ORNL-TM-0910 by Jon Morrow

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T h i s n p o r t was prepared a s on account of Government sponsored work. Naithor the United States, nor the Commission, nor any persan octing on behalf of the Commission: A. Mokes any warronty or npresentotion, expressed or implied, with respect to the occurocy, completemss, or usefutmss of the information contoined in t h i s report, or that the use of any information, opporotus, method, or process disclosed in this report may not infringe privately owned rights; or B. Assumes any liobilities with respect to use of, or for domoges resulting from tho use of any informotion, opporatus, mthod, or proerss disclosed in t h i s report. As used in the above, "person acting on behalf of the Commission'' includes ony employee or controctor of the Commission, or employee of such controctor. to tho extent thot suchemployee or controctor of the Commission, or r m p l o p e of such conhoetor prepores, disseminates, or provides access to, ony informotion pursuont to h i s employment or contract with the Commission, or his employment with such controctor.

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ORNL-TM-910

C o n t r a c t No. W-7405-eng-26

Reactor Division

MSRE DESIGN AND OPERATIONS REPORT PART X MAINTENANCE EQUIPMENT AND PROCEDURES

R. B l u m b e r g

E. C . H i s e

JUNE 1968

OAK RIDGE NATIONAL LABORATORY O a k R i d g e , Tennessee operated by UNION CARBIDE CORPORATION for the U.S. ATOMIC ENERGY COMMISSION 7

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PREFACE A record of t h e methods of maintaining t h e radioactive portions of t h e Molten S a l t Reactor Experiment (MSRE) i s presented i n t h i s report. I n Section 2, o v e r a l l descriptions are given of t h e components and t h e methods of maintenance. Section 3 presents t h e procedures written from t h e standpoint of t h e people who perform t h e work. The Appendix l i s t s reference- material t h a t w i l l be useful when detailed information i s required. The report was originally prepared before t h e MSRE began power operation and thus before t h e r e was any experience i n radioactive maintenance of it. Since t h a t time, t h e MSRE has been operated and maintained successfilly, and we have had t h e opportunity t o observe how our maintenance plans have worked. I n general, our basic methods and o r i g i n a l planning have served quite well. I

There i s one aspect of our experience, however, t h a t bears on We have found t h a t changes i n tools, methods, reactor equipment, and administration of t h e maintenance operation make it necessary t o prepare new and fully detailed procedures f o r most shutdown work. These procedures a r e then used t o implement t h e functioning of a complex operation involving many people. Therefore t h e procedures i n t h i s report r e f l e c t present methods but not t h e full d e t a i l that i s actually required. t h e material contained herein.

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We wish t o acknowledge t h e contributions of other members of t h e Reactor Division t o t h i s report. P. P. Holz did t h e o r i g i n a l design and description of t h e portable maintenance shield. B. H. Webster did t h e same f o r t h e graphite-sampling technique. J. R. Shugart not only wrote and rewrote many procedures, but a l s o made them work at t h e MSFE. R . B. Briggs and Dunlap Scott reviewed t h e o r i g i n a l manuscript and provided many helpful suggestions f o r t h e preparation of t h e finished report.

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INDFX TO REFQRT SERIES d

b *

This report i s one of a series t h a t describes t h e design and operation of t h e volten-Salt Reactor Experiment. All t h e reports a r e l i s t e d below.

ORNL-TM-'(28

MSRE Design and Operations Report, Part I, Description of Reactor Design by R. C. Robertson I

ORNL-TM-729

MSRE Design and Operations Report, Part 11, Nuclear and f i o c e s s Instrumentation, by J. R. Tallackson MSRE Design and Operations Report, Part 111, Nuclear Analysis, by P. N. Haubenreich and J. R. Engel, B. E. Prince, and H. C. Claiborne

Om-IM-732

MSRE Design h d Operations Report, Part V, Reactor Safety Analysis Report, by S . E. Beall, P. N. Haubenreich, R. B. Lindauer, and J. R. Tallackson

MSRE Design and Operations Report, Part VI, Operating L i m i t s , by S . E. Beall and R . H. Guymon MSRE Design and Operations Report, Part V I I , Fuel Handling and Processing Plant, by R. B. Lindauer a

om-m-908

MSRE Design and Operations Report, Part V I I I , Operating Procedures, by R. H. Guymon .

Om-II51-909

gn and Operations Report, Part IX, Safety Procedures and Emergency Plans, by R. H. Guymon

ORNL-m-910

MSRE Design and Operations Report, Part X, Maintenance Equipment and Procedures, by E. C. Hise and R. Blumberg

...

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ix CONTENTS Page .

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ABSTRACT 1 INTRODUCTION 2 DESCRIPTION OF THE MAINTENANCE SYSTEM 2.1 Maintenance Equipment and General Methods 2.2 Maintenance Control Room and Facilities for Remote Operation 2.3 Portable Maintenance Shield 2.4 Jigs and Fixtures f o r Assembling MSRE Components 2.5 Freeze-Flange Maintenance 2.6 Fuel-Pump Maintenance 2.7 Graphite Sampler and Control Rods 2.8 Braze Joint 2.9 Maintenance of the Sampler-Enricher 2.10 Miscellaneous Long-Handled Tools 3 DETAILED MAINTENANCE PROCEDURES 3.1 The Radiation and Contamination Problem 3.2 Maintenance Control Room and Remote Facilities 3.3 Procedure for Use with the Portable Maintenance Shield 3.4 Procedures f o r Using Freeze-Flange Manipulating

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..................................... ........................... ...... ............................. ................................. ..................... ........................................... ................... ...................... ............................. ............... ........ ...............................................

Tools

3.5

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................................. ......................................... ......................... .... ... ................... ........................................... ..... IN-CELL EQUIPMENT .................................. JIGS AND FIXTURES ..................................

Fuel-Pump Maintenance 3.6 Procedures for Handling Surveillance Samples and Control Rods 3.7 Procedure for Bra ng a Joint 3.8 Procedures for Maintenance of the Sampler-Enricher Appendix A LIST OF REM0 INTENANCE REFERENCE INFORMATION Appendix B MSRE PORTABLE MAINTENANCE S H I E D Appendix C GRAPHITE SAMPLER AM> CONTROL ROD MAINTENANCE FACILITY Appendix D LONG-HANDLED TO &ID MISCELLANEOUS EQUIPhBNT

. . . .

Appendix E Appendix F

1 4 4 5

15 15 23 23 28 37 37

41 41 42 43

51 53 62 67 71 72 74 75

77 78

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ABSTRACT A record of t h e methods of maintaining t h e radioa c t i v e portions of t h e Molten S a l t Reactor Experiment (MSRE) i s presented. The maintenance system u t i l i z e s long-handled $001~operated through a movable shield f o r most of t h e i n - c e l l manipulations. For some radioactive t r a n s f e r and setup tasks t h a t cannot be handled otherwise, a crane t h a t i s operated remotely from a shielded cqntrol room i s used. Overall descriptions a r e given of t h e components and t h e methods of maintenance, t h e procedures written f r o m t h e standpoint of t h e people who perform t h e work a r e presented. Reference material t h a t will be useful when d e t a i l e d information i s required i s included.

1 1. INTRODUCTION 236

U The MSRE i s a 7.5-Mwt' circulating-fuel reactor i n which f u e l dissolved i n a solution of lithium and beryllium fluorides A drawing of t h e reactor i s pumped around a closed loop a t 1200'F. arrangement i s shown i n Fig. 1. The reactor plant was completely described i n t h i s series of reports by Robertson.' Some of t h e advantages of t h i s reactor concept a r e r e l a t e d d i r e c t l y t o t h e l i q u i d nature of t h e f u e l and a r e due t o t h e ease of moving t h e bulk of t h e f u e l inside piping systems, removing reactor poisons, reprocessing t o remove f i s s i o n products, and adding new fissionable material t o make up f o r burnup. However, t h e Same l i q u i d property causes r a d i o a c t i v i t y t o be d i s t r i b u t e d throughout t h e primary systems. Therefore special means are required for maintaining a l l t h e equipment t h a t comes i n contact w i t h o r is physically near t h e f u e l salt and off-gas systems. The demonstration of capability i n t h i s area became one of t h e primary objectives of t h e program.

The maintenance system includes many d i f f e r e n t kinds of equipment located both i n and out of t h e radioactive areas. Besides physical equipment, a c e r t a i n amount of information must a l s o be considered as part of our maintenance system. This information e x i s t s as written procedures, drawings, photographs, and "know-how" of t r a i n e d experienced personnel.

Early i n t h e program it was recognized that t h e design of each component had t o include provisions f o r maintenance, and t h e steps i n t h e achievment of t h i s goal included a design surveillance program. Thus those who had t h e maintenance r e s p o n s i b i l i t y had an opportunity t o influence t h e system aad component design i n t h e e a r l y stages. This a c t i v i t y took varying degrees of p a r t i c i p a t i o n from consultation and approval t o detailed designs and layouts. Surveillance of t h e design w a s followed by a similar program during t h e construction, assembly, and i n s t a l l a t i o n stages, Accompanying t h e f i e l d work of i n s t a l l i n g reactor components w a s a demonstration and practice program i n which selected components w e r e handled w i t h remote-maintenance t o o l s and methods. Many corrections were made during t h i s period t o improve t h e basic designs and t o correct f a b r i c a t i o n e r r o r s and maintenance techniques. I n general, t h e process consisted of doing whatever w a s necessary t o make t h e system maintainable. The surveillance program and t h e demonstration program were l o g i c a l methods of assuring t h e maintainability of t h e system before power operation. These programs had t h e further r e s u l t of producing a nucleous of experienced personnel a t t h e beginning of power operation at t h e MSRE, which has since been expanded i n t h e course of several shutdowns t o an adequate and 'R. C. Robertson, MSRE Design and Operations Report, Part I, Description of Reactor Design, USAEC Report ORNL-"M-728, O m , January 1965.

ORNL-WG 634209R I

Fig. 1. Sketch of MSRE Arrangement and Flow Diagram. L

3 competent group. The recognition of' the individual component nature of the maintenance problem, the design and construction surveillance effort, the demonstration program at the reactor, and the utilization of developed personnel skills are parts of the approach used to assure the maintainability of the MSRE.

DESCRIFTION O F THE MAINTENANCE SYSTEM

2.1 Maintenance Equipment and General Methods The system provided t o maintain the MSFE i s based on t h e requirement t h a t any failed component be replaceable with a new interchangeable spare. Decontamination and subsequent repair of f a i l e d components have been found t o be possible and economically a t t r a c t i v e . However, decontamination and repair a r e not considered t o be t h e primarymethods for nabtenanire. L f t t l e e f f o r t has been made t o effect in-place repair. A major'effort w a s made however t o achieve good component r e l i a b i l i t y . As the r e s u l t of a cmbination of many influences, the maintenance system was made flexible, simple, rugged, and low cost. A l l t h e equipment t h a t can be approached d i r e c t l y i s designed f o r conventional maintenance. This report i s concerned only with the equipment t h a t cannot be approached d i r e c t l y because of radioactivity.

The four principal locations where remote maintenance i s required reactor c e l l , t h e drain t a n k c e l l , t h e venthouse, where there i s access t o t h e off-gas system components, and t h e f'uel-processing c e l l . Fairly uniform methods a r e used f o r a l l these c e l l s . The a b i l i t y t o remove and replace every operating cmponent i n these areas has been accomplished through t h e use of appropriate.disconnects and mountings. The 5-in. circulating-system piping i s joined by mechanical disconnects consisting of t h e freeze f3-ange developed especially f o r molten-salt service The 1-1/2-in.. fill-and-drain system piping i s of all-welded construction. Future j o i n t s w i l l be made by cutting and brazing with a technique developed especially , f o r t h i s service. Piping conducting other f l u i d s i s connected by ring- j o i n t flanges or cone-seal disconnects E l e c t r i c a l and instrument wiring has plug-in disconnects constructed of materials suited t o t h e environment. A l l the j o i n t s and disconnects are designed t o be readily operable from d i r e c t l y overhead. They a r e described i n d e t a i l l a t e r . The major components, such as t h e reactor vessel, t h e heat exchanger, t h e pump, and t h e drain tank, as well as the smaller components, such as t h e pipe and vessel heaters, valves, and motors, a r e so disposed and mounted t h a t a f t e r being disconnected they can be removed by l i f t i n g straight upward. are the

The maintenance equipment design provides f o r t h e operation of a l l t h e disconnects and t h e replacement of t h e smaller components by t h e use of r e h t i v e l y simple long-handled t o o l s operated d i r e c t l y through t h e portable maintenance shield. The portable maintenance shield can be placed over and w i l l cover the opening l e f t by t h e removal of two of t h e lower shield plugs, a space 4 ft. wide and up t o 10 long. There are a variety of penetrations f o r inserting lighting, viewing devices, and t o o l s . ~n opening can a l s o be created through which s m a l l cmponent.9 will pass. A penetration may be placed anywhere i n t h e opening covered by the shield by a

s e r i e s of controlled movements. The design and use of t h e portable maintenance s h i e l d ,me described i n d e t a i l later. The-major components a r e t o o large t o pass through an opening 4 ft. wide and t h e i r removal thus requires t h a t a large portion of t h e c e l l t o p shielding be removed and that remote-handling techniques be used. For t h i s operation, a shielded maintenance control room, remotely operated cranes, and closed-circuit t e l e v i s i o n were provided. The maintenance control room (Fig. 2 ) overlooks t h e reactor c e l l j t h e drain tank c e l l , and the building i n t e r i o r through shielding windows. It contains controls f o r t h e 30-ton crane, t h e 10-ton crane, and t h e monitors f o r t h e t e l e v i s i o n system. L i f t fixtures a r e provided t h a t can be picked up by crane and which, i n turn, w i l l pick up, transport, and release t h e lower s h i e l d blocks and beams and each of t h e major components. 2.2 Maintenance Control Room and F a c i l i t i e s for Remote Operation

The maintenance control room and f a c i l i t i e s f o r remote operation consist of t h e remote maintenance control room; 30- and 10-ton cranes operable from t h e control room; lift tongs f o r t h e lower shield blocks f o r t h e reactor c e l l and drain-tank c e l l ; lift fixtures f o r t h e reactor vessel, heat exchanger, f u e l pump, and drain tanks; and a closed-circuit t e l e v i s i o n system. The remote f a c i l i t i e s a r e t o be used during any maintenance operation t h a t requires t h e simultaneous removal of more than two lower shield blocks. Anticipated operations i n t h i s category are replacement of t h e reactor vessel, t h e heat exchanger, t h e pump bowl, and t h e d r a i n and f l u s h tanks. The maintenance control room has 3-1/2-ft-thick concrete w a l l s t o provide adequate shielding f o r any maintenance operation; three . windows t o provide a view of t h e c e l l s and building i n t e r i o r ; crane, television, and l i g h t i n g controls; and radiation monitors, ventilation, sanitary f a c i l i t i e s and lights. I t s f l o o r i s 10 f t . above t h e building main floor and i t s i n t e r i o r dimensions are 14 by 19 ft. Personnel access t o t h e room is by an outside stairway on t h e west side of the building. Equipment acces 4 x 4-ft hatch i n t h e ceiling.

