD) with the best resolution of ∆d/d = 0.035 %, a 0.15 %-resolution powder diffractometer of Ibaraki prefecture (iMATERIA), an engineering diffractometer (Takumi), and a high intensity S(Q) diffractometer (NOVA). A high-pressure diffractometer (PLANET) and a special environment powder diffractometer (SPICA) are under construction. The high quality data of SuperHRPD with high resolution and low background give us information on tiny structural changes which have been overlooked. iMATERIA with high resolution and high intensity is used by many industrial researchers as well as academic users for the study of the structure–function relationship of functional materials. The best intensity NOVA is best suited for the timedependent study of crystal structures. For promoting new crystallographic studies with J-PARC diffractometers, powder diffraction data analysis suite Z-Code has been developed.
- 49 -
SR-O-09
Tuesday, 2 Nov. 14:30 – 15:00 (Room 101)
Young –Ki Kim a*, Sang-Ik Wu a, Yeong-Garp Cho a, Chang-Hee Leea Korea Atomic Energy Research Institute 1045 Daedeok-daero, Yuseong-gu Daejeon, 305-353, Korea *Corresponding author : ykkim1@kaeri.re.kr
a
The HANARO (High-flux Advance Neutron Application ReactOr), an open tank in a pool type multi-purpose research reactor, generating a high neutron flux (fast : 2.1 x 1014 n/cm2/sec , thermal flux : 5 x 1014 n/cm2/sec) has been operating at 30MWth since its first criticality in February 1995. Based on the world-wide trend for an availability of cold neutrons and the national demand for taking full advantage of such a strong neutron source, Korean government decided to commence with the Cold Neutron Research Facility (CNRF) project at the HANARO on 2003. A moderator cell, made of 1mm thickness of aluminium 6061-T6, whose shape is a double cylinder type and is connected to a heat exchanger, establishing two phase flow by a natural convection. These components are contained in the vacuum chamber. The HANARO has been already equipped with a vertical liquidhydrogen moderated cold neutron source (CNS) and had the first cold neutrons on 23:30, September 3, 2009. It’s been verified from the actual measurement that the performance of the HANARO CNS meets our expectations. This paper presents the current status of the HANARO CNRF project driven by KAERI, Korea, together with the actual results of the field performance test.
- 50 -
Source / Reactor
Cold Neutron Research Facility in HANARO
SR-O-10
Tuesday, 2 Nov. 15:00 – 15:30 (Room 101)
Cold Neutron Science at Australia’s OPAL Reactor Michael James a,b*, Andrew Nelson a, Stephen Holt a Bragg Institute, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia b School of Chemistry, University of NSW, Kensington NSW 2052, Australia *Corresponding author: mja@ansto.gov.au
a
Materials and condensed matter research in Australia using cold neutrons scattering has entered the 21st Century with the commencement of operation of the 20 MW OPAL research reactor in Sydney. Similar to the HANARO Facility at Daejeon, the OPAL reactor is a multipurpose facility, built to produce radioisotopes for medical diagnostics and treatment, industrial irradiations, production of doped silicon wafers, and the production of cold and thermal neutron beams for scientific and engineering research programs. The first two cold neutron instruments have are operational: Platypus (neutron reflectometry) and Quokka (SANS) which now forms part of an International User facility; while five other spectrometers are under different stages of construction: Sika (cold neutron three-axis spectrometer), Pelican (time-of-flight spectrometer), Kookaburra (ultrasmall angle scattering), Emu (backscattering spectrometer), and Bilby (our 2nd SANS spectrometer). This presentation will provide technical details of the cold neutron source and the associated supermirror guide optics at the OPAL facility, as well as an overview of the complete suite of cold neutron instruments. Details of the first published studies from Platypus and Quokka will also be given.
- 51 -
SR-O-11
Tuesday, 2 Nov. 15:30 – 16:00 (Room 101)
Alim Tarigan* Center for Multipurpose Reactor - National Nuclear Energy Agency, PUSPIPTEK Complex OB No. 31 Phone : +6221-7560908, Fax : +62217560573 Serpong, Tangerang Selatan 15310 Indonesia *Corresponding author: alimtarigan@batan.go.id
1. Introduction The RSG-GAS reactor was designed as a multipurpose reactor with a nominal power of 30 MW, producing thermal neutron flux in the order within 2.0 x 1014 n.cm-2.s-1. As a multipurpose reactor, RSG-GAS provides facilities for utilization on material testing, radioisotope production, R&D using neutron irradiation as well as training. For the year 1995-1998, the reactor was operated around 5000 h/years at 25-30 MW power level, 5 – 6 cycles/year, 750 MWD per cycle. Since the year 1998, the reactor was operated at the power level of 15MW, up to max. 4 cores cycles annually, 540 – 600 MWD per cycle, based on optimization of the fuel availability, user requirement as well as efficiency,. Since 1999 BATAN has implemented the RSG-GAS reactor core conversion programmed from oxide fuel U3O8-Al to silicide fuel U3Si2-Al with the same uranium density in meat of 2.96gU/cm3. Conversion of the RSG-GAS reactor core was carried out by operating a core of oxide-silicide mixture. It took 10 operational cycles to get the full silicide core. Full silicide core was reached at core 45th in August 2002. Starting the year 2004, the reactor is still operated at power level of 15 MW for 4 cycles a year, but each cycle is divided in 6 phases of operation. Each operation runs for 3 times of 11 days and 3 times 4 days. The shutdown times for maintenance are three times of 10 days and three times of 3 days. Some System have been improvement and still continue. By now, the reactor operates safely in a regular basis and utilization mainly for neutron activation analysis (NAA), Dry Neutron Radiography (NR), Iodine Loop (S-1), TAS (S-4), Neutron Guide for FCD, SANS, HRSANS, and HRPD, Powder Diffractometer, Radioisotope Production (RI) and Gemstone production. The routine isotope productions for supplying domestic and party for regional demand are 99Mo, 131I, 32P, 125I, 82Br, 198Au, 60Co, Zn , 24Na. Rabbit system are mostly used for NAA in the field of industry, geology/mining, agriculture, health and environment.
2. Design Feature of GA Siwabessy Reactor • Type open pool • Power 30 MW thermal • Peak th.neutron flux 2.5x1014cm-2sec-1 • Moderator light water • Reflector Beryllium • No. FE in TWC 40 • No. CFE in TWC 8 • Fuel type U3Si2Al MTR • 235U enrichment 19.75 • 235U density gr cm-3 2.96
- 52 -
Source / Reactor
Current Status Multi Purpose Reactor G.A. Siwabessy, Serpong - Indonesia
Year
Operation time, days
Power developed, MWD
1998
338
2173
1999
334
1575
2000
392
1224
2001
405
2126
2002
382
1842
2003
341
1809
2004
273
1899
2005
415
2551
2006
423
2609
2007
314
1961
2008
315
1960
IRRADIATION FACILITIES AT THE G.A SIWABESSY REACTOR
S = Beam Tube NRS = Normal Rabbit System CIP = Central Irradiation Position Fuel Assembly
Beryllium Reflection Element IP = Irradiation Position (core) IR = Irradiation Position FRS = Fast Rabbit System
PRTF = Power Ramp Test Facility NRF = Neutron Radiography Facility (out of core)
3. Irradiation Facilities There are two different types of uses of irradiation facilities including irradiation facilities for material testing and irradiation facilities for neutron irradiation. While the former consisting of power ramp test facility (PRTF), neutron radiography (NR) and neutron beam tubes the latter consisting of radioisotopes production facility, neutron transmutation doping (NTD) facility, rabbit system facility and topaz stone irradiation facility.
- 53 -
PRTF is employed to carry out start up ramping and in situ ramps on power reactor fuels. The experiments take place in rechargeable capsule. It is expected that in year 2010 PRTF will be ready for fresh pin rod testing. In order to support that purpose mechanical and instrumentation function test has been conducted as well testing for cooling system.
3.2. Neutron Radiography Facility The neutron radiography facility (NRF) which comprising underwater camera, guide rail system and associated accessories, is provided in the reactor pool for use especially in the fuel development program. Due to a long inactive operation, measures are being taken to investigate the readiness of its supporting components such as: handling tool and dark room for processing radiograph film. Another measures are an assessment to determine magnitude of the neutron flux, irradiation time needed and type of radiograph film.
3.3. Neutron Beam Experimental Facilities Six horizontal beam tubes, except the beam tube S1, are provided for neutron beam experiments. Two out of six tubes are arranged tangentially to the core and the remaining is arranged radially. Iodine Loop Facility S1 is applied for irradiation of 124Xe gas to 125I isotope. Neutron Beam Instruments DN1-M Diffract for Residual Stress Measurement (RSM) DN2 Four Circle Diffract. /Texture Diffractometer (FCD/TD) DN3 High Resolution Powder Diffractometer (HRPD) RN1 Neutron Radiography Facility (NRF) SN1 Triple Axis Spectrometer (TAS) SN2 SANS Spectrometer (SMARTer) SN3 High Resolution SANS Spectrometer (HRSANS)
3.4. Irradiation Position in the Reactor Core There are 4 positions in the beryllium reflector consisting of IR1, IR2, IR3, IR4; 4 positions in core (IP) and 1 central irradiation in the centre of the core (CIP) consisting of 4 IP. All of IPs is intended for radioisotope production. A high neutron flux in the reactor core is potential to produce high quality radioisotopes by faster and more efficient irradiation. Various types of radioisotopes from fission and activation process have been produced in GA Siwabessy reactor including for medical purpose: 125I, 131I, 99Mo, 133I; etc , for industrial purpose 192Ir, 82Br, 60 Co, etc, for tracer 14C, 32P, 35S, etc. Irradiation of the FPM target is approximately done for 10 days and generates 1000 Ci of 131I.
- 54 -
Source / Reactor
3.1. Current Status of PRTF
3.5. Neutron Transmutation Doping Facility The facility (TD) is planned for irradiation of crystal materials uniformly. It will consist of an irradiation stand and tubes capable of rotation and variable positioning of irradiated samples, a number of self powered neutron detectors. The sample size of up to 7 inches diameter, 500 cm height can be irradiated. This facility is now under modification. Until now this facility used for topaz irradiation. History telling that in 1990 the NTD facility has experienced be operated to irradiate ingot from Japan. Unfortunately the result was unsatisfied due to technical requirements to operate the NTD facility are not fully yet fulfilled including : neutron fluence, stability of the reactor power, uniformity of irradiation, etc.Quality control to ensure an efficient irradiation process has not been available yet.
3.6. Rabbit System A total of 5 rabbit systems are provided for the irradiation of different materials, 4 rabbit systems with normal rabbit speed (NRS1, NRS2, NRS3, NRS4), that is hydraulic rabbit system and 1 rabbit system with fast rabbit speed (FRS), that is pneumatic rabbit system. There is no up-grading or refurbishment needed for this facility yet.
3.7. Irradiation Positions for Gemstones (topaz) Topaz gemstone may be irradiated in two different positions including in core irradiation facility or out core irradiation facility at which it is interchangeable with NTD.
3.7.1. In core Irradiation Topaz capsule made by aluminum has inside diameter of 60 mm and length of 1500 mm. Coolant flow through the bottom part of the capsule and the upper part is left open to alleviate topaz loading/unloading. There are 12 holes on the bottom part, each holes has a diameter of 2 mm. Upper part of the capsule is connected to aluminum pipe by diameter of 0.25 inch at which its upper end is connected to a steel rope for capsule handling. Maximum capacity of a topaz capsule is 1.5 kg. Loading/unloading of topaz at IP positions occur during reactor operation. Activities generated from irradiation activities of topaz can be calculated by ORIGEN-2 computer program. Estimate target weight is 1.5 kg; the maximum irradiation time is 10 hours. Power reactor is 15 MW and thermal neutron flux at IP position is 8x103n/cm2.s. It is recognized that total activities after 10 hours irradiation is 4.68 Curies/g. Total activities after 7 days decay is 7.183x10-5 Curie/g.
3.7.2. Out core Irradiation Out core location for topaz irradiation is in NTD position. During bombardment of colorless topaz material in out core with fast neutron “color-centers� will be altered to yellow, green and brown color. The half life of these radioactive nuclides is typically between a few days to several years. Irradiation time to get good color is 11 days. Decay time in the storage pool 7 days and radioactivity reduced to around 2 to 10 mrem/h. Estimate target weight is 30 kg; the maximum irradiation time is 8 days. Power reactor is 15 MW and thermal neutron flux at out core position is 8 x 1012n/cm2.s. It is recognized that total activities after 8 days irradiation is 1,358 x1010 Bq/g. Total activities after 7 days decay is 19,48 Bq/g.
- 55 -
• Replacement of all secondary pumps 2 out of 3 pumps have been successfully replaced • Cooling tower : replacement of blower • Chemical addition to the secondary system is accomplished gradually through the injection to address pipe instead of pouring at once to the secondary water pool • Isolation for Chilled Water System have been replaced. • Radiation Monitoring System have been replaced. • Instrumentation system of symatic 5 has been replaced by Instrumentation system of symatic 7 due to unmarketable of the former all of the logic control have been replaced.
5. Conclusion • Some activities were planned to improve RSG-GAS reactor operation and its utilization, especially for RI production, NAA, Gemstones and NTD. • Need further development for optimal utilization to support national program • The RSG-GAS be always operated an effective efficient and safe way.
REFERENCES 1. ANONYMOUS “Safety Analisys Report (SAR)”. PRSG-BATAN, Indonesia, 2009. 2. SUSILOWATI, Mrs. “Progress And Achievement at Multi Purpose Reactor G.A. Siwabessy, Serpong”. BATANIndonesia. November 2008. 3. SUDIYONO, Mr. “Experience On Utilization Of The Multi Purpose Reactor G.A. Siwabessy. July. 2010.
- 56 -
Source / Reactor
4. Improvement of Reactor Systems
SR-O-12
Tuesday, 2 Nov. 16:00 – 16:20 (Room 101)
Consideration of an Available Net Positive Suction Head for Coolant Pump in Down Flow and Open Pool Type Research Reactor Youngchul Park a*, Kyongwoo Seo a, Jaekwang Seo a, Daeyoung Chia, and Juhyeon Yoon a. Research Reactor Design Div. Korea Atomic Energy Research Institute 150 Deokjin-dong Yuseong-gu Daejeon, 305-353, R.O.KOREA. *Corresponding author: ycpark@kaeri.re.kr
a
While a reactor is normally operated, a heat is generated by the nuclear reaction. In research reactor, the heat is cooled by reactor coolant circulation through the primary heat exchanger for maintaining the nuclear reaction in safe. For the reactor coolant is circulated, a reactor coolant pump is necessary. In order to maintain performance requirements of the pump, an available net positive suction head (NPSHa) of the pump suction line should override the required net positive suction head (NPSHr) of the pump. In addition, when a 5 MW research reactor is upgraded to a 10 MW with the same composition of fuel assembly and the same configuration of pipe line, the reactor coolant flow rate increase two times of the original flow rate. The pressure loss increases about four times of the original pressure loss. Hence the NPSHa of the pump upstream can be smaller than the NPSHr of the reactor power upgrade pump. This paper described a consideration to meet that. It was confirmed that the pump can maintain the normal function through an optimization of the core assembly pressure loss, the pump suction friction loss and a static suction head.
- 57 -
SR-O-13
Tuesday, 2 Nov. 16:20 – 16:40 (Room 101)
Hoan Sung Jung*, Gee yang Han, Jong Sup Wu, In Cheol Lim Korea Atomic Energy Research Institute *Corresponding author: hsjung@kaeri.re.kr
Many experiments are carried out at the irradiation holes in the reactor core and reflector tank of HANARO research reactor. To ensure nuclear and structural safety, many aspects of experiments are reviewed and assessed by experts systematically. A general irradiation or experiment with small amount of sample enough not to affect reactivity. Safety significant experiments are subject to review by the Reactor Safety Review Committee consisting of experts in neutronics, thermal hydraulics, mechanical engineering, electrical engineering, radiation safety, etc. This paper describes a safety assessment process for experiments in the HANARO research reactor.
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Source / Reactor
Safety Assessment of Experiments and Irradiations in the HANARO Research Reactor
SR-P-01
Result of the Installation and Alignment for the Neutron Guides in HANARO Jin-Won Shin a*, Yeong-Garp Cho a, Sang-Jin Cho a, Jung-Hee Lee a Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong-gu, Daejeon 305-353, Korea *Corresponding author: jwshin@kaeri.re.kr
a
1. Introduction As a part of a Cold Neutron Research Facility (CNRF) project for the use of cold neutrons in basic science and technical application, we’ve developed a neutron guide system for the delivery of cold neutrons from the cold neutron source to the neutron scattering instruments in HANARO. It consists of the in-pile plug assembly with in-pile guides, the primary shutter with in-shutter guides, out-pile guides in the reactor hall and the neutron guide hall, secondary shutters, vacuum systems, and shielding assemblies. Our neutron guides are rectangular tubes made of Ni/Ti-supermirrors of which reflectivity is more than 88% (at m=2). Each guide has 1 or 2 m length so that they are connected each other with a silicon gap of 0.3 mm. So an accurate alignment is the most important factor which decides the performance of neutron guides as long as they satisfy reflectivity requirements and assembling qualities. But there are some limits of accessibility and workability to use conventional optical measurements while aligning the neutron guides at the CN beam port in a high radiation level. We could overcome such an environment and align the neutron guides successfully by adopting a laser tracker as our measurement system. This paper mainly describes the successful result of the installation and alignment of the neutron guides in HANARO including the in-pile plug and the primary shutter at the CN beam port. The methods of neutron guide alignment for the in-pile plug, the primary shutter, and out-pile parts are also presented. About 350 m of neutron guides were installed in the reactor hall and the neutron guide hall from Aug. 2008 to Sep. 2009.
2. Methods Neutron guides in HANARO are separated into three parts according to the pressure boundaries. In-pile parts are installed in the CN beam port of the reactor, which is filled with 1.2 atm. Helium. In-shutter guides are installed in the primary shutter which enables to open or close cold neutron beam by rotating a drum in a vacuum condition. Out-pile guides with a separate vacuum system from the primary shutter, are installed on the guide supporting structures composed of pillars, I-beam, and adjustment frames. The concept of ‘3-points support’ is applied to supporting structures to avoid any stress by a temperature change or the uneven bolt torques during the installation or operation [1]. In this section the methods of neutron guide alignment for in-pile, in-shutter and out-pile parts are described.
2.1 In-pile guides and in-shutter guides The in-pile plug and the primary shutter contain guide cassettes for the alignment and support of guides. The basic concept and methods of guide alignment in the cassettes using a laser tracker were introduced by Shin and Cho (2008) [2]. The procedures of the guide alignment for the in-pile plug and the primary shutter were established and the alignment was fulfilled successfully within 0.1mm tolerance. The final positions of downstream guides of the primary shutter were measured and saved in the software of the laser tracker, which would be used for aligning out-pile neutron guides.
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Methods of guide alignment for out-pile parts are based on the same concept as those of in-pile and in-shutter guides. But out-pile parts don’t have any guide cassettes except parts of the reactor building penetration. They are installed on the supporting structures and aligned in adjustment frames. When all guides of each beam line are aligned within the permitted tolerance, they are connected with the silicon to keep vacuum pressure inside. The procedure can be summarized into several steps to align out-pile guides. The first step is to place a guide on a flat and stable surface (ex. a granite table), and attach four reference nests on the top of guides and 2 corner nests each at entrance and exit section as shown in Fig. 1. After attaching SMR on each nest, corner points and reference points are measured to acquire coordinates of reference points by matching measured corner points to datum coordinates. The next step is to put the measured guide on the supporting structure and align guides according to the coordinates of reference points using the laser tracker. The screws of upstream and downstream adjustment frames are adjusted for the guide alignment and the center adjustment frame is used for the simple support. Finally the visual inspection is implemented to check the alignment between adjacent guides. The matching between the downstream end of one guide and the upstream end of the other guide can be seen optically if sufficient light is illuminated inside the guides as shown in Fig. 2.
Fig. 1. The measurement of reference coordinates for aligning out-pile neutron guides
Fig. 2. The visual inspection of the alignment between adjacent guides
3. Results In-plug and in-shutter guides for the in-pile plug assembly and the primary shutter were installed in Sep. 2008 [3]. The guide supporting structures for out-pile guides and cases of wall penetration parts were installed in the reactor hall and the neutron guide hall as shown in Fig. 3. The laser tracker was also used for the alignment of the guide supporting structures. Out-pile guides in the reactor hall were installed and aligned from the first units that start in front of the primary shutter (fig. 4). Out-pile guides which penetrate the wall of reactor building were installed as shown in Fig.5. In order to keep the pressure boundary of the reactor building, cases for penetration parts and sealing plates were installed. Fig. 6 shows out-pile guides installed with secondary shutters in the neutron guide hall.
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Source / Reactor
2.2 Out-pile guides
(a) Pillars and 3-point supports
(b) I-beam and adjustment frames
Fig. 3. The installation and alignment of guide supporting structures.
Fig. 4. Out-pile guides in the reactor hall
Fig. 5. Guides for the reactor building penetration.
Fig. 6. Out-pile guides with secondary shutters in the neutron guide hall
4. Conclusions The neutron guide system for the delivery of cold neutron from the CNS to the neutron scattering instruments has been successfully installed in HANARO. About 350m neutron guides have been finely aligned from the CN beam port to the scattering instruments. The laser tracker was used for the measurement and the alignment of the whole guide system. All neutron guides were aligned within the angle tolerance of 10-4 rad and showed great performances at cold neutron beam tests.
REFERENCES [1] Yeong-Garp Cho, Jin-Won Shin, Sang-Jin Cho, Jong-Myeong Oh and Jeong-Soo Ryu, “Development of neutron guides in HANARO”, Transaction of the Korean Nuclear Society Spring Meeting, pp. 685-686, 2008. [2] Jin-Won Shin and Yeong-Garp Cho, “Method for a neutron guide alignment in guide cassettes using a laser tracker”, Transaction of the Korean Nuclear Society Autumn Meeting, pp. 645-646, 2008. [3] Jin-Won Shin, Yeong-Garp Cho, Sang-Jin Cho and Jung-Hee Lee, “Alignment of neutron guides for the in-pile plug assembly and the primary shutter”, Transaction of the Korean Nuclear Society Spring Meeting, pp. 877878, 2009.
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SR-P-02
Ho-young Choi a*, M. Lee a, J.S. Han a, M.S. Kim a, S.H. Cho a, S.O. Hur a, G.H. Ahn a, W.J. Son a HANARO Management Division, Korea Atomic Energy Research Institute, 1045, Daeduk-daero, Yuseong-gu, Daejeon, Rep. of Korea *Corresponding author : choihy@kaeri.re.kr
a
1. Introduction The Cold Neutron Source(CNS) is installed in the vertical irradiation hole of the reflector tank in HANARO, and it produces a high flux cold neutron source(0.1~10 MeV) by moderating the thermal neutron using helium that is 22K. The CNS system consists of a hydrogen system, gas blanket system, helium refrigeration system and vacuum system. Among the related systems the helium refrigeration system(HRS) is the key-system in terms of the hydrogen liquefaction in the heat exchanger of the inpool assembly(IPA). The HRS consists of a helium compressor,oil removal system(ORS), gas management panel, gas analyzer, cold box, helium buffer tank, programmable logic controller (PLC) main control cabinet for its control and a WINCC computer. And proceeding to the operational regulation, it keeps the concentration of impurities(H2O, CxHy, N2) under 10.0 ppm(v) in the normal temperature. But we had experienced of a concentration up to 43.0 ppm(v) during the operation of the helium refrigeration system. The compressed helium gets through the oil separator and charcoal filter for filtering impurities. This paper describes our operation experience of the oil adsorbent regeneration of the HRS.
these oil contents. The set point of the oil contents is 10 ppm(v) of but it is kept under 1.0 ppm(v) in reality. The abnormal behavior of H2O within the cycle helium in HRS which has been operated for about 5,500 hours since the commissioning period in the middle of 2009 was shown during the CNS operation for the 66th reactor operation. The main cause was considered to be that the performance of the oil adsorbent in HRS was degraded. According to the manufacturer’s instruction manual, the charcoal of the absorbent shouldbe replaced after the first 8,000 operating hours and then it should be replaced every 20,000 hours. Figure 1 shows a trend of the oil contents during the purification of the cycle helium. Nitrogen is shown as yellow, hydrocarbon as orange, water as green, and oil aerosol as sky-blue in this figure. Normally, the concentration of nitrogen in the contents tends to soar drastically at the start-up of purification, and then decreased rapidly again. Hydrocarbon also showed as normal as nitrogen. But H2O showed abnormally the peak of it was 43 ppm(v), and the figure of oil aerosol was 9.3. These phenomena occurred after the purification of 7 hours. We were advised to regenerate the charcoal when we asked the manufacturer about the problem, Linde.
2. Method and Results 2.1 Status The HRS(Helium Refrigeration System) which is to cool down and liquefy the gaseous hydrogen to maintain a subcooled state is one of the most important systems in the HANARO-CNS facility. The cycle helium is used 5N(nine) pure and the residual oil contents which are included H2O, hydrocarbon, and nitrogen in it are purified. The HRS has the ORS and various filters to get rid of
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Fig.1. Trend of the oil contents during the purification of cycle helium
Source / Reactor
An Operation Experience of the Oil Adsorbent Regeneration at the HRS in HANARO-CNS
2.2 Method and Results The regeneration of the charcoal was conducted by the temporary procedure according to Linde’s advice. The way of regeneration was to dry out the charcoal using by heated nitrogen. The temperature of the heated nitrogen should be kept 160 at the vessel inlet and 110 at the outlet. The procedure of regeneration is as follows. 1) The charcoal vessel (A2140) was insulated with solvent free insulating material (Fig. 2). 2) 30 kW of the heater was installed at the inlet flange of the vessel. The nitrogen flow for drying was in the opposite direction of normal operation of cycle helium. 3) The gas hose of a four-cylinder header with regulator was connected to the heater. The nitrogen pressure required was approximately 3 bar (g) at the heater inlet. 4) The temperature of the vessel inlet was adjusted to 160 . 5) The nitrogen temperature at the vessel inlet and outlet was recorded every 20 minutes. 6) If the nitrogen temperature at the vessel outlet was higher than 110 for at least 20 minutes, the drying process would be completed.
Fig. 2. Charcoal vessel (A2140) insulation
82 bottles(47L) of nitrogen was consumed for 48 hours in order to get rid of H2O, but the temperature condition at the vessel outlet could not be satisfied. The following are the figures of the temperature measured at the four different parts one hour later after the heater stopped. 1) At the top of the vessel (nitrogen outlet): 70
2) At the second point of the vessel: 90 3) At the third point of the vessel: 120 4) At the bottom of the vessel (nitrogen inlet): 135
Fig. 3. Impurities in the cycle helium after adsorbent regeneration
3. Conclusions Although the temperature condition of nitrogen at the vessel outlet as Linde advised could not be satisfied, we considered that the regeneration work was successful. Figure 3 shows the impurities in the cycle helium after the adsorbent regeneration was conducted. It is certain that the regeneration was successful in the comparison of figure 1 and figure 3, and we finished the regeneration of the charcoal after three times of vacuum cleaning and helium purging. Some lessons were learnt through this experience. 1) The need of regeneration procedure 2) The need of maintenance plan 3) The need of preventive maintenance REFERENCES [1] I.C. Lim et al. “Year 2008 HANARO & Utilization Facility Management”, KAERI/MR-493/2008, 2009. [2] M. Lee, H.Y. Choi, “An Cause Analysis of Hydrogen Increase at the HRS in CNS”, HAN-TNCR-477-10-03, Technical Report, 2010. [3] KAERI, “Safety Analysis Report”, 2009. [4] J.W. Choi, “Helium Refrigeration System” , HANTAP-05-OD-COP-OP-006, Operating Procedure, 2010. [5] J.W. Choi, “Installation and Site Acceptance Test of Helium Refrigeration System for HANARO-CNS”, 2009 HANARO SYMPOSIUM, KAERI. 2009.
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SR-P-03
Mun Lee*, W.J. Son, Y.G. Lee, H.Y. Choi, J.S. Han, S.W. Cho, M.S. Kim, G.H.Ahn Korea Atomic Energy Research Institute *Corresponding author: mlee@kaeri.re.kr
The liquid hydrogen in the moderator cell of IPA (In-Pool Assembly) is used to moderate the thermal neutron to cold neutron. 152±3 kPa (a) of hydrogen pressure is the pressure to be liquefied, and cryogenic helium is used as refrigerant to keep this pressure condition. The operation of the CNS (Cold Neutron Source) in HANARO has three stages; shut-down, start-up, and normal operation. During the start-up, it takes about 12 hours to stabilize the hydrogen pressure at 152±3 kPa (a); four hours for helium gas purification, and 8 hours for cooling down. After that the reactor can be operated. Figure 1 shows hydrogen pressure before and after operating the reactor. The hydrogen pressure has been fluctuating from 123 kPa (a) to 180 kPa (a) at any MW power after the reactor operation. When the hydrogen pressure is out of the range; low pressure of 120 kPa (a) and high pressure of 200 kPa (a), then the reactor is scrammed by the RRS (Reactor Regulating System). The hydrogen pressure is the sole parameter of the reactor trips in the CNS operation. As illustrated on the Figure 2, we can also see the hydrogen pressure at reactor shutdown. Hydrogen pressure falls gently down to 15MW in the full power condition, but it fluctuates very drastically on 15MW. The reactor trips, which were caused by a drop in pressure to 120kPa (a), happened in the 59th, the 61st, and the 62nd cycles. Figure 3 shows hydrogen pressure at 15 MW power. In the figure, the hydrogen pressure fluctuated severely from 140 kPa (a) to 167 kPa in the process of reducing reactor power to 15MW by failure of CAR (Control Absorber Rod) in the 65th cycle. In order to solve this problem we were planned at the beginning of the year 2010 as below. - First, activate the trip by-pass button at the CNS control panel when the reactor power would be changed. - Second, change appropriately the reactor power after observing the trends of hydrogen pressure. - Third, wait until the hydrogen pressure is stabilized. These solutions didn’t prove successful, and it became clear that the basic faults were caused by control logical program of the helium refrigeration system. For this, the control logic program for by-pass valves should be changed.
RX Power
Hydrogen Press
Fig 1. Trend of hydrogen pressure at the RX start-up
RX Power
RX Power
Hydrogen Press
Hydrogen Press
Fig 2. Trend of hydrogen pressure at the RX shut-down
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Fig 3. Trend of hydrogen pressure at 15 MW
Source / Reactor
An Analysis of the Effects of Reactor Operation on Hydrogen Pressure at HANARO-CNS
SR-P-04
Characteristics, Layout and Test Results of a Guide Test Station at CG1 Beam Line of HANARO S. J. Cho*, B. S. Seong, C. H. Lee, K. P. Kim Korea Atomic Energy Research Institute 1045 Daedeok-daero,Daejeon 305-353, Korea *Corresponding author: sjcho@kaeri.re.kr
A neutron guide system that includes neutron guides, a main shutter, and a vacuum system, was successfully installed at the HANARO research reactor of the Korea Atomic Energy Research Institute (KAERI) in 2009, and is now operating with 5 cold neutron instruments. The neutron guides in the in-pile plug, main shutter, and reactor building were delivered by Swiss Neutronics, while the rest of the guides for the guide bunker and the guide hall were provided by KAERI. Due to increasing demand of neutron guide and neutron optical component such as focussing neutron guide, polarizing neutron cavity, beam flight path and so on, we developed a neutron guide reflectivity test station(G-TS) at CG1 beam line in order to improve neutron guide quality. The characterisitics of the G-TS, layout and measurement results will be presented at this meeting.
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SR-P-05
Chang-Hee Lee a*, Sang-Jin Cho a, Young Soo Han a, Ji-Yong So a, Myungkook Moon a, Sungil Park a, Baek-Seok Seong a, Jeong-Soo Lee a, Dong Jin Choi a, Tae-Hwan Kim a, Sung-Min Choi b, Je-Geun Park c, Kwan-Woo Shin d, Uk-Won Nam e, Hong-Ju Kim f Korea Atomic Energy Research Institute (KAERI), 1045 Daedeok-daero, Yuseong-gu, Daejeon, 305-355, Korea b Korea Advanced Institute of Science and Technology (KAIST), 335 Gwahak-ro, Yuseong-gu, Daejeon, 305-701, Korea c Seoul National University (SNU), 599 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea d Sogang University (SGU), 1 Sinsu-dong, Mapo-gu, Seoul 121-742, Korea e Korea Astronomy and Space Science Institute (KASI), 838, Daedeok-daero, Yuseong-gu, Daejeon, 305-348, Korea f Kyungpook National University (KNU), 1370, Sankyuck-Dong, Daegu, 702-701, Korea *Corresponding author: leech@kaeri.re.kr a
HANARO CNRF project was composed of 4 sub-projects, one of which is the development of 6 cold neutron spectrometers to be installed in the cold neutron laboratory building. Those 6 spectrometers were selected from the project planning committee in 2003 after national instruments survey using cold neutron for next phase national R&D demand. There are 3 newly developed spectrometers; 40m small angle neutron spectrometer (40M-SANS), the cold neutron triple-axis spectrometer (Cold-TAS) and the disc-chopper time-of-flight spectrometer (DC-TOF), and another 3 relocated spectrometers from the reactor hall with modification and upgrades to the cold neutron guide environment, which are 18m small angle neutron spectrometer (18M-SANS), reflectometer with vertical sample geometry (REF-H), and the bio-reflectometer with horizontal sample geometry (Bio-REF). There are two important technology development activities for these large scale instruments developments under CNRF scheme, and one of which is the development of neutron mirror and guide fabrication technology and the other is fast neutron counting electronics for large scale neutron detectors for TOF instruments with its firmware and acquisition software. In this contribution, we will present the strategy of instrument selection and development, progress, achievement and present situation of the cold neutron laboratory.
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Source / Reactor
Development of Cold Neutron Spectrometers in HANARO
SR-P-06
Development of Systems for Cold Neutron Source in HANARO Sang Ik Wu a*, Sang Hoon Bae a, Young Ki Kim a Korea Atomic Energy Research Institute (KAERI), 1045 Daeduk-daero, Yuseong-gu, Daejeon, Korea *Corresponding author: siwu@kaeri.re.kr a
The design concept of the system for Cold Neutron Source (CNS) is to ensure that the reactor safety systems and the on-site personnel and equipment are not adversely affected by the hydrogen-oxygen reaction from themselves. The CNS system consists of a Hydrogen System, a Vacuum System, a Gas Blanketing System, a Helium Refrigeration System, and a Control System. The safety design criteria of the system are a defense-in-depth approach that provides several means to avoid any accidental contact between the hydrogen in the system and the air. Therefore, the principles of a conservatism, simplicity, redundancy, fail-safe design, and passive safety features are included to design it with an enhanced safety and efficiency. Although all the equipment and piping which contain hydrogen gas are surrounded by a blanketing gas such as the properly pressurized helium or nitrogen, air ingress into the vacuum area should be analyzed. This assumption was applied to the basic design accident for the HANARO CNS. The final goal of the HANARO CNS is to accomplish an efficient system, which is operated safely with regard to the reactor and its personnel. HANARO CNS was successfully designed and commissioned satisfying not only all the requirements of regulation, but also throughout the engineering experiences performed at HANARO. This paper summarizes key items with regarding to CNS project implemented in HANARO.
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SR-P-07
Sang Ik Wu a*, Kook-Nam Park a, Young Ki Kim a, Kye Hong Lee a Korea Atomic Energy Research Institute (KAERI), 1045 Daeduk-daero, Yuseong-gu, Daejeon, Korea *Corresponding author: siwu@kaeri.re.kr a
The HANARO adopted the liquid hydrogen as a moderator for Cold Neutron Source (CNS). The liquid hydrogen contained in the moderator cell evaporates due to gamma heating. The hydrogen vaporizes up to the condenser, where it is re-liquefied then it returns down to the moderator cell. So, that is why the safety design philosophy for the CNS is a defense-in-depth approach that provides several means to endure the effect of a hydrogen-oxygen reaction as well as to avoid any possibility of a contact between hydrogen and oxygen. The principles of conservatism, simplicity, redundancy, fail-safe and passive design features are included in the design as much as possible. The HANARO has been equipped with a vertical liquid-hydrogen moderated CNS. The vertical hole for the CNS was reserved at the dedicated location during the HANARO construction phase. The developed moderator cell, which made of 1 mm thickness of AL 6061-T6 classified in nuclear safety, is connected to a heat exchanger, establishing two phase flow by a natural convection. The In-Pile Assembly (IPA) including the moderator cell was successfully fabricated and installed in HANARO. This paper presents the achievements of the CNS moderator cell developed in HANARO.
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Source / Reactor
Development of Cold Neutron Moderator Cell in HANARO
SR-P-08
Accomplishment of Cold Neutron Guide System in HANARO Yeong-Garp Cho a*, Jin-Won Shin a, Jeong-Soo Ryu a, Sang-Jin Cho a, Jung-Hee Lee a, Jong-Myeong Oh a, Byung-Chul Lee a, Hak-Sung Kim a, Min-Jin Kim a, Kyeong-Hwan Lim a,Hyun-Jun Kim a Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong-gu, Daejeon 305-353, Korea *Corresponding author: ygcho@kaeri.re.kr a
The HANARO Cold Neutron Research Facility (CNRF) Project has been embarked in July 2003. The objective of CNRF Project is to install cold neutron source, neutron guide system and neutron instruments. The beam port assigned for the cold neutron had been used for an 8-m SANS without neutron guides until early 2008. We have developed a cold neutron guide system for the delivery of cold neutrons from the cold neutron source in the reactor to the neutron scattering instruments in the guide hall. The system consists of the in-pile plug assembly with in-pile guides, the primary shutter with in-shutter guides, out-pile guides in the reactor hall and the neutron guide hall, secondary shutters, vacuum systems, and shielding blocks. It was a big challenge to replace the existing plug and shutter with the new systems with the difficult situations, such as high level of radiation, poor as-built dimensions of the beam port, limited working space and time due to other constructions in parallel in the reactor hall. In 2008, the old plug, shutter and instrument were removed and a new plug and a primary shutter with guides assembled had been successfully installed. In addition to the enough rehearsal for the installation, a laser tracker system was also one of the main roles for our success of the installation under high radiation conditions and limited working space. In 2009, all the guides and accessories are had been installed including the vacuum system of the neutron guides. With a full power of reactor operation, we confirmed the neutron guide system delivers the cold neutrons to the instruments with enough neutron fluxes. Also shielding performance has been verified with the primary shutter open and close.
This paper will be given in oral presentation as well monday
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SR-P-09
Yeong-Garp Cho a*, Jin-Won Shin a, Jung-Hee Lee a, Jeong-Soo Ryu a, Hark-Rho Kim a, Jong-In Kim a Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong-gu, Daejeon 305-353, Korea *Corresponding author: ygcho@kaeri.re.kr a
The principal function of a laser tracker system is using a laser beam pointed toward a reflecting mirror attached on an object for the measurement of the coordinates (x, y, z) using the distance, horizontal and vertical angles between the laser tracker and the reflecting mirror. One of the main reasons of the success installation of neutron guide systems recently accomplished at HANARO was the use of the laser tracker system under various difficult site conditions such as high radiation, limited physical space and time schedule. For more effective fabrication, installation and maintenance of research reactors, this paper proposes the application concepts of the laser tracer system for the various fields as follows. Dimensional inspections (length, diameter, shape, straightness, flatness, angle, horizontality, verticality) at the manufacturing factories for the complex and large components such as reactor structures, reactivity control units, beam ports, pool cover, operation bridge, storage tanks, etc. Pre-assembling and alignment of sophisticated components to confirm the assembling performance for reactor structure, reactivity control units, reflectors and beam tubes. Installation and alignment not only for the reactor assembly but also for other related components or structures such as reactor cooling pipes, pool covers, beam ports and vertical irradiation facilities which should be aligned with the reactor core. Measurement of key points during the construction of reactor building including pool liner and overhead crane. Installation of dance floor, neutron guide system and beam instruments. Measurement or adjustment of levels for control rods and other components in the pool during maintenance of the reactors. The effective using of the laser tracker system will give us precise and reliable dimensional data, time saving, safe accessibility and workability, and safety under radiation field. These will be invaluable benefits compared with the traditional measurement method which uses ruler, leveler, plumb, mercury mirror, theodolite, etc.
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Source / Reactor
Effective Applications of Laser Tracker System for Research Reactors
SR-P-10
OPAL Reflector Vessel - Repairs Options to Mitigate Light Water Leaks Russell Thiering*a, Walter Bermudeza, Carlos Durioneb a
Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234 b INVAP, S.C. de Bariloche, Argentina *Corresponding author: rct@ansto.gov.au
Australia’s multipurpose research reactor, OPAL, was commissioned in 2006. In early 2007 a defect in the reactor’s reflector vessel was discovered. The defect resulted in the permeation of light water from the reactor pool into the reflector vessel, hence causing degradation to the heavy water isotopic purity. A reduction in heavy water purity impacts upon the functionality of a number of the reactors’ irradiation facilities. A series of repair strategies have been developed to mitigate the leakage. Strategies included pressure equalisation, closing the defect by particulate injection, underwater welding, mechanical deformation and covering the defect with a sealing pad. The development of repair strategies was challenging due to the location of the defect under water, restricted access to the area and the very high radiation fields. In 2009, during the most recent repair campaign, OPAL was shutdown for 4 weeks to install flexible graphite sealing pads over the reflector vessel defect regions. This was preceded by extensive testing of flexible graphite behaviour and tooling optimisation. The pads provided a positive seal against light water ingress and currently remain in operation. This presentation details the reflector vessel repair strategy implemented in 2009 and discusses a number of other mitigation strategies that were assessed.
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SR-P-11
Hyungkyoo Kim*, Youngsan Choe, Incheol Lim, Youngki Kim Korea Atomic Energy Research Institute 1045 Daedeok-daero, Yuseong, Daejeon, 305-353, Korea *Corresponding author:kimhk@kaeri.re.kr
1. Introduction
2. Background
The HANARO neutron measurement system is used as a part of the Reactor Regulating System (RRS) and Reactor Protection System (RPS). The HANARO neutron measurement system, which was supplied by Thermo Gamma Metrics (TGM) in 1994, consists of a neutron detector assembly with cable, wide-range neutron amplifier, and signal processor. As shown in Fig. 1, the neutron detector is housed in a vertical well installed symmetrically at three locations on the outer wall of the reflector tank. The vertical well is designed to accommodate two neutron detectors, one for the RPS and the other for the RRS. The first instability of the logarithmic power was observed at RRS Ch. A in 2004, and since then a similar phenomenon has been found several times in the same channel. Although the amplifier and signal processor performed, the neutron detector cable assembly showed a symptom of aging due to radiation damage. It was necessary that the existing neutron detector and cable assembly be replaced with a newly-developed detector model. In 2008, two fission chambers were replaced with a newly-developed detector. The rest of the detectors will be replaced as preventive maintenance this year. This paper describes the upgrade program of the HANARO neutron measurement system and its implementation.
2.1 Description of Neutron Measurement System The neutron detector assembly of the HANARO neutron measurement system consists of a guarded fission chamber inserted into a housing, HN-type connectors, mineral insulated cables, and solid copper sheathed coaxial cables. The fission chambers are used to detect a neutron flux because of their proven high reliability in harsh environments and because of their ability to operate under a high gamma flux without damage or loss of sensitivity. The signal from the detector is composed of a series of charge pulses that result from alpha decay, gamma photon interaction, and the fission of uranium atoms when a neutron is absorbed. The pulse signal from alpha decay and from gamma radiation is eliminated by amplitude discrimination because the neutron pulse signal is much larger. The signals from a wide range of amplifiers are transmitted to the signal processors. The signal processors convert the signals from the amplifiers into surveillance values that represent the percent of reactor power level on a linear scale, percent of reactor power level on a log scale, and the rate of change of the log power level in percent per second. For this reason, fission chambers are widely used for reactor tripping and monitoring reactor power. The fission chambers of HANARO are also used in both the RPS and RRS. The RRS uses the analog signals for reactor power control, and the RPS uses contact outputs for tripping the reactor.
2.2 Evaluation of Neutron Measurement System Electrical insulation starts to age as soon as it is made and this ageing deteriorates its performance. High insulation resistance indicates that the leakage current under DC voltage is low. Generally, neutron detectors are supposed to have higher performance when the insulation resistance is higher. In 2006, all neutron detector assemblies of HANARO, including the cable assemblies, were examined not only for the insulation resistance of the detectors and cables, but also for the discriminator
Fig. 1 Location of the Neutron Measurement System
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Source / Reactor
Upgrade Program of the HANARO Neutron Measurement System
voltage and the band pass filter offset voltage. If the insulation resistance was poor, the detector assemblies were evacuated and backfilled with nitrogen to improve the insulation resistance. The insulation resistance was checked between the signal cable (SIG) and coax shield (RSIG), between the high-voltage cable (HV) and coax shield (RHV), and between center pin of the SIG and that of the HV (RPP). Fig. 2 shows the insulation test results for the neutron detector assemblies. From the examination in 2006, we found that the insulation resistance readings of all channels, except RPS Ch. C and RRS Ch. C, were lower than expected.
with newly developed neutron detectors. The structure of the newly developed neutron detector assembly is shown in Fig. 3. The signal cable assembly of the new detector uses a bellows conduit for easy installation. It is also separated by the splitter so as to improve the maintainability [1]. An insulation resistance test for the new detector assemblies was conducted before installation. We carried out an evacuation and backfilling with nitrogen to improve the insulation resistance several times before installation. Table 2 shows the insulation resistance readings after completion of the installation.
Fig. 2 Insulation Test for Neutron Detector with CableAssemblies
Fig. 3 Structure of New Detector Cable Assembly
The insulation resistance readings were improved after evacuating and backfilling the detector and cable with nitrogen. However, the RHV of RRS Ch. A, where the instability of the logarithmic power had been observed, and the RHV of RPS Ch. B, were not improved. The insulation resistance readings should be greater than 1.0E+10 Ω. Table 1 shows the pre- and post-evacuation insulation resistances of RRS Ch. A. The pre-evacuation insulation resistance readings between the copper coax cable shield and the cable flex-hose (RSH) of RPS Ch. B were quite outside the specification, which is greater than 2E7 Ω at 50 VDC. We also made a plan to replace all detectors for safe and stable reactor operation. RRS A
RPS B
PrePostPrePostevacuation evacuation evacuation evacuation RSIG
1.34E+10
1.89E+10
1.89E+10
4.05E+10
RHV
6.55E+08
BAD
3.78E+09
3.77E+10
RPP
1.62E+10
1.89E+10
1.62E+10
4.05E+10
RSH
4.50E+08
5.00E+08
1.00E+06
1.00E+06
Table 1 Insulation Resistance (Ω) of old RRS Ch. A and RPS Ch. B
2.3 Replacement of Neutron Detector In 2008, the neutron detector of RRS Ch. A and RPS Ch. B, which had been found to be defective were replaced
RRS A
RPS B
RSIG
1.07E+11
5.18E+10
RHV
7.83E+10
7.20E+10
RPP
2.48E+10
9.94E+10
RSH
>1.00E+09
>1.00E+09
Table 2 Insulation Resistance of Newly- Installed Detectors
3. Conclusions The instability of logarithmic power was observed at RRS Ch. A for the first time in 2004. We anticipated that this was a sign of deterioration, and we therefore checked all neutron detectors at HANARO in 2006. Upon further checking and review, it was determined that the deterioration was progressing in all detectors as expected. In 2008, we successfully completed the replacement of two of the worst neutron detectors, including the one in which the instability had been originally observed. The remaining of detectors are going to be replaced with new ones in 2010. When the replacement of all neutron detectors is completed, it will improve the reactor safety and stability. REFERENCES [1] Y. K. Kim, Technical Specification for Neutron Detector Assembly for HANARO, KAERI, Daejeon, Korea, 2007.
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SR-P-12
Su Ki Park*, Heonil Kim, Cheol Park Korea Atomic Energy Research Institute, Daedeokdaero 1045, Yuseong, Daejeon, 305-353, Korea *Corresponding author: skpark@kaeri.re.kr
A convective heat transfer by natural circulation is a very usefull and reliable means to cooldown a reactor core in pool-type research reactors when the reactor is shutdown and a normal forced flow is unavailable. In pool type research reactor, the natural convective heat transfer is generally established by a pool water natural circulation via flap valve. As a flap valve is a key component for the natural circulation cooling, a lot of attention on design parameters of flap valves should be needed. This paper deals with the effects of flap valve design parameters on the core cooling charateristics for research reactors that have a downward flow in the core. Design parameters such as elevations, forward and reverse loss coefficients, and opening-set points of the flap valves have been investigated in case of a loss of total forced flow due to pump failure. The RELAP5/Mod3 code has been used for the thermal-hydraulic analyses here. The results show that the start of flow reversal and the reversal flow rate in the core, the fuel temperatures, and the DNBRs are influenced by the elevations, loss coefficients, and opening-set points of the flap valves. The lower the elevation of the flap valve is, the faster the reversal flow starts and the lower the fuel temperature is. The smaller the loss coefficient of the flap valve is assumed, the bigger the flow rate is predicted. The smaller the opening-set point of the flap valve is, the bigger the DNBR is. However, it is found that the differences between the maximum fuel temperatures and the minimum DNBRs are negligible in the various ranges of the design parameters investigated in this study.