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The ten-ton crane has f i v e speeds i n each of six directions controllable directly from a push-button pendant i n the main building or f'rom a d i a l and toggle-switch console i n t h e maintenance control room. The signals f control room t o st be connected by a travel via a trailing c bridge when remote control i s plug located a t t h e wes desired; it i s disco e r times. This crane w a s in. e l m e c m rereeved f o r a hook t r a v e l 75 ft 10-142i a t o and i s now actually

The 30-ton cran speeds i n each d i r e c t i rollatjle rection controllable from from the cab and t h r a dial and toggle-switch console i n t h e maintenance control room. It a l s o has a power-driven r o t a t i n g hook controllable from e i t h e r point, and a load c e l l with an indicator i n t h e maintenance control

Fig. 2.

. .

High-Bay Side of Remote-Maintenance Control Room.

7 room. The remote-control signals are transmitted v i a t r o l l e y wire and need not be disconnected. The main c i r c u i t breaker f o r both cranes i s i n a shie area under t h e m a 'enance control room and i s accessible during a remote-maintenance operat ion. c

There are four-point (Fig. 3) and two-point l i f t i n g tongs f o r t h e lower shield blocks, and a l i f t i n g tong f o r t h e lower shield beams. The b a i l s f i t t h e hook of t h e 30-ton crane. The tongs lock alternately i n t h e open and closed positions each time they are picked up and s e t down. The sequence of operationsfor t h e tongs i s as follows: engage t h e crane hook i n t h e b a i l and r a i s e t h e tongs (now locked i n t h e open position); lower t h e tongs onto t h e plug with t h e hooks i n t h e lif'ting points u n t i l t h e tong weight i s off t h e crane; raise t h e tongs, which w i l l automatically lock i n t h e closed position, and raise t h e shield plug; transport t h e load and lower it u n t i l t h e tong w e i g h t i s o f f t h e crane hook; r a i s e t h e t ongs, which w i l l now automatically lock i n t h e open position, and release t h e load. A l i f t i n g fixture i s provided f o r each of t h e major cmponents. Each fixture can be picked up and released by t h e crane and can i n t u r n pick up and release i t s component through use of t h e remotely operated crane. These fixtures are on hand and have been used.

The t e l e v i s i o n system consists of t h r e e cameras mounted on pan and tilt mechanisms, &wo monitors, and a s e t of controls. For a remote-maintenance operation t h e cameras are mounted i n t h e building on movable stands, as shawn i n Fig. 4, so as t o command two views of t h e operation which, along with t h e d i r e c t view through t h e shielding window, provide ccanplete coverage of t h e work area. The use of orthogonal positioning of t h e cameras provides a feeling of depth. The remote controls operate t h e pan, tilt, focus, zoom, and iris. t

2.3 Portable Maintenance Shield shield w a s designed and fabricated t o A portable maintenan provide shielding f o r maintenance operations with long-handled t o o l s . It shields t h e access area produced when any two adjacent lower roof blocks are removed f r o m t h e reactor or t h e drain tank c e l l s , It accommodates t h e long-handled tools, t h e lower shield blocks i n both reactor and drain tank c e l l s , and some of t h e i n - c e l l e it i s operated f r o m t h e remote-maintenance control room s of t h i s equipment. 5 through 8 show various

The portable maintenance shield consists of four basic components: slide, modules, frame, and track. The slide i s a slab of shielding whose dimensions are 12 i n . t h i c k by 5 f% wide and e i t h e r 8-1/2 or 13 f't long dchpending on t h e usage. The s l i d e includes a c i r c u l a r cutout t h a t accommodates a 35-in.-diam. geared plug. The plug, i n turn, has a s e r i e s of cutouts f o r lights, windows, and t o o l s .

Fig. 3.

Remotely Operated L i f t i n g Tongs f o r Shielding Plugs.

Fig. 4. Television Camera on Movable Stand.

Fig. 5.

E R E Maintenance Shield.

ORNL-DWG 67-13761

-SLIDE PLUG

-SLIDE

-+MOTOR DRIVE (DRIVE NOT SHOWN

FRAME OVER DUAL LOWER ROOF-PLUG OPENING-

4CCESS OPENING FOR -ARGE TOOLS AND // -EQUIPMENT

-ECCENTRIC PLUG INSERT

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Fig. 6.

Typical Plan V i e w of Setup of Maintenance Shield.

ORNL-DWG

DESIGNED

67-13762

FOR I4-h-THICK

Fig.

Cross Section

Through Frame knd Slide

of Maintenance

Shield.

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ORNL-DWG

MAXIMUM UNDEFLECTED

Fig.,8.

Cross Section

BEAM\

Through Frame of Maintenance Shield.

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14 The s l i d e r o l l s on wheels and i s moved by a drive motor. The f i l l e r modules are a h d i t i o n a l short sections of shielding that can be added t o t h e main s l i d e t o allow positioning of t o o l holes above t h e desired work area. Most of t h e long-handled t o o l operations a r e done through a module referred t o a s the r o t a t i n g work plug. This module, which i s assembled next t o t h e slide, contains a 22-in. diameter rotatable-plug mounted eccentrically within a 50-in.-diam. plug. This arrangement provides t h e necessmy reach t o permit t o o l access over any point within t h e block opening. A special hole layout within t h e inner plug permits multiple t o o l access t o t h e reactor freeze flanges, as specifically required f o r flange maintenance. The plugs a r e operated manually through a geared drive t o allow precise positioning of t h e i r multiple openings. A t o o l access cutout i s located on t h e edge of t h e r o t a t i n g work plug t o provide means of inserting or withdrawing large t o o l s o r items of equipment. This i s sometimes called the " s p l i t section of the r o t a t i n g plug." A l l modules and plugs a r e I 2 i n . t h i c k and fabricated from carbon s t e e l . ' The frame, constructed of heavy s t e e l plate, serves as t h e support f o r t h e slide. After t h e frame i s i n s t a l l e d over arpair of lower shield blocks, t h e s l i d e is moved t o an end'track t o permit t h e removal of t h e blocks, and an opening 52 by 127 i n . i s provided. The plugs a r e removed by operating t h e cranes from t h e remotemaintenance control room and then returning t h e s l i d e t o a position over t h e c e l l opening t o provide complete shielding f o r personnel. A 3/4-hp motor and gearbox canbination mounted on t h e frame moves t h e s l i d e through a rack-and-pinion arrangement. The r a t e of t r a v e l i s about 2 in./sec. E l e c t r i c a l l i m i t stops, backed up by movable mechanical stops, a r e provided t o l i m i t t r a v e l as desired. The motor controls a r e connected t o t h e maintenance control room operating s t a t i o n with a cable.

The track i s an extension t o t h e frame t h a t can be mounted at e i t h e r end o f t h e frame and on which t h e s l i d e and module r o l l e r s move. It consists of "I" beams with channel and angle bracing.

ih.

A shielding thickness of 12 of s t e e l ' i s provided throughout (slides, modules, and frame sides and ends). This shielding i s s u f f i c i e n t t o l i m i t radiation levels 24 hr following reactor shutdown ,

t o awut 10mr/hr. The s e r i e s of holes through t h e shielding t h a t a r e used f o r longhandled tools, lights, and windows a r e provided with various f i l l e r s or i n s e r t s . Some of these contain 150-w lighting f i x t u r e s . Same a r e of a split-bushing design t o accommodate t o o l s of various diameters. Some i n s e r t s contain a d r i l l e d lead b a l l through which t o o l s may be inserted and i n t o positions other than d i r e c t l y underneath t h e work hole. One 8-in.-diam. and one 5-l/2 in.-diam. lead-glass winduw can be mounted simultaneously f o r d i r e c t viewing.

2.4 J i g s and Fixtures f o r Assembling MSRE Components The philosophy of remote maintenance involves t h e replacement of failed components; therefore connection members and mounting dimensions must be t h e same f o r t h e failed and t h e replacement components. J i g s and fixtures a r e used t o make it possible t o replace t h e major canponents i n t h e reactor and drain-tank c e l l s . The following components were f i t t e d t o a j i g as they were assembled or, a j i g w a s fabricated t o f i t t h e as-built component.

2.4 1 React or C e l l Components The major reactor c e l l components t h a t can de removed and replaced are t h e reactor vessel, t h e heat exchanger, t h e pump bowl, t h e rotary element of t h e pump, and t h e pump motor. A j i g w a s designed f o r these major components so t h a t a l l replacement components could be fabricated on t h e one j i g assembly, or t h e j i g could be broken d a m i n t o sections t o accommodate single components. A separate j i g i s available f o r use i f only t h e pump rotary element or t h e pump i s t o be replaced. This j i g makes it possible t o duplicate t h e auxiliary flanges and disconnects i n t h e i r existing locations. After t h e space coolers were i n s t a l l e d i n t h e reactor and drain tank c e l l s and a l l piping and e l e c t r i c a l connections were made, they w e r e removed and a j i g was b u i l t t o f i t t h e u n i t . This j i g makes it possible t o duplicate t h e flange and e l e c t r i c a l disconnects, as w e l l as t h e support s t e e l f o r t h e u n i t . The basic parts of a j i g were a l s o prepared f o r t h e component cooling valves. Af'ter t h e valves were i n s t a l l e d and a l l piping w a s completed t h e valves were removed and placed on t h e jigs, and holes were d r i l l e d t o locate flanges, air lines, disconnects, etc. These holes were i d e n t i f i e d f o r each valve and thus any valve i n the system can be duplicated.

2.4.2

Drain-Tank C e l l Components

A j i g w a s u s e d t o assemble t h e drain tanks and steam domes, . and the'elevations and orientations of a l l piping flanges and thermocouple disconnects were established with fixtures attached t o t h e j i g . The fill-and-flush tank w a s assembled i n + t h esane jig, and t h e helium valves were f i t t e d t o t h e valve j i g described f o r t h e component c o o l i

2.5 Freeze-Flange Maintenance The major compon reactor c e l l are connected f i v e 5-in. freeze flanges described previously by Robertson.a z

Op. c i t . , Ref. 1, pp 178-189.

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These flanges are designed so t h a t they can be separated and remade remotely with tooling operated through t h e portable maintenance shield. The layout of t h e reactor system piping, imposed by other factors, d i c t a t e s t h a t t h e sequence of opening t h e flanges f o r replacement of any component be Umited t o opening t h e flanges on the coolant end of t h e heat exchanger first, then on t h e f u e l end of t h e heat exchanger, and f i n a l l y the flange t h a t connects t h e reactor t o t h e suction of t h e pump. This sequence i s responsible f o r t h e rather lengthy procedure required t o remove a defective gasket in' freeze flange FF 100, and must be taken i n t o account whenever planning a specific maintenance task. \

2.5.1

Operations Required for Gasket Replacement

The operations of breaking and making a flanged joint involve: t h e following procedure, which i s broken dawn i n t o steps corresponding to 1;he Cool used. The disassembly consists of Forcing clamp off t h e flange and thus relieving a l l gasket sealing force,

2. Hanging t h e clamp assembly on a bracket i n s t a l l e d i n ' t h e c e l l ,

3 . Jacking t h e faces of t h e flanges apart t o get a t the'gasket and t o provide clearance f o r displacing components.

Removing t h e ring-gasket assembly,

5 - Covering t h e open flanges to.prevent spread of contamination. The reassembly procedure, which i s t h e reverse of t h e above, and which i s done with t h e same tools, has one extra requirement: the flange faces must be realigned as ithey a r e being jacked together (reverse of step 3) t o assure good gasket sealing. Throughout these steps, viewing i s provided principally by t h e periscope, with i t s various lenses. The periscope i s supplemented by windows i n t h e shield and, when necessary, by long-handled mirrors. 2.5.2

Realignment and Gasket Sealing

The freeze flange assembly, which i s shown i n Fig. 9, consists of t h e flange body containing t h e gasket groove, t h e gasket assembly, the clamps, t h e guide rods, t h e disassembly beams, and t h e l i f t i n g eyes. The gasket loading force i s derived from t h e s t r a i n i n t h e horseshoe section of t h e clamp, which i s sprung open a nominal 0.100 in. when t h e clamp i s forced onto t h e flange. Forces encountered i n seating t h e clamp on assembly and disassembly operations range from 16 t o 34 tons. It i s necessary t o put the clamps on symmetrically f o r two reasons. First, symmetrical loading produces t h e best gaskd-sealing condition, and second, unsymmetrical assembly would cause galling and "digging in" and thereby increase the required

k*1

Fig. 9.

t ion.

V i e w of

reeze Flange with Clamp i n Stowed Posi-

18 assembly forces. Symmetrical assembly i s achieved by using care i n handling and operating t h e remote tooling. Also t h e r e are guide , rods t h a t help center t h e clamp through t h e i r close engagement with t h e ears on t h e flange. The guide rods a l s o serve t o connect t h e upper and lower half of t h e clamp assembly so t h a t it can be handled as one unit. The disassembly beams carry t h e loads imparted by t h e remote tooling from t h e clamps i n t o t h e flange when taking t h e clamps off. The l i f t eyes are provided t o handle t h e clamp assembly. 2.5.3

Permanently I n s t a l l e d Maintenance Equipment /

Some i t e m s of equipment t h a t i n general serve t o simplify t h e remote maintenance operation were permanently i n s t a l l e d at each freeze flange. For example, under t h e piping at each flange there i s a 5-ton worm-gear screw jack t h a t terminates i n a remotely operable hex head, complete with hook, supports, and drive t r a i n s . This jack provides forces i n t h e axial direction of t h e piping t o spread apart o r bring together t h e flange faces. There a r e a l s o pemhnently installed, s l o t t e d brackets t h a t a c t as anchor points t o a l i g n flange faces i n t h e radial direction, and there are supports t h a t hold t h e freeze-flange clamp assembly i n t h e stowed position when t h e flanges a r e sepparated. 2.5.4

Hydraulic Clamp Operator

As mentioned above, t h e horseshoe-shaped section of a filly seated clamp i s sprung open a nominal 0.100 i n . t o produce a gasket load of approximately 200,000 lb. The force required t o seat a clamp ranges from 16 t o 34 tons and i s applied remotely by t h e p a i r of hydraulic clamp operator t o o l s sham i n Fig. 10. Each consists of a long m a s t carrying a 20-ton l3-l/2 in. stroke hydraulic ram. I t s cylinder i s attached t o a stationary outer frame, and t h e piston i s attached t o an inner frame. Extending t h e ram moves t h e inner frame dawn toward t h e stationary member. By engaging t h e outer frame under appropriate surfaces on t h e clamp assembly and t h e inner frame over them, t h e t o o l can accmplish t h e required jobs of -assembly and disassembly. These are sham i n Fig. 10. Engaging t h e t o o l s onto these surfaces remotely i s made somewhat e a s i e r by aligning assembly marks on t h e t o o l with t h e proper surface on t h e i n - c e l l equipment. 2.5.6

Clamp-Handling Tool

When t h e clamps have been separated, t h e "clamp handling" t o o l i s used t o transport t h e clamp assembly out of t h e way and t o s t o r e it so t h a t t h e flanges can 'be spread apart. This t o o l consists of a p a i r of hooks i n s t a l l e d on t h e end of a long mast and spaced t o engage a pair of eyes on t h e upper clamp. When t h e hooks are engaged t h e t o o l i s raised slowly, and it l i f t s t h e upper clamp u n t i l it contacts t h e underside of t h e upper beam. Because of t h e r e s t r i c t e d v e r t i c a l clearance between t h e guide-rod j a w s and t h e flange ears,

-t

ORNL-DWG 64-8821

REMOVING LOWER CLAMP Fig. 10. Freeze F1 assembly Steps.

REMOVING UPPER CLAMP

ing Frame Showing Assembly and D i s -

the motion i s precisely controlled u n t i l t h e e n t i r e weight o f t h e flange clamp assembly i s carried by t h e t o o l . The assembly i s then moved horizontally back along t h e piping and hung on t h e clamp stowing bracket, as sham i n Figs. 9 and 11.

2.5.7

After the clamp assembly has been stowed t h e flanged j o i n t may be separated. This i s accomplished with t h e jacks (Dwg. E-GG-E-41865) mounted i n t h e c e l l beneath t h e piping. As mentioned above, these a r e 5-tonworm-gear screw jacks t h a t are engaged and operated remotely by r o t a t i n g hex-head drives with ordinary socket wrenches on long handles. The jack hook engages with and transmits force through jack bars mounted on t h e piping-suppofi i n s t a l l a t i o n (Dwg. E-GG-E-41860). To avoid r e s t r i c t i n g the motion of t h e piping due t o thermal expansion, the jacks must be l e f t disengaged during reactor operation. For maintenance they must be engaged t o t h e piping t o provide t h e forces required f o r opening flanges and for moving components. 2

.5 -8 Gasket -Handling Tool

The gasket handling t o o l i s used t o replace a ring-gasket assembly. The t o o l i s long-handled p l i e r s with a stationary upper j a w . The muvable l m e r j a w which i s operated from t h e t o p of the tool, engages s l o t s on t h e inside of the r i n g away from t h e four sealing surfaces. On t h e v e r t i c a l center l i n e of t h e gasket there i s a-small bracket t h a t c a r r i e s a pin t o lock t h e gasket t o t h e flange u n t i l t h e flanges a r e pushed together. This det-ail i s shown i n Fig. 12. The pin has 0.045 in. clearance inside a hole tapped i n the flange a t a corresponding location. Thus, t h e pin can.be slipped i n t o t h e hole readily by means of t h e handling tool. The pin has threads on i t s lower side t h a t match those of t h e hole, and t h e weight of t h e gasket assembly i s supported by t h e pin which i s kept i n place by t h e engaged threads. When t h e other flange i s brought i n t o place t h e ring groove cams the r i n g upward; t h i s motion disengages t h e threads on t h e pin and t h e tapped hole and allows the ring t o move-into t h e proper sealing position in t h e groove. For removal, t h e assembly i s raised so t h a t t h e smooth upper surface of t h e pin contacts t h e top of t h e hole. T h i s disengages t h e threads and allows t h e pin t o be withdrawn. 2

.5.9

Flange-Cover-Handling Tool

In order t o reduce t h e release of radioactive p a r t i c l e s from t h e system and the extrance of air, covers a r e placed over t h e open flanges. A cover consists of a steel p l a t e with a raised gasket surface, a wedge device f o r tightening it up against t h e flange face,. a bracket t o hang it on t h e flange ear, and a handling b a i l . The cover i s sham on drawing MSRE-~~-~-263. The s e a l occurs j u s t inside t h e ring gasket groove but outside t h e expected salt-cake area, and it i s not expected t o be a high-quality seal. The handling t o o l contains a hook with a lock and a â&#x20AC;&#x2122; p a i r of remotely operated sockets for operating t h e wedge. The covers require 4 in. of clearance

,+-.

c, 8

Fig. 11. Freeze Flange with Covers and Handling T o d .

ORNL-DWG 67-13764

\FLANGE

Fig. 12. Maintenance.

Detail of Arrangement for Locking Ring to Flange During

between t h e flange faces for remote i n s t a l l a t i o n . For freeze flange FF-200 a s p e c i a l o f f s e t t o o l i s required because t h e open flange i s under a shield support beam. Further, because of interferences with'the stowed clamp, t h e covers must be p a r t l y i n s t a l l e d as t h e flanges are being jacked apart. The handling tool, i n s t a l l e d covers, and stowed clamp are shown on Fig. 11.

2.6

Fuel-Pump Maintenance

The MSRE f'uel pump i s made up of t h e pump bowl, t h e rotary element, and t h e motor stacked v e r t i c a l l y and joined by bolted gasketed j o i n t s . The pump bowl assembly consists of t h e pump tank, t h e volute, t h e suction and discharge l i n e s from freeze flanges FF-100 t o FF-101, t h e f'urnace, t h e support plates, and a number of flanges f o r disconnecting t h e pump auxiliary systems. The rotary element consists of t h e pump shaft, impeller, shield block, bearings, bearing housing, and various a u x i l i a r y l i n e s w i t h flanges. The motor has a power lead-in on t o p and two cooling water l i n e s with flanges. A l l these flanges f o r t h e pump a u x i l i a r i e s are on a common radius from t h e center l i n e of t h e pump and a r e mounted a t three s p e c i f i c elevations. The b o l t s t h a t hold t h e three u n i t s together a r e arranged t o allow t h e choice of removing first t h e motor and then the r o t a r y element or both of these together. Jacking screws are provided t o force t h e r o t a r y element off t h e pump bawl i n the event of a stuck gasket. The procedure f o r removing either of t h e two upper parts i s t o disconnect t h e e l e c t r i c a l 'power lead and t h e auxiliary flanges, unscrew a l l t h e pump flange bolts, and f i n a l l y operate t h e jack b o l t s t o make sure t h e p a r t s w i l l separate. The preparatory work i s done with long-handled socket wrenches and hooks inserted through t h e portable shield. A l i f t i n g yoke i s inserted through t h e s p l i t section of t h e r o t a t i n g plug and engaged i n t h e trunnions provided on both t h e motor and t h e bearing housing, and t h e u n i t i s l i f t e d c l e a r of a l l t h e close f i t t i n g attachments. The p a r t i s then lif'ted by the crane u n t i l it i s j u s t below t h e portable maintenance shield, A t t h i s point it i s necessary t n t o t h e remote-maintenance control room, open t h e s l i d e of t h e p shield, and p u l l t h e part up i n t o t h e high bay f o r storag e of t h e p i t s o r f o r disposal. P l a s t i c covering or other containment i s used t o prevent contamination of t h e high bay area. I n s t a l l i n g a replacement part requires t h e reverse of tkie removal procedure, w i t h the addition of t h e extra care t h a t must be exercised when e aging t h e mating surfaces of the pump.

2.7

Graphite Sampler and Control Rods

The term "graphite s r" refers t o a collection of both permanently i n s t a l l e d and able equipment used t o maintain three important components of t ctor t h a t are physically located near t h e center l i n e of t h e core. These components are t h e graphiteHastelloy N 6urveillance samples, t h e 2-in. removable graphite stringers, and t h e control rods.

Li 2 .7.1 I

Surveillance Samples

Among t h e important r e s u l t s t o be gained from operating t h e MSRE a r e t h e chemical and metallurgical data t o be obtained from examining specimens of graphite and metal exposed i n t h e central region of t h e core f o r long periods of operation. (This program has been described i n detail.=) Figure 13 shows features of t h e sample assembly and i t s location i n t h e core. This sample assembly, which i s roughly a 5-ft-long 2-in.-diam. cylinder, consists of an array of graphite bars, Hastelloy N t e n s i l e specihens, and fluxmeasuring wire inside a basket of perforated sheet metal. End f i t t i n g s accommodate installation, coolant f l o w , and handling requirements. Af'ter exposure i n t h e operating reactor, t h e specimen 'is removed with long-handled t o o l s and taken i n a shielded c a r r i e r t o a hot c e l l where some of t h e samples a r e taken f r a n t h e basket f o r chemical and metallurgical examination. The basket i s then reloaded with new and exposed samples, returned t o t h e reactor, and r e i n s t a l l e d i n t h e core. The graphite sampler, which was designed primarily f o r t h e operation of removing and replacing surveillance samples, is shown in Fig. 14, and consists of t h e following components:

1. A 48-in.-wide lower shield block, which has a 39-1/2-in.d i m . hole Over the center of t h e =actor vessel. During reactor operation a f i l l e r plug i s i n s t a l l e d i n t h e 39-1/2-in.-diam. hole. 2. A 20-in.-diam. standpipe attached t o the.battom of t h e 48-in. shield block by means of a flange and a bolting ring and t o t h e ,2-1/2-in. reactor access flange. An expansion bellows i s used between t h e standpipe and t h e access flange t o allow f o r movement due t o thermal expansion. The standpipe i s attached s l i g h t l y off center at t h e top t o leave access roan f o r control rod maintenance.

3. A cylinder 36-in. high by 47-1/2-in. i n diameter with b i n . thick w a l l s (of canned-lead construction), which i s i n s t a l l e d when preparing t o take a sample. This shield i s sealed a t t h e bottam by t h e weight r e s t i n g on a f l a t gasket. It i s designated t h e graphite-sampler work shield, but it i s sometimes simply called t h e work shield. 4. A gemed work plug, 38-in. dim. by 10-1/2-in. thick, i s inserted i n t o t h e work shield (item 3 above) This plug has a Teflon ring t h a t a c t s as a s e a l and bearing surface. The work plug Fig. 15, has a smaller geared plug eccentric t o t h e large plug, and seven various sized t o o l plugs, viewing ports, and l i g h t i n g inserts Teflon gaskets and neoprene "0" rings a r e used throughout

'R. B. Briggs, Molten-Salt Reactor Program Semiannual Progress Report f o r Period Ending Aug. 31, 1965, USAEC Report ORNL-3872, o m , PP. 87-92.

9 n l d )MOM JO NOllVlN3S3tld3tI 311VlrU3H3s

Q'LIBB-+9 9MQ-1NtlO

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SS333V 8013V38

A18W3SSV NMOa-alOH 83ldWWS-311 HdWS

VL188-t9 SMQ-1NtlO

. SPECIMEN CONTAINER I N PLACE READY TO RECEIVE EXPOSED SAMPLE-

ELEVATION 838 ft 11 3/8 in.

2 1/2-in. REACTOR ACCESS FLANGE

10-in. REACTOR ACCESS

/NOZZLE FLANGE

ELEVATION 837 ft 11 in.

Fig. 14.

Graphite Sampler Assembly.

ORNL-DWG 64-6745

LEAD GLASS VIEWING WINDOWS

WORK PLUG DRIVE

. -

TOOL BUSH I NG

PURGE VENTSORK SHIELD

t o make the overall assembly gastigkrt.

5. The standpipe atmosphere-control system. This consists of a nitrogen supply, a control panel, an exhaust blower and a f i l t e r . When items l t h r o u g h 4 a r e assembled, a sealed compartment i s formed above t h e reactor, through which personnel operating long-handled tools, can open t h e reactor and withdraw a radioactive sample. By feeding a purge of nitrogen i n t o t h e compartment and maintaining a negative pressure inside it, two purposes are served. Air i s kept out of t h e reactor vessel, and contamination i s kept out of the personnel working area.

6. Miscellaneous equipment Once t h e shielding, containment, and atmosphere control have been s e t up, t h e physical handling of t h e i n - c e l l equipment can proceed. With long-handled t o o l s and a variety of standard and special hardware, t h e reactor access port i s opened, and t h e sample i s withdrawn and put i n t o a sealed container within . t h e standpipe. The container i s pulled upward out of t h e standpipe i n t o a c a r r i e r with 6-in.-thick shield walls f o r i t s t r i p t o t h e hot c e l l . I n practice, a lengthy and detailed step-by-step written procedure i s followed by t h e personnel doing t h e work. 2.7.2

The 2-in. Graphite Core Stringers

There are f i v e stringers (moderator blocks) located i n t h e center of t h e core t h a t can be removed f o r examination. They a r e equipped with f i t t i n g s f o r handling. However, access t o remove them i s gained only a f t e r t h e removal of t h e control rods and drive housings, t h e substitution of a 36-in.-diam. standpipe f o r t h e 20-in. standpipe, and finally the removal of t h e control-rod thimble assembly. There a r e no plans t o remove these stringers u n t i l t h e conclusion of reactor operation. 2 -7.3

Control R o d s

Figure 16 shows t h e t o p view of t h e three control rod drive housings and t h e 20-in. standpipe. The control-rod access flange has been removed. The view i s similar t o t h a t of looking down through a window i n t h e graphite-sampler work plug. For maintenance t h e control-rod drive housing i s removed f i r s t . Induced radiation and contamination of t h i s unit i s low s o t h a t repairs can be made with ordinary-methods a f t e r min6r cleanup. . A control Pod can beremoved only a f t e r the drive housing i s out of t h e way. The rods have much induced a c t i v i t y and a r e generally reBlaced rather than repaired. A l l t h e necessary work i s done with long-handled tools. 2.8

Braze J o i n t s

The ,1-1/2-in. Hastelloy N piping f o r t h e salt fill-and-drain system i s of all-welded construction. Component replacement i s t o accomplished by cutting t h e pipe at predetermined points, removing t h e component, preparing t h e i n - c e l l pipe stub, i n s t a l l i n g t h e new

30. component with a prepared f i t t i n g , and brazing t h e p u b i n t o t h e f i t t i n g . The technique, as developed f o r the MSRE, requires a permanent 2-by 3-fY, base plate located at each possible future joint, four tools t h a t can be placed and operated through the maintenance shield, and a 4200-cps 30-kw induction generator. Figure 17 shows an unassembled joint and a section of a brazed joint. The i n - c e l l pipe stub i s machined t o a taper, l i k e the piece on t h e right. The new component i s i n s t a l l e d with a prepared end, l i k e the piece shown on the l e f t , and with the gold-nickel sheetm e t a l braze preform, shown i n t h e center, fastened i n it. The two a r e pressed together while being heated t o 1900째F t o form t h e completed j o i n t . Figure 18 i s the positioning vise suspended from i t s l i f t i n g b a i l . It i s lowered over a continuous piece of pipe, positioned on t h e base p l a t e by dowels, bolted darn, and the three-jaw chuck i s closed t o g r i p the pipe. Figure 19 shows t h e pipe c u t t e r i n operation. It i s lowered, i n t h e open position, over a continuous piece of pipe and onto i t s mounting plate on t h e positioning vise. The knife i s fed i n t o contact with t h e pipe and t h e cutter i s rotated, with automatic knife feed, u n t i l t h e pipe i s cut. The c u t t e r i s then removed. After t h e canponent i s completely disconnected and removed t h e taper c u t t e r i s placed on t h e base plate, Fig. 20. The taper cutter i s driven through an extension shaft by an a3r motor while the positioning vise i s used t o drive the pipe stub i n t o it. A 6" included-angle taper 1-in. long i s machined on t h e pipe. The taper c u t t e r i s then removed, and t h e furnace with induction heating leads and purge-gas connection i s placed on t h e pipe stub as shown i n -the left side of Fig. 21. The new component with t h e prepared braze f i t t i n g , thermocouples, and furnace end piece i s put i n t o place. The fixed vise i s then lowered Over t h e pipe, fastened t o the base plate, and closed t o g r i p t h e pipe as i n t h e right side of Fig. 21. The positioning vise i s then operated t o drive the stub i n t o t h e braze f i t t i n g so t h a t matching tapers jam. The furnace i s closed as i n Fig. 22 and t h e i n e r t gas purge i s begun. After an appropriate purge period, the induction'generator. i s turned on and t h e joint i s heated t o 1700째F in about 2 min. Axial pressure i s maintained on t h e joint with the p o s i t i m i n g vise during heating, and at a b m 1750"Fthe braze metal melts and the pipe stub t r a v e l s about 1/8-in. f'urther in. This reduces the j o i n t thickness from 0.005 t o l e s s than 0.001 in. The joint i s held a t lgOO째F f o r about one minute t o assure complete melting and wetting and then permitted t o cool. The furnace i s then opened, the thermocouples a r e removed, and t h e joint i s inspected. If the joint does not pass $nspection, t h e furnace can be closed, t h e j o i n t heated t o 1900째F and separated. If it does pass inspection, the furnace i s removed by breaking up t h e insulation and cutting loose the coils, t h e vises a r e removed, and t h e l i n e i s restored t o service.