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Source / Reactor
Effects of Flap Valve Design Parameters on Core Cooling Characteristics for Research Reactors
SR-P-13
The Operation Properties of the Gas Blanket System for the Cold Neutron Source in HANARO Chang-Young Joung*, Sung-Ho Ahn, Bong-Sik Sim, Sang-Ik Wu, Young-Ki Kim HANARO Management Division, Korea Atomic Energy Research Institute 150 Deokjin-dong, Yuseong-gu, Daejeon, Korea 305-353 *Corresponding author: joung@kaeri.re.kr
The cold neutron source (CNS), installed recently in the HANARO, is the facility to produce cold neutrons by passing thermal neutrons occurred in the reactor core through the moderator of the liquid hydrogen layer. It has an energy of 5 meV and a wave length of 4~20A. Exploiting the advantage of lower energy and longer wave length, it can be used as an essential tool to investigate the structure of protein, amino-acid, DNA, super lightweight alloys and advanced material in the field of high technology. The CNS has been developed in the KAERI and it was manufactured and installed in HANARO. And the first cold neutron was produced in September of 2009. The gas blanket system was designed for the supply of blanket gas and the protection vacuum system and hydrogen system in the CNS. It can be classified into two compartments as follows. One is dynamic system which supplies gas during normal operation. For gas supplying purposes to drive the valves, Nitrogen gas is supplied through the pipe and a nitrogen buffer tank from nitrogen gas cylinders. And to operate a vacuum system, helium gas is supplied through the pipe from helium gas cylinders. Another is static systems which does not circulate either helium or nitrogen gas filled for gas blanketing purposes during normal operation. Since all the related components are highly gas-tight, no frequent pressure variation is occurred. The system surveillance using the pressure variation is an effective way of monitoring to find leaks in these systems. To realize the effective leakage monitoring for safety, the normal operating pressure of the blanket gas in the gas blanket system is higher than the pressure of atmosphere, vacuum and light water around the blanket, but lower than the hydrogen gas pressure. The gas blanket system is not directly connected to the safety function but acts as an important protective barrier. And it was applied so that air and light water are not flowing into the inside of the piping and tanks including the vacuum system and the hydrogen system to prevent the outside leak of the hydrogen gas, and the cold neutron source could be protected. This paper describes about the main functions and operation properties of the gas blanket system for the cold neutron source installed in HANARO.
- 75 -
SR-P-14
Won-Ho In*, Mun-Jo Choi, Tea-Hwan Kim, Ki-Doo Kang, Chung-Sung Lee HANARO Management Division, Reactor Utilization and Development Dept., KAERI 150 Deokjin-dong, Yuseong-gu, Daejeon 305-353, Korea *Corresponding author: wonho@kaeri.re.kr
HANARO is a 30 MW open-pool type multi-purpose research reactor. It has been utilized for various purposes including the NTD (Neutron Transmutation Doping) which is for production of n-type silicon semiconductors. HANARO has two irradiation holes for NTD, NTD-1 for 6 and 8 inch NTD-2 for 5 and 6 inch of diameter silicon ingots. The practical irradiation services were commenced from Dec. 2002 and Apr. 2008 for NTD-2 and NTD-1 respectively. HANARO has three channels of neutron power monitoring system (Ch-A, B, C) and each channel is composed of two identical fission chambers. One of each channel is for RPS (Reactor Protection System) and the other is for RRS (Reactor Regulating System). The reactor power is regulated by taking the ratio of demand power to neutron power of the middle value among three detectors for RRS and moving thecontrol rods. As NTD-1 hole is closed to Ch-B and the silicon target has a massive volume, a large amount of material change is occurred between the empty hole and target loaded hole and it may give uncontrollable effect on the detector signal of Ch-B. This effect can be observed during the operation and also simulated by the core calculations. In this paper, we analyze and evaluate the action of activity changes due to NTD target upon the stabilization of the reactor power regulation.
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Source / Reactor
A Study on the Effect of NTD Silicon Irradiation on the Reactor Power Monitoring
SR-P-15
Activation Analysis of Beryllium and Graphite Reflectors for a Pool Type Research Reactor Chang Je Park *, Chul Gyo Seo, Gyuhong Roh and Byungchul Lee Research Reactor Design & Engineering Division, Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong-gu, Daejeon, 305-353, Korea *Corresponding author: cjpark@kaeri.re.kr
Light water, heavy water, beryllium, and graphite are widely used as neutron reflectors in nuclear reactor systems due to their low neutron absorption cross section, high neutron scattering cross section and low mass number, which are good characteristics for the moderating power. Among several reflector materials, beryllium and graphite are taken into consideration for a pool type research reactor, which is under design. For an inner high flux region, the beryllium reflector is installed, and outer core region is filled with the graphite reflector, respectively. Beryllium has various applications to nuclear engineering including neutron reflector, window for x-rays and gamma rays, neutron source combined with selective radioactive materials, and neutron multiplier. Graphite has been widely used in gas cooled reactor due to its good structural properties such as ease of manufacturing and excellent thermal properties especially at high temperature. But both reflectors are revealed to highly intense neutron and gamma fluxes, which may involve a radiation heat and a structural damage, eventually resulting in reduction of the life time. In this paper, an activation analysis is carried out by the ORIGEN-ARP code which is one of the sub-modules of the SCALE6 code system. The cross section library for research reactor is constructed using a model based on a plate type fuel assembly and the TRITION/NEWT code in SCALE6 based on ENDF-B/VI. For 450 irradiation days, activity and decay heat are analyzed for both beryllium and graphite reflectors, and gamma spectrum is estimated additionally. Impurity effect is also performed for two reflectors. The weights of both beryllium and graphite are assumed equally as 35 kg. When the beryllium reflector is irradiated for 450 days, several radiation source isotopes are generated such as Be-8, He-6, H-3, and Li-8. Furthermore, the neutron absorption increases due to buildup of Li-6 and He-3. Total activity and decay heat per unit weight of beryllium is estimated as 51 Ci/g and 0.14 W/g, respectively. When impurities added in the beryllium reflector, they give significant effect on activation characteristics, especially on the gamma spectrum. For example, total gamma intensity of pure beryllium is obtained about 2.7E+9 photons/s whereas that of impure beryllium is estimated 8.4E+11 photons/s. In the case of the graphite reflector, total activity and decay heat are obtained as 3.5E-4 Ci/g, 4.8E-6 W/g, respectively, which is quite lower than those of beryllium reflector. Like the beryllium reflector, the impurity yields severe increase in gamma intensity from 3.0E+6 photons/s to 3.9E+11 photons/s. The resulting data will be applicable to the detail design not only for core design but also for structural and mechanical design in the research reactor development.
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A Preliminary Study on Oxidation of Aluminum Alloy Cladding of U3Si2-Al Fuel Plate Y.W. Tahk *, J.Y. Oh , B.H. Lee , C.G. Seo, J. S. Yim Research Reactor Design & Engineering Div., Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon 305-600, Republic of Korea *Corresponding author: ywtahk@kaeri.re.kr
U3Si2-Al dispersion fuel with Al cladding will be used for Jordan Research and Training Reactor (JRTR). Aluminum alloy cladding experiences the oxidation layer growth on the surface during the reactor operation. The prediction of the aluminum oxide thickness of fuel cladding and maximum temperature difference across the oxide film is needed for reliability evaluation based on the design criteria and limits which prohibit spallation of oxide film. In this work, a preliminary prediction of the aluminum alloy oxidation in the JRTR fuel is performed. According to the current JRTR fuel management scheme and operation strategy for 5 MW power, a fresh fuel is discharged after 900 effective full power days (EFPD) with 18 cycles of 50 days loading, which is too long span to predict oxidation properly without an elaborate model. The latest model developed by Kim and Hofman, et al. [1] uses a variable ratelaw power in a function of irradiation time, temperature, surface heat flux, water pH, and coolant flow rate, of which the last 3 terms were not considered in a total manner in the previous known aluminum oxidation empirical models. The model is in good agreement with the in-pile test data available in the literature as well as with the recent RERTR test data, which is regarded as the best elaborate model for the oxidation of aluminum alloy cladding in various operating condition. Accordingly, this model will be used for estimating the oxide film thickness. If a power history and heat transfer coefficient at oxide-water interface is given, the time or cycle dependent heat flux and oxide–water interface temperature could be calculated which enhance the input accuracy for the model. So, preliminary power history of a fuel plate during 900 EFPD was calculated based on the JRTR fuel shuffling scheme, fuel assembly average power history and power peaking data from core analysis. The water pH is expected to be about 5.7 on average and controlled within a range of 5.5–6.5 according to the technical specification. The oxide thickness of discharged fuel and maximum temperature difference across the oxide film was predicted to be 27 mm and 6 oC at a constant pH of 6.2 and in the case of pH 6.5, 110 mm and 23 , respectively. It is noted that the predicted oxide thickness is sensitive to pH. A more accurate prediction can be obtained by following the history of pH variation. If the in-situ measurement of real water pH is not available for the best estimation, it is reasonable to assume that the pH changed linearly with time between the pH level at the beginning of a cycle and at the end of a cycle. When it is considered that initial aluminum cladding thickness is 0.38 mm, water pH level is recommended preliminarily to be controlled lower than 6.2 for the conservativeness in the case of including the spent fuel residence time in the storage rack after discharging.
[1] Yeon Soo Kim, G.L. Hofman, A.B. Robinson, J.L. Snelgrove, N. Hanan, “Oxidation of aluminum alloy cladding for research and test reactor fuel”, Journal of Nuclear Materials, 378 (2008) 220
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Source / Reactor
SR-P-16
SR-P-17
Replacement of the RI Production Facility Control Panel Minjin Kim a, Dong Weon Youn a, Byeong Joo Yoon a, In-cheol Lima a
Korea Atomic Energy Research Institute, 150 Dukjin-dong, Yuseong-gu, Daejeon 305-353, Korea *Corresponding author: kimminjin@kaeri.re.kr
The old control panel of RI Production Facility had been used for 16 years since the commissioning. Failure rate of the parts of control panel was getting increased and major parts are not available any more. It might have caused the longterm shutdown of the facility if major parts had been breakdown. To avoid this situation, we started to design the new control panel using state-of-the art technology in early 2009 and finished at the end of June 2010. We successfully finished the design, fabrication and installation of new control panel as follows Main process of RI production facility is the HVAC system and the exhaust air cleaning system. The old control panel consisted of PLCs that controlled the 6(six) Air Handling Units, dampers, 30(thirty) Fans, and controllers that controlled the negative pressure of the Radioactive Area such as hot cell banks. Since recent PLC technology can provide analog control as well as logic control, the conventional analog controller is removed. The switches, indicators, lamps were replaced with HMI (Human Machine Interface) PC and 2(two) 27” monitors. The PLC logic of old control panel had been working properly for a long time, migration of the old version of PLC logic to new PLC was only required. For HMI design, it took long time because there was no such thing in the old control panel. We provided mimic pages that depict the P&I D and switch board. Also provided were alarm pages and trend pages that enabled the data logging and analysis of events and malfunctions. In new control panel, we extended the width of corridor of the termination panel for cable and wiring work because old one had too narrow corridor to do maintenance work. When the design of the new control panel was finished, we started the fabrication of control panel. It took a bit longer time than we expected because the original contractor became bankruptcy two months before delivery. Panel fabrication was almost finished but the software work was at the stage of beginning. We made a contract with the other company in February 2010 and started design and configuration of HMI. It took four months when we found that the design was acceptable through a review & comment process. Before installing the new control panel, we had to disconnect from the old control panel all the control wiring except those for the important 8(eight) exhaust fans which were to be in continuous operation for four hot cell banks and battery room. To enable the continuous operation of these fans, we disconnected and moved the control wirings of standby fans to the temporary switch panel that was specially designed for this purpose while main fans were in operation. As soon as the wiring was finished, we stopped main fans and started the standby fans from the temporary switch panel. Then we removed the rest of control wirings from the old control panel. At last, the old control panel was removed and the new control panel was placed. Then we moved back the control wirings of the important exhaust fans to new control panel from the temporary switch board. As soon as we finished the wiring work, the exhaust fans were put in operation immediately. When the terminations of the rest of wirings were finished, check out of fan control logic was carried out per loop basis while the breaker of the each fan was in OFF position. After the check out was finished successfully, all the breaker of fans were back to ON position and all the fans were put in service one by one. We successfully finished the installation of the new control panel in a timely manner so that our users could meet their medical and industrial radioisotope production schedule. We chose to use domestic PLCs that have analog control functions as well as logic control function in the new control panel. The HMI displays process parameters such as the temperature, humidity and differential pressure and enables the manipulation of the process equipment such as fans and pumps by using the PC’s mouse. The new control panel does not have switches, lamps and indicators so that we have less chances of parts’ failure than that of the old control panel. Data logging function and trend displays that were added to HMI are useful functions when we investigate an event regarding the process failure. Also the important failure alarm such as Hot Cell exhaust fan trip can be given to the assigned personnel’s cellular phone by the text message alarm broadcasting system using CDMA equipment. Thus we can respond to the emergency situation and take necessary measure within a reasonably short time. The remaining work to do is the procurement of the control panelspare parts that should carefully be determined for future maintenance.
- 79 -
SR-P-18
Jong Sup Wu*, Sang Min Byun, Hoan Sung Jung HANARO Safety Management, Korea Atomic Energy Research Institute, Korea *Corresponding author: jswu@kaeri.re.kr
including outsourcing workers and students. 150 out of the 195 replied to this survey with 77% response rate.
1. Introduction Since its first operation, a reorganization of HANARO has been carried out to enforce the safety culture for the reactor operation and utilization. In May 2010, a survey was conducted for the personnel of the HANARO and subsidiary facilities. The result of survey shows that the general attitude of safety culture is getting better compared to the previous survey. This paper summarizes 2010 survey result and the trend of safety culture.
2. Survey of Safety Culture Attitude HANARO developed its own safety culture indicators based on the IAEA's documents to understand the safety culture status of a plant operation and utilization in 2007. It includes 15 evaluation indicators for operating, research and design groups [1]. Questionnaire for this survey was prepared based on the safety culture indicators. The survey consisted of 68 questions composed of 55 objective questions, 8 subjective questions and 5 basic questions. Each objective question requested two answers, a level of importance and a level of safety attitude. A 5 point scale was applied for the grade of the answers. In the case of ‘strongly agree’, 5 points were assigned, while 1 point was allotted to cases of ‘strongly disagree’. The subjective questions were for the importance of the indicators, the frequency of training and field inspections, the safety culture activities, the status of the organizational culture and the operational safety performance. The basic questions included the division of duty, age, position and experience [2]. A recent survey was conducted for all HANARO employees in the reactor operation, utilization and research groups in May 2010. HANARO Center has 195 employees
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3. Survey Results According to the survey results, the average score of the safety attitude was 3.58(71.6%) while the average score of the importance level was 3.93(78.6%). It means that they think the level of the actual safety attitude is lower than that of the safety importance. The 55 questionnaires from the survey can be grouped into 5 categories; policy, management, individual, research and design. Figure1 indicates that the average scores of the safety attitude for 5 categories are between 69% and 74.4%. Safety level of an individual’s attitude is a little higher than that of the others.
Figure1. Score based on safety culture categories
According to answers, the good attitudes and the bad attitudes of the safety culture could be derived. The good attitudes indicate that most employees have a conscious mind about cooperation with safety matters and the management is concern with periodic inspection, preventive maintenance and safety review on work schedule. Meanwhile the bad attitudes indicate
Source / Reactor
2010 Survey of HANARO Safety Culture
there is a conflict between the safety and the job result and the management lacks the reward and punishment system on safety issues. Another one is that the HANARO safety culture activities are helpful to improve the safety attitude and stimulate employees to carry out their safety effort.
2) An effort is necessary to improve the organizational culture in spite of getting better before. 3) The safety level of a younger person from 25 to 39 is higher than the other age groups. The reason is that the junior employees are more positively concerned about their job. 4) Present safety culture activities are very useful to enhance HANARO safety 5) Improvement of the system safety and a capability against emergency cases for users are necessary According to the survey result, the overall safety consciousness in the HANARO center has been gradually improved. A periodic survey will be helpful to understand the general safety attitudes of the personnel and to set the safety culture activities necessary for the improvement of safe operation.
Figure2. Effectiveness of the safety culture activities
There are remarkable results from the subjective questions. The scores of attitude of the safety culture and the organizational culture are getting better compared to the previous one conducted in 2008. The other one is that the staff thinks that a safety attitude and a capability against the dangerous situation are most important in the operation safety performance indicators.
REFERENCES [1] J.S. Wu, K.H. Lee, KAERI/TR/3432/2007, HANARO Safety Culture Indicators in HANARO, 2007 [2] J.S. Wu, Analysis of the 2008 Survey for the Safety Culture Attitude of HANARO, KNS, May 2009
4. Summary The success of a safety culture depends on the commitment and performance provided by both the managerial intention and the individual practice. The safety culture activities contribute positively to the reactor operation and utilization in general. A survey was conducted based on the HANARO safety culture indicators to understand the current trend of the safety culture attitudes in May 2010. The keynotes of this survey can be summarized as followings; 1) The general attitude of safety culture and organizational culture is getting better compared to the results from two years ago.
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SR-P-19
Jeong-Soo Lee *, Ki-Yeon Kim Neutron Science Division, Korea Atomic Energy Research Institute, 1045, Daedeokdaero, Yuseong-gu, Daejeon, 305-353, Korea *Corresponding author: jslee3@kaeri.re.kr
A neutron reflectometer with a vertical sample geometry which was operated at the ST3 horizontal beam port in HANARO has been translated into the cold neutron laboratory building(CNLB). The monochromator shield was designed, fabricated and installed. The shield's performance was evaluated by using a radiation detector such as a gamma and neutron detector. Also, beryllium filter cooling system, it's performance, lowest reached temperature and time was tested. The available neutron flux at the monochromator and sample position was evaluated by using the gold the wire activation method. The cold neutron beam distribution on the sample position was evaluated with TOF method. As a result, it was certified that translated instrument's performance was improved compared to the existing instrument.
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Source / Reactor
A Vertical Type Neutron Reflectometer at HANARO
SR-P-20
Upgrade of 18M Small Angle Neutron Scattering Instrument at HANARO Baek-Seok Seong*, Eunjoo Shin, Young-Soo Han , Tae-Hwan Kim, Chang-Hee Lee, Kye-Hong Lee Neutron Science Division, Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong-gu, Daejeon, 305-353 , Korea *Corresponding author: bsseong@kaeri.re.kr
The new 18M small angle neutron scattering instrument (SANS) has been relocated at the new cold source of the 30MW HANARO research reactor in the Korea Atomic Energy Research Institute. It is upgrade of old 8m SANS which was installed at CN beam port of Reactor hall. It is opened for the domestic and international users. The instrument is 18m long and utilizes a high resolution mechanical velocity selector, a pinhole collimation system, a changeable sample stage and a two dimensional position sensitive detector with 64cm x 64cm active area. The measurement range of the instruments extends from 0.003 to 1.0 Ă…-1 in scattering vector. This allows the investigation of structures ranging from about 0.6 to 200 nm. In this paper, the design and characteristics of the instrument are described and the beam test results are presented.
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Micro-stepper Motion Controls using EPICS and GALIL Motor Controller for HANARO Diffractometer Kwang-Pyo Honga*, Jeong-Hun Hana, Kye-Hong Leea, Dong-Seok Parka a
Korea Atomic Energy Research Institute, Neutron Science Division, 1045 Daedok-daero, Yuseong-gu, Daejeon, 305-353, Korea *Corresponding author:kphong1@kaeri.re.kr
A standard 4 axis Micro-step motion controller has been developed for HANARO neutron diffractometer using GALIL motion controller (DMC-2183) and micro-stepper module(SDM-20640) based on EPICS platform with SPEC diffraction software. This new generation of motion controllers provided more capability than ever before due to GALIL’s additional hardware features and it’s driving software (EPICS) for sharing motor control information. In spite of it’s small size, it provided better motion performance (accuracy and setting (current gain, etc)), motion coordination (modes of motion profile, application programs), and multiple network communication between PC and master controller. It’s power driver designed with integrated 4 axis power micro-stepper motor driver (full step 1/64 driver resolution; 12,800 pulse/revolution) for small motor (0.5A, 1A, 2A, 3A/phase) and modifiable with 4 axis integrated high power servo motor(500W) for in case more high torque needed. We used an EPICS motor record (PV) for interfacing GALIL motion controller command’s set and verified it’s running motion performances with feedback encoder using an EPICS MEDM motion test software and applied it to the neutron diffractometer motion control based on SPEC diffraction software at the window PC.
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Source / Reactor
SR-P-21
SR-P-22
Effect of Signal Processing on Wall Effect of He-3 Tube Pulse-Height Spectra Yong Suk Choi a, Jong-Yun Kim a*, Yong Joon Park a, Kyuseok Song a, Sung Hee Jung b Nuclear Chemistry Research Division, Korea Atomic Energy Research Institute, Daejeon, 305-353, Korea b Radioisotope Research Division, Korea Atomic Energy Research Institute, Daejeon, 305-353, Korea *Corresponding author: kjy@kaeri.re.kr
a
The He-3 proportional counter is a well-known gas proportional counter for the detection of slow neutrons. In most cases, the use of the pulse-height spectrum of the He-3 proportional counter for the neutron measurements is suffered from the wall effect that can be reduced by using a large size counter or He-3 gases with high pressure. The shape of the signals from the wall effect in the pulse-height spectrum relies on the signal processing method, which might be useful in the neutron moderation method. Therefore, the effect of pulse shaping parameters such as polezero cancellation, shaping time, baseline shift, pulse processing time, etc. on the wall effect of He-3 tube pulseheight spectra are presented.
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The Data Acquisition System of The DC-TOF Spectrometer Ji-Yong Soa*, Uk-Won Nam b, Myung-Kook Moon a, Hyun-Ok Kim c, Hong-Joo Kim c, Je-Geun Parkd, Chang-Hee Leea Neutron Science Division, Korea Atomic Energy Research Institute, Daedeok Daero 1045, Daejeon 305-353, Korea b Korea Astronomy & Space Science Institute, 61-1 Wha-Am Dong, Daejeon 305-348, Korea c School of Physics and Energy Sciences, Kyungpook National University, Daegoo 702-701, Korea d Department of Physics & Astronomy, Seoul National Univerity, Seoul 151-747, Korea *Corresponding author: jiyongso@kaeri.re.kr a
DC-TOF is the time-of-flight neutron spectrometer built in the HANARO cold neutron guide hall. It is being developed since 2003 and its first phase will be completed in April 2011. While DC-TOF is designed to have 352 1dimensional position sensitive detectors(1D-PSD), we are installing 57 PSDs during the first phase. However, full installation of the PSDs in the future necessitates control of huge amount of data by the data acquisition electronics and software. Since 2008, we developed the data acquisition system that can handle data at a very fast rate. We report the test result of the data acquisition system and discuss its future application for neutron instrumentation.
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Source / Reactor
SR-P-23
SR-P-24
DAQ Software Development for KAERI DC-TOF H. O. Kim a*, H. J. Kim a, U. W. Nam b, J. Y. So c, M. K. Moon c, Y. H. Choi c, S. J. Cho c, Y. K. Jeon c, C. H. Lee c, Je-Geun Parkd Department of Physics, Kyungpook National University, Daegu 702-701, Korea b Korea Astronomy & Space Science Institute, Daejeon 305-348, Korea c Korea Atomic Energy Research Institute, Daejeon 305-353, Korea d Department of Physics & Astronomy, Seoul National University, Seoul 151-742, Korea *Corresponding author: hokim@knu.ac.kr a
Disk-Chopper Time-of-Flight spectrometer (DC-TOF) is a new cold neutron instrument under construction at the Korea Atomic Energy Research Institute (KAERI). With a high neutron flux from the 30 MW research reactor, HANARO, it is designed to be optimized for high throughout with a wide dynamic range of 0.1 – 10 MeV. In order to achieve the design goal, it will be equipped with a total of 352 2m PSDs (Position Sensitive Detectors), which are grouped into 11 panels. One of the primary developments of the DC-TOF is to design and construct optimized electronics. Each electronics board of panels has one DSP (Digital Signal Processor) with an Ethernet interface at its back-end to connect with DAQ System. The DAQ software controls and takes data from 11 panels simultaneously featuring graphical user interface. It was developed based on ROOT framework, which is a complete system for development of scientific application from graphics to efficient storage. We note that our software is the first time ever application of ROOT in the area of neutron scattering community. In this paper, we present our development of DAQ software.
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Energy / Engineering
- 88 Energy / Engineering
- 89 -
- 90 Energy / Engineering
- 91 -
EE-O-01
Monday, 1 Nov. 16:10 – 16:40 (Room 103)
Neutron Diffraction Study of Mechanical Behaviors in Energy Materials
Neutron Scattering Science Division Oak Ridge National Laboratory Oak Ridge, TN 37831, USA *Corresponding author: wangxl@ornl.gov
Neutron scattering is a powerful probe for characterizing mechanical behaviors. In this talk, I will show how the technique is used to gain microscopic insights of mechanical behaviors in materials and engineering systems, particularly with regard to energy applications. Examples will include in-situ study of phase transformation in hightemperature alloys, damage mechanisms due to cyclic loading, structure evolution in real batteries during charge and discharge, and residual stress determination for life-time extension in nuclear industry. A state-of-the-art instrument, the VULCAN diffractometer, has been just commissioned at the Spallation Neutron Source, Oak Ridge National Laboratory. New scientific opportunities with VULCAN will also be discussed.
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Energy / Engineering
Xun-Li Wang*
EE-O-02
Monday, 1 Nov. 16:40 – 17:10 (Room 103)
Small-Angle Neutron Scattering Instrument for Nanostructure Analysis Jun-ichi Suzuki a*, Shin-ichi Takata a, Takenao Shinohara a, Takayuki Oku a, Hiroshi Kira a, Takeshi Nakatani a, Yasuhiro Inamura a, Takayoshi Ito a, Kentaro Suzuya a, Kazuya Aizawa a, Masatoshi Arai a, Toshiya Otomo b, Masaaki Sugiyama c J-PARC Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195, Japan b J-PARC Center, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan c Research Reactor Institute (KURRI), Kyoto University, Kumatori, Osaka 590-0494, Japan *Corresponding author: suzuki.junichi@jaea.go.jp a
Small-angle neutron scattering (SANS) technique has been indispensable in research of microstructures, higherorder structure, and hierarchical structures in materials science and life science. However, recent progress in nanotechnology and research of complex multi-component or multi-phase systems and non-equilibrium systems has required the SANS instrument to enable to measure structural information more efficiently with higher structural and time resolution. The smaller-angle neutron scattering instrument TAIKAN has been constructed in J-PARC to meet such requirements. TAIKAN is designed to cover wide q-range (q = 10-3~10 Å-1) simultaneously by using neutrons in broad wavelength bandwidth of about 0.4~8 Å produced at a spallation neutron source (1 MW) of the Materials and Life Science Experimental Facility (MLF). The detector system is composed of small-, medium-, and high-angle detector banks with arrays of one dimensional 3He position sensitive detectors and a high-resolution area detector with spatial resolution of about 0.5 mm, which is used with a focusing system, at the center of the small-angle detector bank. The adoption of the focusing system is based on both the successful application of a magnetic focusing device to the small-angle neutron scattering instrument SANS-J-II at the JRR-3 reactor in JAEA and its subsequent development. Time resolved measurements on transient phenomena such as phase transition become also possible with higher time resolution of about 1~10 sec for materials with typical scattering cross section by utilizing an intense neutron beam. For research subjects in various scientific fields, a goniometer with the load capacity of 750kgf, an automatic sample changer with temperature control system, a high-temperature furnace with thermal dilatometer, and a cryomagnet etc. will be prepared. In this paper, we also show the expected performance of TAIKAN and its role by comparing the performance with the performance of SANS instruments (SANS-J-II, SANS-U, mfSANS, PNO) installed at the JRR-3 reactor (20 MW).
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EE-O-03
Monday, 1 Nov. 17:10 – 17:40 (Room 103)
Studying Potential Hydrogen Storage Materials using Neutrons
NIST Center for Neutron research, Gaithersburg, 100 Bureau Dr, STOP 6102, MD 21702, USA *Corresponding author: craig.brown@nist.gov
Hydrogen storage materials must achieve higher gravimetric and volumetric densities than those of currently available in order to achieve a viable storage system that can be reversibly refueled. Although the storage capacities of metal-organic frameworks (MOFs) have progressed significantly over recent years, some technological obstacles pose challenges for their future improvement. These include the generally low H2 adsorption enthalpy limiting room temperature applications and the lack of understanding of surface packing density hindering the efficient improvement of H2 adsorption uptake. The current approaches to achieving a viable material for hydrogen storage absorbents will be discussed. Neutron methods including powder diffraction, vibrational and rotational spectroscopy, and quasi-elastic scattering, are invaluable to advancing our understanding the performance (or lack of performance) of candidate hydrogen storage materials and systems. This will be illustrated by discussing several examples taken from our recent research involving both MOFs and nano-structured carbon-based materials.
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Energy / Engineering
Craig M. Brown*
EE-O-04
Monday, 1 Nov. 17:40 – 18:00 (Room 103)
In Situ Neutron Diffraction Study of Hydrogen Adsorption in Na-X/Y Zeolites Hee Ju Lee a and Yong Nam Choi a* Neutron Science Division, Korea Atomic Energy Research Institute, Daejeon, Korea. *Corresponding author: dragon@kaeri.re.kr
a
Among the alternative fuels, hydrogen is one of the ideal candidates as a clean energy carrier for both transportation and stationary applications. It is considered to be one of the best alternative fuels due to its abundance, easy synthesis, and non-polluting nature when used in fuel cell. Hydrogen can be stored in solids by chemisorptions or physisorption. For physisorption, new nano-scale materials with high specific surface area are needed. Porous materials, which have large internal surface area, have recently attracted much attention and increasing interest due to their promising use in hydrogen storage [1]. Among many kinds of candidates for hydrogen storage, we have considered zeolites which have regular and single size pores and can be controlled the diameter of the pores by changing the size and the charge of the exchangeable cations relatively easy. In the present study, the He and Ne gas adsorptions were investigated as well as hydrogen (H2 & D2) gas to reveal adsorption mechanism by comparing those adsorption patterns. Neutron powder diffraction patterns show the static and dynamic information of gases within nano-pores of zeolite at various conditions (temperature : 30 ~ 300 K, pressure : vacuum ~ 22 bar). From the analysis of the data, the lattice parameter variations of Na-X/Y according to gas type were carefully investigated. Most materials demonstrate an expansion upon heating, however Na-X/Y is known to contract, i.e. exhibit a negative coefficient of thermal expansivity (NTE) [2]. Interestingly, when the several gases were injected in Na-X/Y, the NTE coefficient of each gas showed a great difference.
Figure 1. Neutron diffraction patterns of Na-X with D2 gas
Broad diffraction patterns which show a short range ordering within nano-pores were observed. These patterns are very similar to the diffraction patterns of pure liquids [3, 4], but the temperature differences of the pattern are very different. From the experimental data and analysis of them, it can be concluded that the gases (H2, D2, He & Ne) reside crystallographic sites near the cation (Na+) first at higher T/ lower P and then a liquid-like condensation is followed near the free occupied sites at lower T/ higher P. Experimental details and analysis with discussion will be presented. References 1. Jinxiang Dong et al, Inter. J. Hydro. Energy 32, 4998 (2007). 2. W. Miller et al, J. Mater. Sci. 44, 5441 (2009). 3. M. Zoppi et al, Phys. Rev. E 48, 1000 (1993). 4. D. G. Henshaw, Phys. Rev. 111, 1470 (1958).
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EE-O-05
Tuesday, 2 Nov. 10:40 – 11:10 (Room 103)
In Situ Neutron Scattering for Microstructural Control of Advanced Steels
Graduate School of Science and Engineering/Frontier Research Center for Applied Atomic Science, Ibaraki University, 4-12-1 Nakanarusawa, Hitachi, Ibaraki, 316-8511, Japan *Corresponding author: tomota@mx.ibaraki.ac.jp
Advanced steels have been studied aiming at higher strength with sufficient ductility and toughness by microstructural control minimizing the use of alloying elements. The measurements of high angle neutron diffraction and small angle neutron scattering (SANS) have been demonstrated to be powerful tools for the quantitative microstructure evaluation that is very important for developing new steels. In situ neutron diffraction during thermomechanically controlled process has revealed the acceleration of austenite to ferrite transformation as well as texture evolution. The spheroidizing kinetics of cementite plates in pearlite steel has well been characterized by SANS. Bainite transformation at a low temperature in a nano-bainite steel was monitored either by Bragg diffraction or SANS simultaneously with dilatometory. These three recent topics will be explained in this presentation.
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Energy / Engineering
Y.Tomota*
EE-O-06
Tuesday, 2 Nov. 11:10 – 11:40 (Room 103)
Application of Neutron Diffraction for the Studies of Friction Stir Welding & Processing Hahn Chooa*, Zhenzhen Yua, Wei Zhangb, Zhili Fengb, Sven C. VogelC Dept. of Materials Science & Eng., University of Tennessee, Knoxville, TN 37996,USA Materials Science & Technology Div., Oak Ridge National Laboratory, Oak Ridge, TN 37831,USA c Los Alamos Neutron Science Center, Los Alamos National Laboratory, Los Alamos, NM 87545,USA *Corresponding author: hchoo@utk.edu a
b
Friction-stir welding (FSW) is a newly developed joining process that offers numerous advantages over traditional fusion welding. FSW is a solid-state joining process that uses a rotating tool, consisting of a threaded pin and pressing shoulder, which applies severe plastic deformation and frictional heating to the base metal and produces a strong metallurgical joint. Friction-stir processing (FSP), a variation of FSW, has recently been used for the modification of microstructure of materials. Examples of such modifications include localized grain refinements and homogenization of precipitate particles. In this talk, I will, first, present the basics of friction stir processing and its application to light weight alloys, such as 6061-T6 aluminum alloy and AZ31B magnesium alloy. Second, neutron diffraction technique will be introduced as a unique tool for the characterization of engineering structural materials and components. Finally, recent research examples on FSP of a Mg alloy will be presented.
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EE-O-07
Tuesday, 2 Nov. 11:40 – 12:00 (Room 103)
Application of Neutron Diffraction to Microstructure Analysis in High-Nitrogen Steels Tae-Ho Lee a*, Eunjoo Shin b, and Sung-Joon Kim a Korea Institute of Materials Science, 531 Changwondaero, Changwon 641-831, South Korea b Neutron Physics Department, Korea Atomic Energy Research Institute, P.O.B. 105, Yuseong, Daejeon 305-600, South Korea *Corresponding author: lth@kims.re.kr
Research activities on application of neutron diffraction to steel research in KIMS were briefly introduced. In the first part, the precipitation behavior of second phase, mainly Cr2N, formed during isothermal aging was investigated with a particular emphasis on the analysis of crystal structure of Cr2N. Based on the analyses of neutron and electron diffraction patterns, the crystal structure of Cr2N was determined to be a trigonal structure (ordered hcp structure). The Rietveld analyses of neutron diffraction profiles were used to determine the lattice parameters, metal atom position and nitrogen occupancy. The accurate position of metal atoms was specified to be x = 0.346(8), and z = 0.244(6), corresponding to deviation from ideal positions (x = 0.333; z = 0.25), which had a significant effect on the scattering intensities of (1/3 1/3 0)-type superlattice reflection. The occupancies of nitrogen atoms in four crystallographic sites [1(a), 1(b), 2(d) and 2(c) Wyckoff sites] were determined to be 1.00(5), 0.0, 0.74(9) and 0.12(3), respectively, which means that a partial disordering of nitrogen atoms occurred along c-axis. Referring to the partial disordering of nitrogen atoms along c-axis, the irradiation-induced disordering was elucidated and a model for order-disorder transition of Cr2N was suggested. In the second part, the stacking fault energy (SFE) of high-nitrogen austenitic stainless steels was determined, for the first time, using neutron diffraction. To evaluate the microstrain and stacking fault probability (SFP), the doubleVoigt size-strain analysis was applied to calculate the Lorentizian and Gaussian components of integral breadths. Based on the linear extrapolation of measured microstrain against SFP, the SFEs could be evaluated and almost linear dependence of nitrogen could be established. Quantitative analysis on deformation microstructure could be attained in terms of volume fraction of constituent phases (austenite, e and a¢ martensites) and deformation faulting (stacking and twin faults) probabilities. The changes in deformation microstructure were observed using TEM. It was found that the deformation microstructure gradually changed from strain-induced martensitic transformation to deformation twinning with increasing SFE, namely nitrogen content. Combined analysis using neutron diffraction and TEM can provide valuable information on microstructure analysis of high-performance steels in different scale.
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Energy / Engineering
a
EE-O-08
Tuesday, 2 Nov. 14:00 – 14:30 (Room 103)
Cooling Rate Dependence of Boron Distribution in Low Carbon Steel Dong Jun Mun a, Jae Sang Lee a, Yang Mo Koo a* Graduate Institute of Ferrous Technology, Pohang University of Science and Technology, Korea *Corresponding author: Koo@postech.ac.kr a
1. Introduction The behavior of grain boundary segregation of boron in low carbon steel was studied by means of particle tracking autoradiography. Non-equilibrium grain boundary segregation(NGS) of boron during continuous cooling was compared with non-equilibrium grain boundary segregation of boron during isothermal holding. Based on the isothermal kinetic equation the grain boundary segregation level of boron during cooling was estimated using effective time method.
2. Experimental Procedure The basic steel contains 0.07%C, 0.2%Mo, and 0.0020%B. The steel was prepared by laboratory vacuum induction melting and hot-rolled to 30mm thick plates followed by air-cooling to room temperature. Cylindrical specimens of 8mm diameter and 12mm length were machined from the plates with the longitudinal direction parallel to the rolling direction. In continuous cooling heat treatment, the specimens were heated to a temperature of 1200 at a rate of 10 /s, austenitized for 300 seconds, and then cooled to room temperature at cooling rates from 1 /s to 100 /s. In isothermal holding heat treatment, the specimens were heated to a temperature of 1200 at a rate of 10 /s, austenitized for 300 seconds, and then quenched to 900 with cooling rate of 50 /s . After quenching the sample were held at 900 for increasing times and quenched in water. The distribution of boron in the specimens was determined by particle tracking autoradiography method. The detecting boron sensitivity of this method is 1ppm and the spatial resolution is 2 . Cellulose nitrate film were used as detecting foils. The thermal neutron flux was 1.0 1013n/cm2 s. Irradiation time was 6hrs. After irradiation, films were etched in aqueous solution of 2.2N NaOH at 55 for 9 min. The etched films were examined by the optical microscope.
3. Experimental Results 3.1 Cooling rate dependence of NGS It is well known that grain boundary segregation of boron in steel occur during the cooling [1,2]. It is generally known as non-equilibrium grain boundary segregation(NGS) phenomena. The mechanism of non-equilibrium segregation depends on the formation of sufficient quantities of vacancy-solute complexes.
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(b)
(c)
(d)
(e)
Fig. 1. Boron distribution after cooling from 1200 : (a) 1 /s, (b) 10 /s, (c) 20 /s, (d) 40 /s, (e) 100 /s
As shown in fig. 1. non-equilibrium segregation of boron in steel is strongly dependent on the cooling rate. The degree of segregation is highest at intermediate cooling rate 10~20 /s when the time has been sufficient to let vacancy-solute atom pairs diffuse to the grain boundary but not to let deposited solute atoms diffuse away from the boundary zone. From the above experimental results, the critical cooling rate is between 10 and 20 /s. At this critical cooling rate a sample can attain the maximum level of grain boundary segregation.
3.2 Time dependence of NGS When a sample is cooled quickly enough from a higher temperature to a lower temperature and then held at this lower temperature, vacancy-solute atom complexes begin to diffuse to the grain boundaries. This is the most characteristic aspect of non-equilibrium grain boundary segregation(NGS) [3]. Quenching-induced segregation to prior austenite grain boundaries have been attributed to diffusion of vacancysolute complexes along vacancy gradients to the grain boundary, the diffusion resulting from the super-saturation vacancies annihilated at boundaries by vacancy-solute complex model [4]. Fig. 2. shows the variation of the segregation levels of boron with increasing holding time at 900 after quenching from 1200 . The segregation level of boron increase with increasing holding time up to 60s. When the holding time is longer than 60s, the segregation level decrease with increasing the holding time. So we can, from the above experimental results, conclude that the critical time of NGS for boron is between 20 and 60s.
(a)
(b)
(c)
(d)
(e)
(f)
Fig. 2. Boron distribution during isothermal holding time at 900 after quenching from 1200 : (a) 5s, (b)20s, (c)30s, (d)60s, (e)120s, (f)1000s
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Energy / Engineering
(a)
The critical time is the holding time of the sample at this lower temperature required for the maximum level of grain boundary segregation. It is clear from the above experimental results that when holding time is shorter than the critical time, the segregation of the complexes to the grain boundary is dominant, called segregation processes, and when holding time is longer than the critical time, the diffusion of solute atoms from grain boundaries to the center is dominant, called desegregation process.
3. Discussion For most of the experiments and the practical problems about non-equilibrium grain boundary segregation, segregation will always occur during the continuous cooling. It is of considerable importance to know how to calculate the non-equilibrium segregation levels for continuous cooling. Any continuous cooling curve for a sample can be replaced by a correspondent stepped curve, each step of which was formed by horizontal and vertical segments so as to calculate an effective time at some temperature for this cooling sample. The effective time formula [5] of the stepped curve consisting of n steps at temperature T was given by te
Where EA is the activation energy for diffusion of complexes in the matrix. ti and Ti are respectively isothermal holding time and temperature at the ith step of stepped curve. When the chosen steps are small enough, the effective time of the stepped curve at some temperature will accurately enough be equal to the effective time of the continuous cooling at same temperature. Therefore, it is possible that calculating segregation levels of solute atoms(or complexes) during continuous cooling can be changed into calculating segregation levels during isothermal holding processes by using effective time concept of the continuous cooling. Using the eq. (1) if we calculate the effective time during the cooling from 1200 to 900 , the effective time of 1,10,20,40 /s is same as 896,73,27,4s at 900 . So, from comparisons with the above calculation and experiment results, we can conclude that cooling rate dependence of grain boundary segregation of boron is agree well with time dependence of grain boundary segregation of boron. In other words, cooling rate dependence of NGS can be explained by time dependence of NGS. It means that the level of non-equilibrium segregation of boron depends on the annihiliation time of supersaturated vacancy during cooling.
4. Conclusions 1. Non-equilibrium grain boundary segregation of boron is strongly dependent on the cooling rate. The degree of segregation is highest at critical cooling rates when the time has been sufficient to let vacancy-boron atom pairs diffuse to the grain boundary but not to let deposited boron atoms diffuse away from the boundary zone. 2. Cooling rate dependence of grain boundary segregation of boron in steel can be explained by the time dependence of grain boundary segregation of boron using effective time concept.
REFERENCES [1] L. Karlsson, H. Norden and H. Odelius, Acta metal., Vol. 36, No.1, p.1-12, 1988. [2] Xiao Hung, M. C. Chaurvedi, N. L. Richards and Jackman, Acta mater., Vol. 45, No. 8, p. 3095-3107, 1997 [3] X. L. He, Y. Y. Chu and J. J. Jonas, Acta metal., Vol. 37, No. 11, p. 2905-2916, 1989 [4] R. G. Faulkner, Journal of materials science, Vol. 16, p.373-383, 1981 [5] Song Shenhua, Xu Tingdong and Yuan Zhexi, Acta metal., Vol. 37, No.1, p.319-323, 1989
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EE-O-09
Tuesday, 2 Nov. 14:30 – 14:50 (Room 103)
Short Range Ordering in Austenitic Fe-Cr-Ni Alloys and its Effect on Mechanical Properties Young Suk Kima*, Sung Soo Kim a, Dae Hwan Kim a Hydrogen cracking team, Korea Atomic Energy Research Institute, 150, Dukjin-dong, Yuseong, Daejeon 305-353, Republic of Korea *Corresponding author: yskim1@kaeri.re.kr
Most of the structural materials used in nuclear power plants including the fourth generation reactors are made of austenitic Fe-Cr-Ni alloys due to their excellent corrosion resistance. Note that Alloy 600 and 316 stainless steel are austenitic alloys containing Fe, Cr and Ni with minor elements such as Mn, Mo or Ti: the former is a nickel-based alloy containing 15.5 wt.% Cr and 8wt.% Fe and 1wt.% Mn and the latter is a Fe-based alloy containing 12wt.% Ni, 18wt.% Cr and 2 wt.% Mo. One of the common features of these austenitic Fe-Cr-Ni alloys such as Alloy 600 or 690 and the 300 series stainless steel are dynamic strain aging (DSA) that is always seen to occur during tensile and fatigue deformation in a high temperature range. Thus, an understanding of DSA is indispensable to mitigating aging of the structural materials used in reactors. As Fe, Ni and Cr atoms are intermixed as the substitutional elements in austenitic Fe-Cr-Ni alloys, the ordered phases of Ni3Fe, Fe3Ni, Ni2Cr will be formed only if sufficient thermal and mechanical energies are supplied to the austenitic Fe-Cr-Ni alloys. Given that all the ordered phases have low ductility, higher strength and hardness, short range ordering (SRO) to nucleate the ordered phases during tensile or fatigue deformation will make the Fe-Cr-Ni alloys harder and brittle. Considering that SRO accompanies diffusion of these atoms in the austenitic alloys, the lower strain rate provides more time for diffusion of atoms required to nucleate SRO. Thus, the lower the strain rate becomes, the higher the magnitude of SRO, causing the austenitic Fe-Cr-Ni alloys harder, leading to dynamic strain aging. The aim of this work is to see if SRO occurs in austenitic Fe-Cr-Ni alloys due to plastic deformation in reactor operating conditions and to understand its effect on mechanical integrity of the structural components used in PWRs. To this end, the lattice spacing of a cold-worked 316L stainless steel and a cold-worked Alloy 600 both of which are well known to show serrated flow due to dynamic strain aging during tensile or fatigue tests was determined using neutron diffraction in Hanaro with aging time at 400 . As expected, the lattice contraction were seen to occur during isothermal aging treatment at 400 in both the alloys and the degree of the lattice contraction was two time larger in the cold-worked 316L stainless steel when compared to the cold worked Alloy 600. The lattice contraction during isothermal aging at 400oC was anisotropic and changed with the plane: the highest lattice contraction occurred on the (200) plane of the 316L stainless steel and the (111) plane of Alloy 600. This study first demonstrates that SRO is the cause of DSA in all kinds of austenitic Fe-Cr-Ni alloys and the degree of SRO is higher in Fe-based Fe-Cr-Ni alloys when compared to Ni-based ones, suggesting that the former would be more susceptible to degradation by SRO than the latter.
- 102 -
Energy / Engineering
a
EE-O-10
Tuesday, 2 Nov. 14:50 – 15:10 (Room 103)
The Use of Diffraction Method to Study Fatigue Crack Growth Mechanics Soo Yeol Lee a,b,c, Peter K. Liaw a*, Hahn Choo a, Ronald B. Rogge c, Ke An d, and Camden R. Hubbard e Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996, USA b Materials Engineering, The University of British Columbia, Vancouver, B.C. V6T 1Z4, Canada c Canadian Neutron Beam Centre, National Research Council Canada, Chalk River, ON K0J 1J0, Canada d Neutron Scattering Science Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA e Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA *Corresponding author: pliaw@utk.edu a
The improvement in lifetime of numerous engineering components exposed to fatigue is highly dependent on the accurate understanding of fundamental principles of the failure mechanism. One aspect that is still not completely understood is the overload-retardation micromechanism and crack-closure behavior in structural materials subjected to fatigue. Here we report in-situ neutron diffraction and electric potential investigations that allow us to observe crack opening/closing processes and internal-stress distributions around the crack tip during fatigue crack propagation following a tensile overload. The results reveal that in the overload-retardation period, the combined effects of the overload-induced enlarged compressive residual stresses and crack-tip blunting with secondary cracks delay the stress concentration to the crack tip, making the closed crack difficult to fully open. The control for the delaying action of the stress concentration to the crack tip seems to be a key to improve the damage-tolerant design in materials subjected to fatigue.
- 103 -
EE-O-11
Tuesday, 2 Nov. 15:30 – 15:50 (Room 103)
Enhancing the Depth of Stress Measurements by using Wavelength Dependence of Neutron Attenuation
1
Neutron Science Division, Korea Atomic Energy Research Institute, Daejeon, South Korea Nuclear Physics Institute ASCR, v.v.i., and Research center Rez Ltd, Rez, Czech Republic *Corresponding author: vtem@kaeri.re.kr
2
Neutron diffraction method enables in-depth measurement of stresses in thick industrial components thanks to penetration of neutrons in most materials. Typically measurement of through thickness stress distribution in 30mm thick steel plate is available. The maximum available thickness depends on neutron source and the instrument. For given instrument it can be increased by increasing the sampling volume or the acquisition time but their effect is comparatively weak. Another effective way to increase the maximum available depth in steel is using wavelength dependence of the neutron total cross section and measuring strains with wavelength near Bragg edges where the total cross section is minimal. The aim of this work was to study performance of a stress instrument with bent perfect crystal Si monochromator at different wavelengths to optimize stress measurements in steel for achieving maximum possible depth. It was shown that bent perfect crystal Si(111) monochromator is optimal to measure diffraction peaks -Fe(110) of ferritic steel, -Fe(111) of austenitic steel and Si(220) monochromator to measure diffraction peaks -Fe(211), Fe(311). The wavelength dependences of the neutron total cross section for -Fe and -Fe in the interval 1.2A – 3A were calculated. The total cross section considerably changes at certain wavelength (Bragg edges) so that near Bragg edges it has local minimums. Depth measurement of strains in austenitic and ferritic steels with different wavelengths near Bragg edges showed that maximum available path length in material strongly depends on wavelength. Results of experiments allow planning deep stress measurement depending on geometry of a sample. For example, measurement of stresses in 50mm thick steel plate is possible using proper chosen wavelength.