4E. C. Hise, F. W. Cooke, and R. G. Donnelly, Remote Fabrication of Brazed Structural J o i n t s i n Radioactive Piping, paper ASME-63-WA-53, American Society of Mechanical Engineers.

32 I

Fig. 18. Positioning Vise for Remote Brazing.

Fig. 19.

Pipe Cutter for Remote Brazing.

* 5

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N a3

m 0 4-1

5 0

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V 0

2.9

Maintenance of t h e Sanler-Enricher

The sampler-enricher system provides t h e means whereby samples of salt a r e removed from t h e reactor f o r analysis and 'additions a r e made t o enrich or poison t h e f u e l . This system w a s described i n 6 A s h e l l of 8-in. of lead has been b u i l t more d e t a i l previously. around t h e equipment f o r shielding during reactor operation. Portions of t h i s s h e l l must be removed f o r access, and other portions a r e i. u t i l i z e d as shielding during maintenance. The maximum source strength can be assumed t o be no more than t h a t of 2 radioactive samples of salt. (Presumably one sample would be associated with t h e equipnent failure and t h e other due t o t h e accumulation of deposits and s p i l l s from t h e routine handling of many samples.) A radiation l e v e l of 400 r/hr a t 12 in. has been estimated f o r t h i s . The arrangement of t h components of t h e sampler i s such t h a t t h e r e are seven d i s t i n c t areas t h a t may be worked on more or l e s s independently. The operating panel board and p a r t s are shown i n Figs. 23 and 24. Maintenance will be accomplished with hand t o o l s and d i r e c t methods with advantage taken of t h e shielding t h a t can be provided by l o c a l stacking of lead bricks. The designs of t h e connectors, fasteners, and movable shielding have, t o a large extent, f a c i l i t a t e d t h i s approach. When t h e particular unit has been disconnected, it w i l l be transported t o a decontamination c e l l t o be cleaned up as much as possible efore f u r t h e r work. Distance, shadow shielding, and t h e d n t e ce control room w i l l be used, depending on t h e radiation l e v e l and t h e complexity of t h e particular task. 2.10

Miscellaneous Long-Handled Tools

2.10.1 e m c e of t h e heaters and The t o o l s for t h e disconnects are, i n general, long-handled l i f t i n g ho cket. I n operation t h e hook i s engaged inside a centering guide nd t h e socket - i s brought dawn over ,in t h e b a i l on t h e equip t o o l . A t t h i s point t h e u n i t i s t h e bail t o lock it inside transported and release s destination. The t o o l i s then remmed. The heaters and e l e c t r i c a l disconnects have i d e n t i c a l bails, which f i t t h e sock t h e end of t h e t o o l . The thermocouple disconnect t o o l hawever r s a different-sized socket and, i n s attached t o t h e socket which a c t a addition, a frame of guid t h e disconnect before t h e e l e c t r i c a l i n aligning t h e two halve contacts have engaged.

60p. cit.,

R e f . 1,

Fig. 23.

Sampler-Enricher Installation Prior to Erecting Shielding.

rl 0 0 PI

.40

2.10.2

Leak-Detector Disconnect Wrench and Hand&

Tool

A remotely operable j o i n t consisting of a p a i r of mating conical surfaces forced together by a single b o l t mounted i n a pivoted yoke i s used i n t h e MSRF: i n t h e leak detector l i n e s and i n pneumatic l i n e s t h a t feed t h e weigh c e l l s i n t h e d r a i n tank c e l l . This j o i n t i s known as t h e leak-detector disconnect. The procedure t o disconnect it i s t o use t h e leak detector disconnect wrench t o unscrew t h e bolt, and with t h e attached hook, t o pivot t h e yoke back out of t h e way. Then by using t h e same t o o l as a long handled "C" clamp, t h e pipe or tube t h a t comes i n t o t h e t o p of t h e disconnect i s grasped, separated from i t s m a t e , and moved c l e a r of t h e area. I n t h e case where it i s necessary t o hold both p a r t s of 'the joint, an additional "C" clamp t o o l i s u t i l i z e d .

' c

DETAILED MAINTENANCE PROCEDURES

The operating procedure i n a radioactive maintenance situation, i n t h e i n t e r e s t of safety and economy, includes

(1) t h e maintenance operation and t h e t o o l s involved,

(2) t h e protection of personnel and equipment,

(3) t h e manipulation of reactor equipment, such as t h e v e n t i l a t i o n system, and \

(4) t h e measures required t o maintain cleanliness both i n t h e c e l l and i n t h e high-bay area.

i I

1 iI

! I

1 j

Details of a procedure depend on knowledge of t h e reactor, i t s operating history, the e f f e c t s of i t s radioactivity, and t h e maintenance operations. It would be impractical t o t r y t o a n t i c i p a t e a l l t h e needs of a procedure; therefore, t h e procedures t h a t follow p e r t a i n only t o t h e operation of t h e maintenance tools, and t h e check out of t h e equipment f o r f'unction, calibration, and defects. I n general, a t t e n t i o n t o d e t a i l and good cooperation among a l l involved are required f o r good r e s u l t s . The verb "insert" as used i n t h e procedures r e f e r s t o t h e e n t i r e operat ion, which consi s t s f picking up t h e t o o l on t h e crane, threading it through t h e proper hole i n t h e portable shield, carefilly l a r e r i n g it i n t o position with whatever manipulations a r e required t o c l e a r i n - c e l l equipment and f i n a l l y using t h e proper bushing t o close up t h e ! gap i n t h e shielding.

Motion o r displacement of t h e t o o l s or equipment i s accomplished generally by moving t h e portable shield with t h e t o o l attached t o it. Motions i n the long d i r e c t i o n of t h e shield blocks (east and w e s t i n t h e reactor c e l l and t h e d r a i n tank c e l l ) are simple t r a n s l a t i o n s of t h e s l i d e . Motions across t h e s l i d e are made with a more complex combination of plug r o t a t and slide t r a n s l a t i o n . Small movements ing t h e clearance betweerr t h e outside may be accomplished by u t of t h e mast of t h e t o o l and t h e hole i n t h e shield i n t o which it i s inserted. The long t o o l s with r e l a t i v e l y heavy lower ends a c t very much l i k e pendulums, so t h e operator cannot exert t o t a l , positive control. For t h i s reason a l l movements of these t o o l s must be made as slowly, smoothly, a rately as possible t o r e t a i n control, avoid violent os c i l l a t prevent damage t o equipment

3.1 The Radiation and Contamination Problem Radiation and contamination l e v e l s vary widely i n t h e MSRE. There a r e s i t u a t i o n s where t o o l s can be inserted and removed repeatedly without becoming radioactive, and t h e r e are a l s o occasions i n which everything i n t h e v i c i n i t y of t h e operation w i l l be ,highly

42 contaminated. Therefore no one simple written procedure w i l l adequately cover a l l situations. However, t h e following guide l i n e s a r e generally applicable:

1. Written health physics procedures and precautions must be provided f o r each job. 2. A health physicist must be present a t t h e start of each operation t o survey and t o evaluate hazards.

3. Anything below t h e shielding (i.e., i n a radioactive area) must be assumed t o be a radioactive hazard u n t i l proven otherwise. It must be wiped, monitored, and/or contained as it i s being pulhed up through t h e shield. 4.

Techniques f o r contamination control, such as c o n t a i h e n t

and personnel shielding, must be considered during t h e preparation

of t h e remute-maintenance procedures.

5. Radioactive, contaminated equipment can be disposed of i n several ways. It can be taken t o t h e hot-equipment storage c e l l or t h e decontamination c e l l a t t h e MSRE, t h e radioactive b u r i a l ground on a hot truck, or t o any of a number of hot c e l l s at ORNL. The choice depends on a number of factors, such as t h e value of t h e part, t h e use of t h e part, how radioactive it is, and what f a c i l i t i e s a r e available f o r handling it. However, containment must be provided t o prevent t h e spread of airborne contamination, and shielding must be provided f o r gamma radiation t o protect personnel. 3.2

Maintenance Control Room and Remote F a c i l i t i e s

The maintenance control room i s used f o r limited operations; f o r example when it is necessary t o move highly radioactive materials from one c e l l t o another o r out of t h e high-bay area of t h e building, and when openings made i n t h e shielding are so large t h a t t h e r e s u l t i n g radiation levels preclude normal occupancy of t h e high-bay area. During t h e actual use of t h e maintenance control room, a l l operations must be accomplished by using t h e two cranes and, further, t h e high bay may not be accessible. Cmplete inaccessibility represents an extreme situation. Usually t h e high-bay area can be'entered, and personnel using distance and/or shadow shielding t o reduce exposure can work f o r short times t o assist with operations and t o remedy troubles. Because t h i s work presents gpecialhazards, t h e following should be done t o assure t h a t t h e operation proceeds smoothly:

1. The written procedure should be gone over thoroughly before s t a r t i n g t o check that t h e procedure i s workable and that a l l necessary equipment (lift fixtures, camera and l i g h t stands, equipment supports, etc.) a r k on hand and a r e located where t h e

--. 1

- h j

crane hooks can get t o them.

2. A l l t h e operating equipment should be t e s t e d j u s t p r i o r t o t h e a c t u a l operation. The cranes should be operated i n a l l directions, a t a l l t h e control settings. The l i f t f i x t u r e s should be visually inspected, lubricated, and t e s t e d under load. Television cameras and l i g h t s should a l l be warmed up and functioning, and f o r a t e s t they should be moved about with t h e crane t o demonstrate t h e i r p o r t a b i l i t y .

3. During operation there should be a t l e a s t t h r e e people but l e s s than seven i n t h e maintenance control rogm. 4. After completing t h e maintenance- operations, t h e high bay should be thoroughly surveyed by t h e health physicist and contamination should be cleaned up before semidirect operations a r e resumed.

3.3

Procedure f o r U s e with t h e Portable Maintenance Shield

Detailed procedures a r e outlined on Dwg. L L - D - D ~ o ~ ~MSRE ~, Main C e l l Plan View Shield Setups Reference Drawing, and on Dwg. U-D-D40669, MSRE Drain Tank C e l l Plan V i e w Shield Setup Reference Drawing. Ten separate drawings (~~-D-D-40663 through LL-D-D-40672) are available t h a t show t h e many possible setups t o be used i n specific locations, including drawing u-D-D-40668, Shield Setups Over MSRE Freeze Flanges. 3

The usual procedures f o r use with t h e maintenance f a c i l i t y are l i s t e d i n t h e sequence of preparations, operations, and closure as follows:

3.3 .1 Preparati ons 1. Select proper setup drawing t o determine applicable shield, module, plug, and t r a c k component requirements

2. Remove s u f f i c i e blocks t o be l i f t e d out.

Cut membrane (1/8-in.

e r roof blocks t o allow lower roof s t a i n l e s s steel).

4. Set t h e frame over he lower roof blocks t o be removed. (Setup as determined i n Step 1, above). Allow 3/4-in minimum side-and-end clearances for t h e lower roof plugs t o be pulled through.

5 . Attach t r a c k s otor base. Level t r a c k s with shims as required. Place s l i d e and module a r r a n g a e n t s as indicated on t h e reference drawing.

3.3.2

Operations

1. Verify t h e folluwing by op6rating the slide with the motor drive: \

t h a t sufficient clearance e x i s t s for removing the blocks,

t h a t t h e device which couplesthe slide t o t h e rotating work plugoperates,

t h a t t h e s l i d e t r a v e l s smoothly on t h e frame and the track,. ,

Clear t h e opening i n t h e frame f o r lower shield block removal.

Attach t h e block-Ufting tongs t o one of t h e blocks t o be

removed.

4. Connect the motor drive power lead i n t o t h e renote-maintenance roan receptacle (located on the w a l l j u s t west of t h e reactor c e l l ) . 5. Evacuate t h e high-bay area and continue t h e operation from t h e remote-maintenance control roan.

6. Remove both shield blocks through t h e frame t o a designated

parking area. This operation can be done with the crane operator watching through t h e winduws and one man observing t h e weigh-cell indicator

7. Ehergize the s l i d e drive m o t o r , and return t h e s l i d e t o cover t h e c e l l opening. Return t o t h e high bay. 8.

Use as many modules as required t o keep t h e c e l l opening

covered.

9. Move t h e r o t a t i n g work plug over t h e desired area and proceed with semidirect operations. 10. To handle large pieces of equipment, t h e s l i d e and rotating work plug are separated, t h e .equipnent hanging on a long-handled t o o l i s passed through t h e opening, and t h e s l i d e i s closed around t h e mast of t h e t o o l at t h e cutout b u i l t i n t o t h e edge of t h e rotating plug. Depending on t h e radiation level, some of these operations may have t o be done from t h e remote-maintenance control room.

3 -3-3 Closure* 1. Remove a l l long-handled tools, close holes, and c l e a r t h e top of the s l i d e and rotating work plug.

+The purpose of t h i s operation i s t o replace t h e lower shield blocks i n t h e roof of t h e c e l l .

2. frame.