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Energy / Engineering
Vyacheslav Em1*, Wanchuck Woo1, Baek-Seok Seong1, Pavel Mikula2, Jongdae Joo1, Mi-Hyun Kang1.
EE-O-12
Tuesday, 2 Nov. 15:50 – 16:10 (Room 103)
Using In-situ Neutron Diffraction and Thermal Measurements to Study Saturation Cycles of the Low-cycle-fatigue Experiments E-Wen Huang a*, Bjørn Clausenb, and Peter K. Liawc Chemical & Materials Engr. Dept., National Central Univ., 300. Jhongda Rd., Jhongli City, Taiwan (R.O.C.) 32001 b Los Alamos Neutron Science Center, Los Alamos National Laboratory, TA-53, Bldg.1, NM, USA 87545 c Materials Science & Engr. Dept., Univ. of Tennessee, 434 Dougherty Engineering Bldg., TN, USA 37996 *Corresponding author: ewhuang@cc.ncu.edu.tw a
Abstract. In-situ neutron-diffraction and thermal characterization were applied to study the low-cycle-fatigue behavior of a nickel-based superalloy. The lattice-strain and temperature evolutions have been investigated. The lattice-strain and thermal responses to the applied load are investigated as a function of fatigue cycles. Cyclic-loading effects were observed with bulk hardening, softening, and eventual saturation evident in the diffraction patterns and the thermalevolution features. The transition to saturation cycles is characterized by the asymmetry of the lattice-strain evolution. Moreover, the inhomogeneity of the thermal response and irreversible lattice-strain asymmetry were found during the saturation fatigue cycles. The developments of the asymmetry during the saturation cycles are discussed.
Acknowledgements This research is supported by the International Materials Institutes (IMI) Program (DMR-0231320) funded by the National Science Foundation (NSF). The Lujan Neutron Scattering Center at the Los Alamos Neutron Science Center (LANSCE) is funded by the DOE’s Office of Basic Energy Science. The Los Alamos National Laboratory is operated by the Los Alamos National Security LLC under the DOE Contract of DE-AC52-06NA25396. EWH appreciates the financial support from National Science Council Program (NSC99-2218-E-008-009).
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EE-O-13
Tuesday, 2 Nov. 16:10 – 16:30 (Room 103)
Neutron Diffraction Measurements of Residual Stresses in a Complex Dissimilar Joining Structure
Neutron Science Division, Korea Atomic Energy Research Institute, Daejeon, South Korea Nuclear Materials Research Center, Korea Atomic Energy Research Institute, Daejeon, South Korea 3 Doosan Heavy Industries and Construction Co., 555 Gwigok Dong, Changwon 641-792, Republic of Korea *Corresponding author: chuckwoo@kaeri.re.kr 1
2
Significant amounts of residual stresses are often generated by welding and result in the critical degradation of the integrity in components. In recent year the distribution of residual stresses in dissimilar material joints has been extensively studied because of the wide applications of the dissimilar welds in many inevitable complex designs such as nuclear power plant, boiling pressure system, and steam generators. We measured the residual stresses from a large scale (120 mm diameter, 500 mm length, 15 mm thickness) of the dissimilar welding pipe, which have joined between the ferrite low-alloyed steel (0.2C-0.9Ni-0.45Cr-Fe) and austenite stainless steel (0.03C-10Ni-17Cr-Fe). The main purpose of this study is to provide the distribution of the residual stresses through the thickness of the dissimilar welding pipe along the weld centerline. We observed over 200 MPa of residual stresses in the hoop and axial components of the pipe when calculated using “stress-free” do spacings obtained from a comb-like specimen. Such tensile residual stress on the pipe inside can be critical in the performance of the dissimilar welding structure. Experimental details and comparison to the results of the computational simulation will be presented and discussed.
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Energy / Engineering
Wanchuck Woo 1*, Vyacheslav Em 1, Ho Jin Lee 2, Jin Gwi Byeon 3, Kwang Soo Park 3, Baek Seok Seong 1
EE-P-01
Thermal Expansivity of Ionic Clathrate Hydrate Kyuchul Shin , Huen Lee *, Department of Chemical and Biomolecular Engineering (BK21 program) and graduated school of EEWS, KAIST, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701, Republic of Korea *Corresponding author: h_lee@kaist.ac.kr
Gas hydrates or clathrate hydrates are a type of inclusion compounds. Since each volume of gas hydrate can contain as much as 170 volumes of gas at standard temperature and pressure conditions, gas hydrate can be applied to storage and transportation media for gases such as carbon dioxide and sulfur hexafluoride. Although a variety of studies of hydrates are ongoing as importance of studying hydrates arises, most of the studies focus on nonionic clathrate hydrates which have nonionic guest molecules in their water host framework. However, research on clathrate hydrates with ionic guests should be done for both methane expoitation and carbon dioxide sequestration because deep sea sediments considered as methane hydrate deposits and carbon dioxide storage places are environments with abundant electrolytes and ions such as sodium chloride. In this work, we analyzed tetramethylammonium hydroxide(Me4NOH), one of the most common ionic clathrate hydrate, for investigating structural characterization and thermodynamic properties differed from those of nonionic clathrate hydrates through powder neutron diffraction measurement. Me4NOH hydrates with guest gases of H2, D2, N2, and O2 are synthesized for neutron diffraction experiments. In case of neutron diffraction experiments, the large incoherent scattering of hydrogen results in background scattering that greatly reduces the signal to noise of the experiment and makes it difficult to detect coherent scattering from the sample. Therefore, we substituted H2O with D2O by diluting Me4NOH路5H2O. Then D2O solution of 5.88 mol% Me4NOD was cooled at 213K for at least 1 day, ground to powders (~200 ), and exposed to gases up to 120 bar at 213 K for at least 1 week. In order to obtain clear diffraction patterns, formed hydrate compounds were ground to powders (~45 ) and then placed on neutron diffraction sample holder. These procedures are done under liquid nitrogen temperature to prevent the dissociation of hydrates. The powder neutron diffraction patterns were collected using the high-resolution powder diffractometer(HRPD) installed at the 30 MW reactor "HANARO" of the Korea Atomic Energy Research Institute (KAERI) by a stepped counting method (with 0.05 per step) in a temperature range of 30-150K.
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EE-P-02
A Study of the Boron Diffusion in Alloys using Neutron Induced Autoradiography
1
Graduate Institute of Ferrous Technology, Pohang University of Science and Technology, Korea 2 Neutron Science division, Korea Atomic Energy Research Institute, Korea * Corresponding author: m9149@postech.ac.kr
By means of particle tracking autoradiography, diffusion coefficients for boron over a wide range of temperature were measured in C-Mn steel, Ni-B, Fe-30%Ni-B and Fe-3%Si-B alloys, and the frequency factor D0, and activation energy Q were obtained respectively. Since boronization is very difficult, the method of surface deboronization was employed to measure diffusivity of boron. In order to quantitatively measure the boron distribution in the deboronization zone, the dependence of boron concentration on the distance(X) from the surface, which proportional to the area fraction of etching pits(S), was measured with an image analyzer. A rectangular frame, 200 in length and 100 in width was utilized for counting the S(X) curve. Based on the present data of boron diffusion coefficients, the mechanism of segregation of boron to grain boundaries was discussed.
Fig1. The distribution of Boron in Fe-30%Ni-B :1000 , 5100s
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Fig2. The distribution of Boron in Fe-30%Ni-B : 1100 , 2700s
Energy / Engineering
Dong-Jun Mun1,2*, Jae-Sang Lee1, Yang-Mo Koo1
EE-P-03
Structural Analysis of Ca7.4Ga5.7Zn1.9O17.85 and a New Interpretation of Structure of A7B8O18 Type Compounds Chung-Yul Yooa , Sung-Chul Kima, Ji-Hye Kima, Nam-Soo Shinb, Seung-Joo Kima * Department of Chemistry, Division of Energy Systems Research, Ajou University, Suwon 443-749, Korea b Westinghouse Electric Co., Science &Technology Dept., 1332 Beulah Rd., Pittsburg, PA 15235-5081 *Corresponding author: sjookim@ajou.ac.kr a
Ca7.4Ga5.7Zn1.9O17.85 has been prepared as polycrystalline powders by solid state synthesis. The crystal structure of this compound, characterized by neutron and synchrotron X-ray powder diffraction measurements, is closely related to the structure of Ca7Co3Ga5O18. Ca7.4Ga5.7Zn1.9O17.85 was found to adopt a cubic structure with a cell parameter a=15.09561(4)Ă…. (space group: F432, Z=8). The structure of Ca7.4Ga5.7Zn1.9O17.85 can be described as a combination of the cationic cluster, [Ca14GaO6]+19 and the anionic framework, [(Ca0.053Ga0.693Zn0.253)15O29.7]19-. The [Ca14GaO6]+19 polycation consists of an isolated GaO6 octahedron surrounded by a capped cube of Ca14 atoms. The anionic framework, [(Ca0.053Ga0.693Zn0.253)15O29.7]19- is structurally divided into an icosahedral oxygen cluster, [O12] and surrounding tetrahedral oxygen clusters, [O4]. According to the oxygen cluster packing view, the unit cell of Ca7.4Ga5.7Zn1.9O17.85 is constituted by a stacking of four [O6], four [O4] and eight [O12] clusters. The [O6] clusters and [O12] ones form a fluorite-type arrangement. The [O4] clusters fill the octahedral cavities generated in the fluoritetype structure. The structure of Ca7.4Ga5.7Zn1.9O17.85 is simply described by a 2 -type stacking mode of the three sorts of the oxygen clusters, where corresponds to the [O6] octahedron, to [O12] icosahedron, and to [O4] tetrahedron.
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EE-P-04
Analysis of Residual Stresses Considering Microstructure in Quenched Steel Minsu Jung a, Mi Hyun Kang b, Wanchuck Woo b, Young-Kook Lee a* Department of Materials Science and Engineering, Yonsei University, Seoul 120-749, Republic of Korea b Neutron Science Division, Korea Atomic Energy Research Institute, Daejeon, 305-353, South Korea *Corresponding author: yklee@yonsei.ac.kr
Residual stresses inside of quenched steel were measured using neutron diffraction. Since quenched steel has a significant variation of microstructure (e.g., martensite phase), the lattice spacing depending on the microstructure should be considered to determine the residual stresses. Most importantly, a precise knowledge of the stress-free lattice spacing (called do spacing) throughout the specimen is necessary. Two methods were used to obtain the stress-free lattice spacing considering the microstructure in a quenched cylinder type S45C steel specimen. First method is a hybrid method. The distribution of martensite phase in the specimen is calculated using the finite element method and then the martensite fraction with each position is combined with the stress-free lattice spacing given as function of martensite fraction in the literature. Second method is a direct method. Stress-free samples are made by cutting the quenched specimen and then the lattice spacing at each position is measured directly using the neutron diffractometer. The stress-free lattice spacing in a cylindrical specimen of quenched S45C steel was obtained and compared using the hybrid and direct methods. Finally, residual stresses in the specimen were calculated based on the two different approaches. In the presentation, both results measured by neutron diffraction will be compared and discussed.
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Energy / Engineering
a
EE-P-05
Investigation of Isothermal Phase Evolution and Thermal Diffusivity Change in U-7wt% Mo/Al and U-7wt% Mo/Al-5wt% Si Fuel Rods Jae Ho Yang*, Jong Man Park, Jae Soon Park, Ho Jin Ryu, Yoon Sang Lee, Chang Kyu Kim Korea Atomic Energy Research Institute, Republic of Korea *Corresponding author: yangjh@kaeri.re.kr
In-situ phase evolutions and isothermal changes of thermal diffusivity of atomized U-7wt% Mo fuel particles dispersed in an Al or Al-5wt% Si matrix were investigated at 550oC by a neutron diffraction method and a laser flash method, respectively. Homogeneous -UMo fuel particles were decomposed to a mixture of -U and -U2Mo (or Mo-rich -UMo) phases in the early stage of annealing. The dominant interaction phase between the fuel particle and matrix was identified as the UAl3 type cubic phase. The kinetics of interaction growth between the fuel particles and matrix depends on the matrix composition. In-situ neutron diffraction patterns showed that a Si addition in the Al matrix retarded the formation and growth of the UAl3 type interaction phase. Thermal diffusivities of dispersion fuel rods were deceased with annealing time in both samples. In the early stage of annealing, thermal diffusivities were decreased rapidly due to the formation of a large number of phase interfaces in the U-Mo particles. Phase interfaces hinder the thermal propagation thereby reduce the thermal diffusivity. In later stage, the thermal diffusivities decreased linearly with annealing time. The formation of low thermal conductive interaction layers corresponds to the reduction of thermal diffusivity. Isothermal thermal diffusivity measurement reveals that the existence of Si in the Al matrix not only prevents the growth of UAl3 type interaction phase but also suppresses the degradation of thermal diffusivity of dispersion fuels.
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EE-P-06
Neutron Diffraction Instrument for the Study of the In-situ Tensile Deformation Behavior
Neutron Science Division, Korea Atomic Energy Research Institute, Daejeon, South Korea Ferrous Alloys Research Group, Korea Institute of Materials Science, Changwon, South Korea *Corresponding author: chuckwoo@kaeri.re.kr a
b
It is necessary to understand the deformation behavior in various metals and alloys. The engineering diffractometer, RSI (Residual Stress Instrument) at HANARO research reactor, has developed a new capability to observe the material properties in situ during tensile loading. The maximum tensile load is 20kN and the crosshead speed can be appropriately controlled in the range of 0.001 to 0.1mm/sec. The cylinder or plate type specimen can be loaded using the scattering volume of about 2x2x2 mm3. As a feasible study, we successfully observed the deformation behavior of the different (hkl) grains from the austenite and ferrite in the newly alloyed duplex stainless steel. 9 different (hkl) peak patterns from (110) to (220) were obtained by rotating the detector with the corresponding diffraction angle. The diffraction peak profiles were measured for about 70 minutes and about 10 MPa of stress relaxation was measured during the temporary stops in a tensile machine with the crosshead fixed.
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Energy / Engineering
Jongdae Joo a, Wanchuck Woo a*, Vyacheslav Em a, Mi-Hyun Kang a, Tae-Ho Lee b, Baek-Seok Seong a
EE-P-07
Study on the Nano-structure of Ni-alloys Eunjoo Shin*, Baek-Seok Seong, Sung Soo Kim Korea Atomic Energy Research Institute, 1045 Daedeok-daero,Yuseong-gu, Daejeon, 305-353, Korea *Corresponding author: it-sej@kaeri.re.kr
Alloy 600 is the most corrosion resistant material, whereas it is easily corroded in the primary water. There are some contradictions for explanation. One of them is that the primary water stress corrosion cracking is occurred by an anisotropic lattice contraction due to ordering reaction. It needs to study of the micro/nano-structure for the alloys. In this study the nano-structure of some Ni-alloys were investigated by measuring the SANS patterns. The samples were prepared with several ageing times after annealing. SANS measurement was performed at hanaro in KAERI. The SANS patterns presented different slops according to the aging time of sample.
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EE-P-08
Analysis of Korean Compact Bones by Using Neutron and X-ray Scattering Methods
Dept. of Advanced Materials Eng., Sunmoon University, Asan, Chungnam 336-840, Korea 2 HANARO, Korea Atomic Energy Research Institute, Daejeon 306-884, Korea 3 College of Medicine, Hanyang University, Hangdaong-Gong, Seongdong-Gu, Seoul 133-731,Korea 4 Institute of Metal Physics, 18-S. Kovalevskaya Str. GSP-170, Ekaterinburg 620219, Russia 5 Quantum Beam Center, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, Japan
1
Human compact bone is a nano-composite containing principally collagen and mineral apatite with complicate and hierarchical structure organization. Neutron and X-ray scattering methods were applied to analyze nano-structure of normal and osteoporosis Korean compact bones to give a criterion for more precise decision and find a unique healing method about bone diseases like osteoporosis. The SANS and SAXS profiles of jaw-bones and ulna reveal a directional and regular distribution of plate-like bony crystals with about 40 nm in size and bundles of bony crystals between collagen fibers with about 300 nm in size. Lattice parameters of the bones depend on the type of bones like ulna, tibia and radius. Osteoporosis compact bones have less amounts of the bony crystal than normal compact bones. C-axis of the bony crystal is mainly reduced, especially, in case of the bones with low bone mineral density (BMD). It seems to be related to extraction of calcium and oxygen ions at special sites of the bony unit cell.
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Energy / Engineering
Y. Choi1, E.J. Shin2, B. S. Seong2, Y. Y. Choi3, D. J. Paik3, A. Pirogov4, Y. Oba5, and M. Ohnuma5
EE-P-09
Synthesis and Characterization of Silica Nanotube prepared by Glycyldodecylamine Young-Hui Seo, Seung-Yeop Lee, Abhishek Burri and Sang-Eon Park* Laboratory of Nano-Green Center for Fine Chemical fusion Technology, Department of Chemistry, Inha University,Incheon 402-751, Republic of Korea *Corresponding author: separk@inha.ac.kr
Novel synthesis method could form novel silica nanotube (SNT) by using glycine type surfactant at neutral condition and room temperature. Glycyldodecylamine as biomimetic surfactant were synthesized from glycine as amino acid and dodecylamine by protecting-deprotecting method. After typical assembly process with surfactant and TEOS, This SNT had the diameter of ranging from 30-50 nm and 20-30 ¾m in length. Nitrogen adsorption – desorption isotherms gave the existence of uniform mesoporosity of 2.8 nm by BJH method pore diameter. Selfassembled silica nanotubes are formed spontaenousely in water by a simple amine headed amide amphiphile; GDA through the hydrogen bond. The tubular shape was proved by SANS as well as TEM. It is well known that silica nanotube represented a highly regular structure of nanotubes.
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Soft Matter
- 116 Soft Matter
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- 118 Soft Matter
SM-O-01
Tuesday, 2 Nov. 14:00 – 14:30 (Room 102)
Critical Nanostructure Transition of Polyelectrolyte Brush at the Air/Water Interface Hideki Matsuoka*, Ajrun Ghosh, Shunichi Nakayama, Shinichi Fujita, Yuta Yamakawa Department of Polymer Chemistry, Kyoto University, Kyoto 615-8510, JAPAN *Corresponding author: matsuoka@star.polym.kyoto-u.ac.jp Ionic amphiphilic diblock copolymers form monolayer on the water surface when spread, and the hydrophilic block forms polyelectrolyte brush just beneath the water surface. However, it has been clarified mainly by X-ray[1] and neutron[2] reflectivity (XR and NR) techniques that the nanostructure of the polyelectrolyte brush is not so simple. Just below the hydrophobic layer on the water surface, there exists “carpet layer”, which is the dense hydrophilic block layer. This layer is thought to be formed to avoid direct contact between hydrophobic layer and water subphase. Below the carpet layer, the polyelectrolyte brush layer is formed but there is some critical condition for brush layer formation as schematically shown in Figure 1. (1) There is the “critical brush density”(cbd). When the brush density is higher than cbd, the brush layer is formed below the carpet layer, but only carpet layer is formed below cbd. (2) There is the “critical salt concentration” (csc). The brush nanostructure is not affected by salt addition when the added salt concentration is below csc. Beyond csc, the brush chains start to be shrunk and changed to carpet only structure by further addition of salt. These critical behaviors have been confirmed to be universal for strong acid brushes such as poly(styrenre sulfonate) (PSS) brush. [1] For weak acid brushes, such as poly(acrylic acid brush) and poly(methacrylic acid brush), cbd was found but quite different behavior was observed for salt effect.[3] In this study, the effect of ion species of added salt on the nanostructure transition of PSS brush at the air/water interface.[4] The polymer used was poly(hydrogenated isoprene)-b-PSS which was synthesized by living anionic polymerization.[5] The polymer was spread on the water surface, and the nanostructure of the monolayer was estimated by XR. So far, we used NaCl as an added salt, but in this study, LiCl and KCl were used in addition to NaCl. Figure 2 shows the density profile of hydrophilic layer normal to the water surface evaluated by XR profile fitting. At 0.2M salt condition, PSS brush already changed to carpet-only structure when LiCl and NaCl was added, while still carpet+brush structure remains for KCl addition. This means that csc is different for LiCl, NaCl, and KCl salts. By careful analysis, the csc for PSS brush was found to be Li+<0.1M<Na+<K+<0.2M. This order is consistent with well-known “Hofmeister series”. By this concept, Li ion is the water structure maker, while K ion is the breaker. One possible interpretation of our observation is “structure maker ion can enter into polyelectrolyte brush layer
easier since the water structure in the brush layer is something special.” Cationic brush study to confirm the universality of the observed phenomena and an investigation on the novel twitter ionic brush on the water surface will be also reported.
Figure 1 Schematic representation of (a) critical brush density and (b) critical salt concentration for polyelectrolyte brush.
Figure 2 density profile of PSS layer in Plp-h2-b-PSS 217:120 monolayer on 0.2M LiCL, NaCL, KCL solutions = 25mN /m
References [1] Ploysai Kaewsaiha, Kozo Matsumoto, and Hideki Matsuoka, Langmuir, 23, 7065 (2007). [2] Hideki Matsuoka, Emiko Mouri, Ploysai Kaewsaiha, Yasuyuki Furuya, Yoshiko Suetomi, Kozo Matsumoto, Naoya Torikai, Trans. MRS-J, 32(1), 297(2007). [3] Hideki Matsuoka, Yoshiko Suetomi, Ploysai Kaewsaiha, Kozo Matsumoto, Langmuir, 25(24), 13752, (2009). [4] Shunichi Nakayama, Thesis, Kyoto University, 2010. [5] Ploysai Kaewsaiha, Kozo Matsumoto, and Hideki Matsuoka, Langmuir, 20(16), 6754 (2004).
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SM-O-02
Tuesday, 2 Nov. 14:30 â&#x20AC;&#x201C; 15:00 (Room 102)
Thermal Fluctuation and Elasticity of Lipid Vesicles Interacting with Trans-Membrane Peptides Sung-Min Choia*, Ji-Hwan Lee a, Changwoo Doe a, Min-Jae Lee a, Antonio Faraone b,c, Phillip A. Pincus d,e, and Steven R. Kline b Deparment of Nuclear and Quantum Engineering, KAIST, Daejeon 305-701, Republic of Korea b NIST Center for Neutron Research, Gaithersburg, 20899, MD, USA c Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA d Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA e Department of Physics, KAIST, Daejeon, 305-701, Republic of Korea *Corresponding author: sungmin@kaist.ac.kr
Cell membranes, which consist of lipid bilayers, play important roles in cells as barriers to maintain concentrations and matrices to host membrane proteins. During cellular processes such as endo- and exocytosis, cell fission and fusion, the cell membranes undergo various morphological changes governed by the interplay between protein and lipid membranes [1]. There have been many theoretical [2] and experimental [3] approaches to understand cellular processes driven by protein-lipid membrane interactions. However, it is not fully established how the membrane elastic properties, which play an important role in membrane deformation, are affected by the protein-membrane interactions. In this talk, the thermal fluctuation and elasticity of lipid vesicles (DOPC, DMPC and DLPC) interacting with trans-membrane peptides (mellitin and gramicidine), which are investigated by small-angle neutron scattering and neutron spin-echo spectroscopy, will be presented [4, 5]. This work is supported by the Basic Atomic Energy Research Institute (BAERI) program funded by the MEST through the NRF. [1] H. T. McMahon and J. L. Gallop, Nature (London) 438, 590 (2005). [2] B. J. Reynwar et al., Nature (London) 447, 461 (2007). [3] M. G. J. Ford et al., Nature (London) 419, 361 (2002). [4] J.-H. Lee, S.-M. Choi, C. Doe, A. Faraone, P. A. Pincus, and S. R. Kline, Phys. Rev. Lett., 105, 038101 (2010) [5] J.-H. Lee, M.-J. Lee, S.-M. Choi et al (in preparation)
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Soft Matter
a
SM-O-03
Tuesday, 2 Nov. 15:00 â&#x20AC;&#x201C; 15:20 (Room 102)
Development of New 40 m Small Angle Neutron Scattering Instrument at HANARO Young-Soo Han a* , Sungmin Choi b, Tae-Hwan Kim a, Myung-Kook Moon a, Chang-Hee Lee a, Baek-Seok Seong a Neutron Science Division, Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong-gu, Daejeon, 305-353 b Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 335 Gwahak-ro, Yuseong-gu, Daejeon, 373-1 *Corresponding author: yshan@kaeri.re.kr a
The new 40m small angle neutron scattering instrument has been constructed at the new cold source of the 30MW HANARO research reactor in the Korea Atomic Energy Research Institute and it is opened for the outdoor users. The instrument is 40 m long and utilizes high resolution mechanical velocity selector, pinhole collimation, two types of sample stages and 1m x 1m two dimensional position sensitive detector. The measurement range of the instruments extends from 0.001 to 1.0 Ă&#x2026;-1 in scattering vector. This allows the investigation of structures ranging from about 0.6 to 600 nm. In this paper, the design and characteristics of the instrument are described and the beam test results are presented.
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SM-O-04
Tuesday, 2 Nov. 15:30 â&#x20AC;&#x201C; 16:00 (Room 102)
Neutron Reflectivity for the Investigation of the Internal Structures of Functional Polymer Thin Films Kookheon Char*
Detailed characterization of surfaces and interfaces in polymer thin films is typically required to design advanced organic or hybrid materials to meet the specific requirements for given applications such as memory devices or biomedical diagnostic platforms. Developments of new experimental techniques to characterize polymer chains at surfaces and interfaces have been the focus of intense interest to many polymer physicists as well as material scientists for decades. Among many available techniques for the characterization of polymer thin films, neutron reflectivity (NR) is one of the most powerful tools for the investigation of surfaces and the interfaces of polymers in detail, when different polymer chains are assembled within the thin films in ordered structure. The NR measurements not only have the ability to provide excellent spatial resolution but those can also be performed under ambient conditions, giving us freedom to investigate biological systems. In addition, repeated measurements on the same sample are also possible owing to the non-destructive nature of neutrons. In the present study, we employed the NR to monitor the changes in the internal structure of two different functional polymer thin films: one is block copolymer (BCP) thin films for nanopatterns and the other is the layer-by-layer assembled polyelectrolyte (PE) multilayer thin films for controlled release systems. In the first part, the surfactant-assisted perpendicular orientation of deuterated polystyrene-block-poly(methyl methacrylate) (dPS-b-PMAA) has been investigated as a function of surfactant concentration. Using NR, it is well documented that the surfactant-assisted orientation of BCP films is strongly influenced by film thickness and the thickness-dependent orientation gradually loses its memory or preference with the increase in both surfactant concentration and film thickness. Such fundamental knowledge to identify crucial control parameters for the perpendicular orientation of BCP films would give further insights on many potential applications such as BCP lithography and nanoscale object ordered arrays. In the second part, the release behavior of model blend multilayer films, consisting of strong and weak PEs, has been studied as a function of external pH and the blend ratio of strong to weak PE. NR measurements successfully demonstrate that the release behavior of target chains (dPMAA; weak PE in this study) is controlled by the amount of strong PE within the blend multilayer. The release behavior demonstrated in this study clearly provides insights on the controlled release of target active materials from polyelectrolyte-based multilayer films, leading to the development of efficient drug delivery platforms in response to external stimuli for many biological applications.
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Soft Matter
Intelligent Hybrids Research Center, School of Chemical and Biological Engineering, The WCU Program of Chemical Convergence for Energy and Environment, Seoul National University, Seoul 151-744, Korea. *Corresponding author: khchar@plaza.snu.ac.kr
SM-O-05
Tuesday, 2 Nov. 16:00 â&#x20AC;&#x201C; 16:30 (Room 102)
Neutron Scattering Researches on Biological Membrane Interfaces Kwanwoo Shina,b Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Seoul, Korea b Sogang-HANARO Joint Center for Biological Interfaces, Daejeon, Korea *Corresponding author: kwshin@sogang.ac.kr
a
In recent years, soft matter science, including biological systems and organic thin films, has received more and more attention for its extensive applications in medical and biotechnological fields, since many important biological processes are regulated at a membrane surface and interface. As the vital component of all living cells, a biological cell membrane acts as a reaction front for an immune response, cell metabolism and adherence, protein transfusion and other crucial life activities. Recently, our research focused on developing new ways to mimic, characterize, and understand the biologically active membrane at the air/water interface. Neutron and X-ray reflections, in particular, have been great important in the last decades for the study at the air/water and water/solid interfaces. They can offer several advantages for the study of structural details of biomembrane in aqueous environment because of nondestructive and higher depth resolution than other techniques. In this talk, we would like to present the structural analysis of bio-fouling and bio-adhesive surfaces, mimicking recognition, binding and penetration of proteins and peptides.Various lipid mono- & bilayer and multilayer systems, interacting with cell penetrating peptides & proteins were detailed. Finally we will correlate those properties to the cellular uptake and penetrating processes of biomolecules.
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SM-O-06
Tuesday, 2 Nov. 16:30 â&#x20AC;&#x201C; 16:50 (Room 102)
The HANARO Bio Reflectometer for the Cold Neutron Source D. Choia,b,c, Y. H. Choib , C.-H. Leeb,c , J. S. Leeb,c , K. P. Hongb,c , J. H. Hanb,c , M. K. Moonb , S. J. Chob , K. Shina,b* Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Seoul, Korea b HANARO Center, Korea Atomic Energy Research Institute, Daejeon, Korea c Sogang-HANARO Joint Center for Biological Interfaces, Daejeon, Korea *Corresponding author: kwshin@sogang.ac.kr
H-9A (Horizontal type neutron reflectometer) was transferred to KOREA in BNL in USA 5 years ago, and the name was changed to the REF-H. REF-H was established in KOREA first time. Then it was completed development as a bio measuring instruments were installed in cold neutron facility and the name was changed to the Bio-REF. Liquid samples and solid samples has been developed for two measurement modes. it has the largest value of Qz (Liquid: 0.23-1, Solid: 0.6--1). Neutron beam path, sample stage and detector motion system are independently to overcome the difficulty of alignment of instruments. as a result of radiation shielding test of monochomator shield, neutron and gamma radiation in shielding surface were evaluated less than reference value, 6.25 Sv/hr. after irradiated rolling gold wire, by the use neutron flux was measured by use of NAA at the location of monochromator after irradiated rolling gold wire and neutron flux was evaluated 9.46x108 n/cm2/sec, the characteristic by using a beryllium filter high harmonic orders was disappeared. it was found by measurement of time-of-flight. To compensate for consecutive time intervals as a function of wavelength conversion was found to be the 4.75 wavelength correctly. Developing of various kinds of sample environments can satisfy the needs of the user. Bio-REF using cold neutron source to study the bio, polymer and metal were prepared
Figure1. 3D Schematic overview of the Bio Reflectomer
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Soft Matter
a
SM-P-01
Diverse Morphologies of Self-Assembled Nanostructures and Their Structural Analysis with Small Angle Neutron Scattering Yeong Ah Choi, Chan Woo Park, Hyun Jin Lee and Jong-Duk Kim* Department of Chemical and Biomolecular Engineering, KAIST, Daejeon, Republic of Korea *Corresponding author: jdkim@kaist.ac.kr
A series of amphiphilic graft copolymers, poly(aspartic acid) grafted with dodecyl chains having different degree of substitution (DS) were synthesized, and their self-assembled nanoparticles in aqueous solution were prepared by a direct dissolution method. In this study, the morphological changes of self-assembled nanoparticles were induced as a function of DS of dodecyl chains, which are related to hydrophilic/hydrophobic ratio. At the same polymer concentration condition, the morphologies of self-aggregates are changed from spherical micelles to wormlike micelles, disk-like micelles, and finally to tubular networks and vesicles in orders of DS of dodecyl chains. Various morphologies were characterized by TEM, DLS and SANS measurement, and their structural transitions could be explained in terms of packing parameter and interfacial energy. On the other hand, in case of tubular network and wormlike micelle aqueous solutions, there was phenomenal increase of viscosity according to the increase of polymer concentration. Their rheological behaviors were confirmed by both steady and dynamic shear measurement using ARES rheometer. And their rheological mechanisms could be explained in terms of the formation of three dimensional tubular networks and the entanglement of wormlike micelles, and this phenomenon was also confirmed by SANS measurement.
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SM-P-02
Size and Morphology Control of Aggregates from Supramolecular Graft Copolymers Stabilized by Ionic Interaction Yeong Min Jo, Chan Woo Park, Bokyung Jung, Hee-Man Yang, Jong-Duk Kim*
A series of supramolecular graft copolymers (SGPs) composed of poly(L-lysine)(PLL)asa main chain and poly(D,Llactic-co-glycolicacid)(PLGA)asa side chain was synthesized with different degrees of substitution (DSs) through ionic interaction in a DMSO solvent. The addition of water induced the self-assembly of PLL-PLGA SPGs into spherical micelles at a critical water content (CWC). The size of the spherical micelles at each CWC decreased with an increase of DS and core-shell structures, which was confirmed by XPS and zeta-potential measurements. The morphological transitions were driven under thermodynamic control when the solvents mixed. Consequently, further increases of water content caused the transition of the spherical micelles to vesicles, while the initial spherical micelles were reconstructed from vesicles when the DMSO was added. The content of water, the boundaries for the morphology transition, depended on the DS. The pH and salt levels affected the stability of the aggregates weakening the ionic interactions between the PLL and PLGA.
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Soft Matter
Department of Chemical and Biomolecular Engineering, Center for Energy and Environment Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea Fax: +82 42 869 3910; *Corresponding author: jdkim@kaist.ac.kr
SM-P-03
Contrast Varied SANS Investigation of Sub-domain Structures of Lamellar and Reverse Hexagonal Pluronic Ternary Systems Changwoo Doe a, Hyung-Sik Jang a, Steven R. Kline b, Sung-Min Choi a* a
Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701, Republic of Korea bNIST Center for Neutron Research, Gaithersburg, Maryland 20899-6102, USA *Corresponding author: sungmin@kaist.ac.kr
The subdomain structures of lamellar and reverse hexagonal phases of Pluronic polymer/water/oil ternary system have been investigated by contrast varied small angle neutron scattering (SANS) measurements. As the neutron scattering length density of either polar or apolar domain was varied, the scattering intensities of the first Bragg peaks changed as expected, but the intensities of the second Bragg peaks did not change significantly. This variation of the relative peak intensities can not be explained by the typical simple models where the polar and apolar domains are regarded as homogeneous mixtures of PEO + water and PPO + oil, respectively, in which case the relative intensities of Bragg peaks do not change. For both lamellar and reverse hexagonal Pluronic ternary systems, the analysis of the contrast varied SANS intensities with subdomain structure models reproduce the experimental data very successfully, showing that a water-rich layer exists in the middle of the polar domain and water- and oildepleted layers exist at the polar/apolar interfaces.
Figure 1. (a) SANS intensities of Pluronic polymer/water/oil (40/40/20 wt %) in the lamellar phase with different H2O weight fractions in water as indicated in the graph. The solid lines are theoretical calculations. (b) Subdomain structures of the Pluronic polymer/water/oil ternary system at lamellar phase. d and are the lamellar periodicity and apolar domain thickness, respectively.
References [1] C. Doe, H.-S. Jang, S. R. Kline, and S.-M. Choi, Macromolecules 42, 2645 (2009).
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SM-P-04
Contrast Varied SANS Investigation of Single-Walled Carbon Nanotubes in a Polymeric Lamellar System Changwoo Doe a, Hyung-Sik Jang a, Steven R. Kline b, Sung-Min Choi a* Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701, Republic of Korea b NIST Center for Neutron Research, Gaithersburg, Maryland 20899-6102, USA *Corresponding author: sungmin@kaist.ac.kr
Fabrication of highly ordered superstructures of single-walled carbon nanotubes (SWNTs) is of great interest for a wide range of potential applications. Here, we investigate the selective distribution of individually isolated SWNTs (1D nanoparticles with very large aspect ratios) in polymer/water/oil ternary systems in a lamellar phase by contrast variation small-angle neutron scattering measurements[1]. Hydrophilically functionalized SWNTs (p-SWNTs) [2,3,4] with an aspect ratio of ca. 100 are mixed with polymer/water/oil systems prepared with two opposite neutron contrasts, a positive contrast for which the neutron scattering length density of the apolar domain is higher than that of the polar domain and a negative contrast for which the relative scattering length density is opposite. The neutron scattering intensity of the first-order Bragg peak, after correcting for the effect of p-SWNT-induced diffuse interface, increases with addition of p-SWNTs in the positive contrast samples and decreases in the negative contrast samples. This shows that p-SWNTs, of which the length is ca. 70 times larger than the thickness of polar domain while its diameter is comparable to the polar domain thickness, are selectively distributed in the polar domains of the polymer/water/oil lamellar phase.
Figure 1.Scattering intensities of polymer/water/oil lamellar phase mixed with p-SWNTs with (a) a positive scattering contrast and (b) a negative scattering contrast condition. The p-SWNT concentrations are indicated as wt% in water. (c) Schematics for the selective distribution of p-SWNTs in a polymer/water/oil lamellar phase.
References [1] C. Doe, H.-S. Jang, S. R. Kline, and S.-M. Choi, Macromolecules 43, 5411 (2010). [2] T.-H. Kim, C. Doe, S.R. Kline, and S.-M. Choi, Adv. Mater. 19, 929 (2007) [3] T.-H. Kim, C. Doe, S.R. Kline and S.-M. Choi, Macromolecules, 41, 3261 (2008) [4] C. Doe, S.-M. Choi, S.R. Kline, H.-S. Jang, and T.-H. Kim, Adv. Funct. Mater. 18, 2685 (2008)
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Soft Matter
a
SM-P-05
Response of SANS Intensities for Block Copolymers to Pressure J. Lee a, D. Y. Ryu b, J. Cho a* Department of Polymer Science and Engineering, Dankook University, 126 Jukjeon, Yongin, Gyeonggi-do 448-701, Korea b Department of Chemical and Biomolecular Engineering, Yonsei University, 134 Sinchon, Seodaemun-gu, Seoul 120-749, Korea *Corresponding author: jhcho@dankook.ac.kr a
The phase behavior of a styrenic diblock copolymer under pressure has been studied by small-angle neutron scattering (SANS) and a compressible random-phase approximation theory. The scattering intensities for the copolymer at selected pressures yield the lower disorder-order transition (LDOT) and its pressure coefficient. It is shown that the change in the scattering intensities upon pressurization is correlated to the change in the bulk modulus (inverse of isothermal compressibility). Those phase data yields the cross-interaction for the copolymer, which is the central molecular information for theory. The experimental behavior of scattering intensities for the copolymer as a function of pressure is compared with that from theory to test its predictability for future use as a design tool.
- 129 -
SM-P-06
Neutron Reflectivity Study on the Surfactant-Assisted Perpendicular Orientation of Block Copolymer Thin Films Jeong Gon Son, Hyo Seon Suh, and Kookheon Char*
Block copolymer (BCP) thin films have recently received intense attention due to many possible applications. The control of BCP morphology is easily achieved by varying the total molecular weight and the volume fraction of each block. However, there is an additional factor to be considered in the case of BCP film geometry: the preferential wetting of a given block at both interfaces to minimize interfacial and/or surface energies. As a result, the parallel orientation of BCP domains is first initiated at both interfaces and then propagates across the entire film. From the practical point of view, the perpendicular orientation of BCP domains is preferred over the parallel orientation in many applications such as nanotemplates for lithography, separation membranes, and nanoscale object arrays. The earlier approach for the perpendicular orientation of BCP films was to apply an external or internal field that overcomes the surface fields. Another alternative was to minimize the difference in interfacial tensions between each block against a substrate by adjusting the surface energy of the substrate. This kind of surface state is referred to as the substrate neutrality, which has been achieved by the deposition or grafting of self-assembled monolayers or copolymer brushes on the substrate. In such cases, the BCP films adopt the perpendicular orientation from the bottom substrate toward the polymer surface exposed to air. From different perspectives, our research group has developed a new approach employing a small amount of surfactants, preferably located at the top surface to tailor the surface properties of a material, which in turn can easily create energetically neutral conditions at the top surface of BCP thin films. In the present study, we analyzed the surfactant-assisted perpendicular orientation of deuterated polystyrene-blockpoly(methyl methacrylate) (dPS-b-PMAA) BCP thin films based on neutron reflectivity (NR) to investigate the effect of surfactant concentration on the surface morphology of BCP thin films. We note that the perpendicular orientation of BCP films assisted by the surfactant addition is influenced by film thickness: the perpendicular orientation is preferred `when the film thickness is at the integers of L0 (characteristic spacing of BCP) while the parallel orientation is favored when the film thickness is close to the half integers of L0. In addition, we found that the thickness-dependent orientation gradually loses its memory or preference with the increase in both film thickness and surfactant concentration.
- 130 -
Soft Matter
Intelligent Hybrids Research Center, School of Chemical & Biological Engineering, Seoul National University, Seoul 151-744, Korea *Corresponding author: khchar@plaza.snu.ac.kr
SM-P-07
Highly Ordered Superstructures of Cylindrical Nanoparticles-Amphiphilic Molecules Complexes Tae-Hwan Kima*, Shin-Hyun Kangb, Changwoo Doeb, Jihyun Yub, Jun-Bo Simb, Jehan Kimc, Steven R. Klined , and Sung-Min Choib Neutron Science Division, Department of Basic Science and Technology, Korea Atomic Energy Research Institute 1045 Daedeok-daero, Yuseong-gu, Daejeon, 305-353, Korea, b Department of Nuclear and Quantum Engineering, KAIST, 373-1 Guseong-dong, Yuseong-gu, Daejeon, 305-701, Republic of Korea, c Beamline Research Division, Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang, Gyeongbuk 790-784, Republic of Korea, and d NIST Center for Neutron Research, Gaithersburg, Maryland 20899-6102 *Corresponding author: greatsalt@gmail.com
a
Self-assembly of cylindrical nanoparticles such as carbon nanotubes, nanowires, and nanorods into highly ordered superstructures has been of great interest. The ordered assembly of cylindrical nanoparticles collectively enhances their physical properties and provides a broad range of potential applications such as optoelectronic devices, biological sensing, and drug and gene delivery. Recently, various techniques for assembling cylindrical nanoparticles into novel superstructures have been actively investigated utilizing external forces or internal interactions. However, the phase behavior of cylindrical nanoparticles interacting with surrounding materials, which is the key information to design self-assembled superstructures, has not been fully exploited yet. Here, we report a new phase diagram of negatively charged cylindrical nanoparticles and cationic liposome (CL) complexes, which exhibit three different highly ordered phases, intercalated lamellar, doubly intercalated lamellar and centered rectangular columnar phases, depending on particle diameter and electrostatic interaction [1]. The negatively charged cylindrical nanoparticles with various radii were synthesized by copolymerization of polymerizable surfactants, which forms worm-like micelles in water, and the anionic hydrotropic salt. The radius and surface charge of the nanoparticles are controlled by the alkyl chain length and the concentration of NaSS during copolymerization, respectively. The structures of the cylindrical nanoparticles with various radii were characterized by the small angle neutron scattering (SANS). The negatively charged cylindrical nanoparticle-CL complexes at their isoelectric points were made with two different membrane compositions (DOPC:DOTAP = 5:5 and 7:3) and were characterized by the small angle x-ray scattering (SAXS). The phase behavior of the negatively charged cylindrical nanoparticle-CL complexes is interpreted and summarized in terms of a simple ratio of two length scales (dspacing/drod) which depends on the surface charge densities of negatively charged cylindrical nanoparticles and membranes and the diameter of negatively charged cylindrical nanoparticles. This simple criterion works not only for the complexes investigated in this study but also for previously reported rod-like biomolecule-CL complexes such as DNA-CL, F-actin-CL, and M13 virus-CL complexes. The new phase diagram can be very useful to understand and design new highly ordered self-assemblies of cylindrical nanoparticles (such as carbon nanotubes) in soft matter and may provide new efficient routes for scalable production of cylindrical nanoparticles composites with new functionalities. Furthermore, the systematic understanding of the interaction between oppositely charged cylindrical nanoparticles and lipid membranes may provide further insight into the interactions of rod-like biomolecules (such as DNA) with biomembranes Reference [1] J. Am. Chem. Soc. 2009, 131, 7456â&#x20AC;&#x201C;7460.
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SM-P-08
Neutron Reflectivity Study on the Release of Target Chains from Model Blend Multilayer Films Yeongseon Janga, B端lent Akg端nb, Sushil Satijab, and Kookheon Chara* Intelligent Hybrids Research Center, School of Chemical and Biological Engineering, Seoul National University, Seoul 151-744, Korea. b National Institute of Standards and Technology Center for Neutron Research, 100 Bureau Drive, MS 6100, Gaithersburg, MD 20899-6100, USA. *Corresponding author: khchar@plaza.snu.ac.kr
Great efforts have been devoted to realize stimuli-responsive polymeric thin films for many potential applications, particularly in the controlled release of active ingredients in biological systems. Among many possible thin film candidates, polyelectrolyte (PE) blend multilayer films prepared by the layer-by-layer (LbL) deposition have the outstanding versatility to engineer functional interfaces with enhanced properties mainly due to its capability to contain different active ingredients at desired positions as well as the accurate tunability of thickness and compositions. However, the fundamental mechanism on the internal rearrangement or the release behavior in the PE blend multilayer films has so far not been well established because of the difficulty in detecting the internal changes of multilayer films. In the present study, we employed the neutron reflectivity (NR) to monitor the change in internal film structure as well as the release behavior of model blend multilayer films, composed of strong and weak PEs. A cationic PE, linear poly(ethylene imine) (LPEI; weak PE), and a mixture of two anionic PEs, sodium poly(styrene sulfonate) (SPS; strong PE) and poly(methacrylic acid) (PMAA; weak PE), were used to prepare the blend multilayer films as a model stimuli-triggered release platform. The blend multilayer films with well-defined internal structure were prepared by the spin-assisted LbL deposition and the release behavior of target weak PE chains (i.e., d-PMAA in the present case) from the films has been systematically investigated as a function of the blend ratio between SPS and PMAA using the NR measurements combined with ellipsometry, AFM, QCM, and FT-IR spectroscopy. NR measurements successfully demonstrate that a rapid burst of the entire multilayer film solely based on weak PE pairs is dramatically suppressed by adding a small amount of a strong PE in the blend layers. Consequently, the strong PE (SPS) is believed to provide robust skeletons in the blend layers independent of pH. In addition, the release kinetics of a weak PE (d-PMAA) could be well controlled simply by varying the content of SPS. This blend approach and its release behavior demonstrated in the present study clearly provide insights on the controlled release of target active materials from multilayer thin films, leading to the development of drug delivery platforms in response to external stimuli for many biomedical applications. Furthermore, we investigated the effect of posttreatment pH and molecular weight of target polymer chains on the release. Such fundamental research to elucidate the release mechanism from PE blend multilayer films would further expand the design capacity of polymeric controlled release systems.
- 132 -
Soft Matter
a
SM-P-09
Neutron Spin Echo Investigation of Phospholipid Vesicles Interacting with Pore-forming Antimicrobial Peptides Ji-Hwan Leea, Sung-Min Choia,*, Changwoo Doea, Antonio Faraoneb,c, Philip A. Pincusd,e, Steven R. Klineb Department of Nuclear and Quantum Engineering, KAIST, Daejeon, 305-701, Republic of Korea b NIST Center for Neutron Research, Gaithersburg, Maryland 20899, USA c Department of Material Science, University of Maryland, College Park, Maryland 20742, USA d Materials Research Laboratory, University of California, Santa Barbara, California 93106, USA e Department of Physics, KAIST, Daejeon, 305-701, Republic of Korea *Corresponding author: sungmin@kaist.ac.kr
a
During most cellular processes, the cell membranes undergo various morphological changes that are governed by elastic properties of membranes. While it is well known that the interplay between membranes and proteins is a key for changes of membrane morphology, it is not fully exploited how the elastic properties of membranes are influenced by the protein-membrane interactions. Here, we report, the neutron spin echo investigation on thermal undulation and elastic properties of dioleoyl-phosphocoline large unilamellar vesicle interacting with pore-forming antimicrobial peptide, melittin [1]. The relaxation behavior of the membrane undulation with different peptide to lipid molar ratio P/L can be divided into three regions, resulting from characteristic changes of the effective bending modulus of the bilayer membrane which includes the effects of internal dissipation within the bilayer membrane. At low P/L, melittin is adsorbed parallel to the surface of membrane and decreases significantly due to perturbation of hydrocarbon chain packing. At a critical P/L, melittins form pores in the membrane and starts to increase slightly due to high rigidity of pores. At higher P/L where the repulsive inter-pore interaction becomes significant, increases rapidly.