Locate t h e s l i d e so t h a t it alone covers t h e opening i n t h e

3. Uncouple t h e s l i d e from t h e rotating work plug.

4. Connect t h e motor drive power lead i n t o t h e rematemaintenance control room receptacle. 5 . Evacuate t h e high-bay area and continue procedure f r o m t h e remote-maintenance control roam.

6. Ehergize t h e s l i d e drive motor and move t h e s l i d e u n t i l t h e opening i s uncovered. 7. Replace both shield blocks i n t o t h e i r places i n t h e roof of t h e c e l l . 8. Return t o t h e high bay. \

3.4 3.4.1

Procedures f o r Using Freeze-Flange Manipulating Tools Hydraulic Clamp Operator

3.4.1.1 The portable maintenance shield must be s e t up with t h e special freeze-flange rotating plug (see Dwg. LL-D-40668), periscope with sheath, rod light, left-hand and right-hand hydraulic clamp operating t o o l s with pump, an A frame, and an overhead crane. (See Fig. 9 f o r flange nomenclature.) I

hole.

3.4.1.2

Assembling t h e Clamps Onto t h e Flange

1. I n s e r t t h e periscope with t h e right-angle lens i n a convenient Lower it u n t i l it i s looking at t h e top disassembly beam.

2. I n s e r t one hydr t o o l with t h e jaws opened t o t h e calibration marks on t h e inner and outer frames. . )

. 3. Lower t h e t o o above t h e upper surfac i s then under t h e ear

of t h e clamp ear.

( t h e movable one) i s j u s t The lower stationary j a w

4. Ehgage t h e t o izontally toward t h e flange. This may be done with a lever-like action w i t h the, mast of t h e t o o l used as t h e lever and t h e portable shield as t h e fulcrum. 4 f o r t h e other side.

Repeat steps 2,

Attach t h e hydraulic pumps t o t h e f i t t i n g on t o p of t h e mast.

7. Operate t h e pumps t o force t h e two clamp halves together. While t h e t o o l ' s upper j a w moves, t h e lower j a w i s stationary,

46 therefore t h e mast must be raised t o compensate f o r t h i s . ' The e n t i r e process i s monitored with the use of t h e periscope t o make adjustments i n t h e t r a v e l of t h e clamp t o keep it l e v e l and t o keep t h e spacing between the clamps uniform. ~

8. .

Disengage t h e t o o l s a d remove them from t h e c e l l .

3.k.l.3

hole.

Removing t h e Bottom Clamp from t h e Flange

1. Insert t h e periscope with t h e right-angle lens i n a convenient Lower it u n t i l it i s looking at t h e top disassembly.beam.

2. I n s e r t one hydraulic t o o l with t h e jaws opened t o t h e proper calibration mark.

3. Lower t h e t o o l till t h e upper j a w (the movable one) i s j u s t above t h e upper surface of t h e lower clamp ear. This i s between t h e two clamps and approximately on t h e center l i n e of t h e flange. The lower j a w of t h e tool, t h e stationary one, i s then under t h e proper surface of t h e lower beam. 4. Engage the t o o l by moving it horizontally toward t h e flange. This may be done with a lever-like action with t h e mast of t h e t o o l used as t h e lever and the portable shield as t h e Wcrum. 5. mast

.6.

Repeat steps 2, 3, and 4 f o r t h e other side.

Attach t h e hydraulic pumps at the f i t t i n g on t h e t o p of t h e

7. Operate t h e pumps t o force t h e lower clamp off t h e flange. This should require approximately 2 in. of power stroke and then t h e clamp should f a l l of i t s own weight. A provision i s made on the t o o l f o r catching t h e clamp. The t o o l i s then lowered u n t i l t h e lower clamp i s resting on the beam. 8.

Disengage t h e t o o l s and remove them from t h e c e l l .

3.4.1.4

Removing t h e Top Clamp f r o m t h e Flange

1. I n s e r t t h e periscope, with the right-angle lens i n a convenient hole. Lower it u n t i l ' i t i s looking a t t h e t o p disassembly beam. \

2. I n s e r t one hydraulic t o o l with t h e j a w s opened t o t h e proper\ calibration mark.

3. Lower t h e t o o l u n t i l the upper j a w ( t h e movable one) i s j u s t above t h e proper surface of t h e top disassembly beam and t h e lower stationary jaw i s under t h e upper clamp.

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cd i

4. Engage t h e t o o l by moving it horizontally toward t h e flange. This i s done with a lever-like action with t h e mast of t h e t o o l used as t h e lever and t h e portable shield as t h e fulcrum.

Repeat steps 2, 3, and 4 f o r t h e other side.

Attach t h e hydraulic pumps .at t h e f i t t i n g on top of t h e mast.

Operate t h e pumps t o force t h e upper clamp o f f of t h e flange.

Disengage t h e t o o l s and remove them f r o m t h e c e l l .

3.4.2

The Clamp-Handling Tool

1. I n s e r t t h e t o o l d i r e c t l y over the center of t h e flange ( i n t h e plan view) 2.

Engage t h e hooks on t h e t o o l i n t h e eyes on t h e upper clamp.

3. L i f t the t o p clamp until it begins t o pick up on the top disassembly beam. 4. Raise the clamp assembly very slowly. When t h e slack has been taken out of t h e pin j o i n t between t h e beam and t h e guide rod t h e t o o l i s supporting t h e weight of t h e e n t i r e clamp assembly and t h e r e i s oniy1/8 i n . v e r t i c a l clearance between t h e guide rod j a w s and t h e flange ears. Thus a movement of 1/16 i n . i s required t o . gain clearance t o move t h e clamp.

5 . When t h e clamp assembly i s f r e e of t h e flange, move t h e t o o l horizontally along the center l i n e of t h e pipe toward t h e clamp stowing bracket. A t t h e instant t h e lifting motion f r e e s t h e r e s t r i c t i o n , t h e clamp assembly w i l l probably come o f f the flange ears in a twisting motion so that one side is upstream and the other side i s downstream. When t h i s occurs move t h e clamp assembly over so t h a t t h e offending s i d e may be swung outboard and around t h e flange ear. The same mi+thod applies when t h e e n t i r e clamp assembly i s on t h e wrong side of t h e flange. 6. Raise t h e t o o l enough t o c l e a r t h e front edge of t h e stowing bracket. Move t h e clamp assembly back against t h e stop on t h e stowing bracket and lower it i n t o place.

7. Before releasing hook examine t h e clamp's position w i t h a l l available means (monocular through window i n portable shield, rs) t o assure that it i s seated properly periscope, and auxiliary m i on t h e bracket. 8 . Disengage t h e t o o l and remove it from t h e c e l l .

3.4.3

Flange Jacking and'Aligning Tools

3.4.3.1 Equipment Required. The jacking system consists of Lnc e l l equipment a t each flange operated by simple rotation of two hex-head screws. One screw operates t h e jack t h a t generates t h e . push-pull forces and, i n general, i s located outboard of the other screw, which operates a l a t c h bar used only f o r t h e pulling operation. Both hex heads a r e the same size (1-1/2 in. across t h e f l a t s ) , and they a r e located close t o one another. Drawing E-GG-E-41878 should be consulted t o assure that t h e operator can identify each screw. A l l t h e jadk operators w i l l push t h e flange closed when turned clockwise. Operation of t h e l a t c h bar varies, and t h e i n s t a l l a t i o n drawing should be consulted f o r each i n s t a l l a t i o n . 3.4.3.2

Pulling t h e Flanges Apart

1. I n s e r t the t o o l onto t h e jack - hex head.

2. Rotate u n t i l contact i s made between t h e bar on t h e pipe support and the pad on t h e j a w of the jack. This operation should be viewed, whenever possible, w i t h the periscope

31 Remove t o o l from t h e jack hex head and engage it onto t h e hook hex head.

4. Rotate t o close t h e hook l a t c h around t h e jack bar t o permit pulling with the jack. This should never require high torque, and i f high torques a r e encountered, they indicate t h a t t h e stop has been reached or t h a t there i s a malf'unction which should be investigated.

5. Switch t h e hook back t o t h e jack hex head and r o t a t e counter clockwise t o p u l l t h e flanges apart. I n t h i s case t h e torque i s proportional t o t h e load.

6. Remove t h e t o o l . , 3.4.3.3

Pushing t h e Flanges Together While U s i n g t h e Pipe-Alignment Tool

1. I n s e r t t o o l onto jack hex head and r o t a t e clockwise u n t i l t h e r e i s only 1 in. between flange faces. 2. I n s e r t pipe a l i g n i n g t o o l so t h a t the arrow-head-shaped guide on t h e t o o l w i l ) 40 i n t o t h e s l o t i n t h e pipe-aligning bracket.

3. Rotate t h e t o o l toward t h e flange, and adjust t h e height and t h e horizontal distance of t h e pin on t h e t o o l u n t i l it i s aligned w i t h t h e hole in t h e ear o f the flange.

Engage t h e pin i n t h e flange ear. I

Using t h e drive rods on t o p of t h e tool, raise, lower, or a l i g n t h e flange being jacked with i t s mate. Check t h i s with t h e viewing equipment

6 . Resume pushing with t h e jack operator, and adjust t h e alignment as necessary u n t i l t h e flanges a r e seated. 7. Back t h e jack hook 4 i n . away f r o m t h e bar on t h e support t o avoid r e s t r i c t i o n t o thermal-expansion movements.

8. Remove t h e t o o l s .

3.4.4

The Gasket -Handling Tool

3.4.4.1

Removing an Existing Gasket

1. With t h e flanges spread apart 4 i n . o r more, lower t h e gasket-handling tobl, with j a w s open, i n t o t h e space between t h e flanges on t h e center l i n e of t h e pipe.

2. Using t h e periscope with t h e right-angle lens and binoculars from above, carefully l i n e up t h e t o o l 'and t h e v e r t i c a l center l i n e of t h e gasket. I

3 . Move t h e t o o l horizontally i n t o position with t h e upper j a w approximately 1/4 i n . above t h e locking-pin bracket.

4. Lower t h e t o o l so that t h e upper j a w contacts t h e locking p i n bracket. 5. Slowly move t h e lower j a w up i n t o locking position by lowering t h e handle on t h e upper end of t h e t o o l . Lock t h e t o o l t o t h e gasket through t h e engagement of t h e lower j a w s i n s l o t s i n t h e ring.

6. Raise t h e t o o l s ly t o clear t h e threads on t h e locking _pin and move t h e tool, with t h e gasket, back f r o m t h e flange face. A minimum of 1-1/2 i n . t r a v e l i s required t o clear t h e m a l e guide on t h e flange. 7 . Raise t h e assembly u n t i l it clears t h e flange. -

8. Gasket and t o o l 34.4.2

ow ready f o r t h e "hot pull" operation.

I n s t a l l i n g a New Gasket

1. I n s t a l l t h e new gasket i n t h e j a w s of the gasket-handling tool, and make sure that it i s securely placed.

2. Lower t h e gasket i n t o t h e space between t h e open flanges u n t i l the locking pin i s i n l i n e with the tapped hole i n t h e flange.

3. Move horizontally, and i n s e r t t h e pin i n t o t h e tapped hole. (The gasket should always be i n s t a l l e d on t h e down-hill flange.)

Lower t h e assembly onto t h e threads of t h e locking pin.

Open t h e jaws on t h e t o o l .

u .

6. Raise t h e t o o l approximately l./4 in. 7. Move t h e t o o l away from t h e gasket. 8. Raise t h e t o o l carefully so t h a t it does not hang on the i n s t a l l e d gasket and i s clear of t h e flange. 9. Remove t h e t o o l from t h e c e l l .

3.4.5

â&#x20AC;&#x2122;

The Flange-Cover-Handling Tool

-3 .4.5.1

Installing; Flange Covers

1. Place the cover f o r t h e male flange i n t h e t o o l securely, and make sure t h a t t h e wedges a r e f u l l y retracted (i.e., maximum opening in t h e bracket).

2. Lower it i n t o t h e c e l l between t h e open flanges u n t i l t h e rim of t h e cover i s past the male guide.

3. Move horizontally toward t h e flange so t h a t the bracket hooks over t h e ears on t h e flange and then lower it u n t i l it i s seated there

4. Release t h e hook and lower the t o o l so t h a t t h e sockets engage t h e hex heads.

5. Tighten up t h e cover by rotating t h e hex heads counterc lockwi se * 6.

Disengage t h e t o o l and remove it from t h e c e l l .

7. Repeat e n t i r e sequence f o r t h e female flange. 3.4.5.2

Removins; Flange Covers

1. Lower t h e t o o l i n t o t h e c e l l and engage hook i n b a i l of female cover. I

2. way.

Lower sockets down onto hex heads and loosen wedges a l l t h e

Pick up t o o l and lock hook around b a i l .

Pick up cover- and prepare f o r "hot pull.

. Repeat sequence f o r male cover. 3.5

Fuel-Pump Maintenance

Removing t h e Fuel-Pump Motor

3.5.1

1. Drain and blow out auxiliary l i n e s .

2 Disconnect auxiliary flanges, e l e c t r i c a l power, and thermocouple leads and stow.

3 . Loosen t h e b o l t s holaing t h e motor housing t o t h e rotary

element housing. tool.

U s e a torque indicator on t h e socket extension

Remove a l l t o o l s except t h e periscope.

I n s e r t pump l i f t i n g yoke through s p l i t i n portable shield.

Engage hooks on yoke i n trunnions on motor.

7. Record two i t e m s of information t o be used i n t h e replacement operat ion : (a) t h e elevation of t h e mast w i t h respect t o t h e operating f l o o r and t h e azimuth location of t h e center l i n e of t h e crane (b) hook.

8. L i f t t h e motor s t r a i g h t up t o a position beneath t h e portable shield.

There i s engagement between r o t a r y element and m o t o r f o r

t h e f i r s t 7 i n . of t h i s t r a v e l .

9. If t h e radioacti bay area and continue t h e maintenance control roan. 10.

Open t h e s l i d e on

v e l requires it, evacuate t h e highion from inside t h e shielded remoteportable shield and p u l l t h e motor up

1. Drain and blow out auxiliary l i n e s . 2.

Disconnect auxiliary flanges, thermocouple, and speed indicator.

3. Loosen t h e b o l t s holding t h e housing t o t h e pump bowl.

Remove a l l t o o l s except periscope.

5 . I n s e r t pump-lifting yoke through s p l i t i n portable shield. 6.

w a g e hooks on yoke i n trunnions on rotary element. 1:

7. Record f o r use i n t h e replacement operation t h e elevation of t h e mast with respect t o t h e operating __ f l o o r and t h e azimuth of t h e crane hook. 8. The i n i t i a l lift i s accomplished by screwing t h e 4 jack b o l t s on t h e outer bolt c i r c l e .d6m against the pump bowl flange. This jacks t h e rotary element up and off t h e bowl.

9. Lif't t h e ratary element straight up t o a position beneath t h e shield. The lowest part of t h e impeller does not Clem t h e pump flange u n t i l after t h e first 22-1/2 i n . of travel, so t h e l i f t i n g must be done slowly and carefully. 10. If the radioactivity l e v e l requires it, evacuate t h e highbay area and continue t h e operation from inside t h e shielded remotemaintenance control room.

1L Open the s l i d e on t h e portable shield, p u l l t h e rotary element up with t h e crane, and take it t o t h e storage area.

12.

I n s t a l l pump bar1 cover. '

Replacing t h e Fuel-Fump Rotary Element

3.5.3

1. Remove t h e pump bowl cover plate. 2. Pick up t h e new unit on t h e crane with t h e l i f t i n g yoke oriented i n reactor position. Locate t h e crane over t h e center l i n e o f t h e pump from measurements made i n t h e removal process.

Open t h e portable maintenance shield, (from the control room, Close t h e shield as soon as t h e round mast section is i n t h e shield. i f necessary), and lower t h e t o o l and new unit.

- 4.

Proceed with semidirect techniques.

I n s e r t periscope.

5 . Lower t h e rotary element darn onto t h e pump bowl. The last 22-1/2 in. of t r a v e l must be slow, since t h e impeller enters t h e bore of t h e pump bowl flasge at this point. To assist the operation, there should be on hand a drawing showing how t h e rotary element f i t s t h e pump bowl. This i s t o be used with appropriate calibration marks on t h e tool, which are referenced t o t h e elevation mark of t h e f i n a l seated position of t h e rotary element. ,

I n s e r t the long-handled sockets and torque t h e flange b o l t s t o t h e desired loading with a torque indicator.

7. Reconnect all auxiliaries. C

3.5.4

Replacing t h e Fuel-Fbmp Mot or

1. Pick up .the replacenient motor on t h e crane with t h e l i f t i n g yoke oriented i n reactor position. Locate t h e crane over t h e center l i n e of t h e pump from measurements made i n t h e removal process. 2. Open t h e portable maintenance shield (from %hecontrol room i f necessary), and lower t h e t o o l and motor. CLose shield as soon as t h e round m a s t section i s i n t h e shield.

Proceed with semidirect techniques.

I n s e r t periscope.

Lower t h e motor onto t h e rotary element. A t t h e start of t h e last 7 i n . of travel, pins i n t h e motor housing engage a slatted cone on top of t h e rotary element t o provide radial guidance. A t t h e last 2 i n . of t r a v e l t h e mating p a r t s of t h e splined coupling engage. If t h e splines meet tooth t o tooth, it i s necessary t o t w i s t t h e motor through t h e clearance between t h e p i n and the s l o t s i n t h e cones, This i s sufficient t o allow t h e splines t o mate properly ,

-a

5. Torque t h e flange b o l t s t o t h e desired loading according t o a torque indicator on t h e long-handled sockets.

6 3.6 3.6.1

. Reconnect a l l auxiliaries. Procedures for Handling Surveillance Samples and Control Rods Removing the Surveillance Sample f r o m t h e C o r e

1. Assemble t o o l s

quipment

2 , Check out t h e operation of a l l t h e long-handled tools, the portable maintenance shield, t h e crane's remote control, t h e graphiteplug, and t h e sample c a r r i e r . sampler work shield

3. Set up t h e and check out i t s op

supply system and the exhaust blower,

4. Remove t h e upp graphite-sampler acc

eld blocks and cut t h e membrane at t h e c t o r must be shut down and drained.

5 . Set up the port sampler access.

m a i n t e m c e shield over t h e graphite-

6. Remove t h e f i l l e r plug (Dwg. D-KK-D-40970)and t h e top control-rod shield piece.

7. Clean up any contaminated equipment l e f t f'rom t h e previous sampling operat ion. 8. Insert, i n t o t h e standpipe, t h e equipment t o be used i n transferring the sample from t h e reactor core t o t h e standpipe. Same of this equipment i s shown i n Fig. 25.

9. Open the poftable maintenance shield s l i d e and s e t up t h e graphite sampler .work shield. 10. Disconnect t h e thermocouple and cooling a i r l i n e i n the standpipe. Turn off t h e valves i n this air line.

11. Remove t h e heater-access flange (Dwg. E-BB-B-40595).and 2 captive b o l t s with 7/8-in. hex heads, and hang t h i s assembly on the hook. 12.

I n s e r t t h e heater t o o l (Dwg. E-LL-D-56392) i n t o position.

13. Tighten up t h e t w o b o l t s on t h e heater t o o l . 14. Connect parer leads from a variac supply t o t h e heater leads, and hook up t h e thermocouple on t h e heater t o o l . Turn t h e parer on. Bring t h e temperatures i n t h e reactor access nozzle (thermocouples R-33, R-42, and R-43) t o approximately llOO째F. Do not allow t h e temperature of t h e tool' t o go above 1600'~. Maintain t h i s condition f o r a minimum of 3 h r or longer i f possible. I

15. Turn t h e parer off and remove t h e heater t o o l from t h e standpipe. 16. Reinstall heater access flange

17. "urn on blower and t h e nitrogen purge of t h e standpipe atmosphere-control system. Check operations t o make sure t h a t t h e helium pressure inside t h e reactor i s as low as possible (vented). 18. Loosen t h e four b o l t s i n t h e reactor access flange and hang t h e h o l d d m assembly (Dwg. E-BB-B-40595) on t h e standpipe hook. 19. I n s t a l l t h e primary container base piece on top of t h e reactor access flange.

20. I n s t a l l t h e primary container i n t h e base piece, and remove t h e l i d of t h e primary container. 21. Insert t h e sample t o o l dawn through t h e primary container, and engage t h e sample with a clockwise t w i s t . Make an elevation measurement f o r use when replacing t h e sample.

ORNL-DWG 67-13765

k S A M P L E TOOL VIEWING WINDOW-

GRAPHITE SAMPLE

c APHITE SAMPLE

/2!

-in. STANDPIPE

SECONDARY CONTAINER-

-SURVEILLANCE -PRIMARY

PIVOTED DOOR, PRIMARY CONTAINER-

/LID,

SAMPLE

CONTAINER

SECONDARY CONTAINER

T L i D , PRIMARY CONTAINER BASE PIECE

SECONDARY 'CONTAINER-

Y CONTAINER 2~ 2 - k REA ACCESS FLF

Fig. 25.

Surveillance Sample.

22. P u l l t h e sample upward i n t o t h e primary container. Figure 25 i l l u s t r a t e s t h i s point i n t h e procedure and shows the equipment i n use. 23. Use t h e long-handled socket wrench t o o l t o close t h e pivoted door i n t h e lower end of t h e primary container. 24.

Release the sample t o o l from the sample.

25. Put t h e l i d on the primary container, put t h e primary container inside t h e secondary container, and put the l i d on t h e secondary container, a l l w i t h a single hook-type t o o l . The sample i s now contained completely.

26. Remove t h e primary container base piece from t h e top of t h e reactor access flange, and stm it i n the standpipe. 27. I n s t a l l t h e blank flange on t h e reactor access flange. primary system i s now closed.

The

28. Remove a l l t h e long-handled t o o l s from t h e standpipe. Use precautions f o r radioactive handling, especially f o r t h e sample removal t 001. 29. A t t h i s point t h e sample i s ready t o be transferred t o t h e shielded c a r r i e r f r o m t h e standpipe. Set t h e spool piece over an open t o o l hole on t h e graphite-sampler work plug. 30.

Rig t h e shielded c a r r i e r on t h e crane as shown i n Fig. 26.

31. Ehgage the hook of t h e special pull-up cable i n t h e eye of t h e secondary container. 32. Lower c a r r i e r onto top of spool piece. Do not allow t h e fill weight t o r e s t on t h e spool piece. Tape p l a s t i c bags as shown.

33.

P u l l container up i n t o c a r r i e r and close t h e door.

34.

Pick c a r r i e r up high enough t o cut p l a s t i c bags and s e a l

t h e ends.

35. Load t h e c a r r i e r on the hot truck, and deliver it t o t h e

hot c e l l .

A t t h e hot c e l l t h e sample i s disassembled and one-third o f t h e specimens a r e removed. New specimens replace those removed and t h e sample i s then reassembled, loaded i n t o t h e shielded carrier, and returned t o t h e %RE.

+ ,,-

57 ORNL-DWG 67-13766

3.6.2

Replacing t h e Surveillance Sample i n the Core

The process of replacing t h e surveillance sample i n t h e core consists basically of t h e reverse of t h e removal process. A list of the general a c t i v i t i e s i s given belowd 1

1. The' sample i s transferred out of t h e shielded c a r r i e r i n t o t h e standpipe. 2. An i n e r t atmosphere i s established i n the standpipe.

3. The reactor access i s opened a n d t h e sample i s transferred i n t o t h e core. 4. The holddown assembly i s reinstalled. t h e standard leak t e s t .

The flange must pass-

The thermocouple and air-cooling l i n e s a r e reconnected.

6. The equipment and long-handled t o o l s a r e removed from t h e standpipe.

7. The standpipe and the various pieces of shielding a r e put back i n t o t h e condition f o r reactor operation. Procedures f o r Removing and Replacing t h e 2-in. Square Graphite Stringers

3.6.3

I n order t o remove and replace t h e 2-in. square graphite stringers (Dwg. BB-B-40416, Items 7, 60, and 61) i n t h e center of t h e core, t h e same control must be maintained over t h e leakage i n t o or out of t h e reactor, t h e c e l l , and t h e working area as t h a t used while removing t h e surveillance sample assembly. An additional standpipe large enough t o accommodate t h e removal and replacement of these s t r i n g e r s has been designed and fabricated (Dwg. D-BB-C-40659)

The following a r e t h e necessary steps f o r t h e i n s t a l l a t i o n of t h e standpipe and t h e subsequent removal of t h e graphite:

1. Drain and f l u s h t h e reactor system, and bleed off t h e pressure. 2.

Remove 5 upper shield blocks.

3. Go through t h e e n t i r e procedure f o r removing t h e surveillance sample assembly with two exceptions, I n s e r t a dummy with an appropriate handling f i t t i n g i n place of t h e usual sample assembly. Remove t h e flange and holddown assembly and s u b s t i t u t e a blind flange.

4. Set up t h e portable maintenance shield, and remove t h e graphite-sampler work shield.

5. Remove t h e t h r e e coutrol rod assemblies, housings, drives, and rods.

6. Remove 20-in. standpipe (sometimes referred t o as standpipe No. 1).

7. Remove t h e balance of t h e control-rod drive shielding, including t h e lead p a r t s and t h e supporting columns. Disconnect l i n e 936 (Dwg. E-GG-D-56377) and flange i n l i n e 956 and move piping outside t h e bolting r i n g of t h e 36-in. standpipe (referred t o as standpipe No. 2 ) .

9. Disconnect 5 thermocouple boxes and move jumper leads aside. I

I n s t a l l 36-in. standpipe, t i e d i n a t t h e t o p by t h e notched flange and a t t h e bottom by a flange on t o p of t h e reactor access nozZle. 10.

11. Set up work shield, remove portable shield, and establish i n e r t atmosphere.

12.

nozzle

Remove t h e b o l t s i n t h e 10-in. flange on t h e reactor access

13. L i f t the access nozzle plug and control-rod thimble assembly and place on 'support bracket inside ^the standpipe.

14. Place dummy s t r i n g e r s i n t h e t h r e e empty spaces l e f t by t h e control rod thimbles t o prevent t h e other s t r i n g e r s from getting out of position. \

i t t i n g t h a t holds t h e tops of t h e f i v e it i n t h e bottom o f ' t h e standpipe. graphite stringers, and There are several options from here on depending upon how many samples a r e t o be removed, t h e type of replacement, t h e timing (how long between removal and replacement), and other operations that are likely, such as ection and r e t r i e v a l of material from the core.

15. Remove t h e spa

16. Remove one s t r i place i n an empty container. The f i t t i n g on t o p of t h e s t r i n g e r i s a male *half of a quick-disconnect fitting.

17. Transfer l i d from container w i t h new stringer t o the one with an exposed stringer. 18. Take new sample out of can and put it i n position i n t h e core

w 19. Repeat for as many stringers as can be stowed i n t h e 36-in. standpipe, or as t h e program requires. 20. Replace plug and thimble assembly i n reactor access nozzle, torque bolts, and have operations personnel check f o r leaks. 21.

Clean up external surfaces with long-handled swabs.

22. Transfer containers t o shipping casks with t h e crane operated from t h e control roan. 23.

Remove all t o o l s and remaining equipment from standpipe.

24.

Set up portable maintenance shield and remove work shield.

25.

Remove 36-in. standpipe.

26. Reinstall a l l equipment required t o bring reactor back t o operating condition. See steps 5 through 9.

3.6.4

Removing Control Rod U n i t s

Access t o t h e control rod kits has been provided through t h e upper flange of t h e 20-in. graphite-sampler standpipe. The folluwing general procedure i s used f o r removing p a r t s of t h e control rod and drive assembly. 1. Remove f i v e upper roof plugs.

2. Assemble t h e following tools: (a) t h e work shield (Dwg. E-BB-C-40646, items 1 and 2; (see a l s o Figs. 15 and 16), (b) work plug and associated t o o l holders, viewing ports, l i g h t receptacles, etc. (see assembly drawing E-B-C-40646), ( c ) wrenches and extension handles f o r bolts, disconnects, e t c . on t h e drive assembly; i n s t a l l t h e short t o o l s in t h e work plug.

3. Blanket t h e area around t h e work area with p l a s t i c sheet and

s e t up a i r monitors and other health physics equipment.

4. Remove t h e cover flange and t h e 39 1/2 in.-diam. plug (Dwg, D-BB-C-40651, 49662)

, 5. Set up t h e portable maintenance sliield. rod drive shielding (Dwg. D-BB-C-56367).

filler

Remove t h e control

6. Remove t h e half-moon shaped access flange and deposit t h e flange over t h e standpipe opening. f

7. Disconnect t h e e l e c t r i c a l and air connections. 8. Remove t h e rod drive access flange.

L i f t flange through

61.

6J access port and place on t o p of access flange l i s t e d above. requires loosening 4 captive hex-head bolts.

This

9. Lower t h e extension wrench i n t o position and disconnect t h e two captive b o l t s connecting t h e drive unit t o t h e control rod. These two b o l t s have hex socket heads with fâ&#x20AC;&#x2122;unnel-shaped guides. 10. Disconnect t h e 3 captive b o l t s t h a t a t t a c h theâ&#x20AC;&#x2122; drive unit lower flange t o t h e rod thimble flange. Remove t h e extension wrench. 11. Replace t h e rod drive access flange removed i n step 8.

Bolt

it down. 12. Lower a pickup hook through t h e s p l i t section of t h e r o t a t i n g work plug.

13.

Engage hook i n lift b a i l and p u l l housing up slowly.

14. Open t h e portable maintenance shield at t h e s p l i t section and complete t h e p u l l . 15.

Use p l a s t i c bags t o contain any loose contamination.