- 133 -
Magnetism
- 134 Magnetism
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- 136 Magnetism
MG-O-01
Monday, 1 Nov. 16:10 â&#x20AC;&#x201C; 16:40 (Room 104)
Cold Neutrons and Pyrochlore Magnets. Jason S. Gardner a* Department of Physics, Indiana University, Bloomington IN 47408 and NCNR, National Institute of Standards and Technology, Gaithersburg, MD 20899 *Corresponding author: Jason.Gardner@NIST.gov a
Rare earth titanate pyrochlore magnets, with the chemical composition A2B2O7, have been a playground for the physics of geometrical frustration. Many magnetic trivalent rare earth ions can reside on the A site of this structure, and such compounds give rise to physical realizations of magnetic moments decorating a network of corner-sharing tetrahedra. Such networks can be combined with antiferromagnetism and ferromagnetism along with different spin anisotropies to produce materials with varied and exotic, sometimes disordered, ground states. I will discuss new neutron scattering work on several magnetic pyrochlores with large moments and different spin anisotropies. Er2Ti2O7 and Yb2Ti2O7, which can be thought of in terms of XY moments decorating a network of corner sharing tetrahedra. The ferromagnet, Yb2Ti2O7 displays an unexpected disordered ground state which can be brought to order in an applied magnetic field [1]. The antiferromagnet, Er2Ti2O7, displays a long range ordered state at low temperatures which can be driven into a disordered state by application of a magnetic field. These results will be compared to the Ising pyrochlores Tb2Ti2O7 and Ho2Ti2O7[3,4]. In collaboration with K. A. Ross, J. P. C. Ruff, J. P. Clancy, B. D. Gaulin, H. A. Dabkowska, Y. Qiu, G. Ehlers, T. Fennell and S. T. Bramwell [1] K. A. Ross, J. P. C. Ruff, C. P. Adams, J. S. Gardner, H. A. Dabkowska, Y. Qiu, J. R. D. Copley, and B. D. Gaulin, Phys. Rev. Lett. 103, 227202 (2009). [2] J. P. C. Ruff, J. P. Clancy, A. Bourque, M. A. White, M. Ramazanoglu, J. S. Gardner, Y. Qiu, J. R. D. Copley, M. B. Johnson, H. A. Dabkowska, and B. D. Gaulin, Phys. Rev. Lett. 101, 147205 (2008). [3] M J P Gingras, B C den Hertog, M Faucher, J S Gardner, S Dunsiger, L J Chang, B D Gaulin, N P Raju and J E Greedan, Phys. Rev. B, 62, 6496 (2000) [4] S T Bramwell, M J Harris, B C Den Hertog, M J P Gingras, J S Gardner, D F McMorrow, A Wildes, A L Cornelius, J D M Champion, R G Melko and T Fennell, Phys. Rev. Lett. 87, 047205 (2001).
- 137 -
MG-O-02
Monday, 1 Nov. 16:40 â&#x20AC;&#x201C; 17:10 (Room 104)
Neutron Scattering Study on the Fe-based Superconductors and Frustrated Quantum Magnets Taku J Satoa,b,* Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, Tokai 319-1106, Japan b TRIP, JST, Tokyo 102-0075, Japan *Corresponding author: taku@issp.u-tokyo.ac.jp
A triple-axis spectrometer has been a versatile and indispensable research tool for various topics in condensed matter science, such as magnetism, ferroelectricity, and superconductivity. As their combinations, e.g., multiferroicity and spin-fluctuation-mediated high-Tc superconductivity, become more and more vital issues recently, the importance of the triple-axis spectroscopy becomes more and more visible. Despite principled low-efficiency of the original triple-axis spectrometer, recent developments on neutron focusing techniques provide the triple-axis spectroscopy renewed potential. In this talk, I will first summarize the recent upgrades to the triple-axis spectrometers installed at the Japan Research Reactor, JRR-3. The Fe-based superconductor, discovered in early 2008, now has the second highest superconducting transition temperature, next to the cuprates, and thus is actively investigated by many researchers all over the world. Since the superconductivity appears as the antiferromagnetic order is suppressed by electron/hole doping or chmical/hydostatic pressure, a close relation between the antiferromagnetic fluctuations and the high-Tc superconductivity was inferred from the beginning. To experimentally reveal the relation, we have performed neutron inelastic scattering experiments on the BaFe2As 2 parent (antiferromagnetic) compound, and its superconducting phases realized by electron doping (Ba(Fe,Co)2As2)[1], or chemical pressure (BaFe2(As,P)2). In the electron doped system, the spin fluctuations in the spin normal (paramagnetic) state are identical in the parent and optimally doped compounds, indicating that the spin fluctuations are indeed not the origin of the antiferromagnetic order in the parent phase. By further increasing the electron doping level, the spin fluctuation spectrum changes qualitatively, and the fluctuations disappear in the low energy region with the superconductivity is suppressed. This clearly indicates that the enhanced spin fluctuations are due to the Fermi surface effect, and further suggests that the superconductivity is strongly affected by the Fermi surface topology. If time allows, I will also talk about our recent results in the field of frustrated quantum magnets. [1] K. Matan et al., arxiv: 0912.4945.
- 138 -
Magnetism
a
MG-O-03
Monday, 1 Nov. 17:10 – 17:40 (Room 104)
SIKA - A Multi-detectors Cold Neutron Triple-axis Spectrometer at ANSTO Wen-Hsien Li*, Peter Voderwisch, and Chun-Ming Wu Center for Neutron Beam Applications, National Central University, Jhongli 32001, Taiwan *Corresponding author: whli@phy.ncu.edu.tw This project is based on an Arrangement signed in 2005 between the representative organizations of Taiwan and Australia governments, in which Taiwan will construct a high performance cold triple-axis spectrometer (TAS) at the OPAL reactor, send 4 scientists to operate the cold-TAS, and obtain 70% of one instrument time for NSC (National Science Council) related scientists that may be distributed over the full set of instruments at OPAL reactor. The project is indeed a follow-up solution to the cancellation of the TRR-II (Taiwan Research Reactor-II) project to build a reactorbased neutron scattering facility for the national and international communities. The project started in early 2006, and is targeted to complete before the end of 2011. The cold-TAS under construction is named SIKA, after the native Taiwanese deer “Formosan sika deer”. The sika deer is commonly known as “plum blossom deer” to reflect the symbolic figures appear on its skin. A beautiful picture of these deer may be found in Taiwanese 500-dollar bill. It is known that a triple-axis spectrometer is mainly for performing inelastic scattering to obtain information in K-space. The scientific term for SIKA is then “Spin-polarized Inelastic K-space Analyzer”. SIKA locates at the Reactor Beam Hall and directly attaches to the OPAL reactor face, receiving neutrons from the CG4 beam tube that extracts neutrons from the cold source, as shown in the left panel of Fig. 1. It has the advantage of receiving all neutrons from the CG4 beam tube, but at the expense of higher background count-rates in comparison to a Guide Hall position. SIKA equips with a double focusing PG monochromator of size 220 340 mm2. The PG monochromator consists of 11 11 ZYA quality HOPG(002) crystals each covers a 20 20 mm2 reflection face, as shown in the center panel of Fig. 2. The take-off angle of the monochromator covers 30 to 1350, giving a useful wavelength range of 1.74 to 6.2 Å or an energy range of 2.1 to 27 meV for the incident beam, when employing the HOPG mono. The distance between the monochromator and sample is 2100 mm long to ensure enough space for polarization or spin-echo devices. SIKA equips with 13 HOPG(002) analyzer crystals, each of size 20 150 mm2, as shown in the right panel of Fig. 3. A detector bank consists of 13 vertical PSD is coupled to the analyzers. These analyzer-detector systems may be operated in horizontal focusing mode or work independently. In addition, a single detector and a diffraction PSD are also available. All these components are arranged in a compact housing. Neutron polarization will become available for the incident and scattered beams through 3He polarizers, when such devices become accessible at ANSTO.
Figure 1. Left panel: Layout of the cold neutron triple-axis spectrometer SIKA at ANSTO. Center panel: Double focusing PG monochromator of SIKA. It consists of 11 11 ZYA quality HOPG(002) crystals each covers a 20´20 mm2 reflection face. Right panel: Analyzer bank of SIKA. It consists of 13 HOPG(002) analyzer crystals, each of size 20 150 mm2
- 139 -
MG-O-04
Monday, 1 Nov. 17:40 â&#x20AC;&#x201C; 18:00 (Room 104)
Current Status and Future Prospects of the HANARO Cold Neutron Triple-Axis Spectrometer: Finishing the Cold Neutron Research Facility Project J. M. Sungil Park a* a
Neutron Science Division, Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong-gu, Daejeon 305-701, Korea *Corresponding author: jmspark@kaeri.re.kr
Magnetism
The HANARO Cold Neutron Triple-Axis Spectrometer (Cold-TAS) is being constructed as part of the Cold Neutron Research Facility (CNRF) Project, which is to end in April, 2011. Although there are still quite a lot to be done in terms of instrumentation even after the project is over, we are currently making every effort to wrap up the project and make the instrument available to users as soon as possible. We will present the status of the construction and what needs to be done afterwards. Also discussed is what is being planned to give users access to the instrument.
- 140 -
MG-O-05
Tuesday, 2 Nov. 10:40 – 11:10 (Room 201)
Ordering and Relaxation Dynamics of Magnetic Nanomaterials Albrecht Wiedenmann a*, a
Institute Laue Langevin, B.P. 156, 38042 Grenoble Cedex 9, France *Corresponding author: wiedenmann@ill.fr
Stroboscopic Small Angle Neutron Scattering (SANS) techniques have been developed which allow ordering and relaxation processes of magnetic moments in nano-particles to be monitored [1,2]. By applying a periodic external magnetic field the time-resolved SANS response to a forced oscillation could be analyzed. For conventional SANS with a continuous neutron flux the shortest accessible time range is limited to few milliseconds resulting due to the wavelength spread. With the pulsed frame overlap TISANE technique [3] a dynamical range of micro-seconds can be exploited which is similar to that of X-ray photon-correlation spectroscopy. Here we present a combination of stroboscopic neutron techniques applied to magnetic colloids and solid magnetic nanomaterials. SANS scattering response in an oscillating magnetic field was measured as a function of frequency and amplitude of the applied field. When low frequencies of the order of 0.1 Hz are used we measure basically the relaxation of magnetic moments to equilibrium. At higher frequencies only some fraction of particle moments can follow the oscillating field producing scattering patterns alternating between fully isotropic and strongly anisotropic. We extended the stroboscopic technique by using polarized neutrons with polarization analysis (POLARIS) for which spin non-flip (--) and (++) and spin-flip (-+) scattering cross-sections are different and depend on time. Since the neutron spin follows adiabatically the applied oscillating field we observed oscillating POLARIS cross sections for the whole time period as long as there was no delay of the magnetic moment reorientation. When the magnetization reversal is delayed for a certain time range neutron spin and particle moment are no longer in phase the time-dependent scattering intensity exhibits a discontinuity which makes the technique very sensitive to the determination of such delayed responses [4]. The analysis of time-dependent SANS data as a function of frequency, amplitude of the field and temperature allowed us i) to proof the validity of the Langevin statistics describing the particle moment orientation, ii) to extract the effect of field-induced inter-particle correlations, iii) to monitor the slowing down of the dynamics of moment rotation with decreasing temperature, iv) to study the effect of freezing of the solvent on the dynamics of the particle moments, and v) to decide between the possible relaxation mechanisms (Néel and Brownian). [1] A. Wiedenmann, U. Keiderling, K. Habicht, M. Russina and R. Gähler, Phys. Rev. Lett. 97, 057202 (2006). [2] Wiedenmann, A., Keiderling, U., Meissner, M., Wallacher, D., Gähler, R., May, R. P., Prévost, S., Klokkenburg, M.,Erné,Kohlbrecher, J. Phys.Rev. B77, 184417(2008) [3] D. Kipping, R. Gahler, K. Habicht; PLA 372 (2008) 1541 [4] A. Wiedenmann et al: ILL experimenta report 2008
- 141 -
MG-O-06
Tuesday, 2 Nov. 11:10 â&#x20AC;&#x201C; 11:40 (Room 201)
Magnetic Depth Profile Analysis of Synthetic Antiferromagnetic Layers at HANARO+ Sungkyun Parka,*, Ki-Yeon Kimb, and Jeong-Soo Leeb Department of Physics, Pusan National University, Busan 609-735, Korea Neutron Science Division, Korea Atomic Energy Research Institute, Daejeon 305-353, Korea *Corresponding author: psk@pusan.ac.kr a
b
This work is supported by NRF Nuclear R&D Program (2009-0083140 and 2010-0018374).
+
- 142 -
Magnetism
The magnetic profile of synthetic antiferromagnetic structure was examined using newly constructed polarized neutron reflectometery at Hanaro, KAERI. It is well known that the synthetic antiferromagnetic structure exhibited antiferromagentic configuration as grown due to the exchange interaction across Ru thin layers. From detail profile analysis we were able to determine the reversed layer to form antiferromagnetic configuration. After annealing, the system configured to ferromagnetic coupling and the magnetization value is similar to the saturated sample before annealing indicating the annealing may affect Ru layer itself. The details profile analysis will be discussed in the presentation.
MG-O-07
Tuesday, 2 Nov. 11:40 – 12:00 (Room 201)
Magnetization Reversal Behavior of Exchange-Biased Heterostructures using Polarized Neutron Reflection and Magneto-Optic Kerr Effect and Magnetic Hysteresis Ki-Yeon Kim a*, Ji-Wan Kim b, Hyeok-Cheol Choi c, A. Teichert d, Chun-Yeol You c, S. Park e, Sung-Chul Shin b, and Jeong-Soo Leea Neutron Science Division, Korea Atomic Energy Research Institute., 305-353 Daejeon, Republic of Korea b Department of Physics and Center for Nanospinics of Spintronic Materials, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea c Department of Physics, Inha University, Incheon 402-751, Republic of Korea d Helmholtz Zentrum Berlin für Materialien und Energie, Glienicker Strasse 100, D-14109 Berlin, Germany e Department of Physics, Pusan National University, Busan 609-735, Republic of Korea *Corresponding author: kykim3060@kaeri.re.kr a
Among the magnetometry techniques widely available nowadays, magneto-optical Kerr effect (MOKE) and superconducting quantum interference device (SQUID) magnetometers have become very popular because they are very accessible and easy to use. [1] MOKE magnetometry is sensitive to the magnetization within a skin depth from film’s surface, but cannot provide a quantitative measure of the magnetization and is limited to the surface. And SQUID magnetometry has the sensitivity enough to measure the magnetic moment as weak as 10-8 emu, but has a disadvantage of providing only the average value of magnetization of whole structure. Polarized neutron reflectivity (PNR) has proven to have a very unique advantage of studying absolute magnetic moment and magnetization reversal behavior with layer selectivity and great accuracy (comparable to commercial SQUID magnetometer) in a variety of magnetic thin films and multilayers.[2] Precise measurement of magnetic moments and comprehensive understanding of magnetization reversal behavior can be made it possible by the combination PNR technique with other techniques, such as MOKE and SQUID. We investigated the magnetization reversal behavior of the exchange-biased Py/FeMn, FeMn/CoFe bilayers, and Py/FeMn/CoFe trilayers by carrying out PNR, MOKE and vibrating sample magnetometer (VSM) experiments. In order to measure separately the longitudinal (M ) and transverse (M ) magnetization components with layer selectivity, we employed both vector MOKE and PNR. Magnetic hysteresis (M -H) loops were also measured by VSM. We witness the compelling experimental evidence that the magnetization reversal of two adjacent Py and CoFe layers are coupled through a thick FeMn layer up to 15 nm and the maximum coupling length is found less than 30nm in the exchange biased Py/FeMn/CoFe trilayers.
References 1. Ultrahin Magnetic Structures , edited by J. A. C. Bland, B. Heinrich (Springer, Berlin, 2005) Chap. 7. 2. C. F. Majkrzak, K. V. O’Donovan and N. F. Berk, in Neutron Scattering from Magnetic Materials, edited by Tapan Chatterji (Elsevier B. V., 2006) Chap. 9.
- 143 -
MG-P-01
Single Crystal Neutron Diffraction Study of the Co Doping Effect on the Magnetoelectric Properties of Mn1-xCoxWO4 Y.-S. Songa, J.-H. Chunga*, S. B. Kimb, J. Schefferc, S.-H. Chund, and K. H. Kimd Department of Physics, Korea University, Seoul, 136-713 Rep. of Korea Department of Physics, Kookmin University, Seoul, 136-702 Rep. of Korea c Laboratory for Neutron Scattering, Paul Scherrer Institut, Villigen, Switzerland d Department of Physics, Seoul National University, Seoul, 151-742 Rep. of Korea *Corresponding author: jaehc@korea.ac.kr a
Multiferroics refer to materials in which two or more ferro-orders are simultaneously observed, and often exhibit strong couplings. In magnetoelectric multiferroics, for instance, ferroelectricity is observed when antiferromagnetic order is established with nontrivial arrangements of spins that break inversion symmetry. The ferroelectric polarization in the majority of multiferroics can be explained based on the spin current model. In this model, the ferroelectric polarization in the form of p = Aeij (Si Sj) arises via relativistic spin orbit coupling. The macroscopic observation of the net polarization demands that the arrangement of spins, Si, has no inversion symmetry. Such long-wavelength magnetic phases are often observed via multiple magnetic transitions in a large number of multiferroics. Such trends suggest that the magnetic energy landscape is rather complicated in the vicinity of the multiferroics phases. MnWO4 is one of the best known magnetoelectric multiferroics.[1] Its magnetism is ascribed to Mn2+ (S = 5/2) ions that form zigzag chains along the c-axis. The materials undergoes three successive magnetic phase transitions at low temperatures, from paramagnetic to a collinear incommensurate(AF1, TN1 = 13.5 K), to an elliptical spiral incommensurate(AF2, TN2 = 12.7 K), and finally to a collinear commensurate(AF3, TN3 = 7.6 K) antiferromagnetic phases. Its ferroelectric order parameter coincides with that of the AF2 spiral antiferromagnetic phase consistently with the spin current picture. In this phase, the spiral plane is parallel to the b-axis and the resulting ferroelectric polatization is observed along the b-axis. In our previous work using neutron powder diffraction, it was found that the incommensurate spiral phase of MnWO4 is stabilized down to the base temperature upon substitution of Mn2+ ions with Co2+ at ~ 5 %.[2] When the Co concentration is increased up to 10 %, the spiral plane is tilted off the b-axis, but the precise orientation of the spiral plane was not revealed clearly. In order to answer the outstanding question, we have grown single crystal samples of Mn1-xCoxWO4 (x = 0.0, 0.05, & 0.1) using floating zone method. The four-circle neutron diffraction measurements were performed using TriCS of the Swiss Spallation Neutron Source (SINQ), and the Rietveld refinement was performed using the FullProf suite. The incommensurate spin structures obtained for x = 0.0 and 0.05, respectively, were consistent with the results from the powder diffraction, in which the spiral plane is parallel to the b-axis. Finally, it was revealed that the spin structure for x = 0.1 in fact is tilted off the b-axis by 90 , so the spiral plane is parallel to both a- and c-axes. We also performed the measurement of ferroelectric polarization under various conditions. For x = 0.1, the magnitude of the polarization is found to be the largest along the a-axis. The polarization remained nearly constant when DC magnetic field is applied along the b-axis. In contrast, it is suppressed greatly when the field was applied along other directions. All these results indicate that the magnetic anisotropy of MnWO4 can be controlled via Co doping. [1] K. Taniguchi et al., Phys. Rev. Lett. 97, 097203 (2006) [2] Y.-S. Song et al., Phys. Rev. B 79, 224415 (2009)
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Magnetism
b
MG-P-02
Single Crystal Neutron Diffraction Study of Al-doped Multiferroic Hexaferrite Ba0.5Sr1.5Zn2(Fe1-xAlx)12O22 H. B. Leea, Y. S. Songa, J.-H. Chunga*, K. Prokesb, M. Reehuisb, S.-H. Chunc, and K. H. Kimc Department of Physics, Korea University, Seoul, 136-713 Rep. of Korea Helmholtz Zentrum Berlin f端r Materialien und Energie, Berlin, 14109 Germany c Department of Physics, Seoul National University, Seoul, 151-742 Rep. of Korea *Corresponding author: jaehc@korea.ac.kr a
b
Currently there is a great deal of research interests in magnetoelectric multiferroic materials in which novel ferroelectric order is established via unconventional long-range spin order. There are still many technical challenges to overcome in order to realize potentially useful devices that utilize the multiferroicity, such as high transition temperatures for magnetoelectric phase and low magnetic fields for controlling ferroelectric polarization. Hexaferrites containing Fe3+ (S = 5/2) ions are attracting much attention because they are expected to provide solutions for both issues. The field switching of ferroelectric polarization in hexaferrites was first observed in the long-wavelength phase of Ba0.5Sr1.5Zn2Fe12O22. [1] This mateiral shows long-range magnetic order up to the room temperature, but the field-induced polarization was observed at low temperatures where the spins are lying in the ab plane and the maximum polarization was observed at ~ 1 T. The low-field (~ 30 mT) switching was later observed in a related compound Ba0.5Sr1.5Zn2Fe12O22. [2]. In this work, the low-field behavior was ascribed to the low magnetic anisotropy and the formation of conical magnetic structures. Upon application of the external magnetic field, the longitudinal cones will flip and become transverse cones that can produce ferroelectric polarization following spin current mechanism. However, the existence of such field-induced transverse conical phase is challenged by the neutron scattering measurement.[3] Recently, our collaborators discovered that Al substitution to Fe sites of Ba0.5Sr1.5Zn2Fe12O22 also greatly reduces the critical field down to vanishing field. [4] This observation is important because it provides a chemical method to fabricate magnetoelectrics with controllable critical field. Since the two materials show very similar low-field behaviors, it is important to understand the spin structures responsible for the magnetoelectric coupling, and subsequently test the validity of the transverse conical spin models. In this work, we have grown single crystal samples of Ba0.5Sr1.5Zn2(Fe1-xAlx)12O22 using Na2O-Fe2O3 flux method. Single crystal neutron diffraction measurements were performed at Helmholtz Zentrum Berlin f端r Materialien und Energie, and the obtained data are analyzed using Rietveld refinement. For x = 0.08, which shows the largest ferroelectric polarization, at low temperatures following initial zero field cooling we observe the formation of longitudinal conical spin structures. This consists of a ferimagnetic component, k0 = (0,0,0), and an incommensurate helical components, k2 = (0,0, ). Upon application of external field (H||b), however, the incommensurate component disappears and does not recover even when the field is removed. Instead, it is replaced by a commensurate component, k1 = (0,0,3/2). In the field range where the maximum polarization is observed, the spin structure turns out to be far from the transverse cones. In contrast, at 150 K the spin structure is reversible after the field cycling. The details of the temperature and the field dependence of the spin structures will be presented. [1] T. Kimura et al., Phys. Rev. Lett. 94, 137201 (2005). [2] S. Ishiwata et al., Science 319, 1643 (2008). [3] H. Sagayama et al., Phys. Rev. B 80, 180419(R) (2009) [4] S.-H. Chun, et al., Phys. Rev. Lett. 104, 037204 (2010).
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MG-P-03
Magnetic Spin Reorientation in Tb3Fe5O12 under External Magnetic Field J. S. Kim1*, A. N. Pirogov2, C. I. Cheon3, and B. S. Sung3 Dept. of Semiconductor and Display Engineering, Hoseo University, Asan,Chungnam 336-795, Korea, 2 Institute of Metal Physics of UD of Russian Academy of Sciences, Ekaterinburg 660990, Russia, 3 Dept. of Neutron Physics, HANARO, KAERI, Daejeon 305-35,3 Korea *Corresponding author: kimjungs@hoseo.edu
Magnetoelectric materials have attracted continual interest of researchers due to a great fundamental and technological importance. In such the materials an external magnetic field H (an electric field E) induces an electric polarization (a magnetization) or a change in dielectric constant ( ) due to a strong magnetoelectric coupling, these effects are called magnetoelectric (ME) and magnetodielectric (MD) effects, respectively. Materials with a large ME coupling can be best candidates for new form of multifunctional devices, because mutual control of the electric polarization by H and magnetization by E becomes possible. Recently gigantic ME effect was discovered in the particular class of multiferroics known as ‘frustrated magnets’ such as TbMnO3, TbMn2O5, and CoCr2O4 [2, 3]. A large MD effect was demonstrated in single crystal Tb3Fe5O12, and its remarkable feature consists in that a change = 3% is induced by low field H < 0.2 T [Hur et al]. Such the low field MD effect is unique because it could be expected in accordance with a phenomenological theory that generally the MD effect is proportional to square of a magnetization and becomes e < 1 % even at substantial only under high H field. Nevertheless, in many MD materials this effect doesn’t exceed H » 10 T, for example, in BiMnO3 and SeCuO3. Frustrated magnets, e.g., DyMnO3 and Tb(Dy)Mn2O5, show a large and abrupt change of the constant (10~500% ) by a spin-flop transition at H > 1 T. A high sensitivity of these dielectric properties to an applied H field relates with the magnetic spin. A magnetic ‘frustration’ originates from competitive ferro-antiferro interactions in magnetic spirals as in RMnO3, Ni3V2O8, and CoCr2O4 or collinear spins with magnetic exchange striction as in RMn2O5 with several magnetic species. The magnetic ‘frustration’, originated from competitive ferro-antiferro interactions in magnetic spirals as in RMnO3, Ni3V2O8, and CoCr2O4 or collinear spins with magnetic exchange striction as in RMn2O5, leads to the breaking inversion symmetry of the lattices through either phase transitions or by H field, and hence the ferroelectric polarizations are induced. The Tb3Fe5O12 has both of the magnetic features observed in the spiral magnets and that of the collinear RMn2O5 with large exchange striction and multiple magnetic species. Firstly, the Tb3Fe5O12 has a canted magnetic structure [8] due to the noncollinear spin alignment of Tb3+-ion moments, which form, so called, “double umbrella” ordering at low temperature (below 130 K). Along with the appearance of the “double umbrella” a lattice distortion from the cubic (I3ad) to rhombohedral symmetry (R -3) occurs, when temperature decreases. Secondly, the TbIG has a huge magnetostriction 111= 2.4 10-6 value (this is the largest 111 for RE-garnets) at low temperature, accompanying a double umbrella magnetic ordering. The cited literatures cannot clearly explain why the Tb3Fe5O12 has a large MD effect at low H field. But, it can be conjectured that this effect is directly related with the coupling of a spin canting of the Tb3+ ions and a lattice distortion in the Tb3Fe5O12 under an application of H field since the ME phenomenon generally involved with a magnetic spin reorientation and lattice distortions. Though these physical parameters can be directly observable using neutron diffraction by applying H field externally, however, we couldn’t find any neutron scattering researches in the literatures on a spin reorientation and lattice distortions under applied magnetic field in the Tb3Fe5O12. The aim of this paper is getting a more clear understanding on the MD effect in the Tb3Fe5O12 by carrying out to a study on evolutions of lattice distortions along with a reorientation of canted magnetic spins in the Tb3Fe5O12 at the external field H = 0.8 T by means of neutron diffraction over the temperature range 8.8K ~ 103K.
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Magnetism
1
MG-P-04
Effect of Structural Distortion on Ferrimagnetic Order in Lu1-xLxFe2O4 (L=Y and Er; x=0.0, 0.1, and 0.5) Han-Jin Noh a*, Hojin Sung a, Jinwon Jeong a, Jinhwan Jeong a, Sung Baek Kim b, Jae-Young Kim c, J. Y. Kim d, B. K. Cho d Dept. of Phys. Chonnam Natâ&#x20AC;&#x2122;l Univ., Gwangju 500-757, Korea b Dept. of Phys. Kookmin Univ., Seoul 136-702, Korea c Pohang Accelerator Laboratory Pohang Univ. of Sci. & Tech., Pohang 790-784, Korea d Dept. of Materials Sci. & Eng., Gwangju Inst. of Sci. & Tech., Gwangju 500-712, Korea *Corresponding author: ffnhj@chonnam.ac.kr a
We have studied the correlation between the structural distortion and the magnetic interaction change in the ferrimagnetic (Lu,L)Fe2O4 (L=Y and Er) by using neutron powder diffraction and x-ray magnetic circular dichroism (XMCD). The Rietveld profile refinements revealed that the Y or Er substitution flattens the hexagonal unit cell of the system and asymmetrically distorts the bipyramidal FeO5 cages with the increase in the substitution. Even in the presence of the Y or Er substitution, 3 3 superlattices are formed by Fe-valence ordering, and the interlayer magnetic coupling behavior does not change very much. Meanwhile, the Fe 2p XMCD spectra indicate that the Fe3+ spins become frustrated as the substitution increases. These results support that the unquenched orbital moment of the Fe2+ ions is the dominant factor for the giant magnetic anisotropy in LuFe2O4.
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MG-P-05
An Estimation of the Oxygen Content in Melt Grown Y1.6Ba2Cu3O2-d Superconductors with Various Numbers of Grain Boundary by High Resolution Neutron Diffraction Sun-A Jung*, Seong-Su Lee, Baek-Seok Seong, Byung-Hyuk Jun, Chan-Joong Kim
The superconducting transition temperature of the high-Tc YBa2Cu3O7-d (Y123) superconductor varies with the oxygen content in the Y123 lattice. To get a high Tc of 90K, the oxygen content (7-d) should be about 7. In case of the polycrystalline Y123 oxides prepared by the powder synthesis method, the oxygen diffusion into the Y123 lattice is easy since the high angle grain boundary (G.B.) acts as an effective diffusion path. In the case of a melt processed Y123 superconductor whose G.B. is very large, the oxygen diffusion is very difficult due to the lack of an oxygen diffusion path. To understand the effect of the G.B. on the oxygen diffusion in the large grain Y 1.6Ba2Cu3O7-d (Y1.6) superconductors, the number of G.B. was varied by controlling the cooling rate of 1 - 10 /h through a peritectic temperature (Tp). The Y123 samples with various numbers of G.B. were oxygenated at 450 for annealing time of 10 200 h in flowing oxygen. The tetragonal-to-orthorhombic phase transition induced by oxygen diffusion was analyzed by powder x-ray diffraction and the oxygen content was analyzed by high resolution power diffraction (HRPD) with a neutron beam. The neutron diffraction analysis for melt processed Y1.6 samples prepared with various cooling rates at an annealing time of 50 h showed that the (7-d) value increased with an increasing cooling rate, which indicates that G.B. acted as an effective diffusion path for oxygen atoms. For instance, the (7-d) values for a cooling rate of 1 /h and 10 /h were 6.847 and 6.891, respectively. In addition to the cooling rate effect, the neutron diffraction data for the Y1.6 samples prepared at a cooling rate of 1 /h showed that the (7-d) value increased as annealing time increased. The (7-d) values of the samples annealed for 10 h and 100 h were 6.873 and 6.884, respectively. The oxygen content increased by the prolonged annealing is relatively smaller than that by the G.B. effect. The very small increase of the oxygen content, even after the prolonged annealing in flowing oxygen, indicates that the oxygen diffusion into the Y123 grain with a low cooling rate is a time consuming process. Acknowledgement This work was supported by the National Nuclear R&D Program of the Ministry of Education, Science and Technology (MEST), Republic of Korea. Keywords: Melt processed YBCO superconductor, cooling rate, grain boundary, oxygen content, neutron diffraction
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Magnetism
Neutron Science Division, Korea Atomic Energy Research Institute (KAERI), 1045 Daedeok-daero, Yuseong-gu, Daejeon 305-353, Korea *Corresponding author: sunamanse@naver.com
CS-P-01
Structural Investigation on LiH2PO4 by Neutron Diffraction In-Hwan Oh a*, Kwang-Sei Lee b, Martin Meven c, Gernot Heger d, Cheol Eui Lee e Neutron Science Division, Korea Atomic Energy Research Institute, Daejeon 305-353, Korea b Department of Nano Systems Engineering, Inje University, Gimhae 621-749, Korea c FRM II, Technische Universitaet Muenchen, Lichtenbergstrasse 1, D-85747, Garching, Germany d Institut fuer Kristallographie, RWTH Aachen, Jaegerstr. 17-19, D-52056, Aachen, Germany e Department of Physics, Korea University, Seoul 136-713, Korea *Corresponding author: oh1905@kaeri.re.kr a
A detailed crystal structural analysis of LiH2PO4 (LDP) was conducted by employing single crystal neutron diffraction, no structural phase transition being identified down to 100K. The Li+ ions were found to be well localized in this crystal structure with an almost harmonic potential, being not involved in the ionic conductivity at least up to room temperature. An almost linear relationship should exist between atomic mean-square displacements and the temperature in harmonic approximation at least down to 50K. For the relatively high ionic conductivity of LDP at 300K, an anharmonic potential of the relevant atoms is necessary, which should become purely harmonic at low temperature. To verify this, we tried to describe the atomic displacement at 300K including 3rd order tensor coefficients but we were not able to obtain a stable refinement of out neutron data. In the pure harmonic case we can expect a ratio between the isotropic mean-square displacement Uiso(300K)/Uiso(100K) = 3.0. From our structure analysis, a Uiso-ratio of 3.15 was obtained for Li in reasonable agreement. All oxygen atoms show Uiso-ratio from 3.9 to 4.2. These increased values may indicate some anharmonic effect. On the contrary, a striking huge Uiso-ratio of 7.57 was found for P. The mean-square displacements of the phosphorous atom, being strongly anisotropic at 100K become almost anharmonicity of the potential but also a softening, which can be related to the variation of electron transfer from the P-O bonds into the adjacent O-H bonds, which is reduced at room temperature according to the increased O3-O4 and O4-O2 distances. Corresponding hydrogen bonds become stronger at 100K as the distance between donor and acceptor becomes smaller. If says for anharmonicity at 300K that the lattice parameters and the volume of the unit cell show a temperature dependent decrease, for example at 100K of about 0.37%. The rotation of the PO4 groups in LDP is hindered from the LiO4 groups being connected by the common oxygen atoms O1 and O2. This could give rise to the â&#x20AC;&#x153;slowâ&#x20AC;? H2PO4 rotation, presumably dictating the dc electrical conductivity in association with the relatively weak hydrogen bonds in the structure. It would be very interesting to enlarge the crystal structure investigation of LDP to higher temperature in order to better understand the role of the hydrogen bonded PO4 groups and the Li+ ions for the electrical conductivity of LDP.
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CS-P-02
Anion Ordering in Oxynitride Perovskites, SrTaO2N, CaTaO2N, LaTaON2, and LaNbON2 Young-Il Kim* and Eunhye Lee
Crystal structures of mixed anion perovskites, SrTaO2N, CaTaO2N, LaTaON2, and LaNbON2 are examined by Rietveld refinements of constant wavelength neutron diffraction patterns collected at 300 K. Unlike the analogous BaTaO2N or BaNbO2N, above four compounds have A-cations that are too small for the dodecahedral cavity. Accordingly their average structures are formed with lower symmetries of tetragonal, orthorhombic, or monoclinic, in which multiple anion sites are provided to open chances of O/N ordering. Present neutron investigation clarifies or contradicts a few points raised in previous reports. First it is suggested that the use of flux mineralizer in the sample preparation stage have little influence on the O/N ordering behavior. We also find distinct O/N ordering schemes for SrTaO2N and LaTaON2 from those determined previously. The dissimilar anion ordering behaviors among the title compounds are discussed in terms of bond valence sum calculations.
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Magnetism
Department of Chemistry, Yeungnam University, Gyeongsan, Gyeongubk, 712-749, Korea *Corresponding author: yikim@ynu.ac.kr
CS-P-03
Thermal Strain Analysis in the Crystal Structures of Biotite at High Temperatures Chul-Min Chon a*, Shin Ae Kim b, Hi-Soo Moon c Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350, Korea b Korea Atomic Energy Research Institute, Daejeon 305-600, Korea c Department of Earth System Sciences, Yonsei University 134, 120-749 Seoul, Korea *Corresponding author: femini@kigam.re.kr a
1. Introduction In this study, crystal structures of biotite were determined by Rietveld refinement from high-resolution, high temperatures neutron powder diffraction. In addition, a structural study of ex situ furnace heating samples is reported. The changes in structural parameters as a function of temperature are examined in detail, and an attempt is made to determine the significance of the variations in the structure with relation to the Feoxidation and dehydroxylation mechanism.
2. Methods and Materials The structural formula of the biotite-1M from Bancroft, Ontario, is (K 1.96 Na 0.13 Ca 0.01)(Mg 3.15 Fe 2+2.59 Ti 0.17 Mn0.09)(Si5.98 Al1.92 Ti0.10)O20[(OH)1.47 F1.98], based on the XRF and TG/DTA analyses. Neutron powder diffraction data was obtained using a high resolution powder diffractometer (HRPD) in the HANARO reactor, Korea Atomic Energy Research Institute. The neutron wavelength was 1.8438 , which was selected by a Ge(331) monochromator, and a vanadium can was used as the sample holder. The neutron data were collected at in situ temperatures of 20 , 300 , 450 , 600 and 900 under vacuum. In addition, the room-temperature neutron data were obtained on samples heated in an electric furnace (in air) at 400 , 500 , 700 800 , and 900 for 12 hours. Crystal structures were refined from the neutron data using the Rietveld method [1]. The crystal structure data were refined using the FULLPROF program [2]. All refinements were performed in the C2/m space group (1M polytype) using the coordinate set reported by Russell & Guggenheim [3]. The atomic occupancy was initially set up according to our chemical analyses. Finally, individual thermal parameters for all atoms were considered as isotropic and refined. Cation ordering was constrained to the room temperature value since no
significant change could be obtained and no regular pattern was observed among the Mg and Fe occupancies across the octahedral sites.
3. Results and Discussion 3.1 Cystal Structures of Biotite at High Temperatures The changes in crystal structure parameters as the experimental conditions were varied were related to mechanisms of Fe-oxidation and dehydroxylation. The increase in the unit-cell volume with in situ heating in vacuum at temperatures up to 600 , occurred mainly along the c axis, as a result of expansion in the K coordination sphere along that direction (Fig. 1).
Fig. 1. Plots of a, b and c cell parameters versus temperature for in situ (solid circles) and heat-treated samples (crosses).
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Table 1. Bond lengths, changes of squared bond lengths , (I) their lattice components and (II) the component of inner deformation are reported for K-O bonds.
in situ
Bond length Bond length ( ) ( )
at 20
( 2)
(10-5
3.097(6)
3.16(1)
0.41
0.11 0.30
11.2
(K-O2)inner[ 4]
3.044(5)
3.143(6)
0.63
0.08 0.55
17.5
(K-O1)outer[ 2]
3.260(6)
3.24(1)
-0.12
0.08 -0.20
-3.09
(K-O2)outer[ 4]
3.214(5)
3.219(6)
0.01
0.10 -0.09
0.29
<K-O>mean
3.145(6)
3.188(4)
(K-O1)inner[ 2]
at 400 3.059(7)
)
at 600
(K-O1)inner[ 2]
ex situ
-1
at 900 3.007(8)
( ) -0.32
(10-5 -0.03 -0.29
3.056(5)
2.971(5)
-0.52
-0.14 -0.38
-14.5
3.323(7)
3.231(8)
-0.61
-0.21 -0.40
-16.0
0.29
-0.08 0.37
3.204(5)
3.249(5)
3.151(6)
3.113(7)
3.2 Crystal Structures of Heat-Treated Biotit In the case of heat-treated biotite in an oxidizing environment, the cell dimensions decreased up to 700 (Fig. 1). This decrease in the dimension was attributed to the mixed effect of octahedral iron oxidation and dehydroxylation. The reduction in the interlayer dimensions occurs because of a weakening interaction of the repulsive forces between the interlayer K + and the H +, which resulted from dehydroxylation [8]. In addition, owing to the attractive forces between K+ and F-, the interlayer coordination sphere was compressed along the c axis [3]. The deformation of the K-O bonds in the interlayer region can be separated into a lattice strain and an inner strain contribution (Table 1). A negative inner strain component indicates that the bond contracts more than expected from unit-cell reduction alone, whereas the opposite is implied by a positive value. The large inner strains observed upon the contraction of K-O bonds in the heated biotite considerably increased ditrigonal distortion (3.57째 at 400 to 6.15째 at 900 ) and confirmed the previous findings [3, 8]. The average coefficient of the contraction over all K-O bonds compares favorably with that along the c axis (-1.81 10-5 -1), so the K layer contraction evidently controls the reduction along that direction (Table 1).
-1
)
-10.5
(K-O2)inner[ 4]
<K-O>mean
is the linear thermal expansion of each band, (d'KO2-dKO2 = I+II) is the difference in the K-O bond length, I = ( K- O)T G( K- O) is the contribution of pure lattice deformation and II = [( K- O)TG'( KT T O)+( KO) G'( K- O)+( KO) G'( KO)] is the strain entirely related to inner deformation [4, 5]. The K and O is the vector of the fractional coordinates of the atom, respectively, with respect to a common origin and the G is the metric matrix (the determinant of which gives the square of the unit-cell volume). Esd's on the last significant digit are in parentheses. Bond multiplicities are given in brackets.
2.33 2
(K-O1)outer[ 2] (K-O2)outer[ 4]
Note:
7.83 -2.38
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4. Conclusions The increase in the unit-cell volume with in situ heating in vacuum at temperatures up to 600 , occurred mainly along the c axis, as a result of expansion in the
Magnetism
The crystal structure deformation caused by a thermal effect can be analyzed in a similar fashion to that produced by mechanical stress [4]. Mookerjee and Redfern [5] developed and elucidated the formalism originally introduced by Catti [4] to understand the strain within a crystal structure. Applying the above to the K-O bonds in our results, except 900 (Table 1), which shows anisotropy in the interlayer region, we find that the six long bonds have a negative inner strain component and the six short bonds have a positive strain component. A positive inner strain contribution indicates that the bond expands more than expected from unit-cell dilation alone, whereas the opposite is implied by a negative value. Thus, in the interlayer region (K coordination sphere) a large effect due to inner thermal strain is observed, indicating the dominance of the inner deformation over the external deformation. Although in long K-O2 bonds, lattice deformation seems to dominate the inner deformation, maintaining the trend of the other short bonds. The ditrigonal distortion decreased (3.76째 at 20 to 2.29째 at 600 ) with temparature, because the shorter bonds expanded and the longer bonds contracted. These findings confirm previous observations in fluorphlogopite [6], muscovite [4, 7] and phengite [5].
K coordination sphere along that direction. The ditrigonal distortion decreased with temparature, because the shorter bonds expanded and the longer contacts contracted. The increase in the interlayer separation and the decrease in the flattening angle of the interlayer octahedron, confirmed that the c axisdominated expansion derived mainly from the interlayer region. In the case of heat-treated biotite in an oxidizing environment, the cell dimensions decreased up to 700 . This decrease in the dimension was attributed to the mixed effect of octahedral iron oxidation and dehydroxylation. The average coefficient of the contraction over all K-O bonds compares favorably with that along the c axis at temperatures above 400 . This suggests that the reduction in interlayer region by dehydroxylation controls the variation in the overall cell parameters with temperature. The large inner strain components in the K-O bonds also increased the ditrigonal distortion.
[7] S. Guggenheim, Y. â&#x20AC;&#x201C;H. Chang and A.F. Koster Van Groos, Muscovite dehydroxylation: Hightemperature studies. American Mineralogist, Vol.72, p. 537-550, 1987. [8] T. Ohta, H. Takeda and Y. TakĂŠuchi, Mica polytypism: similarities in the crystal structures of 1M and 2M1 oxybiotite. American Mineralogist, Vol.67, p. 298-310, 1982.
REFERENCES [1] H. M. Rietveld, A profile refinement method for nuclear and magnetic structures. J Appl Cryst, Vol.2, p. 65-71, 1969. [2] J. Rodriguez-Carvajal, FullProf: Rietveld profile matching and integrated intensity refinement of Xray and neutron data (PC-version). Version 3.5d, 1998. [3] R. L. Russell and S. Guggenheim, Crystal structures of near-end-member phlogopite at high temperatures and heat-treated Fe-rich phlogopite: The influence of the O, OH, F site. Can Mineral, Vol.37, p. 711-729, 1999. [4] M. Catti, Calculation of elasticity and inner strain: a computational model. Acta Crystallographica, A45, p. 494-500, 1989. [5] M. Mookerjee and S. A. T. Redfern, A hightemperature Fourier transform infrared study of the interlayer and Si-O-stretching region in phengite2M1. Clay Minerals, Vol.37, p. 323-336, 2002. [6] H. Takeda and B. Morosin, Comparison of observed and predicted structural parameters of mica at high temperature. Acta Crystallographica, B31, p. 2444-2452, 1975.
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CS-P-04
Structural Changes of Phlogopite Resulting from Oxidation with Increasing Temperature Chul-Min Chon a*, Chul-Kyoo Lee b, Yungoo Song c, Shin Ae Kim d Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350, Korea b POSCO, Seoul 135-777, Korea c Department of Earth System Sciences, Yonsei University 134, 120-749 Seoul, Korea d Korea Atomic Energy Research Institute, Daejeon 305-600, Kore *Corresponding author: femini@kigam.re.kr
1. Introduction The aim of this work was to study the structural changes of the ferroan phlogopite at in situ high temperatures and determine the significance of the changes with relation to the iron oxidation and dehydroxylation in a vacuum condition. In the study, the crystal structures of the ferroan phlogopite were determined by Rietveld refinment at high-temperature, using in situ neutron powder diffraction. In addition, infrared spectroscopy was used to investigate the dehydroxylation mechanism related to Fe2+ oxidation in vacuum using the phlogopite heated at different temperatures.
2. Methods and Materials A natural ferroan phlogopite-1M sample, K2(Mg4.46Fe2+0.83Al0.34Ti0.22)(Si5.51Al2.49)O20[(OH3.59)F0.41] was collected for this study. A High Resolution Powder Diffractometer (HRPD) at HANARO, Korea Atomic Energy Research Institute, was used to obtain neutron diffraction data. The neutron wavelength was 1.836 , which was selected by a Ge(331) monochrometor. The 4.3g of phlogopite powder was loaded into a vanadium container, which had a 12mm diameter and a length of 55mm, within sample environments. The diffraction patterns were analyzed by the Rietveld method [1] using the FullProf program [2]. The initial atomic parameters of all refinements were obtained from the coordinate set determined by Chon et al. [3]. The phlogopite powder samples were heated for a period of 1h at different temperatures over RT - 800 . At 10-3 torr, a graphite vacuum furnace was used. The IR
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(infrared) spectra were collected on a Perkin Elmer FTIR spectrometer. The powdered samples were prepared as KBr pellets (25mg of sample mixed with 300mg of KBr). Those pellets were dried at 110 for 2h under vacuum to eliminate the absorbed water. The spectra fitting was done with the program PeakFit, version 4.11 and the peak-fit function was Guassian-Lorentzian Sum. The detailed fitting procedure was described in Redhammer et al. [4]
3. Results and Discussion The representative results of the Rietveld refinements are illustrated in Fig. 1. In this study, data with a break in slope were obtained for the expansivities of the dimensions a and b. However, the kink of the expansivities was not observed at about 400 but near 500 . It was also interesting to find that the changes of the M-octahedron flattening angles were different from that of previous high-temperature structural studies [5,6]. The <M-O> distance increased over the temperature range of 25-400 , but nearly constant or rather slightly decreased for temperatures for temperatures above that value (Fig. 2). The differences in the structural parameters from 500 to 900 must be related to the dehydroxylation that derived from the structural iron oxidation. The a and b dimensions decreased slightly at higher temperatures rather than increased as observed at lower temperatures. This may be attributed to a change in the octahedral dimension caused by a dehydroxlationoxidation reaction of Fe2+ to Fe3+ in vacuum conditions at the higher temperatures [7].
Magnetism
a
Fig. 1. Comparison of observed (crosses,Yobs) and calculated (solid line, Ycalc) neutron powder diffraction patterns of phlogopite at 25 and 800 , determined by Rietveld refinement. The differences, observed minus calculated, are shown in the lower field. The short vertical bars indicate the positions of possible Bragg reflections.
Fig. 2. Plots of (a) mean <M-O> distance, (b) M-octahedral flattening angle ( ), and (c) M-octahedral thickness as a function of temperature for ferroan phlogopite
Fig. 3. The observed FTIR spectra of OH stretching region for ferroan phlogopite heated in vacuum at (a) room temperature (b) 300 (c) 400 , (d) 500 , (e) 600 , (f) 700 , (g) 800 , and the calculated spectra fitted with the program PeakFit, version 4.11.
Vedder [8] established the main features of the IR spectrums of biotite. Three major bands were distinguished in the hydroxyl stretching region and were termed N, I and V bands [9]. The IR spectra of our sample were fitted by these three N-I bands. The bands centered at around 3712 cm -1 and 3696 cm -1 were assigned to NA and N B respectively, and the other centered at around 3668 cm-1 was assigned to IA. At temperatures below 500 each bands of OH-stretching regions showed no significant changes. For temperatures above 500 , the intensity of the NB band associated with Fe2+ decreased, but there was no significant changes in those of the other bands (Fig. 3). The decrease of the band indicated that the dehydoxylation related to iron oxidation took place at this temperature. Therefore, those FTIR spectroscopic results also confirmed that the oxidation and dehydroxylation of the ferroan phlogopite took place at higher temperatures (500 -800 ) and the dehydroxylation of the phlogopite was associated with Fe2+ oxidation.
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This study found a kink in the expansion rate of unit cell dimensions at about 500 by in situ neutron powder diffraction at high temperature. The structural parameters (M-oct. flattening angle, M-oct. thickness, <M-O> distance) also had significant changes at this temperature. The changes in the expansion mode must have been caused by the iron oxidation and the dehydroxylation that took place in the mica structure. The IR specta bands of the OH-stretching regions confirmed that the dehydroxylation was closely related to the structural iron oxidation of the mica powders that occurred at around 500 in vacuum.
REFERENCES [1] H. M. Rietveld, A profile refinement method for nuclear and magnetic structures. J Appl Cryst, Vol.2, p. 65-71, 1969. [2] J. Rodriguez-Carvajal, FullProf: Rietveld profile matching and integrated intensity refinement of X-ray and neutron data (PC-version). Version 3.5d, 1998. [3] C.- M. Chon, S. A. Kim and H.- S. Moon, Crystal structure of biotite at high temperatures and heattreated biotite using neutron powder diffraction. Clays Clay Miner, Vol.51, p. 519-528, 2003. [4] G. J. Redhammer, A, Beran, J. Schneider, G. Amthauer and W. Lottermoser, Spectroscopic and structural properties of synthetic micas on the annitesiderophyllite binary: synthesis, crystal structure refinement, Mรถssbauer, and infrared spectroscopy, Am Mineral, Vol.85, p. 449-465, 2000. [5] R. L. Russell and S. Guggenheim, Crystal structures of near-end-member phlogopite at high temperatures and heat-treated Fe-rich phlogopite: The influence of the O, OH, F site. Can Mineral, Vol.37, p. 711-729, 1999. [6] F. Tutti, L. S. Dubrovinsky and M. Nygren, Hightemperature study and thermal expansion of phlogopite. Phys Chem Miner, Vol.27, p. 599-603, 2000. [7] R. P. Tripathi, U. Chandra, R. Chandra and S. Lokanathan, A Mรถssbauer study of the effects of
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heating biotite, phlogopite and vermiculite. J inorg nucl Chem, Vol.40, p. 1293-1298, 1978. [8] W. Vedder, Correlations between infrared spectrum and chemical compostion of mica. Am Mineral, Vol.49, p. 736-768, 1964. [9] R. W. T. Wilkins The hydroxyl-stretching region of the biotite mica spectrum. Min Mag, Vol.36, p. 325333, 1967.