Replacement of t h e control-rod drive housing consists of doing t h e above procedure i n t h e reverse order. However, when t h e r e p a i r t o t h e drive mechanism has been completed it must be assembled w i t h a new control-rod-thimble flange-seal r i n g and with only one captive screw i n t h e flange t h a t connects t h e drive t o t h e rod. Also t h e following steps are required t o a t t a c h t h e control rod t o t h e drive. These steps replace s t e p 9. a. I n s e r t t h e threaded rod t o o l i n t o t h e drive housing and thread it through one of t h e threaded holes i n t h e flange on t h e drive. It w i l l go completely through these thread u n t i l t h e smooth shank on t h e t o o l i s i n t h e threads. b.

Lower it until. it g e t s t o t h e control rod.

Screw it i n t o t h e threads on t h e control rod.

Pull t h e control rod upward as far as it w i l l come.

e. I n s e r t t h e wrench t o o l onto t h e captive b o l t on the other side of the flange. f

Screw t h i s bo

.Now t h e control rod i s t i e d t o t h e

Unscrew t h e threaded t o o l and remove it.

62 ,

h. I n s e r t t h e remaining captive bolt on t h e end of a wrench t o o l and screw it i n t o t h e control rod. The rod i s now joined t o t h e drive. withdrawn. Continue procedure at step 8. i.

3.6.5

I ) t

The t o o l s may be

Removing t h e Control Rod

16. Xnsert a threaded t o o l i n t h e threads on t h e control-rod flange

17. L i f t control rod t o within 1 ft of t h e b a t t m of t h e portable maintenance shield

18. Clamp off t o o l and cut off excess length of t o o l .

19. P u l l t h e control rod i n t o a p l a s t i c bag. The upper end w i l l not be too radioactive, but t h e luwer end t h a t has been i n the reactor w i l l be very hat, probably above 200 r/hr, and precautions must be taken t o deal with t h i s source. 20.

Dispose o f t h e control rod or drop it i n t o a shielded c a r r i e r .

Replacement of t h e control rod i s accomplished with t h e reverse of t h e above procedure, steps 1 t o 20.

35'

Procedure for Brazing a Joint

The t o o l s and equipment l i s t e d beluw a r e required f o r brazing a joint

EqApment put i n t o c e l l f o r brazing operation: a. b.

c. d.

e. 2.

positioning vise fixed vise pipe cutter pipe taperer furnace

Long-handled t o o l s used: a. b. C.

handling t o o l extension wrench extension drive f'urnace i n s t a l l a t i o n hook a i r motor (no. 315R Chicago, pneumatic, C a t . 22-387-3283).

3. Auxiliary equipment and supplies >lrsedexternal t o c e l l only f o r brazing operat ion:

* /---

1-ton chain hoist

Ajax 3200-cps 30-kw induction generator

. 1

25-f't induction heating leads

pure argon o r helium with drier 2000째F indicating o r recording instruments f o r the j o i n t thermocouples one complete dummy female braze f i t t i n g with 18-in. nipple

e. f.

5 ?

4. General-purpose equipment: a. b.

10-ton crane maintenance shield.

Perform a t e s t braze i n t h e following manner t o determine t h a t t h e equipment i s i n worki der and t o qualify t h e procedure: 1. Inspect a l l t o o l s and equipment t o make sure they a r e on hand, clean, and i n working order. The pipe c u t t e r knife must read R.C. 60 or b e t t e r on t h e blade. 2. Mount t h e positioning vise on t h e spare base p l a t e . Put a piece of 1 1/2-in. Hastelloy N pipe i n t h e positioning v i s e and clamp it t i g h t l y . Mount t h e c u t t e r and cut t h e pipe. The proper procedure f o r cutting i s t h e following:

Rotate t h e t o o l drive u n t i l t h e knife feed wheel i s up.

Feed t h e knife i n u n t i l it i s snug on t h e pipe.

Rotate t h e t o o l u n t i l t h e knife feed wheel contacts t h e C. pin but does not pass it. d. Rotate t h e t o o l back u n t i l t h e wheel touches from t h e other side.

e . Make f o u r compl advance $he knife feed.

i l l a t i o n s and then pass the pin to

f . Continue i n ion (four o s c i l l a t i o n s and then a revolution) u n t i l t h e pipe i s cut. The prcgress of t h e cut and t h e condition of t h e knife can be determined from the torque ( f e e l ) of t h e t o o l drive and should be observed carefully during t h e practice cut.

g. Feed t h e knife t h e opening i s down, and h.

e way out, r o t a t e t h e t o o e t h e t o o l from the vise.

that

Examine t h e c u t t e r knife, and i f it i s not damaged, use

it f o r t h e i n - c e l l operation.

3. Position the vise a l l t h e way t o t h e back (i.e., away from the s l i d e feed nuts), and mount t h e pipe taperer on t h e base plate. While turning t h e taperer drive by hand advance t h e pipe i n t o t h e c u t t e r by moving t h e positioning vise forward u n t i l yau f e e l t h e cut begin.’ This i s t h e s t a r t i n g point of t h e .tapering cut. Carefully mark t h e position of t h e feed handle and count revolutions from-this point. Place t h e air motor on t h e taperer drive, s e t t h e pressure t o 25 psi, and t u r n on the a i r motor. It i s necessary t o hold t h e air motor by hand t o f e e l t h e torque and t o advance the vise feed by t h e torque f e e l . Too heavy a feed w i l l r e s u l t i n chipped c u t t e r teeth. The operation should take 2 t o 3 hr. After t h e feed has advanced 5 1/2 turns, t h e cut i s complete. Let the a i r motor run 10 min with no f’urther feeding t o obtain a smooth f i n i s h . Back the pipe out Remove t h e taperer. Clean t h e taper with a thoroughly degreased brush. Do not touch the machined surface with anyt hing else. A finger-print w i l l produce an unbonded area.

Slide t h e furnace over the tapered stub.

5. Thoroughly degrease t h e dummy female braze f i t t i n g with thermcouples and f’urnace end attached, as well as t h e braze preform. Assemble t h e preform i n t o t h e f i t t i n g and fasten it with several spot welds. Use white gloves and extreme care. A fingerprint w i l l cause an unbonded area. P

Clamp t h e f i t t i n g i n t h e fixed vise so t h a t t h e end of t h e f i t t i n g projects 4 1/2-in. past t h e end of t h e jaws. Place t h e vise on t h e base p l a t e and b o l t it darn.

7. Bcrttm t h e pipe stub i n t h e f i t t i n g by operating t h e . positioning vise and then back t h e stub out one-fourth t u r n f o r a purge gap. Close t h e furnace over t h e j o i n t . Place pipe plugs i n t h e pipe ends. Connect argon purge t o t h e f’urnace and one pipe plug. Purge at 40 cfh. Connect t h e thermocouple leads t o t h e indicators. Connect t h e furnace leads t o t h e Ajax generator. Set t h e capacitor control t o 15. S t a r t t h e machine, bring it up t o about 5 kw t o heat the j o i n t t o 500°F, and then adjust t h e power t o hold t h e j o i n t at 500°F while purging f o r 1 h r t o bake out and Off-gas the system. Adjust t h e capacitor control i f necessary t o obtain a power f a c t o r of one a t 5 kw.

8. Operate the positioning vise t o firmly seat t h e stub i n t h e f i t t i n g . While one operator maintains pressure on t h e positioning vise drive, t h e second operator r a i s e s t h e machine power t o 60 amp, which r e s u l t s i n readings of approximately 140 v and 11kw. The joint heats t o 1750°F i n about 1 1/2 min, a t which time t h e vise operator drives t h e stub i n 1/8 i n . or about threefourths t u r n and again seats t h e stub firmly in t h e f i t t i n g . The machine operator watches t h e temperature indicator carefully, and when t h e temperature reaches lgOO°F, he immediately cuts t h e power t o 3 t o 4 kw and carefully adjusts it t o hold 1900OF f o r 1min.

* /?

Then he t u r n s t h e power off and permits t h e j o i n t t o cool. The vise operator.holds pressure on t h e j o i n t throughout t h e operation and u n t i l t h e j o i n t cools t o 6 0 0 ' ~ .

9.'

After t h e j o i n t has cooled, it i s removed and inspected.

If t h e operation was successfil, t h e equipment and operators are ready t o proceed t o t h e remote braze i n accordance with t h e following: 10. Set t h e portable maintenance shield over t h e braze point and remove t h e pipe heaters and any other interferences. Attach t h e chain h o i s t t o t h e wane.

11. Put t h e positioning v i s e i n i t s ' f ' u l l forward position with i t s j a w s fully open. Attach t h e 20-ft lift b a i l t o the chain h o i s t and t o t h e vise. Suspend t h e vise over t h e base p l a t e oriented so it w i l l grip t h e pipe t h a t i s t o remain i n t h e c e l l . Open t h e shield slide, lower t h e vise through, and close t h e shield on t h e l i f t rod. Lower t h e v i s e by use of t h e chain hoist and carefully s e t it on t h e base p l a t e while guiding t h e dowels i n t o t h e i r holes. Disengage and remove t h e lift b a i l . I n s e r t t h e extension wrench and b o l t t h e v i s e t o t h e base p l a t e . Operate the positioning drive t o center t h e v i s e i n i t s t r a v e l as indicated by marks. Close t h e jaws on t h e pipe t i g h t l y . If t h e pipe s l i p s i n t h e jaws during a later operation, t h e reference point w i l l be lost

12. Attach t h e lift b a i l t o t h e chain hoist and t o t h e pipe c u t t e r . Suspend t h e c u t t e r over i t s mounting p l a t e on t h e vise. Make sure t h e cut5er i s i n t h e open position so t h a t it w i l l pass over t h e pipe. Open t h e shield slide, lower t h e cutter, and close t h e s l i d e on t h e b a i l rod. Lower t h e c u t t e r and guide it onto t h e mounting p l a t e ( t h e p l a t e i s 3" off v e r t i c a l ) . U s e the chain hoist for f i n a l lowering. Disconnect and remove t h e lift b a i l . I n s e r t t h e extension wrench. Turn t h e c u t t e r drive u n t i l t h e knife feed wheel i s up. Put t h e extension wrench i n t h e feed wheel and f i t t h e c u t t e r knife snugly onto t h e pipe (counterclockwise) Cut t h e pipe following t h e procedure i n paragraphs 2 c . through 2 e, and remove t h e c u t t e r as i n paragraph 2 g.

13. With t h e extens drive 11t u r n s t o t h e r later operat ions

14. Complete t h e d by t h e appropriate p

ench, operate t h e positioning v i s e hat t h e pipe stub w i l l be c l e a r f o r t i o n and removal of t h e component

66 15. hamine the pipe taperer t o be s u r e ‘ i t i s clean, the c u t t e r i s i n good condition, and t h e brush and p i l o t ball assembly i s tackwelded and cannot come off. Attach t h e lift b a i l t o t h e chain hoist, and t h e taperer and i n s e r t it through t h e maintenance shield. Lower it onto t h e base plate, remove the l i f t bail, and bolt it dawn. Perform t h e tapering operation as i n paragraph 3; however, note i n addition, the t o t a l number of turns of t h e positioning vise from i t s position in paragraph 13 t o t h e completion of t h e cut and return the vise t o t h a t position a f t e r t h e completion of t h e cut. Remove t h e taperer from t h e c e l l . Gross particulate contamination i s t o be expected.

a ’

16. Ekamine t h e furnace carefully. Attach t h e induction heating leads, the purge gas line, and t h e handling bail, and t i e o f f t h e leads and purge l i n e t o the top of the b a i l . Attach the bail t o %he chain fall, and i n s e r t t h e furnace i n t h e c e l l . Carefully s l i d e t h e f’urnace Over t h e stub and against the p l a t e of t h e vise. Untie t h e leads f r o m t h e b a i l and secure them on t h e shield. Remove t h e bail. Thoroughly degrease t h e nylon brush which w i l l pass over t h e pipe stub, attach t h e long handle t o it, i n s e r t it i n t o t h e c e l l , and brush off t h e machined surface. Remove the brush. 17. hamine t h e new component t o assure that t h e braze f i t t i n g i s accurately located, i s clean, t h e braze preform i s i n place, t h e thermocouples with 25-f’t f l e x i b l e leads coiled on t h e furnace b a i l a r e i n place and checked e l e c t r i c a l l y , and t h e furnace end with thermocouple leads i s i n place. I n s t a l l t h e new component by appropriate procedures.

18. Examine t h e fixed vise t o see t h a t it i s operating properly and t h a t t h e j a w s are f u l l y open. Attach the lift bail t o t h e chain hoist and t o t h e vise, and i n s e r t it i n t o t h e c e l l . Place it on t h e base p l a t e very carefully t o avoid s t r i k i n g t h e f’urnace end. Remove t h e lift bail, bolt dawn t h e vise, and clamp t h e vise jaws on t h e pipe t i g h t l y . 19. Retrieve t h e thermocouple leads with t h e r e t r i e v a l hook. 20. Proceed w i t h t h e braze as i n steps 7 and 8 w i t h t h e generator power settings obtained i n t h e t e s t braze. The purge t o t h e inside of t h e pipe w i l l have t o be inserted a t sane convenient place i n t h e salt system. I n t h e case of a drain-tank replacement, t h e normal helium connection t o t h e drain tank can be used. i

21. Af’ter the j o i n t i s completed, open t h e furnace and examine t h e joint visually with t h e periscope t o check t h e quality of t h e f i l l e t and wetting around t h e joint. Then inspect it with ultrasonic t o o l s and techniques provided by t h e Metals and Ceramics Division. a

22.

Destructively remove t h e furnace, and then remove t h e t o o l s .

3.8

Procedures f o r Maintenallce 6f t h e Sampler-Enricher

There are nine p a r t s of t h e sampler-enricher t h a t w i l l be i n contact with the radioactive s a l t . Therefore radiation w i l l be a f a c t o r at t h e time of maintenance. "he specific p a r t s a r e (1) t h e inner compartment, (2) the.manipulator arm assembly, (3) the removal s e a l assembly, (4) t h e light bulb, ( 5 ) t h e maintenance valve, (6) t h e operational valve, (7) t h e hot vacuum pump, (8) t h e containment housing, and (9) t h e spool piece connecting t h e pump bowl with t h e sampler. Except f o r items 5, 6, and 8, these items are independent and can be removed f r o m t h e assembly by themselves. I t e m 5, t h e maintenance valve cannot be removed without first removing items 1 and 6. Similarly, i t e m 6 cannot be removed without removal of 1. Parts of t h e sampler-enricher are shown i n Figs. 23 and 24. Radiation levels affecting maintenance w i l l depend on the duration and power levels of reactor operation, t h e amount of spillage, deposits from gaseous activity, and whether there i s a radioactive sample within t h e sampler t h a t must be removed i n a nonroutine manner. Thus, t h e range of conditions that might be encountered i s large. While t h e reactor i s operating, approximately 8 i n . of lead shielding covers the. u n i t . This provides protection f o r personnel during t h e normal sampling operation, The shieldin$ i s mostly i n t h e form of stacked lead brick. Several cast prices are used where complex shapes are needed. Doors and windows w e r e b u i l t i n t o t h e shell f o r maintenance access. A generalized version of t h e maintenance procedure follows. Details f o r each individual piece of equipment vary and have t o be applied as required. Item 9, t h e spool piece, however, i s an exception because it i s located within t h e reactor shield; t h e portable maintenance shield and long-handled t o o l s are used f o r maintaining it. 1. Shut darn t h e equipment. This includes the reactor and t h e ler-enricher various subsystems of t h e s

Remove shield blocks t o give clearance and working room.

3 . Gather, clean, and prepare tools, shielded carriers, equipment, and t h e decontamination c e l l . er and p l a s t i c , and s e t up contamination 4. Spread out b l o t t e r control measures f o r t h e high bay.

Remove outer pieces of shielding.

6 . Take health physics precautions throughout remainder of procedure.

7. Decontaminate as much as possible and pass cleaning swabs through t h e removal s e a l assembly,by using t h e sampler-enricher manipulator t o pickup t h e radioactive material. 8. Remove sufficient shielding f o r access t o t h e attachments.

9 Disconnect mechanical, e l e c t r i c a l , and piping connections. Use hand tools, extensions, and stacked lead brick shiexding. Radiation surveys should be made t o locate and correct l o c a l streaming. 10.

Attach lif'ting devices.

11. Rig shielded c a r r i e r and p l a s t i c bags t o encase the equipment as it clears t h e structure of t h e sampler.

12.

Transport t o decontamination c e l l f o r cleanup.

13. Decontaminate and repair the unit. not possible, prepare a new replacement.

If decontamination i s

14. I n s t a l l the repaired or t h e new component. 15. Reconnect a l l f i t t i n g s and attachments.

16. Replace t h e shielding.

APPENDICES

is Appendix A a

LIST O F REMOTE MAINTENANCE REFEXEXTCE INFORMATION 1. R. Blumberg, Remote Maintenance of t h e MSRE, MSW Semiann. Frogr. Rept. July 31, 1964, USAEC Report ORNL-3708, pp 190-200, ORNL. 2.

E. C. H i s e , F. W. Cooke, and R. G. Donnelly, Remote Fabrication of Brazed Structural J o i n t s i n Radioactive Piping, ASME-63-WA-53, American Society of Mechanical Engineers, New York.

Unpublished book of detailed maintenance procedures f o r MSRE.

Unpublished catalog of MSRE maintenance t o o l s (contains t o o l description and method of operation); compiled by J. R. Shugart.

Collection of photographs taken i n reactor c e l l , drain c e l l sampler, e t c . (There are t h r e e loose l e a f binders.)

'NOTE:

Items 3, 4, and 5 are available from J. R. Shugart at t h e MSRE.

Appendix B

SHIELD

MSRE PORTABm MAI"ANCE

LL-D D r a w i n g No.

Title

E 40660

Module Assembly, Cros s-Sect ions

D 40661

D 40662 D 40663 D 40664 D

40665

Cutting Schedule

- General - Reactor C e l l Layout Plan - Reactor Cell - S . Ctr. Bays Layout Plan - Reactor Cell - N. S t r . and W. Layout Plan

D 40667

40668

, Index

D 40666 D

E. Bay a t Sampler E. Bays

Over Freeze Flanges

- Drain Tank Cell,

D 40669

General

D 40670

Drain Tank C e l l

D 40671

D 40672

D 40673

Track Details

D 40674

Sheet 2

D 40675

Sheet 3

- End Bays

Mid Bays

Corner Bays Typical Track Assembly

- Sheet 1

D 40676

B a l l Plug, Lights, Special Mod. I n s e r t

D 40677

Frame and Motor Drive

- Assembly - Sections

D 40678

Details, Sheet 1

D 40679 D 40680

Sheet 2

Special Attachment Module

D 40682

14 in. Fill Module 2 ft 6 1/2 in. Fill Module

D 40683

Eccentric Plug Module

D 40681

D 40684

- Sheet 1 Eccentric Plug Module - Sheet 2

D 40685

General Information Layout, Ecc

D 40686

Plugs A and A'

40687

Bays

- Sub Assemblies Details

Plug Module

U-D Drawing No.

T i tl e -

D 40688

Plugs B and B'

D 40689 D 40690 D' 40691 D' 40692 D 40693 B/M 40694 D 40695

Plugs B and B'

- Sub Assemblies - Details

Long Slide and S l i d e I n s e r t s Short Slide and Slide Extension Spacer Hole I n s e r t s I1

- Misc.

Plugs

Sheet 1 Sheet 52, B a l l Plugs

Master B i l l of Materials, Portable Shield Lead Glass Window Plugs

Appendix C

GRAPHITE SAMPLER AND CONTROL ROD MAINTENANCE FACILITY Number

T i tl e -

E-BB-C-40646 40647

7/811 Graphite Sampler ,- Gen. Assembly

40648 40649

Graphite Sampler Detail, Tool Bushing and Pb. G l a s s Holder Graphite Sampler Work Plug No. 1, Alternate Constr. I1

Work Plug No. 2, Assembly and Details

40650

Airline Piping f o r 7/8" Graphite Sampler

40651

Graphite Sampler Detail

40652

- Shield Plug and I n s e r t

Work Plug No. 1 Assy. and Details

40653 40654

7/8" GrFphite Sampler Details Gaskets f o r 7/8" GrKphite Sampler

40655

Graphite Sampler, Details Floodlights and Pb Glass Holder

40656

Graphite Sampler Detail, Tool Bushings arid Seals

40657 40658

Work Shield, Graphite Sampler

40659

Graphite Sampler, Standpipe No. 2 Assy. and Details, Sheet 1

Details Standpipe No. 2, Sheet 2 Assy and Details

V a r d Corp. Drawings

F- 114'729

Housing Assembly, Drive U d t

F-114800

Drive U n i t Assembly, MSRE Control Rod

F-119786

Plate Assy. MSFE Drive U n i t Access Hatch Plate

Appendix D

TOOLS AND MISCELLANEOUS EQUIPMnVT

LX)NG-”DLED

MSRE-SK-NO

Title

2 50

Handling Tool f o r Freeze Flange Gaskets Freeze Flange Cover Handling Tool, f o r FF-200

, Details

It It

Clamp Stowing Tool

Adjustable L i f t i n g B a i l f o r Maintenance Tools Offset Handling Tool f o r E l e c t r i c Heaters Television Camera Stand f o r Remote Maintenance Portable Shield L i m i t Switch Ring Gasket Handling Tool f o r Auxiliary Flanges Freeze Flange Covers, Assembly

, Details

It c

Thermocouple Disconnect Tool with Guide Fuel Pump Rotary Element L i f t i n g Tool

Motor Lif’ting Tool

Remote Maintenance A l l W p o s e Handling Tool Heater Unit Handling Tool Remot e Maintenance Socket Extension Tool and Bolt Retainer

E71

Details, 1/2” and 1/8” Auxiliary

D-272

f o r Leak Detector Disconnect Handling Tool

D-273

Handling Tool f o r Drain Tank C e l l , Space Cooler Support Hanger

C274

E76 E77

Gear Tool f o r Jacking F’ump Assembly

c278

Freeze Flange Clamp Operator Assembly,

Shield, Eccentric Plug Module Drive Mechanism

MSRE-SK-NO

a79

T i tl e

Freeze Flange Clamp Operator Details II

~280

~281

Lif'ting Bails and Masts f o r Fkeeze Flange Clamp Operating Tools Handling Tools f o r Breco Fittings

Tool Calibration f o r Freeze Flange Maintenance Rod Light f o r Remote Maintenance Alignment Tool f o r Freeze Flange, 100, Assembly 11

Det a i 1.

MSRE Pipe Alignment Tool Assembly 11

Details

Freeze Flange Clamp Aligning Gage for Clamp Operating Tool Valve Support Beam Handling Tool Offset Handling Tool f o r Drain C e l l Pipe V i s e

Freeze Flange Clamp Staring Tool for FFlOO and 102

Remote Maintenance G a n t r y Handling Tool f o r Snap-tite Disconnects Handling.Too1 f o r 2 in. Graphite Samples Offset Socket Drive Tool Lifting B a i l f o r 1-1/4" Pipe Mast Tools S a l t Plug Heater Tool Assembly II

Detai Is

â&#x20AC;?

Appendix E *

IN CELL EQUIPMENT P

Number

E-c&E-41868 41869 42370 E-BB-E-41872 E-BB-Z-41873

D-GG-E-41874 D-GG-E-41875 E-GG-E-41876 D-GG-E-41895

E-GG-c-40610 E-GG-C-40609 -~a~-~-40607 D-~~~-40608 D-GG-c-40466 E-CC-C-41450 D-CC-C-41453 D-CC-C-41511 E-EE-C-41491 E-EE-D-41492 E-DD-D-41493 E-DD-D-40742 D-U-E-40734 E-BB-D-40724

bid

Title Equipment Installation, Freeze Flange Maintenance Freeze Flange Jack, Installation and Assy. ' Pipe Jack Mounts, Freeze Flange FF-100, 102, 200, and 201 Heat Exchanger Jack, Pipe Alignment Bracket, FF-101 Reactor Cell Equipment Supporting Steel, Sheet 2 Clamp Stowing, Pipe Alignment Bracket, FF-200 If FF-201

Freeze Flange Jack, Modification Details Flange Jacking Hook, Support Pedestal Assy. and Details~

5 in. Freeze Flange No. 100,. 102, 200, and 201 Assy. l,

5 in. 5 in.

101 Assy. Freeze Flange Details II Weldment, Rough Machine Freeze Flange No. 101, Bottom Clamp Weldment

Fuel Pump Support Assembly 0 Fuel tip Support Details 0 Arrangement Heat Exchanger Support Assembly Heat Exchanger Support Primary Heat Exchanger Support Suspension Beams Heat Exchanger Support Detail. Quick Disconnect Block and Yoke Details Reactor Thermal Shield Assembly and Sections

. Appendix F f

JIGS AND FIXTURES

Number

T i tl e -

E-U-Ey56269

Valve Clamp J i g Parts, PCV-960, HCV-903

56270 F-GG-D-55417

55418 55419 55484 E-IrL-E-41830

Assembly Fixture Fuel Pump, A m . Flanges Assembly 11

Flanges, Body Weld

Assembly Fixture Fuel Pump Aux. Flange Details Fuel Pump Aux. Flange Motor Adapter Drain Cell Canponent Jig, D.Ti No. 1 11

41832

41837 41838 41839

, Aux.

41831 41833 E-U-E-41836

915, 956, 961, 962

, Fuel Drain Tank No. ,

2 Fuel Salâ&#x201A;Ź Plush. Tank

, Detail Sheet

No. 1

Assy Fixture Major Components, Elevation 11

Y It

11-

41840

41841

plan Pedestal Weldmerrt

, , R e e z e Flange Nests FF-101 , Freeze Flange Nesting : Stand

, Details

79 1

om-m-910 I n t e r n a l Distribution 1. G. M. Adamson 2. L. G. Alexander 3. D. D. Ausmus 4. J. M. Baker 5. F. Barnes 6. H. F- B ~ u u I ~ ~ 7 . S. E. Beall 8. M. Bender 9. C. E. B e t t i s 10. E. S. B e t t i s 11. Re E. Blanc0 12. R. Blumberg 13 E. G. Bohlman 14. C . J. Borkowski 15 G. E. Boyd 1 6 R. B. Briggs G:D. Brunton 17 18. D. A. Canonico 19. W. L. Carter 20. G. I. Cathers 21. 0. B. Cavin 22. W e Re Cobb 23. C. W. Collins 24. E. L. Compere 25. We He Cook 26 D. F. Cope (AEC-ORNL) 27. W. B. C o t t r e l l 28. J. L. Crowley 29. F. L. Culler 30. D. G. Davis R. J. DeBakker 31 32 S. J. D i t t o 33 W. P. Eatherly 34. J. R. Engel 35. D. E. Ferguson 36 A. P. Fraas H, A. Friedman 37 38. J. H. Frye, Jr. 39. C. H. Gabbard 40. R. B. Gallaher 41. H. E. Goeller 42. W. R. Grimes 43, A. G. Grindell

47* P a N. 48. P. G. 49. D. N. 50, E. C. 51. Ha W e 52. 53. 54. 55. 56.

57. 58. 59. 60. 61. 62. 63.

64.

81. 82. 83. 84. 85. . 86. 87.

44.

R. H. Guymon

45. 46.

B. A. Hannaford P. H. Harley

65. 66. 67. 68. 69. 70. 71. 72. 73. 74. 75. 76. 77. 78. 79. 80.

88. <â&#x20AC;&#x2122;

89.

90. 91. 92.

Haubenreich Herndon Hess Use Hoffman P. P. Holz T. L. Hudson R. S. Jackson P. R. Kasten R. J. Ked1 H. T. Kerr S . S. Kirslis J. W. Koger A. I. Krakoviak J. W. Krewson R. B. Lindauer A. P. L i t m a n G. H. Llewellyn E. L. Long M. I. Lundin R. N. won H. G. MacPherson R. E. MacPherson T. H. Mauney He McClain R. W e MCClUng H. E. McCoy H. C. McCurdy H. F. McDuffie C. K. MCGlOthlan J. R. McWherter A. J. Miller R. R. Minue R. L. Moore H. H. Nichol E. L. Nicholson L. C. Oakes A. M. Perry T. W. Pickel H. M. Poly G. L. Ragan J. L. Redford M. Richardson R. C. Robertson H. C. Roller M. W. Rosenthal

80 ,

93. H. C. Savage 94. A. W. Savolainen 95. Dunlap Scott 96. H. E. Seagren 97. J. H. Shaffer 98. J. R. Shugart 99. W. H. Sides 100. M. J. Skinner 101. G. M. Slaughter 102. A. N. Smith 103. G. P. Smith 104. 0. L. Smith '105. .P. G. Smith 106. I. Spiewak 1W.- R. C. Steffy 108. W. C. Stoddard 104. D. Sundberg 110. J. R. Tallackson lll. W. Terry

R. E, Thoma W e De Todd D. B. Trauger ' R. W. Tucker H. L. Watts B. H. Webster 118. A. M. Weinberg l l 9 . J. R. Weir 120. M. E. Whatley 121 G. D:Whitman 122. L. V. Wilson 123 F. C. Zapp Central Research 1Z-125 Library 126-127 . Document Reference Section Laboratory Records 128-130 Department 131. Laboratory Records (RC) ll2. 113. ll4. 115 116 117

c) c e

External Distribution

. A.C. Giambusso, B. Deering, AEC, OR0 AEC, Washington, D.C. l34. W. J. Larkin,.AEC, OR0 135. T. W. McIntosh, AEC, Washington, D.C. 136 He Roth, AE, OR0 132 133

M a

137. M. Shaw, AE, Washington, D.C. 138. W. L. SmaVey, AEC, OR0

139. 140-1%

Laboratory and University Division, AEC, OR0 Division of Technical Information Extension

. ?