Magnetism
4. Conclusions
Activation Analysis
- 157 Activation Analysis
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- 159 Activation Analysis
AA-O-01
Tuesday, 2 Nov. 10:40 â&#x20AC;&#x201C; 11:10 (Room 104)
Analytical Science and Research from Neutron Capture Reactions R. Gregory Downing* National Institute of Standards and Technology Gaithersburg, MD 20899 U.S.A. *Corresponding author: downing@nist.gov Discovery and commerce depend on ideas and materials that require characterization by analytical tools. Neutron reaction techniques are robust analytical probes of most materials and they complement other lab-based techniques. For more than a half century neutron reaction techniques have played a key role in the metrology conducted at the National Institute of Standards and Technology (NIST) and throughout the world. This span of time has seen the measurements evolve from isotopic fast neutron sources, to primarily thermal, and now include cold neutron beam applications. But regardless of the neutron temperature, these techniques quantify our ideas and materials to serve the needs of the researcher, industrialist, and the consumer. Experience has encompassed neutrons analysis to support a broad scope of sciences. To illustrate the influence of neutron metrology, measurements included the fields of biology, agriculture, environmental, electronics, forensics, medicine, geology, petroleum products, archeology, energy storage, urban and industrial dust, nanoparticles and nanotubes, aerospace, industrial materials, metallurgy, and perhaps most important are the certified reference materials. Truly, neutron metrology reaches almost every aspect of our world. Contamination and sample losses will defeat the effort of a good measurement. But unlike most other chemical techniques, NAA requires very little sample preprocessing before analysis, a trait often overlooked by those unfamiliar to NAA. The removal of this step avoids much of the opportunity for sample loss, contamination, weight change from evaporation and other fundamental errors. Very recently, the ability to establish the total error analysis in NAA was demonstrated, representing a major advance to this mature technique. This achievement places the scientific credibility of INAA on par with mass spectrometric and electrochemical techniques. The increasing availability of intense beams of cold neutrons has led to more neutron depth profiling (NDP) and prompt gamma neutron activation analysis (PGNAA) instruments. Cold neutrons enable better determination of small quantities of hydrogen by PGAA in diverse samples to study such applications as hydrogen in fuel storage materials to nanotube moisture content. Although PGAA enjoys much less neutron fluence rates than in-core applications, the cold neutron reactions provide gain through increased reaction cross section for most elements and the reduction of concurrent gamma rays background from the reactor core. In situations where the sample size is small, neutron focusing lenses can be used with cold neutrons to increase detection limits. Of course NAA is key to a number of less published neutron techniques that include neutron activation analysis â&#x20AC;&#x201C; mass spectroscopy (NAA-MS), the nuclear track technique (NTT), delayed neutron activation analysis, (DNAA), and a number of pre- and post processing techniques such as radiochemistry, tracer, and scintillation counting. Neutron reaction techniques have much to offer the analytical sciences. NAA methods provide, in part, the fundamental ability to advance the quality of life and safety in our world.
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AA-O-02
Tuesday, 2 Nov. 11:10 – 11:40 (Room 104)
Se Content of Meats according to Country and Type Using INAA Method Okhee Leea*, Suhyun Jua, Yongsam Chungb, Jongwah Moonb Dept. of Food Science and Nutrition, Yongin Univ.,470. Samgadong, 449-714 b Korean Atomic Nuclear Energy Institute, Neutron activation anlaysis Lab., 1045 Daedug daero, Yuseong go, Daejeon, 305-353 Korea *Corresponding author:okheel@hotmail.com
The deficiency of mineral database on foods is a major obstacle for the exact evaluation of Korean mineral intake. Selenium is an essential micro-mineral and an antioxidant protecting the free radical- induced lipid peroxidation. The accuracy of existing data is questionable because they were analysed by AAS or ICP methods. These methods are known to be inaccurate due to large losses of Se during pre-treatment process. This study was aimed to evaluate the Se contents in foods using INAA-method. The Korean preferred meats such as beef, pork, chicken, and egg were selected for the Se analysis. The origins of beefs were Korea, USA and Australia. To minimize contamination, all the instruments and storage tools were used after washing with HNO3. Each food samples were individually mixed using homogenizer made with titanium. The homogenized food samples of 10~20g were freeze-dried at temperature of –60 C° for 48~96 h. Subsequently, instrumental neutron activation analysis was employed to determine the contents of Se in the freeze-dried food samples. Analytical quality control was conducted using NIST SRMs. The Se contents in meats showed difference according to meat type and country. Beef showed difference in the Se contents by body region, and were in the range of 0.065ppm~0.509ppm. Se contents in beefs showed difference by the production country. The comparison of Se contents by the analysis method showed rather higher values from INAA-method rather than ICP-method. These results could be used to accumulate basic data for the Se contents in Korean foods and to evaluate the nutritional status of Koreans.
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Activation Analysis
a
AA-O-03
Tuesday, 2 Nov. 11:40 – 12:00 (Room 104)
A Neutron Generator - Plasma Ion Accelerator for Activation Analysis (PIAAA) Ralph H. Condita , Shi-Surk Kimb, Wigbert J. Siekhausc, Harvey S. Hopkinsc , Kyung Mi Leeb, Ka-Ngo Leungd MatApCo, LLC, 4669 Almond Circle, Livermore, CA 94550, U.S.A. NANOCMS Co., Ltd., 281, Moshi-ri, Jicksan-eup, Seobuk-gu, Chenoan-si, Chungnam, Korea c Monterey Analysis Associates, LLC, 387 Cordell Drive, Danville, CA, 94526 U.S.A. d Berkion Technology, 109 Columbine Drive, Hercules, CA94547, U.S.A. *Corresponding author: franz@nanocms.co.kr, matapco@gmail.com a
b
1. Introduction Neutrons can activate changes in materials and this makes them useful in many ways. Atoms of a material, when activated, yield activated product atoms, which are unique to that material. This is important, because the products are often much more easily detected by the signals they emit, gamma- and x-rays, than are the original materials. Thus, we have a process whereby very small amounts of material can be detected if they are first activated using neutrons. The activated materials may also have important properties of their own. They can be used as tracers in biological investigations and medical treatments and also in various industrial research programs. Often, such activated materials must be produced close to where they are to be used, because their activities die away rapidly, within days, hours, or even minutes. The identification and production of activated materials requires that one have a neutron source. For many applications, it would be desirable that the source to be compact enough to be portable or at least semi-portable. That would allow the neutron source to be brought to the work instead of bringing the work to the neutron source as would be the case if we used an immobile facility like a nuclear reactor. On the other hand, being compact implies that only a small, low power neutron source will be available. We believe we have created a neutron generator, which is called a plasma ion accelerator for activation analysis (PIAAA) and is able to supply a good flux of neutrons while remaining relatively small [1]. By small we mean that it occupies a few cubic meters and can be disassembled and moved and reassembled at a new location in less than a week to ten days. A considerable fraction of the volume of this equipment is contributed by the radiation shielding enclosure, polyethylene blocks
and lead sheets. These are in the form of a wall, which is built up from interlinked, portable bricks around the PIAAA. The objective of our design has been to achieve the highest possible, continuous flux of neutrons (neutrons/ /sec) at some sample material of interest. We start with a small target source size giving 1E+10 to 1E+11 neutrons/sec from which the neutrons radiate in all directions. The sample will intercept only a portion of these. An additional procedure of major importance is that the neutrons be slowed down from the high energies, which they have as first emitted from the target. Their energies must be slowed, “moderated,” to those of atoms at room temperature.
2. Methods and Results 2.1 The neutron generation reaction (1) Neutrons are generated in the spontaneous fission of californium, 252Cf. In many ways this is convenient, but it requires handling a continuously radioactive californium source. (2) Tritium in some solid matrix such as titanium can be bombarded with deuterons producing the D, T reaction. This gives a good yield of neutrons but it involves working with the radioactive isotope, tritium. In addition, the energies of the neutrons as first produced are very high, 14.1 MeV (million electron volts per neutron), and by the time the necessary thickness of moderator has been used to thermalize them the neutron flux at a sample is not better then with the D,D reaction. (3) Deuterium ions bombarding titanium metal with an energy of about one hundred thousand electron volt (eV) penetrate into the surface and form a thin surface
- 162 -
er of titanium deuteride, TiD 2 (the same chemical structure as TiH2, a metallic looking compound stable at room temperature, but unstable at elevated temperature in vacuum). Subsequent impinging deuterium ions collide with the implanted deuterium and react with them. This D, D reaction produces neutrons and helium. The neutrons as first produced have an energy of 2.4 MeV. This is the reaction we employ.
The ion source is in the right arm of the glass cross. It is an enclosure where deuterium gas is fed into a plasma. The plasma is produced by a radio-frequency (13.5 MHz) discharge. The ions pass through a molybdenum plate with seventeen small apertures. The openings are designed so that the beam as its heads toward the target is uniform in intensity across its width rather than having a gaussian intensity distribution on the target surface.
The D, D nuclear reaction may be written, D1 + 2D1
2
He2 + 1n0
3
The ability of neutrons to activate most materials goes up as their energy goes down. In effect, a neutron moving slowly has a better chance than a fast neutron of being captured by the atoms of a material to be activated. In practice, the neutron energies need to be degraded to the same energies as the room-temperature energies of the sample. This degrading is achieved by diffusing them through a moderator, which is typically blocks of polyethylene plastic.
The features of the equipment for managing the reaction, the neutron generator (PIAAA), are shown in the accompanying diagram. This is a vacuum system in the shape of a quartz glass cross. The source of deuterium ions is on the right. These ions are directed toward the target, TiD2, which is at the center of the cross. The D, D reactions in this target create the neutrons, which then irradiate the sample toward the left. The ion source works by admitting a small stream of deuterium gas into the vacuum chamber where it is ionized in a microwave plasma generator. This gives the D+ ions. These ions are drawn toward the target because it is held at a voltage of about 100 kV, relative to the source, which is at ground potential. At the target most of the deuterium ions just imbed themselves into the titanium, forming TiD2, but some impact D atoms already in this target and yield the nuclear reaction shown above.
Fig. 1: The neutron generator as described in the text.
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The target is machined from a thick solid cylindrical slice of titanium. The front facing the ion source has a Vshaped recess in its center. Its diameter is close to the diameter of the center hole of the molybdenum plate. A V-shaped recess ring is machined the molybdenum plate. The V-shape is designed such that the power density of the impinging deuterium ion beams is less than what would be needed to raise its temperature high enough to decompose the thin layer of TiD2. The back-side of the titanium cylinder is hollowed out leaving a thin layer of titanium around each of the recesses, made thin to facilitate water cooling. It is closed vacuum tight using a viton O-ring by a fused glass plate. Other charge carriers in this system are free electrons. Secondary electrons will be emitted from the target as it is bombarded by D+ ions and they would be accelerated back toward the plasma source and create bremsstrahlung if not blocked. This blocking is achieved by magnets embedded in the target. Their fields divert the electron trajectories back to the target. Magnets are also installed around the ion source chamber so as to provide plasma confinement. The titanium target is mounted on a double-walled hollow copper post that extends down from the top of the glass cross.This post is electrically isolated from the rest
Activation Analysis
2.2 The design of the generator
Fig 2: The central part of the PIAAA glass cross shown with surrounding polyethylene shielding. The shielding would be built up higher to fully surround the cross before actual operation. The target is in the center, held by a hollow copper rod extending down from the top. The source of ions is on the right. The gas inlet valve extends up from the right arm of the cross. The sample to be irradiated (not shown here) would be placed at the left end of the cross. Moderator material would be placed between the sample and the target and also around the outside of the glass. The base of the glass tube is mounted on the vacuum line.
of the system by the glass tube that forms the upper part of the cross. The post is hollow so that water can flow through it in order to cool the target. The post has an inner tube to bring the water down to the target and the return flow runs up between this inner tube and the outer wall of the post. Polyethylene, the neutron moderator material, is placed between the target and the sample to be activated, although this diagram does not actually show it. The moderator slows down the neutrons to thermal energies. It is desirable to place the sample as close as possible to the neutron source, but it is necessary to interpose enough moderator material between the two so that when the neutrons arrive at the sample they are at thermal energy. Thus a balance is needed between “close” and “far enough.” The optimum configuration is found by computer modeling [2].
and would tend to sputter away the TiD2 target surface. It is essential to keep the proper balance between gas inflow and gas. Secondly, the moderator thickness and placement have been calculated so as to achieve maximum thermal neutron flux at the sample [2]. Monte Carlo computer calculations have been used to optimize these parameters. They incorporate into the source term the angular distribution shown in Fig. 3. These calculations then take into account the diffusion of neutrons between the source and the sample through the moderator and the scattering of neutrons from moderator and other materials that stand to the side of the direct path between source and sample. The calculated neutron fluence (neutrons/ s) in the thermal energy range per high energy neutron produced in the D, D reaction is shown in Fig. 4 [2].
2.3 Interplay between the PIAAA components All of the components in this system interact with one another. We have tried to optimize this interplay so as to obtain an optimum performance from the system as a whole. Our design is, to our knowledge, the only neutron source design that makes constructive use of the fact that the fast neutrons emitted by the D, D reaction is not isotropic, but rather shows a strong increase in the direction of the incoming ions, as Fig. 3 shows [3]. We make use of this fact by placing the sample in the direction of enhanced neutron flux. Fig. 4: The calculated flux per D, D source neutron for the optimized configuration of the CH2 moderator. For example, the sample will receive 1.7 x 10^6 thermal neutrons per centimeter squared per second if the D, D source emits 1 x 10^10 high energy (~2.4 Mev) neutrons per second.
Fig. 3: Angular and energy distribution of neutrons emitted by the D, D reaction
The first step in the operation of the equipment is to feed in deuterium gas at the correct rate so that the gas pressure in the ion plasma source does not become too high. If that happens, the stream of ions toward the target would contain many D2+ ions in addition to D+. The binary ions would not contribute to neutron generation
Thirdly, the ion trajectories from the plasma to the target need to be tailored so that there are no localized high intensity spots on the target that become overheated. This means that the arrangement of electrodes in the ion source has to be designed with care and the target needs to be shaped to spread out the flux of impacting ions so that no spot becomes too hot. This can be achieved by inclining the surface to the incoming beam as described above in more detail. These ion trajectories were calculated using Berkion computer codes [1]. Finally, the cooling of the target is critical. The ions impacting the target will heat it and it would be easy to let the target become too hot. The cooling of the target is a principal factor in determining what bombardment current is possible. In our PIAAA the ion current can run up to 30 ma at 100kV which means a target heating of 3 KW.
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If the ion bombardment current is pushed too high, the target becomes too hot, the TiD 2, which holds the deuterium in the target, will decompose, and then no deuterium will remain in the target. This means that the water cooling system must be designed with care. The cooling pump must be robust and the flow channels must be large enough. Also, thermally insulating the incoming water from the outgoing water avoids preheating the water before reaching the target and gives a greater temperature drop right at the target.
these fan out from the target and through the thickness of the polyethylene moderator, about 10 cm., their density at the sample has been shown by our modeling to be between 1E+06 and 1E+07 thermal neutrons/ /sec with the upper part of this range being reasonable. Other equipment includes the electrical racks containing the plasma generator power supply, the high voltage equipment, the high vacuum system, and the water cooling heat exchangers.
The system has been designed for easy assembly and disassembly. Connections between support components are easily put in place. The support elements include the electrical power supplies, the vacuum system, and the water cooling lines and pump. We have tried to minimize unwanted activation of equipment components by neutrons. Thus, the parts of the vacuum line exposed to neutrons from the target have been made from aluminum rather than steel. Steel would become radioactive under neutron bombardment whereas aluminum does not become significantly activated and its activity decays quickly.
2.5 Operating the equipment and fine tuning
Fig. 5: The PIAAA is shown in operation with a hydrogen plasma. This ion source is on the right. The pink glow is characteristic of a plasma containing H+ or D+ ions. These ions are drawn toward the target visible in the middle of the glass cross. This target is at the bottom of a copper rod, which extends to the top of the glass. The polyethylene radiation shielding around the outside had been built up only part way when this picture was taken.
The yield of the D, D reaction goes up as the energy of the D+ ions goes up. Therefore, one might like to run the high voltage power supply up to its limit, 120 kV. However, running at 100 kV is better. Full power would not increase the neutron yield by more than 15% and it would tend to age the electrical system faster. The neutron generator has been shown to operate stably, without arcing under these conditions. Operating the plasma is a bit of an art rather than a science. One operating parameter that would be valuable to know is the ion plasma density. Unfortunately, we do not have good instrumentation for observing this. However, it turns out that the color of the plasma can be used as an indicator. A characteristic pink glow is associated with a plasma of high D+ ion density but the plasma shifts color to a washed out white if D2+ ions are too large a component of the plasma. The color can be observed using a periscope to look over the radiation shielding. The ion current to the target can be run up to about 30 milliamperes, which is 1.8E+17 ions per second. The fast neutron generating efficiency per deuteron is in the range of 1E-06. The efficiency depends on a range of factors and can only be stated within an order of magnitude. Hence we might expect to generate something like 1E+10 to 1E+11 neutrons/sec. When
An important feature of the equipment is the way in which samples to be irradiated can brought quickly into the proper position for irradiation and then quickly withdrawn for analysis or other use. Safety plans need to be an intrinsic part of the operation of equipment such as this. A full safety analysis should be conducted by an operator. A fence or equivalent barrier should be placed around the equipment so that nobody can approach it while it is running. This is because there are electrical hazards and the machine does produce neutrons, x-ray and gamma-rays from activated materials. These radiations are shielded by the polyethylene blocks and lead sheets around the quartz cross. We have calculated that neutron radiation field around the shielding enclosure would be very low [2], but there are some access channels which might allow their escape in a few specific directions. Efforts have been made to use materials in the construction of the PIAAA that are not made radioactive by exposure to neutrons. However, there are some parts, most notably the magnets in the plasma source and in the target assembly, which contain samarium and cobalt, and they are likely to carry residual radioactivity after the equipment has been operating for months and longer.
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Activation Analysis
2.4 Other design considerations
2.6 Uses for neutron activation
2.7 Uses for high energy neutrons
This PIAAA should find its special niche in applications calling for short-lived activation products. Such work would take advantage of its high neutron flux and the ability to insert the sample into the flux and remove it rapidly after a short irradiation. It provides sufficient neutron flux to allow identification of very small amounts of materials. In some cases it offers a means for more sensitive detection than almost any other technique. Table 1 indicates the sensitivity for the detection of a range of elements. The data in this table were originally obtained using a nuclear reactor as a source of neutrons [4]. Its flux would be 106 greater than from our neutron generator. The sensitivities as quoted in this table have been adjusted so that they relate to our circumstances. In the more powerful reactor it would be possible to detect picograms of elements such as Dy or Eu rather than micrograms as is the case for our PIAAA.
1
Dy, Eu
1 - 10
In, Lu, Mn
10 - 100
Au, Ho, Ir, Re, Sm, W
One additional use for the PIAAA should be mentioned. If the polyethylene blocks for moderation are removed, a sample could be exposed directly to the high energy neutrons which are first generated at the TiD2 target. They have an energy of 2.4 MeV, actually 2.7 MeV in the forward direction, see Fig. 3. These could be directed at samples of interest, and such samples could be placed close to the neutron source in the absence of the moderator material. Such neutrons have sufficient energy to displace atoms from their normal positions in a solid material. This displacement causes ionization in the material and moves the atoms to positions in the solid structure where they would not normally appear. Thus, such irradiation allows us to modify materials and impart properties to them which they would not normally possess. Their electrical and optical properties can be changed and some new chemical reactions can be initiated. Fast neutron fluxes of 1E+09 to 1E+10 neutrons/ /sec at a sample should be available. Such fluxes are not sufficient to affect the properties of polyethylene over a time span of years. It is not particularly radiation sensitive, and this allows us to use it as a moderator. Silicon diodes, on the other hand, would show a change in electrical properties after about an hour [6]. Thus, each system has its own response characteristics.
100 – 1E3
Ag, Ar, As, Br, Cl, Co, Cs, Cu, Er, Ga, Hf, I, La, Sb, Sc, Se, Ta, Tb, Th, Tm, U, V, Yb
3. Conclusions
1E3 – 1E4
Al, Ba, Cd, Ce, Cr, Hg, Kr, Gd, Ge, Mo, Na, Nd, Ni, Os, Pd, Rb, Rh, Ru, Sr, Te, Zn, Zr
1E4 – 1E5
Bi, Ca, K, Mg, P, Pt, Si, Sn, Ti, Tl, Xe, Y
1E5 – 1E6
F, Fe, Nb, Ne
1E7
Pb, S
Sensitivity (micrograms)
Elements
Table 1: Detection limits for neutron activation analysis using decay gamma-rays. This assumes irradiation with a neutron flux of 107 neutrons/ /sec (this data derived from Ref.4).
Our experiments have generally corresponded with the sensitivity trends reported in this table, although we have often obtained significantly better sensitivities. Our results have been obtained with a 252Cf source or a D, D neutron generator. In both these cases the thermal neutron flux spectrum can differ from that in a reactor irradiation port. Also, we have taken special pains to select special gamma-detection and analysis equipment [5]. This PIAAA should also find applications in the synthesis of medical isotopes. Almost the whole periodic table has been studied at one time or another for such purposes and the availability of a new, convenient source for some of those activities should make available new diagnostic techniques.
We have described a powerful and reliably stable neutrons source generated by a plasma ion accelerator for activation analysis (PIAAA), which NANOCMS now has in house. This features an easily accessible source from which activated samples can be inserted for the exposure and then removed quickly. It should find many applications. REFERENCES [1] The principal engineering design and construction supervision was carried out by Berkion Technology, 109 Columbine Drive, Hercules, CA 94547, under contract and coordination from MatApCo, LLC. [2] Harvey S. Hopkins, Monterey Analysis Associates, LLC, 387 Cordell Drive, Danville, CA 94526, U.S.A., private communication. [3] Fernando Ariel Sánchez, Bariloche Atomic Center, CNEA. Argentina , private communication. [4] An Overview of Neutron Activation Analysis, M. D. Glascock, University of Missouri Research Reactor, http://archaeometry.missouri.edu/naa_overview.html [5]Curtis Cochran, MatApCo internal report in preparation. [6] John F. Kirscher and Richard E. Bowman, “Effects of Radiation on Materials and Components,” Reinhold Pub, New York (1964).
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AA-O-04
Tuesday, 2 Nov. 14:00 â&#x20AC;&#x201C; 14:20 (Room 104)
Determination of Total Bromine and Chlorine in ABS Candidate Reference Materials by Instrumental Neutron Activation Analysis I. J. Kim* and K. H. Cho
KRISS (Korea Research Institute of Standards and Science) has developed RoHS related ABS (acrylonitrilebutadiene-styrene) CRMs (5 levels). The analytical elements are Cd, Cr, Hg, Pb and Total-Br, Cl, etc. Actually total concentration of bromine and chlorine is not regulated by the law. But the major venders of electronics, Sony, Nokia, Panasonic, Dell, Samsung, LG, etc., control these elements. Bromine and chlorine were added in the forms of DECA PBDE and copper chlorinated phthalocyanine (C32N8Cl16Cu). Range of the elemental concentration is 10 mg/kg â&#x20AC;&#x201C; 1000 mg/kg. It is not easy to accurately measure the concentration of total bromine and chlorine in polymer with high precision. Bromine is easily evaporated from the sample while it is being dissolved in acids. Chlorine can be easily contaminated in a laboratory. INAA has advantages on measuring these elements. INAA is non-destructive and it has no worry about the loss of bromine. It is less sensitive to chlorine contamination than other methods, because it does not need dilution of sample. In addition, INAA has excellent sensitive to bromine and chlorine because of their large neutron capture cross sections and gamma-ray intensities. In this study, the concentration of total bromine and chlorine in the ABS CRMs was measured by INAA, using the standard comparator method. Other CRMs of ERM 680k, ERM 681k, BCR 681 were used for the validation of the method. Proficiency test on the measurement of total-bromine in the 3 classes of the ABS CRM were also performed. The results are shown and discussed. Key words: ABS CRMs, RoHS related, Total Bromine, Chlorine, INAA
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Activation Analysis
Korea Research Institute of Standards and Science, 209 Gajung-Ro, Yuseong-gu, Daejeon 305-340, Korea *Corresponding author: reisi-fard.1@osu.edu
AA-O-05
Tuesday, 2 Nov. 14:20 â&#x20AC;&#x201C; 14:40 (Room 104)
A New Cold Neutron Activation Station under Developmentat the Cold Neutron Beam Guides of the HANARO Research Reactor G. M. Sun*, J. H. Moon, Y. S. Chung and K. H. Lee Neutron Science Division, Korea Atomic Energy Research Institute, 305-353, Korea *Corresponding author: gmsun@kaeri.re.kr
A new cold neutron source at the HANARO Research Reactor had been constructed in the framework of a five-year project and ended in 2009 and has seven neutron guides, among which five guides were already allocated for a number of neutron scattering instruments. A new two-year project to develop a new Cold Neutron Activation Station (CONAS) has been under way since May 2010, which is supported by the program of a Ministry of Education, Science and Technology, Korea. CONAS includes two neutron activation systems like a new Cold Neutron-Prompt Gamma Activation Analysis (CN-PGAA) system and Cold Neutron-Neutron Depth Profiling (CN-NDP) system. The CN-PGAA will be installed at the end position of a CG2B neutron guide and the CN-NDP at the end position of a CG1 neutron guide extended from the REF-V system. Because two guides are adjacent each other, the two systems hold an outer shield bunker in common. CN-PGAA is designed to be composed of two HPGes and two BGOs and will be operated in Compton suppression and pair spectrometer modes and there is a gap for a diskchopper for a time-of-flight PGAA and the clean environment around the detectors will make the background at the HPGe detector very lower than that at the Thermal Neutron PGAA on the ST1 horizontal beam line. The CN-NDP has a design adopting two spectroscopy systems like a conventional charged particle spectrometer using several silicon surface detectors and a time-of-flight spectrometer using two MCPs, among which one MCP detects a secondary electron emitted from the shallow surface in the sample by an escaping charged particle and the other MCP detects a charged particle. Two MCPs give timing signals for time-of-flight. TOF-NDP is expected to give better energy and depth resolution rather than a conventional NDP. The CONAS is planned to be open to users until the end of 2012 and will serve as a basic tool for quantitative elemental analysis and nuclear spectroscopy.
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AA-O-06
Tuesday, 2 Nov. 14:40 â&#x20AC;&#x201C; 15:00 (Room 104)
Performance Evaluation of Compton Suppression System for Detectable Nuclides by Neutron Activation Analysis of Geological Reference Materials Jong Hwa Moon*, Sun Ha Kim, Gwang Min Sun, Yong Sam Chung
A Compton suppression gamma-ray spectrometer was implemented at a neutron activation analysis (NAA) laboratory of Korea Atomic Energy Research Institute in 2009. The Compton suppression system (CSS) consists of a n-type HpGe detector with 40% relative efficiency encompassed by four BGO (Bismuth Germanate) scintillators as guard detectors and electronic modules such as timing filter amplifier (TFA), constant fraction discriminator (CFD), gate and delay generator, high voltage power supply(HV), single channel analyzer (SCA), time-to-amplitude converter (TAC) and DSPECPLUS. NAA was executed to evaluate the performance of CSS for four geological certified reference materials which are NIST 1632C-Bituminous Coal, NIST 2709-Sanjoaquin Soil, NIST 2711Montana Soil and NIST 8704-Buffalo River Sediment. These samples were prepared for short and long neutron irradiations and irradiated by using NAA#1 irradiation hole in the HANARO. Gamma-ray spectrum with normal mode and anti-coincidence mode were acquired at the same time. Thirteen and twenty seven nuclides can be detected under the measurement condition of short and long lived nuclides, respectively. An average advantage factor of CSS for each nuclide detected by both normal and anti-coincidence mode was calculated on the basis of signal to noise ratio (the ratio of net and background counts) and its range was from 1.20 upto 3.30. In short lived nuclides, 1014 keV of 27Mg shows the highest advantage factor, 2.95 and 95 keV of 165Dy is the lowest, 1.20. For long lived nuclides, 531 keV of 147Nd is the highest, 3.30 and 1596 keV of 140La is the lowest, 1.28. Hence, it can be affirmed that CSS is advantageous to enhance gamma-ray counting statistics and to reduce detection limits of NAA.
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Activation Analysis
orea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong-gu, Daejeon, 305-353, Korea. *Corresponding author: jhmoon1@kaeri.re.kr
AA-O-07
Tuesday, 2 Nov. 15:00 â&#x20AC;&#x201C; 15:20 (Room 104)
Evaluation of Measurement Uncertainty of U Concentration in Soil and Ginseng Samples Determined by Delayed Neutron Activation Analysis Jong-Myoung Lima*, Jong-Wha Moona, Gwang-Min Suna, Yong-Sam Chunga, Jin-Hong Leeb Department of Nuclear Basic Science, Korea Atomic Energy Research Institute, Daejeon 305-353, Republic of Korea b Department of Environmental Engineering, Chungnam National University, Daejeon 305-764, Republic of Korea *Corresponding author: ex-now33@kaeri.re.kr
a
Uranium and its salts are both toxic and radioactive. Inhalation of fine uranium particles presents increased radiation hazards; isolated uranium particles in the lungs may be a long-term cancer hazard. The more soluble uranium compounds are considered most toxic to the kidneys. However, some high sensitivity methods including ICP-MS, laser microanalysis, and INAA are widely applied; there are many limitations such as acid digestion or dilution to apply for solid samples (e.g., soil, food, particulate, and rock). DNAA (Delayed Neutron Activation Analysis) is the analytical method for measuring U-235 by neutron activation followed by delayed neutron counting. U analysis by DNAA has big advantages in terms of lower detection limits and shorter analytical time than that by INAA. DNAA system of HANARO in KAERI has been implemented successfully. In this study, we present the analytical results of U for both ginseng and the corresponding cover soil collected in the five farm areas, Korea. Furthermore, the measurement uncertainty with DNAA was also evaluated for U concentration in SRM 2709. The standard uncertainties categorized into sample preparation, irradiation, delayed neutron counting, and interferences for DNAA were identified and quantified. Expanded uncertainties of measurements were calculated by applying Monte-Carlo technique. The sensitivity test of the measurement uncertainties was also conducted for evaluating the major factors of uncertainty variations.
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AA-P-01
Verification of In-house Reference Materials for Non-destructive Analysis of the Precious Metals in Geological Samples Using NAA Chan-Soo Park *, Hyung Seon Shin, Haeyoung Oh, Ha Yan Park , Min Seok Choi
Inductively coupled plasma mass spectrometry (ICP-MS) has acquired popularity in analytical work on geological materials because of its multi-elemental capability, high sensitivity and wide dynamic range. High sensitivity and excellent detection limits are particularly beneficial in work involving determination of precious metals (gold, silver and platinum). These elements are usually encountered at low or trace levels in geological materials. Traditionally, accurate determinations of low concentration by ICP-MS have been difficult and time consuming because of pretreatment such as dissolution of samples. Also, precious metals occurring in very low or at trace levels in complex matrices are subject to interferences by several polyatomic interferences generated in the dissolution procedure. Laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is one of the most promising methods for non-destructive quantification analysis. It is a multi-elemental analytical method with low detection limits, which requires such small samples to be taken. However, it has been necessary to prepare appropriate matrix-matched standards. In this study, we will produce in-house solid reference materials (RM) of the precious metals (Au, Ag, Pt) in geological samples for LA-ICP-MS analysis. Verification of the RM will be performed by NAA (neutron activation analysis).
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Activation Analysis
Division of Earth and Environmental Science, Korea Basic Science Institute, 113 Gwahangno, Yuseong-gu Deajon 305-333 Korea *Corresponding author:cspark@kbsi.re.kr
AA-P-02
NAA Activity at KRISS, a National Metrology Institute of Korea I. J. Kim*, K. H. Cho and E. Hwang Korea Research Institute of Standards and Science, 209 Gajung-Ro, Yuseong-gu, Daejeon 305-340, Korea *Corresponding author: kimij@kriss.re.kr
KRISS is an NMI (National Metrology Institute) of Korea, which provides national measurement standards and seeks the international equivalence of the standards. KRISS has used the ID-ICP/MS (Isotope Dilution Inductively Coupled Plasma Mass Spectrometry) for a long time as a primary method in the field of inorganic analysis. However, ID-ICP/MS cannot be applied to mono-isotopic elements. And a requirement has been revealed to deeply consider the basic assumption of ID-ICP/MS, the chemical equilibrium between a sample and a spiked enrichedisotope. Hence NAA as another primary method has been studied since 2004. The elements of interest are As, Au, B, Br, Cl, Cr, Hg, Mn, Na, Sb, Se, Zn, etc. From 2004 to 2007, feasibility studies on the elements were performed using various CRMs (Certified Reference Materials) by comparing NAA results with the certified values or with the results of other methods. During that period, a basic strategy has been prepared and operating procedures on NAA work at KRISS were established. NAA is currently used for the measurement of elemental contents such as As, Br, Cl, Cr, and Zn in newly developed CRMs. And some studies to enhance the reliability and reproducibility are going on. It will be presented how and what has been done in the past and what should be done in the near future in KRISS.
Key words: NAA, National measurement standard, Feasibility study, Certification, Certified reference material
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AA-P-03
Determination of Inorganic Elemental Composition in Korean Space Foods using Instrumental Neutron Activation Analysis Yong-Sam Chung a*, Sun-Ha Kim a, Gwang-Min Sun a, Jong-Myung Lim a, Jong-Hwa Moon a, Kye-Hong Lee a,Jong-Il Choi b, Ju-Woon Lee b Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong-gu, Daejeon, 305-353, Republic of Korea. b Korea Atomic Energy Research Institute,1266 Shinjeong-dong, Jeongeup-si, 580-185, Republic of Korea. *Corresponding author: yschung@kaeri.re.kr The special food created for consumption by astronauts in outer space may different with those of common foods on the earth to avoid the decrease of taste and nutrition by strong cosmic ray, gravity and pressure, and closed space environment. In April 2008, Koreaâ&#x20AC;&#x2122;s first astronaut ate various kinds of Korea space foods in the international space station. In the viewpoint of a inorganic nutrition, the analysis of mineral contents in space foods is needed to obtain fundamental information and the investigation on human nutrition and health based on the dietary intake of mineral elements. Major, minor, and trace elemental contents in six kinds of Korean space foods such as bulgogi (marinated barbecued beef), kimchi, bibimbap (mixed rice with hot pepper paste), ramyun, a mulberry beverage and a fruit punch which was developed by the KAERI are determined by using instrumental neutron activation analysis at the HANARO research reactor. The comparison of elemental concentrations is performed for the samples treated with and without gamma-ray irradiation. Five biological certified reference materials, NIST SRM were used for analytical quality control of the method. The distribution of concentrations for an essential elements like Ca, K, I, Zn, Se, Cu, Mo, Cr, Mn, V and a toxic elements like Cd, Hg, As, Al, Sn are presented, and optimum analytical condition, measurement uncertainty and detection limit of elements measured are evaluated.
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Activation Analysis
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AA-P-04
Determination of Iodine Contents in Oriental Herb Medicinal Products for Cancer Patient using Instrumental Neutron Activation Analysis Yong Sam Chung a*, Sun Ha Kim a, Gwang Min Sun a, Jong Hwa Moon a, Young Jin Kim a, Hwa Seung Yoo b Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong-gu, Daejeon, 305-353, Republic of Korea. b Dunsan Oriental Hospital of Daejeon University, 1136 Dunsan-dong, Seo-gu, Daejeon, 302-122, Republic of Korea. *Corresponding author: yschung@kaeri.re.kr a
Iodine is an essential constituent of the thyroid hormones thyroxine [3,5,3’5’-tetraiodothyronine(T4)] and 3,5,3’triiodothyronine(T3)] associated with the growth and development of humans and animals as an inorganic nutrition. This element may be accumulated in human blood, tissues and body through the intake of foodstuffs, a beverage, a nutritional supplement and a medicine, etc. The iodine contents of foods and of total diets differ appreciably and are influenced by geochemical, soil and cultural conditions which modified the iodine uptake of staple crops and foods of animal origin. (Trace elements in human nutrition and health, WHO/FAO/IAEA, 2000) The aim of the research is to find out better medicinal stuff for a thyroid cancer patient who is required to have a low level of iodine diet. Neutron activation analysis (NAA) is one of nuclear analytical techniques using radiation and radioisotopes and very useful as a sensitive analytical technique for performing both qualitative and quantitative multi-elemental nondestructive analysis of major, minor and trace components in variety of terrestrial samples and extra-terrestrial materials. In this study, iodine contents in ten kinds of oriental herb medicinal products which are frequently used for cancer patients are determined by using instrumental neutron activation analysis (INAA) at the HANARO research reactor. The samples prescribed by the oriental hospital are manufactured in powder form for taking medicine easily. The biological certified reference materials, NIST SRM-1572 Citrus leaves (1.84±0.03 /g I), were used for analytical quality control and measurement uncertainty assessment of the method. The standard deviation and relative error for the iodine analysis were less than 10% and 2.9%, respectively. The detection limit was 0.9 /g under given analytical conditions. The level of iodine contents of three samples detected is less than 6 /g except one sample and five samples were not detected. The statistical error of the measured values were different with a net and background counts of nuclide detected. Detection limit of iodine for the samples measured by INAA is in the range of 0.5 to 10 /g under optimum analytical condition. Hence, it turns out that most of the testing samples can be used to classify the level of iodine diet samples considering the recommended critical intakes of iodine for normal adult of 150 to 200 /day.
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AA-P-05
Determination of Henryâ&#x20AC;&#x2122;s Law Constant of Radon (Rn-222) by Using LSC Kil Yong Lee*, Yoon Yeol Yoon, Kyung Seok Ko Environmental Geologic Division, KIGAM, Gwahangno-92, Yuseong-gu, Daejeon 305-350, Korea *Corresponding author:kylee@kigam.re.kr
Activation Analysis
A simple but precision method for determining the Henryâ&#x20AC;&#x2122;s law constant of radon (Rn-222) was developed by using a liquid scintillation counter (LSC). In contrast conventional technique such as equilibrium partitioning in a closed system or air striping methods, the described method allow for a simple and uncomplicated determination of the constant. In this work, activity concentration of radon in aqueous phase instead of gaseous phase was analyzed for the constant. For validation of the method, activity concentration of radon of gaseous phase sample was also analyzed and compared with that of aqueous phase sample. The result shows good agreement with each other.
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AA-P-06
Hot Spring Waters Age Determination Using Natural Radionuclides Yoon Yeol Yoon*, Kil Yong Lee, Seung Gu Lee, Tong Kweon Kim, Tae Jong Lee Korea Institute of Geoscience and Mineral Resources, Gwahang-no 92, Yuseong-gu, Daejeon, 305-350, Korea *Corresponding author: yyyoon@kigam.re.kr
The use of radioactive isotopes as a groundwater-dating tool plays an important role in assessing the dynamics of groundwater systems, essential for the characterization of water resources and planning its exploitation. In hydrogeological studies the application of radioisotopes with a short half-life (below 100 year) is limited in dating old groundwater. However, they can be extremely helpful in solving another type of questions such as the identification of mixing between old and young groundwater systems. Within the environmental radioisotopes, 3H cannot be detected in waters more than approximately 50â&#x20AC;&#x201C;60 years old due to the short half-life (t1/2=12.32 year). Among the radioactive isotopes with a half-life greater than 1 ka, 14C (t1/2 = 5730 year) represents the most important tool in groundwater dating. This radioisotope is present in the atmosphere, soil, aquifer matrix, etc. Using these two radioisotopes, the age of the hot spring waters in Korea were estimated. Fifteen hot spring waters were collected and the contents of 3H, 14C were determined. Tritium concentrations in hot spring waters were very low, therefore, they were concentrated using the Ni-Ni electrolytic enrichment method. They were analyzed using low background liquid scintillation counter. Dissolved carbonate was precipitated with BaNO3 to BaCO3 form and it was reacted with phosphoric acid to produce CO2. Finally, CO2 was converted to graphite. After then, it was analyzed using AMS. In most hot spring samples tritium could not be detected and its concentrations ranged <0.5-1.31 TU. And 14C contents ranged 2.62-94.13 pMC(%). From the 3H and 14C analysis, we found that some hot springs are mixed with recent groundwater and that hot spring water aged from 490 years to 33680 years..
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AA-P-07
Determination of Efficiency in Gamma-Ray Spectrometry of Voluminous Sample by Using EGS5 Code Sangho Yooa,b, Gwang-Min Suna*, Sy Minh Tuan Hoang a, Yong-Uhn Kimb Neutron Science Division, Korea Atomic Energy Research Institute, 305-353, Korea b Department of Physics, Chungbuk National University, 361-763, Korea *Corresponding author : gmsun@kaeri.re.kr
During last several decades, the development of a variety of gamma-ray detector and its associate electronic modules has made more precise measurements. But the determination of detection efficiency still remains most important issue in the gamma-ray spectroscopy. The use of samples with various shapes and sizes limits an application of the efficiency ( p) measured using point standard source to the volume samples. Because cultural, archeological samples or environmental samples, which have been investigated in the neutron activation analysis laboratory, are voluminous, we should derive the appropriate efficiency values from p. There are many methods to calculate the efficiency for voluminous samples ( v) from p. In this study, we approached v by a concept of effective solid angle, which is considered to be an averaged efficiency over the source volume considering the self-attenuation of photons in the source. p was measured at various positions along the radial and axial direction using point source and v for voluminous source was also measured. We simulated the detection efficiency by using Monte Carlo simulation code (EGS5) and compared with the measurements.
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Activation Analysis
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AA-P-08
Simulation of a Depth Profile of Boron in Silicon based Thin Film Material using MCNP-TRIM Codes Yuna Leea and Gwang-Min Suna* a
Neutron Science Division, Korea Atomic Energy Research Institute, 305-353, Korea *Corresponding author: gmsun@kaeri.re.kr
The spatial distribution and concentration of important element in material may affect materialâ&#x20AC;&#x2122;s electrical and optical properties. So there are many analytical techniques utilized for elemental depth profiling. Among them, Neutron Depth Profiling (NDP) is considered to be a powerful and non-destructive method for some technologically important light elements such as He, Li, Be, B, N and Na. In KAERI, a new project to install a NDP system on the cold neutron beam guide has started May 2010 and the conceptual design of target chamber and charged particle spectroscopy system has been done. And we planned to open the NDP system to users until the end of 2012. For testing the system before installation, we tried to simulate the system by using two Monte Carlo simulation codes of MCNP and TRIM. MCNP code was used to simulate the nuclear reaction of slow neutron with the target elements emitting charged particles and TRIM code was used for transportation of emitted charged particle from the generation site in the material to the detector. We assume a material to have 10 micrometer thick boron layer in silicon based thin semiconductor material because one of the important applications of NDP is a study of boron in the thin materials. The alpha particle from the 10B(n,alpha)7Li reaction will undergo the attenuation of its energy in the medium and detected at the detector after transmitting the exit surface of medium. By performing the MCNP, we calculated the initial energy spectrum and distribution of the reaction site with the neutron in the medium, and we anticipated the deposit energy spectrum of alpha particle at the detector by the TRIM.
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AA-P-09
A Study of the Physical Properties and Provenance of Traditional Joseon-era Roof Tiles Using Neutron Activation Analysis Kwang-Yong Chung*
Although the restoration of Sungnyemun, Korea’s National Treasure No. 1, has become an issue for the entire nation as a result of the fire that struck it, the reality has been that, compared to other fields, there is a scarcity of thorough historical research on production methods for traditional roof tiles of the Joseon era. This lack of knowledge has led to ambivalence towards the use of traditional roof tiles in the repair and maintenance of structures; consequently, modern roof tiles have been used in the construction and renovation of buildings in the traditional architectural style. However, the molding method for modern roof tiles (compression) involves high specific gravity, resulting in weight increase and related serious problems caused by structural instability. In order to resolve these issues, this study was carried out to analyze the physical and chemical properties of traditional roof tiles and to propose standards for traditional-style roof tiles for use in the restoration of Sungnyemun. A total of 72 traditional roof tiles were selected as samples from among resources such as Sungnyemun, excavations of six historic Joseon era sites, and tiles produced by a master tile artisan designated Important Intangible Cultural Property No. 91, along with modern roof tiles. The study utilized polarizing microscope observation; measurement of bending strength, frost resistance, absorption rate, and specific gravity; whole-rock magnetic susceptibility analysis, XRD analysis, differential thermal analysis (DTA), and neutron activation analysis (NAA). Through statistical analysis of the results of various tests, we were able to determine the origin of the clay used to make the roof tiles, as well as the physical properties of traditional roof tiles and modern roof tiles. Regardless of the site of origin, pronounced differences were found between traditional and modern roof tiles, in terms of physical properties. The results indicated that these disparities arise from differences in the production methods for traditional and modern roof tiles; when preparing clay for traditional roof tiles, the tile makers practice ‘treading,’ a process in which they tread upon and mix the clay with their feet, whereas clay for modern roof tiles is crushed and mixed in de-airing pugmills to remove air pockets, after which it is compressed in a vacuum mold to form the tiles. In conclusion, as a result of this study’s determination of the physical and chemical properties of traditional Joseonera roof tiles and presentation of standardized data on traditional roof tiles, and with the ability of Jaewajang (master roof tile artisan) Han Hyung-joon, Important Intangible Cultural Property No. 91, to recreate traditional roof tiles in the traditional method, it has been decided that traditional roof tiles will be used in the restoration of Sungnyemun.
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Activation Analysis
Dept. of Conservation Science,The Korean National University of Cultural Heritage, 430 Hapjung-ri Kyuam myeon, Buyeogun, Chungcheongnam-do, 323-812, Korea. *Corresponding author: kychung@nuch.ac.kr
AA-P-10
Determination of Elemental Concentration in PM10 at Roadside Area in Korea Using Instrumental Neutron Activation Analysis Byoung-Won Junga, Jin-Hee Jeonga, Jong-Myoung Limb, Jong-Wha Moonb, Yong-Sam Chungb, Jin-Hong Leea* Department of Environmental Engineering, Chungnam National University, Daejeon 305-764, Republic of Korea b Department of Nuclear Basic Science, Korea Atomic Energy Research Institute, Daejeon 305-353, Republic of Korea *Corresponding author: jinlee@cnu.ac.kr a
Instrumental neutron activation analysis was used to measure the concentrations of about 23 elements associated with airborne PM 10 samples that were collected from a roadside sampling station at a moderately polluted urban area of Korea. A total of 80 samples were collected from July 2009 to March 2010. The PM 10 samples were irradiated with thermal neutrons using the Pneumatic Transfer System (PTS, th = 2.95 x 1013 cm-2s-1, Rcd Âť 250) of the HANARO research reactor at the Korea Atomic Energy Research Institute. The magnitude of elemental concentrations was clearly distinguished and spanned among different elements over four orders. If compared in terms of enrichment factor, it was found that certain elements (e.g., As, Br, Cl, Sb, Se, and Zn) are enriched in PM 10 samples of the study site. The results of correlation analysis showed that PM 10 concentrations were significantly correlated with the elements of crustal components. The common findings of strong correlations between PM10 and elements of crustal origin are directly compatible as such elements can constitute the major fraction of PM10.
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AA-P-11
Indoor Air Pollution at a Subway Station: PM2.5 and Metals Jin-Hee Jeonga, Byoung-Won Junga, Jong-Myoung Limb, Jong-Wha Moonb, Yong-Sam Chungb, Jin-Hong Leea* Department of Environmental Engineering, Chungnam National University, Daejeon 305-764, Republic of Korea b Department of Nuclear Basic Science, Korea Atomic Energy Research Institute, Daejeon 305-353, Republic of Korea *Corresponding author: jinlee@cnu.ac.kr
The contaminants originated from indoor pollution sources as well as various outdoor sources are easily accumulated in indoor environment dissimilar to the outdoor. Especially, since the natural ventilation is nearly impossible in the subway station, its pollution status can be worsened under the circumstance that contaminants are constantly originated and circulated inside of station by the repetitive action of subway trains. In this study, a total of 60 PM2.5 samples were collected during 4 seasonal campaigns in 2009 with a low-volume air sampler at one subway station in Daejeon, Korea. We undertook the measurements of up to 25 elements in PM2.5 using instrumental neutron activation analysis (INAA) and X-ray fluorescence (XRF). The PM2.5 concentrations in the subway station varied in the range of 16.1 to 72.7 µg m-3 with average (± standard deviation) of 36.9 ± 12.4 µg m-3. The concentrations of As, Cr, Mn, and Zn in PM2.5 averaged as 1.63 ± 0.87, 25.5 ± 11.7, 175.5 ± 38.3, and 135.4 ± 51.6 ng m-3, respectively. The Fe concentrations in PM2.5 varied in the range of 0.7 to 16.0 µg m-3 with average (± standard deviation) of 8.1 ± 8.9 µg m-3. The Fe concentrations in the PM2.5 were apportioned by about 22% to show that they were substantially higher than all other elements.
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Activation Analysis
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AA-P-12
Analysis of Korean Ginsengs by Prompt Gamma Activation Analysis G. M. Sun, Y. S. Chung and Y. J. Kim Neutron Science Division, Korea Atomic Energy Research Institute, 305-353, Korea *Corresponding author: gmsun@kaeri.re.kr
Prompt Gamma Activation Analysis (PGAA) is a non-destructive analytical technique and gives a very low residual activity after neutron irradiation, which means the reuse for another successive analytical techniques such as instrumental neutron activation analysis, delayed neutron activation analysis, ICP, XRF and so on. In this study, we analyzed light elements such as B, Na, K and so on in the Korean ginseng samples. Korean ginseng samples were collected from five representative production areas like Ganghwa, Geumsan, Gochang, Hongcheon, Pocheon. The samples were prepared into parts such as central body, periderm, main root, lateral root, fine root and rhizome.
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AA-P-13
Theoretical Validation of the Back Scattering Gamma-ray Spectra by Using Monte Carlo Codes Hoang Sy Minh Tuana,b, Gwang Min Sun a* and Sangho Yooa, Korea Atomic Energy Research Institute (KAERI), PO Box 105, Yuseong, Daejeon 305-353, Korea b University of Science and Technology 113 Gwahangno, Yuseong, Daejeon, Korea *Corresponding author: gmsun@kaeri.re.kr
a
Nowadays, the non destroyed technique (NDT) is wellestablished technique in industrial, medical and security applications. The conventional NDT such as transmission, radiographic and ultrasonic methods give the quick results with high accuracy. However, in many cases these methods are limited or not applicable if access to both sides of an object is restricted. In such case, an alternative approach is to use single sided method in which source and detector are arranged on the same side of the object [1]. This method is based on the measurement of Compton scattered photons [2], this process relies on measuring of back scattered radiation from the interior of an object surface when a gamma rays irradiate on the object surface. Back scattering is the phenomenon when gamma rays collide inside the material is scattered backward compared to the original direction. When the material thickness is very thin, the back scattering phenomena do not occur. With each incident gamma photon energy come to object surface, the number of single and multiply back scattered photons increases with increase in target thickness and reaches saturation values [3, 4]. Based on the detailed structure of the HPGe detector at the NAA lab (KAERI) we carry out to simulate the gamma spectrum of back scattering on aluminum using both MCNP5 [5] and EGS5 [6] simulation codes. Based on this experiment we investigated the back scattered spectrum of aluminum when rotating the source collimator from position at 600 to 1200 using 137Cs source with a 622 keV energy to find the location at which the contribution of singly scattering is largest. From that
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position we change the thickness of the aluminum target to find the saturated thickness of the aluminum with singly scattering.
2. Methods and Results Monte Carlo based codes have prove to be a valuable tool in designing the experiments because they allow the testing of experimental conditions which would be difficult or expensive to perform otherwise. A number of Monte Carlo codes are available that simulate in detail photon and electron transport. Among these, we chose to use MCNP5 and EGS5 because they are widely used in the industry, medical and security applications and these codes have the advantage of allowing the simulation of an arbitrary geometry. In addition, we use both codes in order to verify these simulations of MCNP5 and EGS5 in this problem together. MCNP5 is a general purpose code, which simulated coupled neutron, photon and electron transport. It can simulated radiation transport in any element, compound or mixture materials. The attractiveness of MCNP5 is mainly associated with its user friendly input file in which a generic configuration of materials can be created with the aid of user defined cells and surfaces. EGS5 is the state-of-the-art implementation of the Electron Gamma Shower (EGS) Monte Carlo code system, which is written purely in FORTRAN language. EGS5 contains most of the bug-fixes and enhancements made to EGS4. It also implements substantial additional improvements. It is also a general purpose code that simulates coupled photon and electrons transport. The physical mechanism in this problem is only concerned
Activation Analysis
1. Introduction
with the shower of electron and gamma ray therefore the EGS5 is suitable to these simulations. In the present study, the experimental measurement was performed in back scattered geometry. A 137Cs radioactive source emitting 662 keV gamma rays was used. This source was placed in a cavity of square lead container of dimensions 10 cm X 10 cm x 10 cm was especially prepared to enclose the source. The lead cylindrical collimator with 5 cm long and 0.5 cm diameter was used to obtain a narrow beam of gamma rays. The target in this study is aluminum slab with 2.5 cm diameter and 0.4 cm thickness, this target was lopsided 300 compared with incident beam. The gamma back scattered ray was recorded by HPGe detector, it was shielded by a lead cylindrical shield so that the crystal axis perpendicular to the beam source at the center sample surface. The HPGe detector was rotated from position 600 to 1200 compared to incident rays emanating from the source. Fig. 1 presents the experimental layout of this study.
efficiency of the HPGe detector was measured to be 40% with peak-to-Compton ratio of 59:1. In the Monte Carlo codes, by using the some tools such as Visual Editor [7] and Cgview [8] for simplify the experimental geometry design. We also use the Worm code [9] to quickly changing the parameter of input file when changing the geometry parameter setups such as angle of detector rotations, thickness of aluminum target. When simulations this study to get the good gamma back scattered spectrum, it is need to running the larger history (about 2 x 109 particles) in both MCNP5 and EGS5. In order to test the reliability of MCNP5 and EGS5 geometry models, the comparison between experimental and calculated efficiencies of these geometry models have carried out with the multi-nuclide standard source because the efficiency strongly depends on the geometry of this system. Consequently, this is the best way to verify the reliability of the geometry models in this work. Full energy peak efficiency calibration was carried out in the 60 - 1836 keV energy range using multi-nuclide standard source with the following radionuclides as 241 Am, 109Cd, 57Co, 123mTe, 51Cr, 113Sn, 85Sr, 137Cs, 88Y and 60 Co. Result indicated that a good agreement between calculated and measured efficiencies within 6% and these results provide sufficient justification to validate the use of the MCNP5 and EGS5 models to simulated the gamma back scattered spectrum of this experimental system.
3. Results and Discussion Fig. 2. The experimental layout of the back scattering effect experiment
A reverse-electrode closed-end coaxial HPGe detector was in this present study. It includes the Ge crystal cylinder with 60.7 mm outer diameter, 49.5 mm length. Inside the Ge crystal these is a hole with 10.3 mm diameter, 33.5 mm depth. The outer n-type contact layer is lithium layer and a boron layer is made for inner ptype contact layer. The detector is hold in an aluminum cylinder with 0.8 mm thickness. The rounded corners of the Ge crystal were given by the manufacture as 8 mm radius. This HPGe detector has a resolution of 1.95 keV (FWHM) at 1.33 MeV 60Co energy line. The relative
3.1 Investigation of the gamma back scattered spectrum with the aluminum plate placed at 30 and 40 degrees The simulation results show that the detector was rotated back from 600 to 1200 then the gamma back scattered peak shifted to low energy. Its means that the gamma back scattered peak have tend to be a shift toward lower energy when increasing the back scattered angle. This agrees with Compton scattering equation 1.
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3.2 Investigation of the gamma back scattered spectrum with the aluminum thickness In this case, we change the thickness of the aluminum target from 0.4 cm to 2 cm when the HPGe detector was placed at 1200 compared to incident rays emanating from the source. The result shows that the intensity of single and multiply back scattered photons increases with increase in target thickness. However, the intensity of back scattered photons increase to particular value of aluminum thickness. We consider this particular value as saturation depth of back scattering inside the aluminum target with given energy and the q back scattered angle. This is explain by increased target thickness, the gamma ray have high probability to make the scattering effect but the distance path of the gamma back scattered spectrum coming out increase and the absorb and scattering process compete together. Finally, a stage is reached when the thickness of aluminum target becomes to sufficient to compensate between two these process and we have the saturation depth.
3. Conclusion In this present study, the Monte Carlo simulation of the gamma back scattered spectrum was presented by using MCNP5 and EGS5. The simulation and experiment were made with 662 keV of 60Co point source. The 60Co point source was placed inside the collimator and the aluminum target was placed at several q angles, measured from the direction of the source beam, as well as the change thickness of the aluminum target to investigated the effect of the gamma back scattered spectrum following the angle and thickness parameters. The results show that the detector was rotated back from
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600 to 1200 and the aluminum target was lopsided 300compared with incident beam then the single back scattered photons increases and the multiply back scattered photons decrease. When the aluminum thickness was changed then the single and multiply back scattered photons increases and reaches saturation values with particular thickness value. These results are the base for getting the best condition while applying this method in testing densities or thickness of the sample and finding sample defects.
REFERENCES [1] Glenn F. Knoll, Radiation Detection and Measurement, John Wiley & Sons, Inc (2000). [2] L.M.N. Tavora, W.B. Gilboy, Study of Compton scattering signals in single-sided imaging applications using Monte Carlo methods, Nuclear Instruments and Methods in Physics Research B213 (2004) 155–161. [3] Gurvinderjit Singh, Manpreet Singh, B.S. Sandh, Bhajan Singh, Experimental investigation of multiple scattering of 662 keV gamma rays in zinc at 900, Radiation Physics and Chemistry 76 (2007) 750–758. [4] Manpreet Singh, Gurvinderjit Singh, B.S. Sandhu, Bhajan Singh, Effect of detector collimator and sample thickness on 0.662MeV multiply Comptonscattered gamma rays, Applied Radiation and Isotopes 64 (2006) 373–378. [5] Pelowitz, D.B., MCNPX™ User's Manual, Version 2.5.0. Los Alamos National Laboratory Report LACP-05-0369, 2005. [6] H. Hirayama, Y. Namito, A. F. Bielajew, S. J. Wilderman and W. R. Nelson, The EGS5 Code System. Report SLAC-R-730, Stanford Linear Accelerator Center, Stanford, CA, (2005). [7] http://www.mcnpvised.com/ [8] http:// rcwww.kek.jp /research/egs /kek/Cgview / index.html [9] http://worm.csirc.net/index.htm
Activation Analysis
When E ’ and E are incident and scattered energy, is the back scattered angle. In addition, the intensity of back scattered peak increase and the number multiply back scattered spectrum decrease with increase in the back scattered angle. It made the analysis of the gamma back scattered spectrum to become easy when the back scattered angle was chosen in larger value. We also achieved the location at which the contribution of singly scattering is largest.
Irradiation Tests
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IR-O-01
Monday, 1 Nov. 16:10 – 16:40 (Room 102)
The Application of Research Reactors to Irradiation Testing of Nuclear Fuels and Materials W. Wiesenack Institutt for energiteknikk – OECD Halden Reactor Project Corresponding author: wowi@hrp.no
Material test reactors have accompanied the commercial utilisation of nuclear power since the beginning in the 1950s. Although many have been decommissioned since then and only a few new ones such as Hanaro were built in the past decades, they continue to play an indispensable role in the nuclear industry. Their purpose is to support existing reactors regarding knowledge on the properties and behaviour of fuels and materials applied in them, and the development of new reactor types. LWR related needs for fuels and materials experiments in research reactors stem from developments driven by extended fuel utilisation, increasing demands regarding reliability and operational flexibility, and lifetime extension. The presentation briefly describes the background, current status and future perspectives of materials testing (both structural and fuels) and the associated facilities. Concentrating on the needs of light water reactor technology for fuels and materials testing, it includes an overview of ancillary systems and instrumentation to address performance and operational issues.
- a typical fuels irradiation experiment with ample instrumentation for on-line measurement of fuel performance parameters an overview of separate effects cladding creep studies forming the basis of modelling safety related phenomena such as clad lift-off due to rod overpressure - irradiation assisted stress corrosion cracking illustrating materials testing applications Finally, a brief outlook on future needs with respect to water cooled as well as advanced
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Irradiation Tests
A few practical examples from irradiation testing in the Halden reactor are used to illustrate how the industry’s and regulators’ requirements are supported by experiments in research reactors. The examples include
IR-O-02
Monday, 1 Nov. 16:40 â&#x20AC;&#x201C; 17:10 (Room 102)
Test Facility Requirements of HANARO for Nuclear Fuel Integrity Evaluations Kyu-Tae Kim*, Joo-Hyun Moon Energy & Environment Dept, Dongguk University, 707 Seokjang-Dong Gyeongju, Gyeongbuk, Korea, 780-714 *Corresponding author: ktkim@dongguk.ac.kr
As a part of basic atomic energy research institute program funded by the ministry of education, science and technology, Dongguk university has been investigating high burnup fuel performance and interim-dry storage fuel integrity by simulating in-reactor high burnup fuel irradiation and interim-dry storage conditions. To have a better knowledge of the irradiation-induced nuclear fuel materials performance, the HANARO capsule tests and fuel test loop tests are to be utilized in concert with in-reactor irradiation tests. In this paper, HANARO irradiation tests, inreactor irradiation tests and interim-dry storage spent fuel performance tests are discussed in detail and some experiences on irradiation tests are described. In addition, the HANARO irradiation test facility requirements needed for complete nuclear fuel integrity evaluations are presented.
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IR-O-03
Monday, 1 Nov. 17:10 â&#x20AC;&#x201C; 17:30 (Room 102)
Integral Performance Test with Test Fuels for Pressurized Water Loop in HANARO Sung Ho Ahn *, Chang Yong Joung, Bong Shick Sim, Guk Hoon Ahn, In Cheol Lim
The FTL (Fuel Test Loop) is a facility which can conduct a fuel and material irradiation tests at HANARO. The FTL simulates the steady-state operating conditions of PWR and CANDU such as their pressure, temperature, flow and water chemistry to conduct the irradiation and thermo-hydraulic tests. The commissioning of the FTL had been performed from April 2007 to September 2009. The commissioning of the FTL is performed in three stages. An individual system performance test under room temperature is performed in the first stage, and the integral performance test with mock-up fuels under high temperature is performed in the second stage, and finally the integral performance test with test fuels under high temperature is performed in the third stage. In this paper, the integral performance test with test fuels is introduced. The FTL is composed of an OPS (Out Pile System) and IPS (In-Pile teat Section). The OPS includes several process systems such as main cooling water system, emergency cooling water system, penetration cooling water system, letdown, makeup and purification system, waste storage and transfer system, intermediate cooling water system, sampling system, etc. The IPS including the test fuels is to be loaded into the IR-1 position in the HANARO core. The IPS accommodates the 3 pins of PWR fuel and has instruments such as a thermocouple, LVDT and SPND to measure a fuelâ&#x20AC;&#x2122;s performance during a test. The OPS contains several pieces of equipment such as a pressurizer, a cooler, a heater, pumps, valves and a purification system which are necessary to maintain the proper fluid conditions. The FTL coolant is supplied to the IPS at the required temperature, pressure and flow conditions that are consistent with a test fuel. The nuclear heat generated within the IPS is removed by the main circulating water cooler. The OPS also controls the water chemistry conditions. The performance of the FTL is performed finally at the integral performance test with test fuels. The main purpose of this test is to confirm again the major parameters after the test fuels are installed, which is already performed at the integral system performance test with mock-up fuels. The integral performance test with test fuels includes the reactor power increasing test, the flow measurement test for main cooling system, the water chemistry analysis test for main cooling water system, the neutron flux measurement test, the radiation measurement test for equipment rooms. FTL operation modes are divided into LSD (Loop Shutdown), CSB1 (Cold Standby 1), CSB2 (Cold Standby 2), HSB (Hot Standby) and HOP (Hot Operation). The integral performance test with test fuels was performed at each operation mode as table 1.
LSD
CSB1
CSB2
HSB
HOP
Water chemistry analysis test for main cooling water system Neutron flux measurement test Radiation measurement test for equipment rooms Flow measurement test for main cooling system Reactor power increasing test Table 1. Test items in integral performance test with test fuels
The experimental results show that all test results are satisfied to the design criteria. The integral test results will be applied to the irradiation tests using the fuel test loop facility.
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Irradiation Tests
HANARO Management Division, Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong-gu, Daejeon, 305-353, Korea *Corresponding author:shahn2@kaeri.re.kr
IR-O-04
Monday, 1 Nov. 17:30 â&#x20AC;&#x201C; 17:50 (Room 102)
Neutron-induced Reliability Issues in Advanced Metal-Oxide-Semiconductor Devices with Novel Materials Rino Choi Inha University, 253 Yonghyun-dong, Nam-gu, Incheon 402-751, Korea *Corresponding author: rino.choi@inha.ac.kr
Since cosmic lay was revealed as a source of reliability of static and dynamic CMOS memories [1-2], the effects of ionizing particles including atmospheric neutrons have intensively studied to improve the reliability characteristics of electronic devices. In particular, because the number of occasions to use the electronics in military and space applications is increasing, it becomes more important to understand the effect of neutron radiation on the reliability of electronic devices. One of famous examples of reliability issues induced by radiation is soft errors (SE). Ionizing particles passing through electronic devices generate charges in Si substrates of modern integrated circuits (ICs). If more charges than the so-called critical charge (Qcrit) is collected in a device, a transient data corruption might occur and this failure is called SE [3]. After 30 years of aggressive downsizing of Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs), geometrical scaling has clearly reached fundamental material limits, and is now in the era where further scaling can be realized mainly by new materials and/or device architecture. Traditional gate stacks based on SiO2 and poly-Si are now being replaced by high-k and metal gates. After 10 years of serious research, hafnium based gate dielectrics and metal gate electrodes are finally implemented to replace conventional silicon based dielectrics and polysilicon gate electrodes in high performance logic devices at 45nm node technology and beyond [4,5]. Since the hafnium based dielectric appears to be more vulnerable to charge trapping [6,7], radiation-induced reliability issues need to be more closely re-evaluated in MOS devices with novel materials In this presentation, the background of neutron-induced reliability studies are introduced and technology progress of high-k dielectric and metal gate electrode in CMOS application will be summarized along with impact on device performance and reliability. The reliability issues associated with novel materials will be discussed, as well.
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IR-O-05
Monday, 1 Nov. 17:50 â&#x20AC;&#x201C; 18:10 (Room 102)
Preliminary Analysis of the Thermal Hydraulics for HANARO FTL Test of Dual-Cooled Annular Fuel Rod Chang Hwan Shin*, Yong Sik Yang, Tae Hyun Chun, Dong Seok Oh, Wang Ki In
A dual-cooled annular fuel for a pressurized water reactor (PWR) has been introduced for a significant amount of reactor power uprate. Due to an expended heat transfer area and a low fuel temperature, it is expected that the dual cooled annular fuel can show higher safety features and economical advantage. DNBR(Departure of Nucleate Boiling Ratio) analysis in the thermal hydraulics is one of the key parameter in a fuel design and operation to ensure the fuel safety. Especially, since the coolant flows through the circular inner channel of annular fuel as well as the outer subchannels formed between the fuel rods, it is primary task to balance the minimum DNBR(MDNBR) between the inner and outer channel. The MDNBR balance has been known to largely depend on the thermal conductance in the inner and outer gaps between the fuel pellet and claddings. Since development of a new fuel requires in-reactor performance test to confirm its design and integration, an irradiation test is being pushed in the FTL(Fuel Test Loop) at HANARO research reactor. In the in-reactor test, heat flux of inner and outer channel can be varied during irradiation due to the imbalance of both sides gap conductance. The thermal hydraulic design is determined for the MDNBR not to exceed the DNBR limit during anticipated operational occurrences as well as normal operation. In this preliminary analysis, the proper ranges of thermal hydraulic condition for the FTL test are suggested to appropriately accomplish the temperature difference between inner and outer channel as well as inlet and exit of test section. A thermal-hydraulic analysis using the subchannel method is performed to calculate the MDNBR depending on the gap conductance. Through the conservative evaluation, it is confirmed that the MDNBR of the annular fuel rod for the FTL test is sufficient to preserve DNBR margin.
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Irradiation Tests
Innovative Fuel Development Division, Korea Atomic Energy Research Institute (150-1 Deokjin-Dong), 1045 Daedeokdaero, Yuseong, Daejeon, 305-353 Korea *Corresponding author: shinch@kaeri.re.kr
IR-O-06
Tuesday, 2 Nov. 10:40 – 11:10 (Room 102)
Nuclear Fuel Developments in Korea and HANARO’s Role Kwangheon Park1, K.L.Jun2, K.W.Song3, M.S.Cho3, J.M.Park3, and C.B.Lee3 Kyung Hee University, Suwon, South Korea Korea Nuclear Fuel Company, South Korea 3 Korea Atomic Energy Research Institute, South Korea 1
2
Many types of nuclear reactors are being developed in Korea, and nuclear fuels for the reactors are also under development as well. The current status of nuclear fuel developments for the pressurized water reactor, the high temperature gas cooled reactor, research reactors, and the sodium cooled reactor is briefly mentioned. And the contribution of HANARO for these fuel developments is also reviewed. The future direction of HANARO’s improvements especially for the fuel development is treated.
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IR-O-07
Tuesday, 2 Nov. 11:10 – 11:30 (Room 102)
Current Activities and Prospect of Neutron Irradiation Test in HANARO Kee Nam Choo a*, Man Soon Cho a, Young Hwan Kang a, Bong Goo Kim a, Cheol Yong Lee a, In Cheol Lim a Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Daejeon 305-353 *Corresponding author: knchoo@kaeri.re.kr
As one of the major utilizations of the HANARO, HANARO has been actively utilized for various nuclear fuel and material irradiation tests requested by users from research institutes, universities, and industries. More than 10,000 specimens from research institutes, nuclear industry companies and universities, have been irradiated at HANARO using the developed capsule and rabbit irradiation systems since 1995. Most irradiation tests have been related to R&D relevant to commercial nuclear power reactors such as ageing management and safety evaluation of the components. Most irradiation capsules were made for KAERI research projects, but some capsules were made as a part of national projects for the promotion of HANARO’s utilization for universities and for the irradiation tests requested by an international research project of I-NERI (International Nuclear Energy Research Initiative). The INERI Project is a Generation IV R&D plan for the structural materials in VHTR's, which is a bilateral research agreement between the Republic of Korea and U.S. HANARO has also applied several commercial-based irradiation tests relevant to the extension of the life time of current nuclear power reactor (Kori-1), new alloy and fuel developments (Doosan Heavy Industry Co. (DHI) and Korea Nuclear Fuel Co. (KNF). The archive material of RPV of Kori-1 reactor, which is the 1st nuclear power plant in South Korea, was irradiated and evaluated to support the extension of the life time of the reactor and the neutron irradiation performance of the Korean-made commercial RPV materials was also evaluated in HANARO. Several capsules were irradiated for the evaluation of the neutron irradiation properties of the parts of the nuclear fuel assemblies fabricated by KNF. Based on the accumulated experience and the user’s sophisticated requirements, HANARO has recently started new support of R&D relevant to future nuclear systems including the SMART (System-integrated Modular Advanced ReacTor) and VHTR (VeryHigh-Temperature Reactor System). As one of the most advanced SMRs (Small and Medium sized Reactors), the Korean government recently decided to develop the SMART as one of its new growth engines. The VHTR is a leading reactor design in which South Korea and the U.S. are jointly participating. The development of the future nuclear systems is one of the most important projects planned by the South Korean government. To effectively support R&D relevant to future nuclear systems, the development of advanced irradiation technologies concerning high-temperature irradiation tests is being preferentially developed in HANARO. At present, another research reactor that will specialize in radioisotope production and demonstration of reactor design is being planning in South Korea. Therefore, HANARO will be more specialized in the irradiation research.
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Irradiation Tests
a
IR-O-08
Tuesday, 2 Nov. 11:30 – 11:50 (Room 102)
Status of an In-situ Creep Testing Capability Development for the Advanced Test Reactor at INL Bong Goo Kima*, Joy L. Rempeb KAERI, HANARO Operation Division, 1045 daedeok-daero, Yuseong-gu, Daejeon, 305-600, Korea b INL, Irradiation Testing, P.O. Box 1625, MS 3840, Idaho Falls, ID 83415, USA *Corresponding author: bgkim1@kaeri.re.kr
a
An instrumented creep testing capability is developing for specimens irradiated in PWR coolant conditions at the Advanced Test Reactor (ATR) as part of the ATR National Scientific User Facility (NSUF). The test rig is developed such that samples will be subjected to applied loads ranging from 92 to 350 MPa at temperatures between 290 and 370°C up to at least 2 dpa (displacement per atom). The status of Idaho National Laboratory (INL) efforts will be described to develop the test rig in-situ creep testing capability for the ATR in this paper. In addition to providing an overview of in-pile creep test capabilities available at other test reactors, this paper will focus on efforts to evaluate a prototype test rig in an autoclave at INL’s High Temperature Test Laboratory (HTTL). And, initial results of stainless steel 304 from autoclave tests will be also included.
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IR-O-09
Tuesday, 2 Nov. 11:50 â&#x20AC;&#x201C; 12:10 (Room 102)
Effects of Thermal-Neutron Irradiation on the Microwave Properties of C-axis Oriented MgB2 Thick Films Sang Young Lee a*, Ho Sang Jung a, W. I. Yang a, W. K. Seong b, N. H. Lee b, W. N. Kang b, Man Soon Cho c, Bong Goo Kim c, Kee Nam Choo c Department of Physics and Center for Wireless Transmission, Konkuk University, Seoul, 143-701, Korea b BK21 Physics Division and Department of Physics, Sungkyunkwan University, Suwon, 440-746, Korea c Korea Atomic Energy Research Institute, Daejeon,305-600, Korea, *Corresponding author: sylee@konkuk.ac.kr a
Irradiation Tests
Magnesium diboride (MgB2) is the first superconducting material having two s-wave energy gaps, for which possibility of replacing Nb with MgB2 as the material for accelerator cavity has been studied due to its extremely low surface resistance at low temperatures. We study effects of thermal-neutron irradiation on the microwave surface resistance and the complex conductivity of thick MgB2 films grown on c-cut sapphire substrate by using the HPCVD method. The MgB2 films appear to be well c-axis oriented with a very low surface resistance (RS) of about 30 at 10 GHz and the pi-band energy gap of about 1.8 meV. The depth profile data show that the TC appears to decrease continuously as the thickness gets smaller down to 400 nm by using Ar ion-milling, which accompanies reduced normal-state resistivity. We irradiate the MgB2 films with thermal neutrons having the fluencies of 5 x 1017 n/cm2 â&#x20AC;&#x201C; 2 x 1018 n/cm2 to enhance interband scattering, between the two bands. We compare the microwave properties of the irradiated MgB2 films with those of pristine MgB2 films. We discuss the complex conductivity of the pristine and the irradiated MgB2 films along with dependence of the quasiparticle coherence peaks on the orientation of MgB2 films.
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IR-P-01
Development of the Irradiation Technology for Future Nuclear Systems in HANARO Man Soon Cho*, Kee Nam Choo, Young Hwan Kang, Yun TaeK Shin, In Cheol Lim Korea Atomic Energy Research Institute 1045 Daedeok-daero, Yuseong-gu, Daejeon, 305-600, The Republic of Korea *Corresponding author: mscho2@kaeri.re.kr
An irradiation device was recently developed to meet the requirements for the irradiation of high-temperature materials in HANARO. The irradiation tests of materials in HANARO have been performed usually at about 300 at which the RPV materials of the commercial reactors such as the light-water reactor are operating. And also the irradiation tests using a capsule have been performed at the CT test hole with a relatively higher neutron flux. However, as the VHTR (very high temperature reactor) and the SFR (sodium fast reactor) projects are being carried ahead as a part of Gen-IV program at present in Korea, the requirements for the irradiation of materials at temperatures higher than 500 are recently being gradually increased. In addition, an irradiation with relatively lower fluence is being demanded. To meet these requirements, a capsule for the irradiation of high-temperature materials at the out-core region of HANARO was developed. In this capsule, Fe, Zr, Ti, Mo materials were used as the thermal media instead of aluminum which has been used as a thermal media of the standard material capsule in HANARO. Specimens of STS 304 material with a rectangular shape were inserted in this capsule. The tests on a pressure drop and vibration for this capsule were performed to see if the hydraulic and vibration conditions required in HANARO were satisfied. And the thermal performances for Fe, Zr, Ti, Mo materials were investigated. The temperature of the specimen reached 500 in the thermal media of Mo, Zr, and 670 in the thermal media of Ti, Fe. Based on the technical data for these performance tests, a new capsule with double thermal media composed of other materials such as Al-Ti and Al-graphite was designed and fabricated for irradiation at high temperatures. At the irradiation with the new capsule, the temperature successfully reached 700 in Ti thermal media.
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IR-P-02
The Development of the Centerline Temperature Measurement Technology of Nuclear Fuel using a Heating Furnace Chang-Young Joung*, Sung-Ho Ahn, Bong-Sik Sim and Chul-Yong Lee HANARO Management Division, Korea Atomic Energy Research Institute 150 Deokjin-dong, Yuseong-gu, Daejeon, Korea 305-353 *Corresponding author: joung@kaeri.re.kr
Irradiation Tests
The Fuel Test Loop (FTL) which is essential for developing new and high performance nuclear fuel was installed to meet the increasing demand for irradiation tests at HANARO in 2007. The FTL was installed to conduct in-core fuel performance tests in operating condition and has performed operations conforming to the functional and performance requirements of the system. A commissioning test, including on-power experiments with test fuel loaded in the FTL, was successfully accomplished in September, 2009. The centerline temperature resulting from the irradiation properties of the nuclear fuel is an important factor for evaluating nuclear fuel properties in pile, and instrumentation and measurement techniques for nuclear fuel are necessary to measure the exact temperature. To simulate irradiation performance tests for high performance fuels using the above FTL facility, a tube-type heating furnace was manufactured. It was possible to achieve a temperature of more than 1700 and to control the atmosphere in the test area. In the present study, instrumentation and measurement techniques for nuclear fuel at high temperatures were developed with a heating furnace in non-irradiation condition, and a method was established to validate technology pertaining to the centerline temperature of nuclear fuel.
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IR-P-03
Double Sealing of an Irradiation Test Fuel for Measuring the Centerline Temperature Chul Yong Lee *, Kee Nam Choo Korea Atomic Energy Research Institute 150, Deokjin-dong, Yuseong, Daejeon, 305-353, Korea *Corresponding author: lcy@kaeri.re.kr
The sealing method of the KAERI irradiation test for measuring the centerline temperature used a swage lock by using a seal tube and a laser micro-welding. But this method could not guarantee a perfect sealing of the irradiation test fuel. So, the method of double sealing was designed. As the first sealing, the micro-welding work was carried out to obtain the optimum welding parameters for a jointing of the Zr-4 end cap to the tantalum thermocouple sheath. The method of the second sealing was a swage lock by using a seal tube. So, this double sealing method acts very important function to an instrumentation irradiation test for the measuring the centerline temperature.
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IR-P-04
Fracture Toughness Tests of Nuclear Graphite IG-110 S.J. Lee a, Y.S. Lee b*, J.H. Kim a, Y.M. Lee a, Y.K. Yoon a, Y.H. Kang c, K.N. Choo c, M.S. Cho c BK21 Mechatronics Group, Dept. of Mechanical Design Eng., Chungnam National University, Daejeon, Korea b Director of BK21 Mechatronics Group, Chungnam National University, Daejeon, Korea c Korea Atomic Energy Research Institute, Daejeon, Korea *Corresponding author: leeys@cnu.ac.kr a
1. Introduction
2.2 Fracture toughness test for CT specimens.
Nuclear graphite has a good thermal conductivity, high melting point, high chemical stability, and with excellent resisting on both irradiation and corrosion. Nuclear graphite also has a resistance to relatively high fast neutron fluence. Han[1] studied the fracture characteristics of nuclear graphite IG-110. In this study, fracture characteristics of isotropic graphite IG-110 were studied using two different methods of fracture toughness tests. Fracture toughness was evaluated by CT and three point bending test.
In order to measure the fracture toughness for CT specimens, the 10 CT specimens along ASTM E399[3] standards were prepared. Fig. 1 shows the schematic drawing of CT specimen. Fig. 2 shows the mounted IG110 specimen in the load frame under CT test using COD gauge. Constant displacement control method was used for load control and applied load velocity was 0.1 mm/min. Fig. 3 shows the fractured shape of the specimen. The equation (1)[4] was used to evaluate the fracture toughness for CT tests.
2. Tests and Methods
In this study, the isotropic graphite IG-110 of Japan ToyoTanso was investigated. The material properties of nuclear graphite IG-110 were shown in Table I.
Properties
Fig. 1 The schematic drawing of CT test specimen.
IG-110
Bulk Density (g/ )
1.76
Young's Modulus
8.93
Flexural Strength (MPa)
37.4
Compressive Strength (MPa)
76.8
Shore Hardness
51
Immpurity (ppm)
<20
Ave.Grain Size ( m)
10
Table I: Properties of Nuclear Graphite IG-110.[2]
Fig. 2 CT test of IG-110 graphite by MTS-810.
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Irradiation Tests
2.1 Properties of nuclear graphite IG-110
Fig. 5 Three point bending test of IG-110 graphite by MTS-810. Fig. 3 Fractured shape of IG-110 graphite under CT test.
Fig. 6 Fractured shape of IG-110 graphite under three point bending test.
2.3 Fracture toughness test for three point bending specimens. The 10 three point bending specimens along ASTM E399[3] standards were prepared. Fig. 4 shows the schematic drawing of three point bending specimen. Fig. 5 shows the mounted IG-110 specimen in the load frame under three point bending test using COD gauge. Load velocity was same with CT test. Fig. 6 shows the fractured shape of the specimen. The equation (2)[4] was used to evaluate the fracture toughness.
3. Results The peak load PQ was obtained from CT test graph. Fig. 7 shows a CT fracture toughness test result. This PQ value was applied to equation (1). Averaged fracture toughness value was 0.86 MPa m1/2 for 10 specimens.
Fig. 4 The schematic drawing of three point bending specimen.
Fig. 7 The result of CT fracture toughness test.
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The peak load P Q was obtained from three point bending test graph. Fig. 8 shows a three point bending fracture toughness test result. This PQ value was applied to equation (2). Averaged fracture toughness value was 0.90 MPa m1/2 for 10 specimens.
for Linear-Elastic Plane-Strain Fracture Toughness KIC of Metallic Materials, An American National Standard, 2005. [4] K. Y. Lee, "Stress Analysis and Mechanical Behaviors of Materials", pp. 344 - 352. 2003.
Acknowledgment This work was supported by Nuclear Research & Development Program of the National Research Foundation of Korea (NRF) grant funded by the Korean government (MEST). (grant code : 20100018569) Fig. 8 The result of three point bending fracture toughness test.
In Han's[1] study of graphite IG-110, the fracture toughness value was 0.88 MPa m1/2.
Two different fracture toughness tests of nuclear graphite IG-110 was conducted. Through the CT and three point bending tests fracture toughness value was investigated. CT fracture toughness value was 0.86 MPa m1/2 for 10 specimens and three point bending fracture toughness value was 0.90 MPa m1/2 for 10 specimens. A study on the neutron irradiated strength and stress evaluation of nuclear graphite material is planned.
REFERENCES [1] D. Y. Han, E. S. Kim, S. H. Chi And Y. S. Lim, Fracture Properties of Nuclear Graphite Grade IG110, Journal of the Korean Ceramic Society, Vol.43, No.7, pp. 439-444, 2006. [2] K. Y. Cho, K. J. Kim, Y. J. Chung and S. H. Chi, Specimen Geometry Effects on Oxidation Behavior of Nuclear Graphite, Carbon Science, Vo.7, No.3, pp. 196-200, 2006. [3] ASTM Standard E399-09, Standard Test Method
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Irradiation Tests
4. Conclusions
IR-P-05
The Ordering Reaction and Its Effects in Alloy 690 SungSoo Kim* and Young Suk Kim Korea Atomic Energy Research Institute, Reactor Material Research Dept. 150 DuckJin-dong YouSung-gu,Daejeon 305-353, Korea *Corresponding author: sskim6@kaeri.re.kr
Alloy 690 is a standard material for steam generator in pressurized water reactor at present. The ordering reaction in Alloy 690 is systematically investigated using a differential scanning calorimeter. The activation energy for the ordering reaction is determined using the cold worked and the water quenched specimens. The cold worked and the water quenched specimens from 1095 cause an exothermic reaction, and the ordering treated specimen shows an endothermic reaction. The effect of the ordering on the lattice is examined by a high resolution neutron diffraction using a series of aging specimens at 400 , at which the ordering reaction occurs in Alloy 690. The ordering in alloy 690 causes the contraction of the lattice. The lattice contraction due to ordering results in dimensional change and/or grain boundary stability of component made of Alloy 690. This suggests that the ordering reaction changes the Alloy 690 during reactor operation.
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IR-P-06
Development of Double Cladding Fuel Rod for High Temperature at HANARO Jaemin Sohn*, Sungjae Park, Yoontaeg Shin, Mansoon Cho, Jongmyung Oh, Boonggoo Kim, Sooyeol Oh, Keenam Choo Korea Atomic Energy Research Institute, 150 Deokjin-dong, Yuseong-gu, Daejeon 305-353, Republic of Korea *Corresponding author: jmsohn@kaeri.re.kr
Figure 1. Design and fabrication of the Double Cladding Fuel Rod
Irradiation Test Subjects
09F-08K
HANARO Power
30 MW
Experimental Vertical Hole
OR5
Maximum Linear Power
13.0 kW/m
Average Linear Power
11.73 kW/m
Burn-up
2,620 MWD/MTU
Effective Full Power Days
24.99 EFPD
Maximum Centerline Temperature of Nuclear Fuel
Figure 2. 09F-08K Instrumented Fuel Capsule
770
HANARO Operation Cycles
62 th
Irradiation Test Period
2010.1.10 ~ 2.9
Table 1. The results of the irradiation test of the dual cladding fuel rods by using 09F-08K instrumented fuel capsule
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Figure 3. The trends of Irradiation Test Data for Double Cladding Fuel Rods
Irradiation Tests
The double cladding fuel rods have been designed and fabricated for high temperature of nuclear fuels during the irradiation test using an instrumented capsule for the nuclear fuel irradiation test(hereinafter referred to as “instrumented fuel capsule”) at HANARO(High-flux Advanced Neutron Application Reactor) as shown in Figure 1. Each double cladding fuel rod contains five UO2 pellets(17x17 PWR type, 0.71 w/o(NU)), an inner cladding, an outer cladding, two alumina insulators and a plenum spring. A C-type thermocouple was installed to measure the centerline temperature of the nuclear fuels. As shown in Figure 2, the 09F-08K instrumented fuel capsule was designed and fabricated for a design verification test of the double cladding fuel rods at HANARO. Two double cladding fuel rods and two SPNDs(Self-Powered Neutron Detector) were installed in this capsule. The irradiation test of the 09F-08K instrumented fuel capsule, which contains the two double cladding fuel rods, was carried out in the OR5 vertical experimental hole of HANARO from January 10 to February 9, 2010 for 24.99 EFPD(Effective Full Power Days). The acquired maximum centerline temperature of nuclear fuels was 770 as shown in Table 1. During the irradiation test, the data for the following measurements was acquired; thermocouple signal for the centerline temperature of the fuel, the SPNDs’ signals(mV and mA) for the neutron flux. Data of HANARO’s reactor power level(MW) and control rod height(mm) were also acquired as shown Figure 3.
IR-P-07
Out-of-pile Qualification of Irradiation Capsule for U-Zr SFR Fuel Test in Hanaro Jin-Sik Cheon*, Chong-Tak Lee, Jun Hwan Kim, Chul Yong Lee, Byoung-Oon Lee, Chan-Bock Lee Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong, Daejeon 305-353, Korea *Corresponding author: jscheon@kaeri.re.kr
An SFR fuel irradiation is going to begin in 2010 in Hanaro. We have carried out several out-of-pile tests to qualify the irradiation capsule as well as fuel rodlets. The irradiation capsule satisfied the requirements specified to guarantee the compatibility with the Hanaro core; pressure drop limit, vibration limit, and endurance limit. As for the fuel rodlets, fuel slug was characterized not only by measuring dimensions, density and chemical composition, but also by observing microstructure and gamma radiography. The integrity of welding in the fuel cladding with end plugs was investigated through metallography and tensile test. Also, a Cr layer which was electroplated on the inner surface of the cladding for an FCCI barrier was characterized. It is expected that the SFR fuel irradiation meets the schedule.
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IR-P-08
Neutron Irradiation of Fuel Samples for Atomic Diffusivity Measurement of Xe-133 during Annealing Heemoon.Kim a*, Kwangheon Park b, Man Soon Choc, Ung Sup Song a, Sang Youl Baek a, Ki Ha Kim a, Sang Bok Ahn a PIE&Radwaste division, Korea Atomic Energy Research Institute, Daejeon, Rep. of Korea b Dept. of Nuclear Eng., Kyunghee Univ., Yongin, Kyunggi, Rep. of Korea c Capsule development division, Korea Atomic Energy Research Institute, Daejeon, Rep. of Korea *Corresponding author: hkim1211@kaeri.re.kr a
Irradiation Tests
In the operation of a nuclear reactor, the xenon gas generated in nuclear fuel by fission is released out to the inner gap of the fuel rods, which causes low conductivity and high pressure in the gap. This behavior degrades the stability of fuel rods due to high fuel temperature and mechanical deformation. Therefore, the mobility of xenon has been studied in many experimental tests. To make xenon in a fuel matrix, the HANARO research reactor is used. To measure the atomic diffusivity, fuel samples must be irradiated slightly without bubble creations. Additionally, the safety of the irradiation capsule and radiation exposure during the sample treatment must be considered. Based on the above conditions, sample weight and irradiation time were decided. An irradiation capsule, a quartz ampoule was used at first but was changed to a zry-4 tube for the thermal safety. Heating 7.2 and ORIGEN-2 codes were used to calculate the sample heating power and the capsule temperature for arbitrary irradiation times. The sample shape was 3 cubes in the beginning but was changed to a disk with same weight. In those days, sample preparation for irradiation at HANARO was set up via trial and error. Those samples were annealed to measure the released Xe-133 and then diffusivity was observed in various conditions. During 10 years, over 50 samples were irradiated at HANARO and much diffusion data has been accumulated for UO2, (Th,U)O2, SIMFUEL, UN and doped UO2.
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IR-P-09
Irradiation Test of Ferritic/Martensitic Steels in HANARO Sung Ho Kim *, Chang Hee Han, Ji-Hyun Yoon, Woo Seog Ryu Nuclear Materials Research Division, Korea Atomic Energy Research Institute, Yuseong-Gu, Daejeon, 305-353, Republic of Korea *Corresponding author: shkim7@kaeri.re.kr
Ferritic/martensitic steels such as Gr.91 and Gr.911 are candidate structural materials for the Gen-IV nuclear systems due to their many favorable properties including high thermal conductivity and low irradiation swelling. However, irradiation data for these alloys are need for the application to the Gen-IV nuclear system. Neutron irradiation test in HANARO for the FM steels were performed to evaluate the irradiation characteristics of FM steels. Irradiation temperature was consistently maintained in the range of 390+10 . A fast neutron fluence was obtained in the range of 1.1~4.4x1019 (n/cm2) (E>1.0MeV). Impact tests for the irradiated FM steels were performed at IMEF in KAERI. The upper shelf energy of base metal in G91 & G911 steels did not change by neutron irradiation. But the temperatures at 68 J and 41 J changed by neutron irradiation. The increase of the temperature at 68 J and 41 J was 11 and 10 in G91 steel, respectively. And the increase of the temperature at 68 J and 41 J was 13 and 18 in G911 steel, respectively. The degradation of impact properties of base metal by neutron irradiation was not severe in both G91 and G911 steels. The DBTT of base metal in G91 and G911 steels after irradiation were below room temperature. The irradiated base metal of G91 and G911 steels showed good impact property.
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IR-P-10
Irradiation Test of Dual Cooled Annular Fuel in the HANARO: Preliminary Result and Analysis Yong Sik Yang*, Dae Ho Kim, Je Geon Bang, Yang Hyun Koo, Kun Woo Song Innovative Fuel Development Division, Korea Atomic Energy Research Institute (150-1Deokjin-Dong), 1045 Daedeokdaero, Yuseong, Daejeon, 305-353 Korea *Corresponding author: yys@kaeri.re.kr
Irradiation Tests
The worldâ&#x20AC;&#x2122;s first irradiation test of sintered dual cooled annular fuel was completed successfully in the HANARO. The goal of the irradiation test was to obtain an in-pile behavior data of dual cooled annular fuel pellet during an early stage of irradiation. In an annular fuel design, heat balance between inner and outer channel is one of the key issues and it is greatly affected by the change in both inner and outer gap width during operation. While densification and swelling play a major role in determining the gap width change, it is unclear whether densification and swelling models for current solid fuel pellet can be applied to the annular fuel pellet. Due to the low pellet temperature and structural characteristics of an annular fuel pellet, it is expected that densification and swelling behavior of an annular pellet could be different from that of conventional solid fuel pellet. Therefore, we performed a short-term irradiation test of dual cooled annular fuel pellet in the HANARO. The six test rods were irradiated at OR4 hole in the HANARO and the maximum and minimum rod average burnup reached up to 10.9 and 8.1MWd/kgU, respectively. After several months of cooling, the test rods were transferred to PIEF(Post Irradiation Examination Facility) and detailed PIE is being performed. Detailed design of test rods and operation history during irradiation period are introduced in this paper. Preliminary PIE and performance analysis results will be discussed.
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IR-P-11
Irradiation Test of Dual Cooled Annular Fuel in the HANARO: Test Rig Design and Manufacturing Dae Ho Kim*, Yong Sik Yang, Je Geon Bang, Yang Hyun Koo, Kun Woo Song Innovative Fuel Development Division, Korea Atomic Energy Research Institute (150-1 Deokjin-Dong) 1045 Daedeokdaero, Yuseong, Daejeon, 305-353 Korea *Corresponding author: kdh@kaeri.re.kr
An irradiation test of dual cooled annular fuel for LWR nuclear fuel was completed successfully in the HANARO. The purpose of irradiation test was to obtain an in-pile behavior data of sintered annular fuel pellet during an early stage of irradiation. The test rig and annular fuel rod for the irradiation test were designed and manufactured. The test rig was fabricated to include a structural characteristic of the double cooled fuel of the interior and exterior. Outpile test for the irradiation test rig was performed at the Flow-Induced Vibration and Pressure drop Experimental Tester(FIVPET) to confirm the test rigâ&#x20AC;&#x2122;s compatibility and integrity in the OR-4 hole of the HANARO. All the outpile tests for pressure drop, rig vibration and endurance showed that the test rig satisfies the operation limits of the HANARO. The test rig was composed of the upper and lower rod assemblies, each of which had three fuel rods. Each fuel rod had 6 annular pellets and, depending on the rod number, annular pellets with different densities of 90, 93, 96, and 98%TD were used. The enrichment of the annular pellet was 2.67% and the cladding was made of stainless steel (STS-316L). At the end of the irradiation test that lasted 94 effective full power days, fuel rod burnup reached 8.19-10.9 MWd/kgU.
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IR-P-12
Present and Future PIE Status of the Nuclear Fuels and Materials Irradiated in HANARO Sangbok Ahn*, Woongsub Song, Kiha Kim, Sangyul Baek, Gilsoo Kim, Woo-Seog Ryu
Most of Post Irradiation Examinations (PIE) for the irradiated the nuclear fuel and structural materials in HANARO have been performed in the Irradiated Material Examination Facility (IMEF). IMEF was originally constructed by domestic technology to support the R&D for nuclear fuels and reactor materials, has been operating since 1994. The facility has three stories and a basement with a total floor area of about 4,000 m2, and concrete cells of about 72m. The facility consists of fuel examination cells, material examination cells, and multiple examination cells and has 31 work units. Within fuel examination cells, activities conducted are as follows; dismantling capsules, fuel examination, visual examination, visual inspections, dimensional measurements, gamma scans and eddy current tests for nondestructive tests, and metallographic sample preparations for destructive tests. Within material examination cells, mechanical properties of irradiated materials are measured through impact, tensile, fracture tests. Also the thermal diffusivity and density are measured in there. In multiple examination cells the handling examinations of the spent PWR fuels are performed with various chemical and mechanical machines. Furthermore the hot laboratory apart from hit cells is available for EPMA and TEM investigations. Various PIEâ&#x20AC;&#x2122;s of the R&D nuclear fuels for the advanced research reactor, the HANARO drive, DUPIC, SMART have been performed during normal operations. Also the structural materials for Gen-IV reactor, new PWR vessels and the fuel skeleton materials have been examined after irradiation in HANARO. For the future usages the new equipments are now introduced or under development as an FE-EPMA, a mini type SEM, a multiplex cutting machine, a skeleton dimension measuring machine and so on. To meet the future PIE requirements in R&D projects the new PIE techniques are under development as thermal diffusivity measurement, fission gas diffusivity measurement, FTL dismantling and reconstitution and SMART S/G tube tests, and furthermore fuel test techniques of SFR, VHTR at now. These development activities will give the PIE data to support nuclear R&D projects successfully.
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Irradiation Tests
Korea Atomic Energy Research Institute, PIE & Radwaste Div., 1045 Daedeok-daero, Daejeon, Korea, 305-353 *Corresponding author: sbahn@kaeri.re.kr
IR-P-13
Neutron Fluence Measurement at HANARO Yong Kyun Kim a*, Seung Kyu Lee a, Kwang Ho Jo a, Kee Nam Choob, Jin Suk Parkb Department of Nuclear Engineering, Hanyang University, Seoul, 133-791, Korea b Korea Atomic Energy Research Institute, Daejeon, 305-353, Korea *Corresponding author: ykkim4@hanyang.ac.kr
a
The neutron fluence measurement and evaluation technology is very important for material irradiation test. The most essential technology in this study is the neutron irradiation evaluation method using a fluence monitor. The fluence monitors were fabricated with metal wires of the purity â&#x2030;Ľ 99.9%, whose dimensions were 0.1mm diameter, about 3mm length, and around 150-200 mass range. Three wire samples (Fe, Ni, Ti) were prepared for one irradiation aluminum capsule. Five capsules were irradiated in the OR5 hole of the HANARO reactor at 30 MW power for about 25 days. After irradiation tests, radiation activities were measured with the high purity germanium (HPGe) detector. The reaction rates were calculated by using the measured radiation activity data, and then neutron fluence were obtained from the reaction rates and the weighted neutron cross section with calculated neutron spectrum at the fluence monitor position. The neutron fluence values at the installed positions were calculated by using MCNP code. The MCNP calculation results were 1.40 x 1019, 2.33 x 1019, 3.52 x 1019, 3.70 x 1019, 2.90 x 1019 cm-2, E > 1 MeV. The measured neutron fluences were compared to the calculated ones.
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IR-P-14
The Effect of Irradiated Grid Spring and Dimple on Fuel Rod Vibration K.J. Kim a*, K.B. Eoma, J. M. Suha, K.L. Jeona Korea Nuclear Fuel Co., Deajeon, 305-353, Korea *Corresponding author: Kyoungjoo@knfc.co.kr
a
Spacer grid springs support fuel rods so that the rods keep the position laterally and axially in pressurized water reactor fuel assemblies. The grid spring characteristic, especially stiffness, is one of the most important factors in the fuel rod dynamic response. The grid material mechanical properties are changed according to irradiation. Accordingly, the grid spring stiffness must be changed as it undergoes irradiation. The irradiated grid spring will affect the fuel rod dynamic properties. In this paper, the results of the irradiated and unirradiated grid spring characteristic tests which were performed in HANARO hot cell are introduced to show the difference in the grid spring stiffness according to the irradiation. Then the modal analysis for the fuel rod is performed to study how the difference in the spring stiffness will affect the fuel rod dynamic properties.
The MTS810 was used as the compression test machine. The grid springs were tested using a block which accommodates the unit cell with the spring. Then a loading bar is moved down to deflect the spring simulating the fuel rod insertion into the grid cell. The test block and loading bar are in Fig.3. The spring load-deflection characteristic test was performed for both irradiated and unirradiated specimens at room temperature. The test results of zirconium mid grid and Inconel-718 bottom grid springs are shown in Fig.4 and Fig.5 respectively. In Fig.4, the stiffness of irradiated and unirradiated zirconium alloy mid grid springs is 104.03 N/mm and 91.23 N/mm, respectively. Therefore the irradiatedunirradiated stiffness ratio is 1.14. In Fig.5, the stiffness of irradiated and unirradiated Inconel alloy bottom grid springs is 67.99 N/mm and 65.37 N/mm, respectively. Therefore the irradiatedunirradiated stiffness ratio is 1.04. Irradiation Tests
1. Introduction
2. Methods and Results 2.1 Grid Spring Load-Deflection Characteristic Test The zirconium alloy and Inconel alloy grid spring specimens are shown in Fig.1 and Fig.2 respectively. The specimens were irradiated in the irradiation test hole of HANARO with a 30 MW thermal output at 300 over approximately 96 days (4 cycles). While the neutron flux of current nuclear power plant (KSNP) is around 6.19x1013 n/cm2 . sec (E>1.0 Mev), the maximum neutron flux of HANARO is 1.54x1014 n/cm2 . sec (E>1.0 Mev).
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Fig. 1 zirconium alloy mid grid
Fig. 2 Inconel alloy bottom grid
Fig. 3 Setup of the irradiated specimen
2.2 Fuel Rod Modal Analysis The fuel rod is supported by two dimples and one spring at each grid location based on twodimensional plane. Therefore, the fuel rod finite element model consists of two-dimensional beam and one-dimensional linear spring elements. The fuel rod modal analysis was performed to determine the natural frequencies and mode shapes.
2.2.1 Natural frequency
Fig. 4 Test results for zirconium alloy mid grid
The natural frequencies are expanded up to 6th mode.
Fig. 5 Test results for Inconel alloy bottom grid Fig. 6 Natural frequency of fuel rod The flux ratio of current nuclear power plant to HANARO is about 0.4. The irradiated-unirradiated stiffness ratio of zirconium alloy mid grid and Inconel alloy bottom grid springs is expected to be 2.01 and 1.29 respectively when the springs are irradiated in the current nuclear power plant for 3 cycles (54 months). The current unirradiated grid stiffness was multiplied by the calculated ratio, and the results are shown in Table 1.
Unirradiated (N/mm)
Irradiated (N/mm)
Spring
62
80
Dimple
209
270
Grid Top Mid Bottom
Spring
131
263
Dimple
611
1228
Spring
104
135
Dimple
257
331
Table 1: Test Results for Spring Stiffness
The natural frequency of the fuel rod supported by irradiated grids was 7 % ~ 16 % higher than that of the fuel rod supported by unirradiated grids as shown in Fig.6. The analysis result means that the system natural frequency was increased because the irradiated springs and dimples made the rod supports stiffer. Critical velocity in the fuel rod with irradiated supports increases according to increased natural frequency; Therefore it is concluded that the fuel rod instability with irradiated supports can be minimized compared to the fuel rod with unirradiated supports.
2.2.2 Mode Shape Fig.7 shows the fuel rod mode shapes. The mode shape was not changed since the stiffness of the fuel rod supports is simultaneously increased.
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The current unirradiated grid stiffness was multiplied by the calculated ratio, and the results are shown in Table 1. Acknowledgments This work was supported by the Power Generation & Electricity Delivery of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Knowledge (No. R-2005-1-391). (a)Mode 1
Irradiation Tests
(b)Mode2
(c)Mode3
Fig. 7 Mode Shape of fuel rod
3. Conclusions The flux ratio of current nuclear power plant to HANARO is about 0.4. The irradiated-unirradiated stiffness ratio of zirconium alloy mid grid and Inconel alloy bottom grid springs is expected to be 2.01 and 1.29 respectively when the springs are irradiated in the current nuclear power plant for 3 cycles (54 months).
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IR-P-15
The Mechanical and Irradiation Properties of Zirconium Alloys Irradiated in HANARO Oh-Hyun Kwon *, Kyong-Bo Eom, Jae-Ik Kim, Jung-Min Suh, Kyeong-Lak Jeon KEPCO Nuclear Fuel Co. Ltd., 493, Deokjin-dong, Yusung-Gu, Daejon 305-353, South Korea *Corresponding author: ohkwon@knfc.co.kr
1. Introduction Zirconium-based alloys are used widely for fuel cladding and other core components. Therefore, the effect of neutron-irradiation of these alloys has been investigated well. Especially, the changes in mechanical properties are well organized [1]. Generally, with more irradiation, the zirconium alloys have irradiation hardening effect [1]. Irradiation growth under fast neutron irradiation is the main source of dimensional change in zirconium alloy. It is thought to result from the partitioning of irradiation-induced interstitials and vacancies between various point defect sinks, such as dislocations, grain boundaries and solute atom traps. The metallurgical factors (texture, grain size, grain shape and dislocation density) affecting irradiation growth are well known from previous studies [2]. The effect of crystallographic texture on irradiation growth is well established and organized. The free irradiation effect with the combined crystallographic texture is also analyzed [3]. Harbottle reported the difference in growth strains of transverse and longitudinal strips by using an equation where axial growth is proportional to 1-3f (f : texture parameter) [4]. The grid strap component of a fuel assembly under irradiation in the plant is considered to be free of growth and without internal stress. In this study, free growth under irradiation in both HANARO and in the plant reactor is compared for the analysis of differences between two results.
2. Experimental For mechanical properties measurement, zirconium
alloys specimens (A, B and C) with a length of 2mm were prepared for testing. The thickness (0.66mm) was used for each of the zirconium alloy specimens. For irradiation growth measurement, zirconium alloys specimens (A, B and C) with a length of 77mm were prepared for testing. The thickness (0.66mm) was used for each of the zirconium alloy longitudinal and transverse specimens. These specimens were encapsulated and irradiated in the HANARO facility, a multi-purpose research reactor with a world-class high neutron flux. The amount of fluence with fast neutron (E > 1.0 MeV) was 1021 (n/cm2). The temperature approximately 1.1 (300 Âą 10 ) was maintained during the irradiation test. After irradiation testing, for mechanical properties, universal testing machine in hot cell was used with the condition of 0.5mm/min loading rate. For irradiation growth measurement, the longitudinal length and transverse lengths of each specimen were measured with a micrometer. The dimensional changes were compared. Additionally the dimensional changes of the grid strap, which was irradiated in the plant, were also compared for free irradiation growth measurement. The data was acquired through results from previous studies. [5].
3. Results 3.1 Mechanical Properties of Zirconium Alloys The results shown in Fig.1 and 2 explain that the zirconium alloys have similar average mechanical properties, even though each of the zirconium alloys has different alloying elements. Alloy B has shown the highest yield strength and tensile strength properties than that of other alloys in irradiated condition.
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Even though each of the zirconium alloys has a different alloying content, this various content does not seem to affect the mechanical properties effectively under an unirradiated condition and low fluence. Alloy B has respectively 61% and 41% increases in yield strength and tensile strength after irradiation. And all the other alloys have shown the tendency of increase in yield strength and ultimate tensile strength.
3.2 Irradiation Growth by the texture
Fig. 3. The average Irradiation Growth Ratio (Longitudinal specimen growth (%) / Transverse specimen growth (%))
Alloy
Fig. 2. The average Ultimate Tensile Strength between unirradiated and irradiated zirconium alloys specimens.
Longitudinal Specimen
Transverse Specimen
Alloy A
0.075
0.256
Alloy B
0.066
0.233
Alloy C
0.109
0.138
Table II: Zirconium Alloy Texture Parameter (Kearns Number)
3.3 Irradiation Growth in the plant reacto Element
Alloy A (wt%)
Nb
1.1
Alloy B (wt%) 1.0
Alloy C (wt%) -
Sn
-
0.95
1.32
O
0.125
0.120
0.120
Fe
0.050
0.115
0.275
Zr
Bal.
Bal.
Bal.
Table I: Major and minor element content of each alloy
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For our analysis, the condition of irradiation is thought to be the beginning of irradiation cycle, and the alloy B specimen results of the irradiation tests are very considerable in comparison with the growth of the alloy B grid strap in table III. The test results seem that, without any stress, the free irradiation growth could be more than we previously predicted in the plant. More irradiation growth in the HANARO seems to be due to the measurement uncertainty from not enough length.
Irradiation Tests
Fig. 1. The average Yield Strength between unirradiated and irradiated zirconium alloys specimens.
According to Harbottleâ&#x20AC;&#x2122;s study, the texture parameter (kearns number) has the relation of 1-3f [4]. Likewise, the irradiation growth of all the transverse specimens shown in Fig.3 is smaller than those of longitudinal specimens. However, the overall differences between transverse and longitudinal specimens are not comparable to the relation of the 1-3f equation with considering the textures shown in Table II. These results seem to be due to the low fluence. Therefore, for clear analysis of texture effects, testing under higher irradiation conditions is needed.
Alloy B Grid
Growth (%)
Fluence (1021n/cm2)
Temperature ( )
In the Plant*
0.46
8.790
291 ~ 334
In HANARO
0.10
1.100
290 ~ 310
Table III: The grid strap growth results comparison in the plant and HANARO *The grid strap temperature in the plant is acquired through the inlet and outlet reactor temperature [5].
4. Conclusions From these tests and results, the mechanical properties of each individual zirconium alloy seem to be similar in unirradiated or irradiated condition. Alloy B has shown the highest yield strength and tensile strength properties than that of other alloys in irradiated condition Even though each of the zirconium alloys has a different alloying content, this content does not seem to affect the mechanical properties effectively under an unirradiated condition and low fluence. And all the alloys have shown the tendency of increase in yield strength and ultimate tensile strength. Transverse specimens of each of the zirconium alloys have a slightly lower irradiation growth tendency than longitudinal specimens. Therefore, for clear analysis of texture effects, testing under higher irradiation conditions is needed. In comparison to irradiation growth in the plant, the result of these irradiation tests are more considerable than predicted based on the plant experience. More irradiation growth in the HANARO seems to be due to the measurement uncertainty. Therefore, further study is required with high fluence and longer specimen.
REFERENCES [1] H.R. Higgy, F.H. Hammad, “Effect of Neutron Irradiation on the Tensile Properties of Zircaloy-2 and Zircaloy-4”, Vol. 44, p. 215, 1972. [2] A. Rogerson, “Irradiation Growth in Zirconium and its Alloys, Journal of Nuclear Materials”, Vol.159, p. 43, 1988. [3] John Williams, Edward C. Darby, and David C.C. Minty, Zirconium in the Nuclear Industry : Sixth International Symposium, ASTM STP 824, p. 376-393, 1984. [4] J.E. Harbottle, “ The Temperature and Neutron Dose Dependence of Irradiation Growth in Zircaloy-2”, ASTM-STP-485, p. 287-299, 1970. [5] Steven J. King, Ronald L. Kesterson, Ken H. Yueh, Robert J. Comstock, William M. Herwig, and Scott D. Ferguson, “Impact of Hydrogen on Dimensional Stability of ZIRLO Fuel Assemblies”, Zirconium in the Nuclear Industry, ASTM STP 1423, p. 471, 2009. .
Acknowledgements This work was supported by the Power Generation & Electricity Delivery of the Korea Institute of Energy Technology Evaluation and Planning(KETEP) grant funded by the Korea government Ministry of Knowledge (No. R-2005-1-391).
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Radioisotopes
- 220 Radioisotopes
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RI-O-01
Tuesday, 2 Nov. 10:40 – 11:10 (Room 105)
Production of Fission-Product 99Mo using High- and Low-Enriched Uranium Targets George F. Vandegrift* Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue., Argonne, IL 60439 USA *Corresponding author: vandegrift@anl.gov
The decay product of 99Mo, 99mTc, is the most commonly used medical isotope in the world, with an estimated usage of 20-25 million procedures performed annually. Most is now produced by irradiating high enriched uranium (HEU) targets. Currently, two producers are using low enriched uranium (LEU) targets--Comisión Nacional de Energia Atómica, Argentina (CNEA) and the Australian Nuclear Science and Technology Organisation (ANSTO). Both the South African NTP Radioisotopes (Pty) Ltd. and BATAN Teknologi, Indonesia are close to converting to LEU. The United States’ National Nuclear Security Agency’s Office of Global Threat Reduction Initiative’s Reactor Conversion Program is (1) developing technology to allow current producers to convert their operations from HEU to LEU and new producers to begin production without the use of HEU and (2) establishing a reliable U.S. domestic supply of the critical medical isotope Mo-99 without the use of HEU. This paper will discuss the current worldwide status of 99Mo production and provide insight into Argonne National Laboratory’s development activities that will allow economic production of 99Mo using LEU.
of only 66 hours, this requires the production of between 34,000 and 46,000 Ci out-of-reactor each week to meet U.S. demand. Fig. 1, based on calculations from a 1997 report by Sandia National Laboratories, [1] illustrates this point. Taking into account processing losses and a 30-hour processing and shipping time, ~34,000 Ci must be produced each week in a reactor to meet a demand of 5000 6-day Ci. The worldwide demand is ~12,000 6day Ci/week, meaning that ~82,000 Ci must be produced every week to meet that demand.
3. Large-Scale Production of 99Mo Production of fission-product Mo-99 includes the following steps: (1) target fabrication, (2) target irradiation, (3) dissolution or digestion of target and uranium fuel, (4) recovery and purification of molybdenum from all other target components, and (5) shipment of purified 99Mo solutions to generator producers. Each of these steps is summarized below.
Radioisotopes
1. Introduction
2. Weekly Production of 99Mo The U.S. consumption of 99Mo is in the range of 5000–7000 6-day Ci/wk. (A 6-day Ci is the amount of Mo-99 that would generate a Ci of radiation six days after it is shipped to the generator manufacturer.) Because Mo-99 continuously decays and has a half-life
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Fig. 1. Comparison of Ci of Mo-99 produced at the time targets leave reactor to Curies shipped following processing and 6day Ci that are sold to 99mTc generator suppliers
Target fabrication for IRE, NTP, Mallinckrodt, ANSTO, and CNEA is quite similar. The targets are essentially mini fuel plates, where a uranium-aluminum alloy or compound is mixed with aluminum powder and sandwiched between two pieces of aluminum cladding. In the case of IRE, the plates are shaped into cylinders. The Atomic Energy of Canada Ltd. (AECL)MDS-Nordion target is similar, but the fuel meat is extruded into an aluminum-clad pin—a short version of National Research Universal (NRU) reactor fuel. The HEU Cintichem target currently used in Indonesia consists of UO2 electrodeposited onto the inside of a closed stainless-steel cylinder. Target irradiation is generally performed in five to twelve days in a high flux area of the reactor. A thermal neutron flux of ~1 x 1014 neutron/cm2-sec is generally considered to be required for economical production. This flux and a 5-day irradiation time translate to production of 150 Ci of 99Mo/g-235U irradiated at the end of irradiation. The targets are allowed to “cool” in the reactor pool for about 10 hours before being shipped to the processing facility. This allows the short-lived, highly radioactive isotopes to decay and significantly lowers the radioactivity in the targets. Target dissolution/digestion is done using either nitricacid (Canada and Indonesia) or alkaline solutions (IRE, NTP, Mallinckrodt, ANSTO, CNEA). In the acidic process, the irradiated uranium is dissolved and the target material is left behind. Uranium and the fission and activation products are completely dissolved. Dissolution times are one hour. In the alkaline process, the aluminum in the target meat and the target cladding is dissolved, and the uranium in the target meat is converted to an insoluble hydrous uranium oxide. Part of the fission products (including Mo and I) dissolves, while the majority of the fission and activation products precipitate with the uranium from the alkaline solution. Dissolution times are typically between one and three hours. Recovery of Mo-99 varies from process to process, as does subsequent purification of the Mo. However, the equipment is generally small-scale, with solution volumes being 0.1 to 6 liters. The use of ion-exchange columns for the recovery of Mo is widespread in these processes, which have between two and six recovery/purification steps. The final product is sodium
molybdate in a solution of 0.2 M sodium hydroxide, which is the required feed for loading the Mo into the generator. Total processing times following dissolution vary between four and twelve hours. Shipment of 99Mo to the generator producer requires adequate infrastructure to ship this rapidly-decaying material in a timely fashion and to assure reliable delivery.
4. The LEU-Foil Target Most 99Mo production is being performed using HEU, most enriched to 93% 235U. To produce fission-product 99 Mo from low-enriched uranium (LEU--<20% 235U) requires five times the amount of uranium. Because of the high-density of uranium metal, its use allows LEU targets with the high density of 235U required to substitute LEU for HEU in the same irradiation position with similar or even higher 99Mo yields than conventional HEU targets. Targets containing LEU in the form of a uranium metal foil (125-150 µm thick) held between two cylindrical aluminum tubes were developed to meet this requirement. [2] The annular target was designed to allow good thermal contact between the foil and the target walls and to keep good thermal contact during irradiation due to the hoop stress afforded by a cylinder. A thin fission-recoil barrier (15µm Ni foil for acid dissolution or 40-µm Al foil for alkaline digestion) is wrapped around the U foil to stop bonding of the uranium foil to the target walls during irradiation. The annular target is fabricated by expanding an inside tube into an outside tube; after the drawing process the ends of the target are cleaned and welded closed. A schematic of the annular target is shown in Fig. 2.
Fig. 2. Schematic of the ANL annular foil target
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An example of how an LEU target can provide the same or more 235U than a conventional HEU dispersion target can be seen in the possible conversion of the current IRE HEU target. The IRE target is in the form of an HEU-aluminide dispersion plate that has been curved and then welded into an annular target. [3] The current target contains 3.7 g of 235U at 93% enriched uranium. An LEU-foil target with a standard 135-µm thick foil of the same dimensions of 19.9% enriched uranium would contain 4.1 g of 235U. If the LEU foil were made as thick as the current fuel meat (510 µm), the target would contain 16.6 g of 235U. As well as developing the LEU-foil annular target, Argonne has been developing technology to allow it to be used in established processes that currently use HEU. Information on these developments can be found in conference papers presented at the RERTR International meetings [4].
Work supported by the U.S. Department of Energy, National Nuclear Security Administration's (NNSA's) Office of Defense Nuclear Nonproliferation, under Contract DE-AC02-06CH11357.
REFERENCES [1] Edward J. Parma, Mo-99 Production at the Annular Core Research Reactor-Recent Calculative Results, SAND-97-1569C, Sandia National Laboratories, June 1997. [2] G. F. Vandegrift and E. T. Fei, “Mo-99 Production Using LEU,” proceedings of INMM Annual Meeting, July 2007. [3] C. J. FALLAIS ET AL., “Production of Radioisotopes with BR2 Facilities,” BR2 Reactor Meeting, Mol, Belgium, INIS, MF 4426, pp. IX-1 to -11 (1978) [4] http://www.rertr.anl.gov/
5. Conclusions The daughter of 99Mo, 99mTc, is an important medical diagnostic radioisotope that is used worldwide. Currently, most of 99Mo is produced by fissioning of HEU targets. Argonne and others are developing methods to produce fission-product 99Mo using LEU. Based on these developments, use of LEU-foil targets should produce 99Mo at similar or even lower costs than the current targets.
Government License Notice The submitted manuscript has been created by UChicago Argonne, LLC, Operator of Argonne National Laboratory (“Argonne”). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357. The U.S. Government retains for itself, and others acting on its behalf, a paid-up nonexclusive, irrevocable worldwide license in said article to reproduce, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, by or on behalf of the Government.
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Radioisotopes
6. Acknowledgements
RI-O-02
Tuesday, 2 Nov. 11:10 – 11:40 (Room 105)
Radioactive Particle Tracking for Flow Mapping in Multiphase Reactor Vessels Shantanu Roy a*, Harish J. Pant b, Rajesh K. Upadhyay a Department of Chemical Engineering, Indian Institute of Technology - Delhi, New Delhi 110016, India b Isotope Applications Division, Bhabha Atomic Research Centre, Mumbai 400085, India *Corresponding author: roys@chemical.iitd.ac.in
a
1. Introduction The design, scale-up and troubleshooting of chemical reactors is a problem of pressing interest to chemical and process engineers. In spite of more than 150 years of organized effort in the chemical and oil industry, and the corresponding advancements, this continues to be more of an "art" rather than a "science". As their name suggests, chemical engineers are primarily employed in translating the laboratory scale chemistry (in case of reactions) and physics (in case of both reactions and separations) to industrial scale reactors and separation equipment. The chemistry and physics, which operates at a molecular scale and shows its intrinsic behavior in the laboratory, often shows significantly reduced activity in the large scale plant because of the masking inefficiencies of the flow pattern and transport phenomena. Assessment of these inefficiencies and corrective follow-up actions are of prime importance both at the design and scale-up stage, as well as during the actual operation of an industrial unit (troubleshooting). In the industry, simply owing to the huge sizes involved and also our limitations on experimentation in a running plant, popularly radioactive isotopes are used as dispersed tracers (the so-called "radio-tracer technique") for assessment of pathological flows (stagnancy, bypassing and improper mixing situations). In this, a radioactive tracer is introduced into a process stream at the inlet of the vessel of interest, and photon counts are recorded by placing scintillation detectors at the inlet, exit and other locations around the vessel. While this is perhaps the only technique which works in an industrial environment, which justifies its use in
spite of severe difficulties in their implementation, this technique too has limitations and cannot be used for fundamental investigations into the fluid mechanics of multiphase vessels. As a response to this need, in recent years the Radioactive Particle Tracking (RPT) technique is becoming increasingly popular. This communication presents some recent innovations in the RPT technique and a demonstration of its accuracy and versatility.
2. Experimental Technique Radioactive Particle Tracking Technique (RPT) is a unique non-invasive methodology for measuring velocity fields and mixing patterns in multiphase vessels [1]. In the RPT technique, a single radioactive particle (which is a gamma ray emitter) is used as the marker of the phase whose velocity field is to be mapped. The tracer particle motion is interrogated by an array of scintillation detectors which are strategically placed around the vessel of interest. Subsequently, the Lagrangian trace of this particle is used to decipher the instantaneous position time series of any “typical” fluid element and from that the instantaneous velocity time series. From this information, a rich database of flow quantities such as mean velocity fields, kinetic energies of the turbulence and other parameters that represent the prevailing flow regimes and flow characteristics can be extracted. Fig. 1 shows a picture of the setup developed and installed in IIT Delhi, and Fig. 2 shows a summary of the experimental steps.
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3. Typical Results While the HANARO Symposium 2010 presentation will discuss many different results obtained in different systems and under differing flow conditions, here some typical results are being presented from two flow situations, viz. a gas-liquid system (in which liquid is tracked), and a pilot plant scale bioreactor (in which solid wagon-wheel shaped biofilm substrates are being tracked).
Fig. 1. Radioactive particle tracking (RPT) setup.
3.1 Laboratory Scale Gas-Liquid Bubble Column (2D) A reference is made to the 2D bubble column experiments of Pfleger et al. [1] (which is a literature standard), in which the overall gas volume fraction is less than 5%, so that a reputedly accurate technique Laser Doppler Anemometry could be used for accurate measurements of liquid velocity [2]. As a challenge to the RPT technique, experiments with that technique were performed in the same setup as that reported in [2], and the liquid velocity profile was compared at three elevations, as shown in Fig. 3. In Fig. 4, comparison of the mean fluctuating kinetic energy of liquid phase eddies is shown. RPT reports a profile, while the LDA experiments could be only performed at a point in the vessel.
Fig. 2. Steps for reconstruction and data processing in RPT.
Radioisotopes
For tracking solid particles in RPT (such as in a fluidized bed), a tracer particle is prepared which has the size, shape and density same as the particles constituting the solids phase. For tracking liquid eddies, the tracer particle has to be made neutrally buoyant with respect to the liquid and of small size. Further, we have innovated to be able to study size distributions as well as flow of dissimilar particles (differing density) in the same system. Details of this will be discussed in the presentation. Fig. 3. Comparison of mean axial velocity at different levels obtained by RPT and LDA
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The results (Figs. 3 and 4) indicate that at all levels the quantitative comparison is very promising. What is remarkable that this good agreement in the two measurements is not only at one particular location, but at multiple levels in the column. Thus, if one restsconfidence in a technique like LDA, we believe it is fair to say that the RPT technique is at least as accurate. In fact, the data from Pfleger et al. [1] serves as reference data for benchmarking models and CFD codes. Thus, it is only fair that we use that for benchmarking the accuracy of RPT. It is also seen that the kinetic energy of flow calculated by RPT and LDA clearly are of the same order of magnitude. Total kinetic energy found by LDA is 0.0016 m2/s2 while at same position total kinetic energy found by RPT is 0.0021 m 2/s 2. The two values are clearly in fair agreement, which seems to suggest that the accuracy of RPT involving second moments of velocity are also fair and acceptable. RPT of course provides a full profile, while LDA has to be performed point-by-point.
Fig. 4. Comparison of mean axial velocity at different levels obtained by RPT and LDA
Thus, it would be no exaggeration to state that RPT is definitely as accurate as the state-of–the-art LDA technique. Further, it is much more versatile, in that it can be employed in high holdup systems where LDA or other comparable technique simply would not work.
3.2 Pilot-plant Scale Aerobic Bioreactor Recently, the team of authors of this communication successfully implemented RPT for the first time in a pilot plant scale unit, an aerobic bioreactor. Fig. 5 shows a schematic.
Fig. 5. Comparison of mean axial velocity at different levels obtained by RPT and LDA
As shown in Fig. 5, wastewater enters into the reactor from one side and exits from the other side. Air enters from the bottom of the reactor through the small holes made on 5 stainless steel rods which are placed along the reactor length. The holes are placed off centre on these stainless steel rods such that the air enters in the reactor tangentially and with its angular entry is able to rotate the wastewater and media azimuthally, along the circular periphery of the reactor. The vessel also contains wagon-wheel shaped “media”, made of polypropylene, on which the bio-film is grown which eventually does the waste-water treatment. It is of priority to “mix” the media (which are in batch) with water and air to the highest extent possible, so that the water treatment can take place in an optimal fashion, and there should be no localization of stagnancy in the media. To create more turbulence and for better mixing, air enters counter-clock-wise through four rods and in clock-wise direction from one rod. Other than rotating the wastewater and the media along the periphery of the reactor, air also fluidizes the media for better mass transfer. However, doubts remained with the manufacturers whether the media mixing was adequate, and whether there were any stagnancies or dead zones. RPT came to their rescue.
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along the z-axis. However, at wall the number of occurrences is still low which shows that even at this operating condition also wall is not well utilized. When the reactor is operated at high water and high air flow rate, as indicated in the last figures (Fig. 6 – bottom right graph) the situation is markedly improved and media is relatively well mixed along the z-axis. However, before making definitive conclusions even in this case, it is required to quantify the mixing in radial direction.
For better performance of bioreactor, it is desired that media should well mixed in the whole reactor volume and should available for the waste water coming into the reactor. This information regarding the mixing of the media in whole reactor volume could be deciphered by monitoring the visits of the tracer particle, which is tracking the media, at different locations inside the reactor. If the data is acquired for a sufficiently long time (in this case data is acquired for 15 days), then one can find the number of occurrences of tracer particle at different locations inside the reactor. A high occurrence shows that the phase that is being tracked by the tracer particle is dominant in that part of the column. Fig. 6 shows the occurrences of the tracer particle along the axial direction (z-axis) for all the investigated flow conditions. Results indicate that at low air flow rate and low water flow rate, no occurrences are recorded on the extreme ends of the side walls of bioreactor. This does not mean that there is no media present near the side walls of the bioreactor. However, it does indicate that these media are changing their positions in the vessel and are relatively stagnant. In other words, there are dead zones near the side walls. Results (Fig. 6) also indicate that at low flow rate, middle of the column is also not well utilized. The increase in air flow rate by keeping the waste water flow rate constant improves the situation and now media reaches the end walls (flat surfaces). The increase in liquid flow rate while keeping the air flow rate at minimum (bottom left histogram), further improves the condition. Now at the centre part of the reactor, media is relatively well mixed
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3. Summary We believe that our studies demonstrate beyond doubt that RPT is not only a versatile technique (which of course was known in the past [1]), but also at least as accurate as the more “common” and commercially available techniques like LDA [2]. Furthermore, good agreement was also obtained amongst higher order moments of velocity fluctuations. What adds to the versatility of the technique that not only can it be used in different kinds of systems, but also accurately at larger scales, as the study of the bioreactor reveals. The presentation at the HANARO Symposium 2010 will discuss these results in greater detail, and will focus on other aspects of the RPT technique as well as other applications.
REFERENCES [1] S. Roy, A. Kemoun, M.H. Al-Dahhan and M.P. Dudukovic, Experimental Investigation of the Hydrodynamics in a Liquid–Solid Riser, AIChE J., 51, No. 3, pp 802-835, 2005. [2] D. Pfleger, S. Gomes, N. Gilbert and H.G. Wagner, Hydrodynamic Simulations of Laboratory Scale Bubble Columns Fundamental Studies of the Eulerian-Eulerian Modeling Approach, Chem. Engng. Sci. 54, pp 5091-5099, 1999.
Radioisotopes
Fig. 6. Tracer particle occurrences at various flow conditions, indicating segregation towards ends and middle of bioreactor.
As a consequence of this study (which could be done in no other way in a pilot plant), the designers could implement modifications in the gas-entry tubes so that a state of uniform occurrences and media mixing could be achieved.
RI-O-03
Tuesday, 2 Nov. 11:40 â&#x20AC;&#x201C; 12:00 (Room 105)
An Effort to Improve U Foil Fabrication Technology of Roll-casting for Fission Mo Target Chang-Kyu Kima*, Yun-Myeong Wooa, Ki-Hwan Kima, Jong-Myeong Oha, Moon-Soo Simb Korea Atomic Energy Research Institute, Research reactor Fuel Development Division, DukJin 150, Yuseong, Deajeon, Republic of Korea b Chungnam University, Green Energy Technology, Goongdong 220, Yuseong, Daejeon, Republic of Korea *Corresponding author: ckkim2@kaeri.re.kr a
Mo-99 isotope has been produced mainly by extracting fission products of 235U. The targets for irradiating in reactor have used as stainless tube coated with highly enriched UO2 at the inside surface and highly enriched UAlx plate cladded with aluminum. In connection with non-proliferation policy the RERTR program developed a new process of Mo-99 using low enriched uranium (LEU) instead of highly enriched uranium (HEU). LEU should be put about five times more quantity than HEU because the 235U contents of LEU and HEU are 20% and higher than 90%, respectively. Accordingly pure uranium metal foil target was adopted as a promising target material due to high uranium density. ANL and BATAN developed a Cintichem process using uranium metal foil target of 130 mm in thickness jointly and the RERTR program is trying to disseminate the new process world-widely. However, uranium foil is made by lots of times rolling work on uranium plate, which is laborious and tedious. In order to avoid this difficulty KAERI developed a new process of making foil directly from uranium melt by roll casting. This process is very much simple, productive, and cost-effective. But the outside surface of foil is generally very rough. A typical transverse cross section had a minimum thickness of 65 mm and a maximum thickness of 205 mm. This roughness could affect (1) target fabrication, where the U foil, or the Ni foil might be damaged during drawing, and (2) irradiation behavior, where gaps between the target walls and the U metal might affect cooling of the target. After issuing this problem KAERI launched a further effort for improving this foil fabrication technology by direct casting on roll in 2008. The ideas of improving the technology were as following; (1) enhancing a longer holding time of thin layer melt as liquid phase for flattening the surface by surface tension, (2) rolling the solidified thin layer for smoothening the upper surface in-situ before cooling much, (3) replacing the slot crucible of quartz with the common plugging type crucible and slot tundish for eliminating the leaking problem of slot quartz, (4) implementing an automatic winding system to avoid the foil to be winkled. Based on the above ideas a new equipment was designed and manufactured in the industry in 2009. While the new equipment being test-operating, some phenomena of occurring problems appeared as following; (1) slow solidification induced the thin melt to be agglomerated and separated into many pieces, (2) the 2nd roll was too loaded from plastic deformation by pressing on rough upper surface and caused the revolution speed to decrease. Accordingly Cu roll is absolutely required. The 2nd roll press is not enough to make the rough surface smooth. When the 2nd roll is removed, a sound thin foil with long length can be made without any disconnection. If this sound foil is roll-worked separately, the newly designed equipment would have some various advantages as followings; (1) thicker foil is available, ( 2) foil yield is improved much, (3) pouring failure from melt leakage can be reduced much, and (4) slower foil speed at coming out from the slot makes automatic in-situ winding easier. Using a surrogate material of Cu for U some sound foils with various thicknesses were made successfully. Thickness variations observed for Cu foils will be reported.
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RI-O-04
Tuesday, 2 Nov. 14:00 – 14:20 (Room 105)
Development Status on Fission 99Mo Production at KAERI Hyon Soo Han*, Jun Sig Lee , Ul Jae Park , Kwang Jae Son, Chang Kyu Kim, Byung Chul Lee, Sun Ju Choi Korea Atomic Energy Research Institute, P.O. Box 105, Yusung, Daejeon 305-600, Korea *Corresponding author: hshan2@kaeri.re.kr
Mo plays a key role in medical applications of radioisotope, which is base material for production of 99Mo/99mTc generator. Korea Atomic Energy Research Institute (KAERI) produced 99Mo on basis of (n, gamma) reaction for supply of 99mTc solution in domestic user in 1970’s. Since 2003 99mTc solution was supplied by chromatographic generators which were produced by a private company in Korea. For more than twenty years, KAERI has studied on feasibilities of fission 99Mo production and continued to develop related techniques for the production of fission 99 Mo using uranium targets. In 1987 studies on fission 99Mo was started for utilization of Korea Multipurpose Research Reactor (renamed HANARO) and a small area was reserved for process development in future. Before HANARO operation it was needed to give shape to a plan of fission 99Mo production to increase efficiency of utilization of HANARO. In middle 1990s the technical and economic feasibility study for fission 99Mo production utilizing HANARO was carried out. With this feasibility study a project for mass production of 99Mo was launched to develop a production process of 99Mo utilizing high enriched uranium (HEU) target. Final goal of this project was to enter commercial market of 99Mo supply in 2006 but the plan was miscarried due to failure to get HEU target material from abroad. Contents of the project had been changed to confine to development of fabrication technology of target using low enriched uranium (LEU) foil. KAERI developed cylindrical 20% LEU targets which were fabricated by extruding process after inserting LEU metal foil (100-160 micrometer in thickness) between two Al tubes. For a performance test the developed LEU targets were irradiated in abroad research reactors in the favor of member states of IAEA CRP on “Establish Techniques for Small Scale Indigenous Molybdenum-99 Production using Low Enriched Uranium Fission or Neutron Activation.” For the development of separation technology of 99 Mo from the irradiated target, a mock-up test employed a modified Cintichem process was carried out. Facing a recent global shortage of 99Mo, Korean government came to be concerned with the commercial production of fission 99 Mo in Korea and sent delegates to OECD/NEA conference to share information as well as to strengthen international cooperation. According to Comprehensive Radiation and Radioisotope Promotion Plan started in 1997, Korea has a plan to grow as a hub of isotope supply of Asian region. Producing fission 99Mo is one of the best ways for Korea to acquire a leading position in Asian market. Korean government plans on building a 20 MW new research reactor with radioisotope production facilities in Busan by 2015 which will be dedicated only for radioisotope production and neutron transmutation doping of Si semiconductor. This will mainly contribute to the stabilization of the commercial production of fission 99Mo. Final goal of the plan is to be capable of producing and commercially supplying 2000Ci per batch (6 days reference) of 99Mo by 2016. KAERI would develop related technologies such as preparation of target using LEU metal foil, neutron irradiation of the target in reactor, chemical process based on modified Cintichem process, hot cell facility handling irradiated materials, and waste management, etc. Successful accomplishment of this project would contribute to a more stable supply of 99Mo for the medical use in global as well as regional markets.
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Radioisotopes
99
RI-O-05
Tuesday, 2 Nov. 14:20 – 14:40 (Room 105)
Dosimetry of P-32 Ophthalmic Applicators: Comparison between Measurements and Monte Carlo Simulations Chang Heon Choi1,2*, So Yeon Park1,2, Hyon Soo Han3, Kwang-Jae Son3, Ul Jae Park3, Il Han Jim1,2, Sung-Joon Ye1,2 Interdisciplinary Program in Radiation Applied Life Science, Seoul National University Graduate School, Seoul, Korea 110-744 2 Institute of Radiation Medicine, Medical Research Center Seoul National University College of Medicine, Seoul, Korea 110-744 3 Hanaro Applications Research, Korea Atomic Energy Research Institute, Daejeon, Korea 305-353 *Corresponding author : dm140@snu.ac.kr 1
Introduction: A 90Sr/Y applicator has been widely used as a pure b-source for postoperative irradiation after pterygium excision. As an alternative to 90Sr/Y irradiation, we proposed treatments with pure betas of a 32P-source. A new cylindrical 32P applicator was fabricated in the Korea Atomic Energy Research Institute by using the Hanaro nuclear reactor. This study aims to provide the dosimetry for this new applicator prior to the clinical implementation. Methods/Material: We developed new 32P ophthalmic applicators. In order to optimize the proper design and materials, Monte Carlo simulations were performed. The applicators were manufactured by the Hanaro reactor group of KAERI, according to this proposed design (Fig.1.). A common method of measuring the absorbed dose at the surface of a sealed beta source is by means of an extrapolation ionization chamber. It provided the calibrated dose rate at the reference point. Radiochromic film has been developed to measure absorbed dose of radiation, it provided an 1-D depth doses, and two-dimensional dose distributions, and it has been one of the most convenient techniques. Semiconductor detector (MOSFET) was used for purpose. Result: The absorbed dose rates to the reference point in water were 0.238 ± 0.012 cGy/s for an extrapolation ionization chamber, 0.280 ± 0.001 cGy/s for radiochromic films (RCF), and 0.257 ± 0.020 cGy/s for MOSFET dosimeters (Table 1). The axial depth doses measured by RCF and MOSFET decreased very rapidly with increasing depths. The dose rate was reduced into approximately 1/10 as 32P betas penetrate every 2 mm depth. Being considered very high dose gradient and measurement setup uncertainties, measured data sets in depths of 1 mm to 3.5 mm agreed with Monte Carlo data (Fig.2). Due to nonuniform absorption of 32P to an absorbent disk, the dose at the center of transaxial plane were 2%-4% less than the peak dose around the periphery (Fig.3). But it provided a better transaxial dose uniformity than Monte Carlo data that assumed an uniform absorption of 32P. We confirmed no leakage of 32P activities in the applicator and negligible
exposure rate around the hand grip . Discussion/Conclusions: The clinical doses at any points from the 32P applicator can be calculated from these measured data sets. The 32P applicator can deliver uniform therapeutic doses to the surface of the conjunctiva for postoperative irradiation of pterygium, while sparing the lens better than 90Sr/Y applicators. The safety of the 32P applicator was confirmed. However, prior to the clinical application of every new source, the integrity, dose uniformity, and absorbed dose rate at the reference point should be evaluated by the methods described in this study.
Depth (mm)
Extrapolation chamber
Radiochromic film
0 (surface)
0.238± 0.012
0.280 ± 0.001 0.257±0.020
MOSFET
Table 3. Absorbed dose rate (cGy/s) to water at the reference point measured by three different dosimeters.
Fig 1. A prototype of 32P applicator and parts a) various components (isotope, sealing, and protector,etc.), b) a part of grip, c) eyecontact surface
Fig 2. Measured and calculated (MCNP) depth dose distributions for the 32P planar source
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Fig 3. Relative dose distribution for the 32P source obtained with radiochromic film at surface
RI-O-06
Tuesday, 2 Nov. 14:40 â&#x20AC;&#x201C; 15:00 (Room 105)
The Development of Amino Acid based Bifunctional Chelators for the Preparation of Radiophamaceuticals Kang-Hyuk Choi, Young-Don Hong, Ul-Jae Park, Jun-Sig Lee and Sun-Ju Choi* Radioisotope Research Division, Department of Research Reactor Utilization and development, Korea Atomic Energy Research Institute, Daedeok-daero 1045, Yuseong Gu, Daejeon 305-353, Rep. of Korea *Corresponding author: choisj@kaeri.re.kr
Background An interest in receptor-based radiopharmaceuticals both as clinical diagnostics and as therapeutics has increased during the past two decades, because radiopharmaceuticals provide the visualization and quantification of in vivo alterations without any surgery. In general, radiopharmaceuticals are composed of 3 parts; targeting biomolecule (TM), bifunctional chelating agent (BFCA), and radionuclide (RI). BFCA plays an important role in connecting radiometallic nuclides with biomolecules. The choice of BFCA for imaging and therapeutic applications is mainly determined by the nature of the metal ion required for the given application. In addition, BFCA requires a robust metal complexation with a high thermodynamic stability and kinetic inertness. For this purpose, many researchers are focusing on developing more effective chelating agents. The radioisotope research division has also developed novel BFCAs with improved metal ion complexation kinetics.
Diethylene triamine pentaacetic acid (DTPA) derivatives containing an isothiocyanate(-NCS) moiety for the selective conjugation with the biomloecules have been synthesized. In order to easily synthesize the novel chelator, These have been a focus to use amino acids as starting materials. The preparation of the phenylalanine based DTPA is described here. The p-nitrophenylalanine methyl ester as a starting material was reacted with tert-Butylacetate to form a 5-benzyl 1-tert-butyl glutamic acid (1). After purification, the compound (1) was reacted with tert-butyl 2,2â&#x20AC;&#x2122;(2-bromoethylazanediyl)diacetate and then the reduction of the nitro group was performed with Pd/C. Deprotecton of t-Bu was performed with 3M HCl and then isothiocyanatation was completed by using thiophosgen. This final product was purified with column chromatography. The overall yield was about 60%. Additionally, 4 different amino acids based DTPAs and 3kinds of multiful DTPAs were prepared with slight modification. The labeling procedure was performed just by mixing the 2 mCi of Lu-177 or Y-90. During the reaction, the DTPA derivatives can easily be radiolabeled at room temperature with high purity (>98%).
Conclusions In summary, Novel DTPA derivatives as bifunctional chelating agents (BFCA) were prepared by simple synthetic procedure. These DTPA derivatives can easily be applied for preparation of peptide based radiopharmaceuticals and radioimmunotherapy, and are useful to utilize radio-metallic isotope.
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Radioisotopes
Methods and Results
RI-O-07
Tuesday, 2 Nov. 15:30 â&#x20AC;&#x201C; 15:50 (Room 105)
The Application of Technetium in Nuclear Medicine Young-Don Hong, Kang-Hyuk Choi and Sun-Ju Choi* Radioisotope Research Division, Korea Atomic Energy Research Institute Dukjin-dong 150, Yuseong, Daejeon, 305-353, Republic of Korea *Corresponding author: ydhong@kaeri.re.kr
Technetium (Tc) is an artificial radiometal with a very low atomic number (Z=43). The isotopes of great importance are 99Tc and 99mTc. 99Tc was mainly produced by fission of nuclear fuel with a half life of 2.13 105 yrs. It decays into stable 99Ru with the emission of pure beta particle with an energy of 0.29 MeV which makes it less detectable compared to gamma emitting nuclides. Whereas, short-lived isomer 99mTc is one of the most widely used radionuclides in nuclear medicine because of its preferable properties(T1/2= 6.02 hr, E = 140 keV). More than 85% of diagnostic scans were performed using 99mTc in hospitals worldwide. A variety of 99mTc-based radiopharamceuticals have been developed for evaluating organ function and assessing disease status by imaging methods. In this presentation, we review 99mTc-radiophamaceuticals that are routinely used in nuclear medicine, to give an introduction on the chemistry of technetium, and to outline new areas of research. We also briefly discuss several chelator systems that are being used to design new 99mTc-radiophamaceuticals as well as organometallic technetium(I) complexes with 99mTc(CO)3-core.
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RI-O-08
Tuesday, 2 Nov. 15:50 â&#x20AC;&#x201C; 16:10 (Room 105)
The IAEA Activities and Prospects on Radioisotope Techniques for Industrial Applications Joon-Ha Jin* Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Wagramer Strasse 5, A-1400 Vienna, Austria *Corresponding author: j-h.jin@iaea.org
Radioisotopes
Radioisotope-based techniques have been widely used in industry for troubleshooting, analysis of industrial process to optimize process management, solving operational problems, improving product quality, saving energy and reducing pollution. The IAEA has been playing an important role in coordinating the knowledge generation in this field and facilitating transfer of the technology to interested developing countries. A number of coordinated research projects (CRP) and technical cooperation (TC) projects have been implemented for this purpose. The results of these R&D and TC activities in the field of radiotracer and sealed source technology are introduced herein. Some emerging industrial radioisotope techniques and the problems on the availability of radioisotopes for industrial applications in developing countries are presented and the strategy to overcome the problems is discussed for the further development and dissemination of the technology.
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RI-O-09
Tuesday, 2 Nov. 16:10 – 16:30 (Room 105)
Enhanced Biodistribution Property of 177Lu Labeled F(ab’)2 Fragment of Anti-Flt 1 for Radioimmunotherapy So-Young Leea,b, Young-Don Honga, Sun-Ju Choia* Radioisotope Research Division, Korea Atomic Energy Research Institute (KAERI), Republic of Korea Dept. of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Republic of Korea * Corresponding author:choisj@kaeri.re.kr a
b
1. Introduction The vascular endothelial growth factor (VEGF) is a potent pro-angiogenic growth factor abundantly expressed in most tumors. Hypoxia and increased VEGF levels induce enhanced expression of VEGF receptors, such as the receptor tyrosine kinase VEGFR1 (Flt 1) and VEGFR-2(KDR/Flk-1). Consequently, several VEGF- and VEGFR-antagonists have been developed, e.g. VEGF antisense oligonucleotides, anti VEGF and anti-VEGFR antibodies and VEGFR inhibitors.1-3 In previously, we prepared the 177Lu labeled anti-Flt 1 antibody as a VEGFR 1 specific antagonist and evaluated the therapeutic potential for cancer treatment.4 Radioisotope labeled antibody (Ab) has advantages in terms of radiation doses delivered to tumors. 177Lu labeled full anti-Flt 1 mAb have shown promising results in animal models. For more effective radioimmunotherapy, the choice of RIs for RIT depends on the size of targeted tumors. The high energy of 90Y and its long proticle rage make it suitable for irradiadion large metastases, where medium-energy beta emitters, such as 177Lu is better suited for the irradiation of small-sized, disseminated metastases.5-9 And optimal tumor targeting is necessary to achieve therapeutic levels of the chosen radionuclides at the tumor site. The 177Lu labeled antiFlt 1 mAb is also showed the substantial accumulation in tumor tissues but high liver uptake at our previous study.10 From the reference, size is one factor that impacts the circulation time and metabolism of Ab.11 A
full IgG Ab is a large 150kDa protein that can remain in circulation for 3-4 weeks while smaller molecules tend to exhibit faster uptake. However, in contrast to full Abs, antibody fragments have not been used frequently for RIT. In this study, we selectively cleaved anti-Flt 1 mAb into F(ab’)2 (having two antigen binding regions) and conjugated with 177Lu using cysteine based DTPANCS.12-13 To compare the biodistriburion properties, we analyzed the percent injected doses per gram of organ (%ID/g) in tumor xenografts of 177Lu labeled full antiFlt 1 and F(ab’)2 fragment. The purpose of this study was to demonstrate significantly superior biodistribution property of 177Lu-cysteine based DTPANCS-F(ab’) 2 fragment of anti Flt 1 with minimal toxicity to characterize its potential for RIT.
2. Methods and Results 2.1 Anti Flt 1 fragment Anti-Flt 1 monoclolnal Ab was purchased from Santacruz, and fragmented with immobilized pepsin (Pierce). 50ug of anti Flt 1 was added to the spin column containing the immobilized pepsin and incubated for 3 hours at 37 . The F(ab’)2 fragment of anti-Flt 1 was separated by centrifugation and analyzed in non-reducing SDS-PAGE. Thirty micrograms of radioimmunoconjugate was mixed with 2 of the sample buffer (5 containing 125 mM Tris–HCl (pH 6.8), 4% SDS, 20% glycerol, and 1 /ml of bromophenol blue (BPB)) and developed using
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Fig.1) Chelator used for 177Lu labeling of full antibody and fragment; cysteine based isothiocyanatobenzyl-DTPA (DTPA-NCS)
The F(ab’)2 fragment of anti-Flt 1 was prepared by digesting with immobilized pepsine and purified with centricon filter system. The purified fragement of Ab was conjugated with cysteine based DTPA-NCS by mixing for 10 min at room temperature and pH 7.4 with the molar ratio of 1:1 and analyzed in nonreducing SDS-PAGE. It migrated with an apparent molecular weight of 110kDa and showed no degradation products of the immunoconjugates. (Fig. 2)
2.2 Radioimmunoconjugationt Lu was produced at the HANARO research reactor (30MW) installed at the Korea Atomic Energy Research Institute (KAERI) by the neutron irradiation of natural 176 Lu [176Lu (n, ) 177Lu]. After the irradiation of a double capsulated 176Lu2O3 target for 5 days at a neutron flux of 1.0 x 1014n/cm2, it was cooled for 48hrs and dissolved in 3ml of 0.05N HCl solution. The anti-Flt 1 and F(ab’)2 fragment were conjugated with cysteine based DTPANCS at the molar ratio of 1:1 at room temperature and for 10 min. For the purification and buffer exchange, Centricon filter system (Millipore) was used in 50mM Na-actetate buffer (pH5.5). The purified immunoconjugates, cysteine based DTPA-NCS-anti Flt/fragmented anti Flt 1, were added to 3.7MBq/ml (100uCi/ml) of 177Lu solutions. The reaction mixtures were stirred gently and allowed to stand at room temperature for 10 min. Two to three microliters of 177Lu or 177Lu –DTPA-NCS or 177Lu –DTPA-NCS-anti-Flt 1 mAb or 177Lu –DTPA-NCS- F(ab’)2 fragment of anti-Flt 1 mAb were dropped on the ITLC (Instant Thin-Layer Chromatography) silica gel paper (Gelman Science Inc.). ITLC was developed with saline as the mobile phase and analyzed with Cyclone Storage Phosphor System (PerkinElmer). Glassware, materials and solutions for the labeling procedure were sterilized and metal-free. The radioactivity was measure using an ionizing chamber (Capintec 115R, BIODEX Atomlab 200) by setting the calibration value for 177Lu that was corrected and calibrated by the manufacture. The Rf values of the 177Lu, 177Lu –cysteine based DTPANCS, and 177Lu –cysteine based DTPA-NCS-anti-Flt 1/fragmented Ab were 1, 0.8~0.9, and origin, respectively. We easily obtained a high radiolabeling yield (>98%) of 177Lu-cysteine based DTPA-NCSF(ab’)2 fragment of anti-Flt 1 as well as 177Lu-cysteine based DTPA-NCS-anti-Flt 1 177
2.3 In vitro stability
Fig.2 Analysis of electrophoresis of cysteine derivative DTPA-NCSF(ab’)2 fragment of anti-Flt 1 using polyacrylamide gel. The gel was stained by coomassie brilliant blue R-250. The protein size markers include protein sizes of 250, 150, 75, 50 and 25kDa
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For assessment of the in vitro stability of 177Lu-cysteine based DTPA-NCS-F(ab’)2 fragment of anti-Flt 1 were stored at room temperature and 37 in saline. After 4 days, aliquot was taken and analyzed by ITLC. The radiolabeled anti-Flt 1 and its fragement were stable in vitro saline at 37 for 4 days. No free 177Lu formation was observed with ITLC. (Fig. 3)
Radioisotopes
Hoefer Scientific Instruments electrophoresis apparatus. In our previous study, the immunoconjugation steps of anti Flt-1 monoclonal Ab and cysteine based DTPA-NCS were optimized by varying incubation times, molar DTPA-NCS to Ab ratio and method of purification. The cysteine based DTPA-NCS derivative was conjugated to antibodies as isothiocyanato-derivative (Fig. 1).
Fig.3 In vitro stability of 177Lu-cysteine derivative DTPA-NCS-F(ab’)2 fragment of anti-Flt 1 at oC for 4 days determined by ITLC-SG using an autoradiographic system. The x-axis shows distance in cm from origin (left); the y-axis shows proportional activity count
The radiolabeled anti-Flt 1 and its fragement were stable in vitro saline at 37 for 4 days. No free 177Lu formation was observed with ITLC. (Fig. 3)
tumor accumulation. And similar activities of 177Lucysteine derivative DTPA-NCS and 177Lu-cysteine derivative DTPA-NCS-anti-Flt 1 fragment was remained in the blood at 1 day (0.41±0.17%ID/g and 0.33±0.11%ID/g, respectively), while the 177Lu labeled full anti-Flt 1 was ~2-fold higher. This result shows the fragmented anti-Flt 1 reached the maximal blood clearance level. In addition, the 177Lu labeled full anti-Flt 1 had high liver uptake. It is regarded as maximum blood clearance level. In contrast to previous results with 177Lu-cysteine derivative DTPA-NCS-anti-Flt 1, the radioactivity present in the blood was 0.71±0.04%ID/g at 1 day after injection. Its fragmented conjugate is characterized by 1.6-fold lower levels of blood clearance. In addition, the 177Lu labeled full anti-Flt 1 showed high kidney and liver uptake like other RI labeled full Abs. The comparative biodistribution results indicated the decreasing hematopoietic toxicity significanlty. The radioactivity level of 177Lu labeled fragmented anti-Flt 1 in the liver was 1.73±0.7%ID/g compare with 3.55±1.76%ID/g.
2.4 Biodistribution study The in vivo behavior of the radioimmunoconjugate was studies in female BALB/c nude mice (Orient Co.) bearing Calu6 (human non- small cell lung carcinoma) xenografts. The nude mice at 7 to 8 weeks age (22g) 106 Calu6 cells with 0.1ml were injected with 1 Materigel (BD bioscience) subcutaneously. The mice were used 2 weeks post inoculation of tumor cells, when tumors reached a weight of approximately 0.2g. For biodistribution studies, 0.185MBq (5uCi) of 177Lucysteine based DTPA-NCS-anti Flt 1 or 177Lu-cysteine based DTPA-NCS-F(ab’)2 fragment of anti-Flt 1 was injected intravenously into the tumor-bearing mice. The mice (n=5) were sacrificed 24hr after injection and the radioactivities in the tumor, kidney, liver, spleen, heart, small and large intestine, lung, stomach and blood were determined using -scintillation counter (Perkin Elmer)and expressed as percentage of the injected dose per gram tissue (% ID/g). The biodistribution results at 1 day post-injection are compared and presented on Table 1. The tumor-to-blood ratio of 177Lu-cysteine derivative DTPA-NCS-F(ab’)2 fragment of anti-Flt 1 was as high as 13:1. In the previous result with 177Lu-cysteine derivative DTPANCS-anti-Flt 1 was 3.25:1. In this study, its fragmented conjugate is characterized by 4-fold higher levels of
Table 1) Biodistribution of 177Lu-cysteine derivative DTPA-NCS, 177Lucysteine based DTPA-NCS-anti-Flt1 and 177Lu-cysteine derivative DTPA-NCS- F(ab’)2 fragment of anti-Flt 1 in mice bearing Calu6 non small cell lung cancer 24h post injection .Values are percentage of the injected dose per gram tissue (% ID/g). 177
Lu-cysteine derivative DTPA-NCS
177
177
Lu- cysteine based DTPANCS-anti-Flt1
Lu-cysteine derivative DTPA-NCSF(ab’)2 fragment of anti-Flt 1
Blood
0.41±0.19
0.71±0.04
0.33±0.11
Liver
0.31±0.08
3.55±1.76
1.73±0.75
Kidney
1.17±0.2
8.4±0.2
7.09±0.76
Spleen
0.52±0.02
0.76±0.16
0.66±0.13
Heart
0.56±0.02
0.85±0.16
1.0±0.27
Small Intestine
0.2±0.05
0.72±0.23
0.92±0.16
Large Intestine
0.39±0.22
0.53±0.08
0.28±0.02
Lung
0.83±0.31
1.12±0.38
0.82±0.16
Stomach
0.28±0.06
1.2±0.520.6
7±0.35
Tumo
r0.57±0.17
2.31±0.54
4.34±0.79
* Each value is the average of at least five animals.
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3. Conclusions The F(ab’)2 fragment of anti-Flt 1 was successfully radioimmunoconjugated with 177Lu using cysteine based DTPA-NCS on same procedure of 177Lu labeled full Ab. And we compared the biodistribution properties of 177Lu labeled anti-Flt 1 and its fragment in human non-small lung cancer cell xenogragts. The 177Lu labeled anti-Flt 1 fragment was remained in circulation shorter, significantly increasing tumor accumulation rate and decreasing hematopoietic toxicity. This radioimmunoconjugate using anti-Flt 1 fragment has a potential for tumor imaging and/or therapy. And faster clearance rate can lead to increased tumor-to-background ratio as angiogenesis tracer, enhanced tumor uptake rate can improve therapeutic efficacy as RIT.
REFERENCES [1] Xin Jin, Xiaoli Ge, Ding-liang Zhu, Chen Yan, YuFeng Chu, Wen-dong Chen, Jianjun Liu, Ping-jin Gao. 2007. Expression and function of vascular endothelial growth factor receptors (Flt-1 and Flk-1) in vascular adventitial fibroblasts. J Mol Cellular Cardiology. 43, 292–300 [2] Yan Wu, Andrea T. Hooper, Zhaojing Zhong, Larry Witte, Peter Bohlen, Shahin Rafii and Daniel J. Hicklin. 2006. The vascular endothelial growth factor receptor (VEGFR-1) supports growth and survival of human breast carcinoma. Int. J. Cancer: 119, 1519–1529 [3] B. A. Fine, M.D., P. T. Valente, M.D., G. I. Feinstein, M.D., and T. Dey, M.D. 2000. VEGF, flt1, and KDR/flk-1 as Prognostic Indicators in Endometrial Carcinoma Gynecologic Oncology 76, 33–39 [4] S.Y.Lee, Y.D.Hong, M.S.Pyun, Penelope M Felipe,S.J.Choi. Radiolabeling of monoclonal anticascular endothelial growth factor receptor 1(VEGFR 1) with 177Lu for potential use in radioimmunotherapy. Applied Radiation and Isotopes, 2009; 67:1185-1189
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[5] C.Andrew Boswell, Martin W.Brechbiel. Development of radioimmunotherapeutic and diagnostic antibodies : an inside-out view. Nuclear Medicine and Biology, 2007;34:757-778 [6] Jurgen Grunberg, Ilse Nivak-Hofer et.al. In vivo evaluation of 177Lu- and 67/64Cu-labeled recombinant fragments of antibody chCE7 for radioimmunotherapy and PET imaging of L1-CAMpsitive tumors. Clin Cancer Res, 2005;11(14):51125120 [7] Sun-Ju Choi, Young-Don Hong, So-Young Lee. 2006. Therapeutic radionuclides. Nucl Med Mol Imaging. 40(2), 58-65 [8] Volkert, W.A., Goeckeler, W.F., Ehrhardt, G.J., Ketring, A.R. Therapeutic radionuclides: production and decay property considerations. J. Nucl. Med. 1991; 32: 174–185. [9] Srvastava, S.C., 1996, Therapeutic radionuclides : making the right choice. In : Mather, S.J. (ED.), Current directions in radiopharmaceutical research and development, Kluwer Academic Publications, Dordrecht, Boston, London, 63-79 [10] S.Y.Lee, Y.D. Hong, M.S. Pyun, Penelope M Felipe, S.J. Choi. Radiolabeling of monoclonal antiCD105 with 177Lu for potential use in radioimmunotherapy. Applied Radiation and Isotopes. 2009; 67:1366-1369 [11] S.Y. Lee, M.S. Pyun, Y. D. Hong and S.J. Choi, Preparation and characterization of Cysteine based DTPA derivative and its immunoconjugate for Radioimmunotherapy, The Korea Society of Nuclear Medicine, 2007 Oct. 460011 [12] K.H. Choi, Y.D. Hong, M.S. Pyun and S.J. Choi. Preparation of an Amino Acid DTPA as BFCA for Radioimmunotherapy, Bull.Korean Chem. Soc, 2006, 27(8), 1194-1198 Radioisotopes
These results show that the biodistrubution property of the 177Lu labeled fragmented anti-Flt 1 is enhanced especially regarding tumor accumulation, blood clearance and liver uptake.
RI-O-10
Tuesday, 2 Nov. 16:30 â&#x20AC;&#x201C; 16:50 (Room 105)
Status of Industrial Application using Radioisotope Jinho Moon, Sung-Hee Jung*, Jong-Bum Kim Radioisotope Research Division, Department of Research Reactor Utilization and Development, Korea Atomic Energy Research Institute, Daedeok-daero 1045, Yuseong Gu, Daejeon 305-353, Rep. of Korea *Corresponding author: shjung3@kaeri.re.kr
The radioisotope technology for industrial application includes radiotracer and sealed source application for process diagnosis, environmental systems, nucleonic gauge and Non Destructive Test. In many cases radioisotope technology is categorized to radiation technology along with the irradiation technology. But radioisotope technology is based on the utilization of radioisotope from the reactor while irradiation technology is based on the utilization of gamma rays from irradiation facilities. The industrial applications of radioisotope are basically fusion technology which has more than two areas. One is radiation technology and the other is related to application industries. Application to the industries is deeply engaged with cultural and natural background of each country. So each country has developed its technology depending on its own industrial situation. Normally industrialized countries have developed inspection technology by radioisotopes because they have big plant industries. Maritime countries have developed sediment transport studies by radiotracer. Recently there have been new studies in addition to traditional industrial radioisotope applications. Tomography by using radioisotope, industrial radioisotope generator, nano tracer and fusion technology on CFD/RTD/CT are the examples.
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RI-P-01
Development of bi-Radioisotope Labelled Nanoparticles by Radiation Reduction Method Jin-Hyuck Jung and Seong-Ho Choi* Department of Chemistry, Hannam University, 461-6 Jeonmin-dong Yuseong, Daejeon 305-811, Korea *Corresponding author: shchoi@hnu.kr
Radioisotopes
The radioactive tracers have been widely used in various sectors of science and engineering particularly in industrial and environmental area. A radioactive tracer should be prepared in appropriate physical and chemical form to make it same movement characteristics with the process material under investigation. In order to evaluate water resource system, the radioactive tracer with core-shell 197Au-M@SiO2 (M=Ag, Ir, Ni, Co) has been prepared by Stober method. The 197Au-M@SiO2 is irradiated from neutron by HANARO in order to obtain radioactive tracer. The neutron is irradiated in a nuclear reactor to activate gold nuclide into Au-198 with the emitting gamma radiation of 0.412 and 1.088 MeV. Core-shell particles have also been prepared with various size ranges 20nm to 200nm. In addition, various organic compounds are introduced onto the surface of core-shell nanoparticles in order to increase delivery in water system. The physical and chemical properties of the core-shell particles are evaluated by XRD, XPS, EDAX and TEM after the gamma irradiation process. The results indicate that the preparation method of core-shell nanostructure is useful for the synthesis of various radiotracers.
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RI-P-02
Analysis on the Pollutant Dispersion using a Radioisotope Tracer in Groundwater System Kyung-Suk Suh*, Ki-Chul Kim, Geon-Hyeong Park and Sung-Hee Jung Korea Atomic Energy Research Institute, 1045 Daedeokdaero, Yuseong-Gu, Daejeon, Korea *Corresponding author: kssuh@.kaeri.re.kr
The radioactive waste repository is now constructed in order to bury the low and intermediate-level waste in Korea. The analysis on the transport of radionuclide in subsurface soil is important with respect to the establishment of environmental safety and monitoring systems near a nuclear waste repository. The radionuclides in subsurface soil are advected by groundwater flow and transported by the hydrodynamic dispersion. In this study, laboratory-scale experiments by using a radioisotope were conducted to evaluate the characteristics of the transport and dispersion of pollutants in the soil. The radioactive waste repository near Gyeong-ju in Korea was selected with experimental area and the hydraulic model of the laboratory-scale was manufactured based upon its geometric similarity. Tc-99m having a short half-life was used with a tracer and it was injected instantaneously into the soil. Tc-99m milked from a 99Mo/99mTc portable generator fabricated for medical purposes had 0.141mEv of gamma radiation and 6.02 hours of a half life. The detection was made with 2 inch NaI(Tl) scintillation detectors at 3 transverse lines at a downstream direction from the release point. The arrival times of the maximum concentration of radioisotope tracers were observed after about 7.5 hours at the center point of 1st transverse line, 16.5 hours at the center point of 2nd transverse line and 27 hours at the center point of 3rd transverse line, respectively. The dispersion phenomenon using the radioactive tracer was measured quite well by the advection and hydrodynamic dispersion throughout this experiment. The observed results can be used to estimate the groundwater flow and the pollutant migration in the normal operations of nuclear facilities.
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RI-P-03
Preparation and Biodistribution of 166 Ho-DTPA-Cetuximab O. D. Awha*, D. H. Kima, T. S. Leeb Dept. of Biomedical Laboratory Science, College of Health Science, Yonsei University, 223 Maeji-ri, Heungup-myun, Wonju-si, Kangwon-do, 220-710, Korea b Molecular Imaging Research Center, KIRAMS, Seoul, Korea *Corresponding author: immunoch@yonsei.ac.kr a
Radioisotopes
Holmium-166 has decay characteristics suitable for radioimmunotherapy of cancer. Cetuximab, a chemeric monoclonal antibody against epidermal growth factor receptor (EGFR), is currently used to treat several solid tumors. To evaluate the effectiveness of 166Ho-DTPA-Cetuximab as an agent for radioimmunotherapy, the labeled compound was prepared and it's biodistribution examined. Cyclic DTPA anhydride was conjugated to Cetuximab with the different molar ratios of DTPA to Cetuximab. The number of bound DTPA per Cetuximab was determined to be 22.0, 39.2, 49.2, 59.8, 73.2, and 88.4 at the DTPA/Cetuximab ratios of 50:1, 100:1, 200:1, 300:1, 500:1, and 1000:1, respectively. The rabeling yields of 166Ho to DTPA-Cetuximab prepared at 50:1, 100:1, 200:1, 300:1, 500:1, and 1000:1 molar ratios of DTPA to Cetuximab were 63.5%, 69.4%, 97.2%, 98.2%, and 98.9%, respectively. The stability of 166Ho-DTPA-Cetuximab was maintained with above 95% radiochemical purity for 24 hr. at 37 . In vitro cell binding assay was performed with 166Ho-DTPA-Cetuximab to determine its immunorectivity to A549 tumor cells. The immunoreactivity of 166Ho-DTPA-Cetuximab was about 60.7%. 166Ho-DTPA-Cetuximab was injected to mice bearing A549 tumors and its biodistribution was analyzed at varied time points. Intratumoral uptake of the 166Ho-DTPA-Cetuximab was increased time elapsed, 3.04±1.36, 3.58±1.90, 6.91±0.34, 7.84±1.74,and 9.10±1.83 at 2hr, 6hr, 24hr, 48hr, and 72hr postinjection, respectively. These data showed that 166Ho-DTPACetuximab would be a renovated molality of radioimmunotherapy for EGFR-expressing tumors.
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Author Index
Abstract No.
Page No.
Author Name
Abstract No.
Page No.
A. N. Pirogov
MG-P-03
146
Byung-Hyuk Jun
MG-P-05
148
A. Pirogov
EE-P-08
114
C. H. Lee
SR-P-04
65
A. Teichert
MG-O-07
143
C. H. Lee
SR-P-24
87
A.V.Belushkin
SR-O-04
38
C. I. Cheon
MG-P-03
146
Abhishek Burri
EE-P-09
115
C. Tippayakul
SR-O-06
40
Ajrun Ghosh
SM-O-01
119
C.B.Lee
IR-O-06
195
Albrecht Wiedenmann MG-O-05
141
C.G. Seo
SR-P-16
78
Alim Tarigan
SR-O-11
52
C.-H. Lee
SM-O-06
124
Amares Chatt
Plenary
27
Camden R. Hubbard
EE-O-10
103
Andrew Nelson
SR-O-03
37
Carlos Durione
SR-P-10
71
Antonio Faraone
SM-P-09
133
Chan Woo Park
SM-P-01
125
Antonio Faraone
SM-O-02
120
Chan Woo Park
SM-P-02
126
B. K. Cho
MG-P-04
147
Chan-Bock Lee
IR-P-07
207
B. S. Seong
EE-P-08
114
Chang Hee Han
IR-P-09
209
B. S. Sung
MG-P-03
146
Chang Heon Choi
RI-O-05
231
B.H. Lee
SR-P-16
78
Chang Hwan Shin
IR-O-05
194
Baek Seok Seong
EE-O-13
106
Chang Je Park
SR-P-15
77
Baek-Seok Seong
SR-P-20
83
Chang Kyu Kim
EE-P-05
111
Baek-Seok Seong
EE-O-11
104
Chang Kyu Kim
RI-O-04
230
Baek-Seok Seong
EE-P-07
113
Chang Yong Joung
IR-O-03
192
Baek-Seok Seong
MG-P-05
148
Chang-Hee Lee
SR-O-09
50
Baek-Seok Seong
SR-P-05
66
Chang-Hee Lee
SR-P-20
83
Baek-Seok Seong
EE-P-06
112
Chang-Hee Lee
SR-P-23
86
Baek-Seok Seong
SM-O-03
121
Chang-Hee Lee
SR-P-05
66
Bjørn Clausen
EE-O-12
105
Chang-Hee Lee
SM-O-03
121
Bokyung Jung
SM-P-02
126
Chang-Kyu Kim
RI-O-03
229
Bong Goo Kim
IR-O-08
197
Changwoo Doe
SM-O-02
120
Bong Goo Kim
IR-O-07
196
Changwoo Doe
SM-P-07
131
SM-P-09
133
Bong Goo Kim
IR-O-09
198
Changwoo Doe
Bong Shick Sim
IR-O-03
192
Changwoo Doe
SM-P-03
127
Bong-Sik Sim
SR-P-13
75
Changwoo Doe
SM-P-04
128
Bong-Sik Sim
IR-P-02
200
Chang-Young Joung
SR-P-13
75
Boonggoo Kim
IR-P-06
206
Chang-Young Joung
IR-P-02
200
Bülent Akgün
SM-P-08
132
Chan-Joong Kim
MG-P-05
148
Byeong Joo Yoon
SR-P-17
79
Chan-Soo Park
AA-P-01
171
Byoung-Oon Lee
IR-P-07
207
Cheol Eui Lee
CS-P-01
149
Byoung-Won Jung
AA-P-10
180
Cheol Park
SR-P-12
74
Byoung-Won Jung
AA-P-11
181
Cheol Yong Lee
IR-O-07
196
Byung Chul Lee
RI-O-04
230
Chong-Tak Lee
IR-P-07
207
Byungchul Lee
SR-P-15
77
Chul Gyo Seo
SR-P-15
77
Byung-Chul Lee
SR-P-08
69
Chul Yong Lee
IR-P-07
207
- 243 -
Author Index
Author Name
Abstract No.
Page No.
Gernot Heger
CS-P-01
149
154
Gilsoo Kim
IR-P-12
212
CS-P-03
151
Guenter Mank
SR-O-05
39
CS-P-04
154
Guk Hoon Ahn
IR-O-03
192
Chul-Yong Lee
IR-P-02
200
Gwang Min Sun
AA-O-03
162
Chung-Sung Lee
SR-P-14
76
Gwang Min Sun
AA-P-13
183
Chung-Yul Yoo
EE-P-03
109
Gwang-Min Sun
AA-O-07
170
Chun-Ming Wu
MG-O-03
139
Gwang-Min Sun
AA-P-07
177
Chun-Yeol You
MG-O-07
143
Gwang-Min Sun
AA-P-08
178
Craig M. Brown
EE-O-03
94
Gwang-Min Sun
AA-P-03
173
D. Choi
Author Name
Abstract No.
Page No.
Chul Yong Lee
IR-P-03
201
Chul-Kyoo Lee
CS-P-04
Chul-Min Chon Chul-Min Chon
Author Name
SM-O-06
124
Gwang-Min Sun
AA-P-04
174
D. H. Kim
RI-P-03
242
Gyuhong Roh
SR-P-15
77
D. J. Paik
EE-P-08
114
H. B. Lee
MG-P-02
145
D. Y. Ryu
SM-P-05
129
H. J. Kim
SR-P-24
87
Dae Ho Kim
IR-P-10
210
H. O. Kim
SR-P-24
87
Dae Ho Kim
IR-P-11
211
H. Y. Choi
SR-P-03
64
Dae Hwan Kim
EE-O-09
102
Ha Yan Park
AA-P-01
171
Daeyoung Chi
SR-O-12
57
Haeyoung Oh
AA-P-01
171
Danas Ridikas
SR-O-05
39
Hahn Choo
EE-O-06
97
David Taylor
SR-O-10
51
Hahn Choo
EE-O-10
103
Dong Jin Choi
SR-P-05
66
Hak-Sung Kim
SR-P-08
69
Dong Jun Mun
EE-O-08
99
Han-Jin Noh
MG-P-04
147
Dong Seok Oh
IR-O-05
194
Harish J. Pant
RI-O-02
225
Dong Weon Youn
SR-P-17
79
Hark-Rho Kim
SR-P-09
70
Dong-Jun Mun
EE-P-02
108
Harvey S. Hopkins
AA-O-06
169
Dong-Seok Park
SR-P-2
184
Hee Ju Lee
EE-O-04
95
E. Hwang
AA-P-02
172
Hee-Man Yang
SM-P-02
126
E.J. Shin
EE-P-08
114
Heemoon.Kim
IR-P-08
208
Ed Bradley
SR-O-05
39
Heonil Kim
SR-P-12
74
Eunhye Lee
CS-P-02
150
Hideki Matsuoka
SM-O-01
119
Eunjoo Shin
SR-P-20
83
Hiroshi Kawamura
Plenary
28
Eunjoo Shin
EE-P-07
113
Hiroshi Kira
EE-O-02
93
Eunjoo Shin
EE-O-07
98
Hi-Soo Moon
CS-P-03
151
E-Wen Huang
EE-O-12
105
Ho Jin Lee
EE-O-13
106
F. Mezei
Plenary
26
Ho Jin Ryu
EE-P-05
111
G. H. Ahn
SR-P-02
62
Ho Sang Jung
IR-O-09
198
G. H.Ahn
SR-P-03
64
Hoan Sung Jung
SR-O-13
58
G. M. Sun
AA-O-05
168
Hoan Sung Jung
SR-P-18
80
G. M. Sun
AA-P-12
182
Hoang Sy Minh Tuan
AA-P-13
183
Gee yang Han
SR-O-13
58
Hojin Sung
MG-P-04
147
Geon-Hyeong Park
RI-P-02
241
Hong-Joo Kim
SR-P-23
86
George F. Vandegrift
RI-O-01
222
Hong-Ju Kim
SR-P-05
66
- 244 -
Ho-young Choi
Abstract No.
Page No.
SR-P-02
62
Author Name
Abstract No.
Page No.
J.M.Park
IR-O-06
195
Huen Lee
EE-P-01
107
J.Y. Oh
SR-P-16
78
Hwa Seung Yoo
AA-P-04
174
Jae Ho Yang
EE-P-05
111
Hyeok-Cheol Choi
MG-O-07
143
Jae Sang Lee
EE-O-08
99
Hyo Seon Suh
SM-P-06
130
Jae Soon Park
EE-P-05
111
Hyon Soo Han
RI-O-04
230
Jae-Ik Kim
IR-P-15
217
Hyon Soo Han
RI-O-05
231
Jae-Joo Ha
Plenary
24
Hyun Jin Lee
SM-P-01
125
Jaekwang Seo
SR-O-12
57
Hyung Seon Shin
AA-P-01
171
Jaemin Sohn
IR-P-06
206
Hyungkyoo Kim
SR-P-11
72
Jae-Sang Lee
EE-P-02
108
Hyung-Sik Jang
SM-P-03
127
Jae-Young Kim
MG-P-04
147
Hyung-Sik Jang
SM-P-04
128
Jason S. Gardner
MG-O-01
137
Hyun-Jun Kim
SR-P-08
69
Je Geon Bang
IR-P-10
210
Hyun-Ok Kim
SR-P-23
86
Je Geon Bang
IR-P-11
211
I. J. Kim
AA-O-04
167
Je-Geun Park
SR-P-23
86
I. J. Kim
AA-P-02
172
Je-Geun Park
SR-P-24
87
Il Han Jim
RI-O-05
231
Je-Geun Park
SR-P-05
66
In Cheol Lim
SR-O-13
58
Jehan Kim
SM-P-07
131
In Cheol Lim
IR-O-03
192
Jeong Gon Son
SM-P-06
130
In Cheol Lim
IR-P-01
199
Jeong-Hun Han
SR-P-21
84
In Cheol Lim
IR-O-07
196
Jeong-Soo Lee
MG-O-06
142
Incheol Lim
SR-P-11
72
Jeong-Soo Lee
MG-O-07
143
In-cheol Lim
SR-P-17
79
Jeong-Soo Lee
SR-P-05
66
In-Hwan Oh
CS-P-01
149
Jeong-Soo Lee
SR-P-19
82
J. Cho
SM-P-05
129
Jeong-Soo Ryu
SR-P-08
69
J. H. Han
SM-O-06
124
Jeong-Soo Ryu
SR-P-09
70
J. H. Moon
AA-O-05
168
Ji-Hwan Lee
SM-P-09
133
Plenary
29
Ji-Hwan Lee
SM-O-02
120
J. Lee
SM-P-05
129
Ji-Hye Kim
EE-P-03
109
J. M. Suh
IR-P-14
214
Ji-Hyun Yoon
IR-P-09
209
J. M. Sungil Park
MG-O-04
140
Jihyun Yu
SM-P-07
131
J. S. Han
SR-P-03
64
Jin Gwi Byeon
EE-O-13
106
J. S. Han
SR-P-02
62
Jin Suk Park
IR-P-13
213
J. S. Kim
MG-P-03
146
Jin-Hee Jeong
AA-P-10
180
J. S. Lee
SM-O-06
124
Jin-Hee Jeong
AA-P-11
181
J. S. Yim
SR-P-16
78
Jinho Moon
RI-O-10
239
J. Scheffer
MG-P-01
144
Jin-Hong Lee
AA-O-07
170
J. Y. Kim
MG-P-04
147
Jin-Hong Lee
AA-P-10
180
J. Y. So
SR-P-24
87
Jin-Hong Lee
AA-P-11
181
J.-H. Chung
MG-P-01
144
Jinhwan Jeong
MG-P-04
147
J.-H. Chung
MG-P-02
145
Jin-Hyuck Jung
RI-P-01
240
IR-P-04
202
Jin-Sik Cheon
IR-P-07
207
J. Harvey Turner
J.H. Kim
- 245 -
Author Index
Author Name
Abstract No.
Page No.
Jung-Hee Lee
SR-P-08
69
59
Jung-Min Suh
IR-P-15
217
SR-P-08
69
Jun-ichi Suzuki
EE-O-02
93
SR-P-09
70
Jun-Sig Lee
RI-O-06
232
Ji-Wan Kim
MG-O-07
143
J端rgen Duppich
SR-O-01
35
Ji-Yong So
SR-P-23
86
Ju-Woon Lee
AA-P-03
173
Ji-Yong So
SR-P-05
66
K. H. Cho
AA-O-04
167
Jong Hwa Moon
AA-O-03
162
K. H. Cho
AA-P-02
172
Jong Man Park
EE-P-05
111
K. H. Kim
MG-P-01
144
Jong Sup Wu
SR-O-13
58
K. H. Kim
MG-P-02
145
Jong Sup Wu
SR-P-18
80
K. H. Lee
AA-O-05
168
Jong-Bum Kim
RI-O-10
239
K. P. Hong
SM-O-06
124
Jongdae Joo
EE-O-11
104
K. P. Kim
SR-P-04
65
Jongdae Joo
EE-P-06
112
K. Prokes
MG-P-02
145
Jong-Duk Kim
SM-P-01
125
K. Shin
SM-O-06
124
Jong-Duk Kim
SM-P-02
126
K.B. Eom
IR-P-14
214
Jong-Hwa Moon
AA-P-03
173
K.H. Andersen
SR-O-02
36
Jong-Hwa Moon
AA-P-04
174
K.J. Kim
IR-P-14
214
Jong-Il Choi
AA-P-03
173
K.L. Jeon
IR-P-14
214
Jong-In Kim
SR-P-09
70
K.L.Jun
IR-O-06
195
Jong-Myeong Oh
RI-O-03
229
K.N. Choo
IR-P-04
202
Jong-Myeong Oh
SR-P-08
69
K.W.Song
IR-O-06
195
Jong-Myoung Lim
AA-O-07
170
Kang-Hyuk Choi
RI-O-06
232
Jong-Myoung Lim
AA-P-10
180
Kang-Hyuk Choi
RI-O-07
233
Jong-Myoung Lim
AA-P-11
181
Ka-Ngo Leung
AA-O-06
169
Jong-Myung Lim
AA-P-03
173
Kazuya Aizawa
EE-O-02
93
Author Name
Abstract No.
Page No.
Jinwon Jeong
MG-P-04
147
Jin-Won Shin
SR-P-01
Jin-Won Shin Jin-Won Shin
Author Name
Jongmyung Oh
IR-P-06
206
Ke An
EE-O-10
103
Jongwah Moon
AA-O-02
161
Kee Nam Choo
IR-P-01
199
Jong-Wha Moon
AA-O-07
170
Kee Nam Choo
IR-P-13
213
Jong-Wha Moon
AA-P-10
180
Kee Nam Choo
IR-O-07
196
Jong-Wha Moon
AA-P-11
181
Kee Nam Choo
IR-O-09
198
Jong-Yun Kim
SR-P-22
85
Kee Nam Choo
IR-P-03
201
Joo-Hyun Moon
IR-O-02
191
Keenam Choo
IR-P-06
206
Joon-Ha Jin
RI-O-08
234
Kentaro Suzuya
EE-O-02
93
Jorbi
SR-O-07
48
Kevin Alldred
SR-O-05
39
Joy L. Rempe
IR-O-08
197
Ki Ha Kim
IR-P-08
208
Juhyeon Yoon
SR-O-12
57
Ki-Chul Kim
RI-P-02
241
Jun Hwan Kim
IR-P-07
207
Ki-Doo Kang
SR-P-14
76
Jun Sig Lee
RI-O-04
230
Kiha Kim
IR-P-12
212
Jun-Bo Sim
SM-P-07
131
Ki-Hwan Kim
RI-O-03
229
Jung-Hee Lee
SR-P-09
70
Kil Yong Lee
AA-P-05
175
Jung-Hee Lee
SR-P-01
59
Kil Yong Lee
AA-P-06
176
- 246 -
Author Name
Page No.
SR-P-02
62
M.S. Cho
IR-P-04
202
M.S.Cho
IR-O-06
195
122
Man Soon Cho
IR-P-01
199
SM-P-06
130
Man Soon Cho
IR-P-08
208
Kookheon Char
SM-P-08
132
Man Soon Cho
IR-O-07
196
Kook-Nam Park
SR-P-07
68
Man Soon Cho
IR-O-09
198
Kun Woo Song
IR-P-10
210
Mansoon Cho
IR-P-06
206
Kun Woo Song
IR-P-11
211
Martin Meven
CS-P-01
149
Kwang Ho Jo
IR-P-13
213
Masaaki Sugiyama
EE-O-02
93
Kwang Jae Son
RI-O-04
230
Masatoshi Arai
EE-O-02
93
Kwang Soo Park
EE-O-13
106
Mi Hyun Kang
EE-P-04
110
Kwangheon Park
IR-O-06
195
Michael James
SR-O-03
51
Kwangheon Park
IR-P-08
208
Mi-Hyun Kang
EE-O-11
104
Kwang-Jae Son
RI-O-05
231
Mi-Hyun Kang
EE-P-06
112
Kwang-Pyo Hong
SR-P-21
84
Min Seok Choi
AA-P-01
171
Kwang-Sei Lee
CS-P-01
149
Min-Jae Lee
SM-O-02
120
Kwang-Yong Chung
AA-P-09
179
Minjin Kim
SR-P-17
79
Kwanwoo Shin
SM-O-05
123
Min-Jin Kim
SR-P-08
69
Kwan-Woo Shin
SR-P-05
66
Minsu Jung
EE-P-04
110
Kye Hong Lee
SR-P-07
68
Moon-Soo Sim
RI-O-03
229
Kye-Hong Lee
SR-P-20
83
Mun Lee
SR-P-03
64
Kye-Hong Lee
SR-P-21
84
Mun-Jo Choi
SR-P-14
76
Kye-Hong Lee
AA-P-03
173
Myungkook Moon
SR-P-05
66
Kyeong-Hwan Lim
SR-P-08
69
Myung-Kook Moon
SR-P-23
86
Kyeong-Lak Jeon
IR-P-15
217
Myung-Kook Moon
SM-O-03
121
Kyong-Bo Eom
IR-P-15
217
N. H. Lee
IR-O-09
198
Kyongwoo Seo
SR-O-12
57
N. Klaysuban
SR-O-06
40
Kyuchul Shin
EE-P-01
107
Nam-Soo Shin
EE-P-03
109
Kyung Mi Lee
AA-O-06
169
Nathan Peld
SR-O-05
39
Kyung Seok Ko
AA-P-05
175
O. D. Awh
RI-P-03
242
Kyung-Suk Suh
RI-P-02
241
Oh-Hyun Kwon
IR-P-15
217
Kyuseok Song
SR-P-22
85
Okhee Lee
AA-O-02
161
Kyu-Tae Kim
IR-O-02
191
P.M. Bentley
SR-O-02
36
M. Bรถhm
SR-O-02
36
Pablo Adelfang
SR-O-05
39
M. K. Moon
SR-P-24
87
Pavel Mikula
EE-O-11
104
M. K. Moon
SM-O-06
124
Peter K. Liaw
EE-O-12
105
M. Kreuz
SR-O-02
36
Peter K. Liaw
EE-O-10
103
M. Lee
SR-P-02
62
Peter Voderwisch
MG-O-03
139
M. Ohnuma
EE-P-08
114
Philip A. Pincus
SM-P-09
133
M. Reehuis
MG-P-02
145
Phillip A. Pincus
SM-O-02
120
M. S. Kim
SR-P-03
64
R. Gregory Downing
AA-O-01
160
Abstract No.
Page No.
Ki-Yeon Kim
MG-O-06
142
M. S. Kim
Ki-Yeon Kim
MG-O-07
143
Ki-Yeon Kim
SR-P-19
82
Kookheon Char
SM-O-04
Kookheon Char
- 247 -
Author Index
Abstract No.
Author Name
Abstract No.
Page No.
Author Name
Abstract No.
Page No.
Rajesh K. Upadhyay
RI-O-02
225
Seung-Yeop Lee
EE-P-09
115
Ralph H. Condit
AA-O-06
169
Shantanu Roy
RI-O-02
225
Rino Choi
IR-O-04
193
Shin Ae Kim
CS-P-03
151
Ronald B. Rogge
EE-O-10
103
Shin Ae Kim
CS-P-04
154
Russell Thiering
SR-O-10
37
Shin-Hyun Kang
SM-P-07
131
Russell Thiering
SR-P-10
71
Shinichi Fujita
SM-O-01
119
S. B. Kim
MG-P-01
144
Shin-ichi Takata
EE-O-02
93
S. B. Soek
SR-P-04
65
Shi-Surk Kim
AA-O-06
169
S. Chue-inta
SR-O-06
40
Shunichi Nakayama
SM-O-01
119
S. H. Cho
SR-P-02
62
So Yeon Park
RI-O-05
231
Author Name
S. J. Cho
SR-P-04
65
Soo Yeol Lee
EE-O-10
103
S. J. Cho
SM-O-06
124
Sooyeol Oh
IR-P-06
206
S. J. Cho
SR-P-24
87
So-Young Lee
RI-O-09
235
S. O. Hur
SR-P-02
62
Stephen Holt
SR-O-03
37
S. Park
MG-O-07
143
Steven R. Kline
SM-P-07
131
S. W. Cho
SR-P-03
64
Steven R. Kline
SM-P-09
133
S.Chongkum
SR-O-06
40
Steven R. Kline
SM-O-02
120
S.-H. Chun
MG-P-01
144
Steven R. Kline
SM-P-03
127
S.-H. Chun
MG-P-02
145
Steven R. Kline
SM-P-04
128
S.J. Lee
IR-P-04
202
Su Ki Park
SR-P-12
74
Sang Bok Ahn
IR-P-08
208
Suhyun Ju
AA-O-02
161
Sang Hoon Bae
SR-P-06
67
Sun Ha Kim
AA-O-03
162
Sang Ik Wu
SR-P-06
67
Sun Ju Choi
RI-O-04
230
Sang Ik Wu
SR-P-07
68
Sun-A Jung
MG-P-05
148
Sang Min Byun
SR-P-18
80
Sung Baek Kim
MG-P-04
147
Sang Youl Baek
IR-P-08
208
Sung Hee Jung
SR-P-22
85
Sang Young Lee
IR-O-09
198
Sung Ho Ahn
IR-O-03
192
Sangbok Ahn
IR-P-12
212
Sung Ho Kim
IR-P-09
209
Sang-Eon Park
EE-P-09
115
Sung Soo Kim
EE-O-09
102
Sangho Yoo
AA-P-07
177
Sung Soo Kim
EE-P-07
113
Sangho Yoo
AA-P-13
183
Sung-Chul Shin
MG-O-07
143
Sang-Ik Wu
SR-P-13
75
Sung-Chul Kim
EE-P-03
109
Sang-Ik Wu
SR-O-09
50
Sung-Hee Jung
RI-O-10
239
Sang-Jin Cho
SR-P-01
59
Sung-Hee Jung
RI-P-02
241
Sang-Jin Cho
SR-P-05
66
Sung-Ho Ahn
SR-P-13
75
Sang-Jin Cho
SR-P-08
69
Sung-Ho Ahn
IR-P-02
200
Sangyul Baek
IR-P-12
212
Sungil Park
SR-P-05
66
Seong-Ho Choi
RI-P-01
240
Sungjae Park
IR-P-06
206
Seong-Su Lee
MG-P-05
148
Sung-Joon Kim
EE-O-07
98
Seung Gu Lee
AA-P-06
176
Sung-Joon Ye
RI-O-05
231
Seung Kyu Lee
IR-P-13
213
Sungkyun Park
MG-O-06
142
Seung-Joo Kim
EE-P-03
109
Sung-Min Choi
SM-O-02
120
- 248 -
Author Name
Page No.
EE-P-06
112
W. I. Yang
IR-O-09
198
W. J. Son
SR-P-03
64
121
W. J. Son
SR-P-02
62
SR-P-05
66
W. K. Seong
IR-O-09
198
Sung-Min Choi
SM-P-03
127
W. N. Kang
IR-O-09
198
SungSoo Kim
IR-P-05
205
W. Wiesenack
IR-O-01
190
Sun-Ha Kim
AA-P-03
173
Walter Bermude
SR-P-10
71
Sun-Ha Kim
AA-P-04
174
Wanchuck Woo
EE-O-11
104
Sun-Ju Choi
RI-O-06
232
Wanchuck Woo
EE-O-13
106
Sun-Ju Choi
RI-O-07
233
Wanchuck Woo
EE-P-04
110
Sun-Ju Choi
RI-O-09
235
Wanchuck Woo
EE-P-06
112
Sushil Satija
SM-P-08
132
Wang Ki In
IR-O-05
194
Sven C. Vogel
EE-O-06
97
Wei Zhang
EE-O-06
97
Sy Minh Tuan Hoang
AA-P-07
177
Weijian Lu
SR-O-10
51
T. S. Lee
RI-P-03
242
Wen-Hsien Li
MG-O-03
139
Tae Hyun Chun
IR-O-05
194
Werner Wagner
SR-O-01
35
Tae Jong Lee
AA-P-06
176
Wigbert J. Siekhaus
AA-O-06
169
Tae-Ho Lee
EE-O-07
98
Won-Ho In
SR-P-14
76
Tae-Ho Lee
EE-P-06
112
Woo Seog Ryu
IR-P-09
209
Tae-Hwan Kim
SR-P-20
83
Woongsub Song
IR-P-12
212
Tae-Hwan Kim
SM-O-03
121
Woo-Seog Ryu
IR-P-12
212
Tae-Hwan Kim
SM-P-07
131
Xun-Li Wang
EE-O-01
92
Tae-Hwan Kim
SR-P-05
66
Y. Choi
EE-P-08
114
Takashi Kamiyama
SR-O-08
49
Y. G. Lee
SR-P-03
64
Abstract No.
Page No.
Sung-Min Choi
SM-P-04
128
Vyacheslav Em
Sung-Min Choi
SM-P-07
131
Sung-Min Choi
SM-P-09
133
Sungmin Choi
SM-O-03
Sung-Min Choi
Takayoshi Ito
EE-O-02
93
Y. H. Choi
SM-O-06
124
Takayuki Oku
EE-O-02
93
Y. H. Choi
SR-P-24
87
Takenao Shinohara
EE-O-02
93
Y. J. Kim*
AA-P-12
182
Takeshi Nakatani
EE-O-02
93
Y. K. Jeon
SR-P-24
87
Taku J Sato
MG-O-02
138
Y. Oba
EE-P-08
114
Tea-Hwan Kim
SR-P-14
76
Y. S. Chung
AA-O-05
168
Tong Kweon Kim
AA-P-06
176
Y. S. Chung
AA-P-12
182
Toshiya Otomo
EE-O-02
93
Y. S. Song
MG-P-02
145
U. W. Nam
SR-P-24
87
Y. Y. Choi
EE-P-08
114
Uk-Won Nam
SR-P-05
66
Y.H. Kang
IR-P-04
202
Uk-Won Nam
SR-P-23
86
Y.K. Yoon
IR-P-04
202
Ul Jae Park
RI-O-05
231
Y.M. Lee
IR-P-04
202
Ul Jae Park
RI-O-04
230
Y.S. Lee
IR-P-04
202
Ul-Jae Park
RI-O-06
232
Y.-S. Song
MG-P-01
144
Ung Sup Song
IR-P-08
208
Y.Tomota
EE-O-05
96
Vyacheslav Em
EE-O-11
104
Y.W. Tahk
SR-P-16
78
Vyacheslav EM
EE-O-13
106
Yang Hyun Koo
R-P-10
210
- 249 -
Author Index
Abstract No.
Author Name
Author Name
Abstract No.
Page No.
Author Name
Abstract No.
Page No.
Yang Hyun Koo
IR-P-11
211
Young-Don Hong
RI-O-09
235
Yang Mo Koo
EE-O-08
99
Young-Hui Seo
EE-P-09
115
Yang-Mo Koo
EE-P-02
108
Young-Il Kim
CS-P-02
150
Yasuhiro Inamura
EE-O-02
93
Youngki Kim
SR-P-11
72
Yeong Ah Choi
SM-P-01
125
Young-Ki Kim
SR-P-13
75
Yeong Min Jo
SM-P-02
126
Young-Kook Lee
EE-P-04
110
Yeong-Garp Cho
SR-P-08
69
Youngsan Choe
SR-P-11
72
Yeong-Garp Cho
SR-O-09
50
Young-Soo Han
SR-P-20
83
Yeong-Garp Cho
SR-P-01
59
Young-Soo Han
SM-O-03
121
Yeong-Garp Cho
SR-P-09
70
Yun TaeK Shin
IR-P-01
199
Yeongseon Jang
SM-P-08
132
Yuna Lee
AA-P-08
178
Yong Joon Park
SR-P-22
85
Yungoo Song
CS-P-04
154
Yong Kyun Kim
IR-P-13
213
Yun-Myeong Woo
RI-O-03
229
Yong Nam Choi
EE-O-04
95
Yuri Solokov
Plenary
25
Yong Sam Chung
AA-O-03
162
Yuta Yamakawa
SM-O-01
119
Yong Sam Chung
AA-P-04
174
Zhenzhen Yu
EE-O-06
97
Yong Sik Yang
IR-O-05
194
Zhili Feng
EE-O-06
97
Yong Sik Yang
IR-P-10
210
Yong Sik Yang
IR-P-11
211
Yong Suk Choi
SR-P-22
85
Yongsam Chung
AA-O-02
161
Yong-Sam Chung
AA-O-07
170
Yong-Sam Chung
AA-P-10
180
Yong-Sam Chung
AA-P-03
173
Yong-Sam Chung
AA-P-11
181
Yong-Uhn Kim
AA-P-07
177
Yoon Sang Lee
EE-P-05
111
Yoon Yeol Yoon
AA-P-05
175
Yoon Yeol Yoon
AA-P-06
176
Yoontaeg Shin
IR-P-06
206
Young Hwan Kang
IR-P-01
199
Young Hwan Kang
IR-O-07
196
Young Jin Kim
AA-P-04
174
Young Ki Kim
SR-P-06
67
Young Ki Kim
SR-P-07
68
Young 窶適i Kim
SR-O-09
50
Young Soo Han
SR-P-05
66
Young Suk Kim
EE-O-09
102
Young Suk Kim
IR-P-05
205
Youngchul Park
SR-O-12
57
Young-Don Hong
RI-O-06
232
Young-Don Hong
RI-O-07
233
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Korea Atomic Energy Research Institute
HANARO Symposium 2010 15th Anniversary of HANARO Operation and Inauguration of the Cold Neutron Research Facility November 1-2, 2010 Daejeon Convention Center (DCC), Daejeon, Korea