Np 18955

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NP- 18955

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MOLTEN-LT

BREEDER REACTOR CONCEPT

Q u a r t e r l y Report f o r t h e Period Ending A p r i l 30, 1 9 7 1

nformation Extension, Oak Ridge, Tennessee \

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NP- is955

MQUTti SAUCI&BEUFi EUACTOR CONCEEC r QUiETmY IiitPOKT FOR TIiE PERIOD~EMIINC APRIL 30, i971.

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Chemical investigations on th6 feasibility of a plutonium stesf;' up Moltsn Salt'.Reactor have been in progress in.the Radiochemistry Ditisicm. at Trombay for over two years. The-work programm6'andthd pro&ress cf work have been reported in a series of semi-annual and quarterly progress. reports (1-63.. oUri& the per-i&under report a seoond experimfnt.,has been qarried &t on ths solubility of P"F5 in LiF-136F2-ThF4(71d3i. $5yd5,,f3.s m/O)'in the temperature range of. 510'. to'787'Ci. Th6 s,olubility'of PuF3 in th6 salt mixtur6 of the. above composition was found to ba between 0.7 m/o at the lowest temperatur-6 and around 4 m/c at th6 highest temperature.. Analysis of the salt scmp~fs withdrawn from'equilibrated melts using 10 micron and 15 m/iFron (OHNLsupplied) porosity filter frits '. at the sam6'temp6rature agreed within 5s thereby indicating that the measured.solubility values’ are -e’tie 'within ths limits of sxperimental 'errors.

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DISCUSSIONS

The MSBRCommittee met on several ti’oas%ons 6& w$Qi the assistarM of the workinS group ?n l&%R finalised a working paper,. outlining the various devslopm6ntal effort required t0 be put i+ In this 0Ontext:tha committee also pr6pared a pap6r cm th6 development vjprk that , oould be aarrisd out within the neti four yea&i A stat8m6ntof the propoasd four year proe;ramm8with the personnel and stores' szid 6quipm6nt requireDSntt3 have been prspared and submitted to the DiI%?ot'O~,-CT’ The main feature of ,the paper on the four year development programmeis that it is oonfin6d to the presently acO8pt6d and mOS+feEtSib conoept naely,a Sin&s fluid two-r6&ion'reaotor system.

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E""TAL

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Labarptow SP ace

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FACILITIES -*

Four old glove boxes i n t h e RadiOChemi6try Division have been decontaminated and handed over t p

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not be reused because of corrosion and d e t e r i o r a t i o n of perspex p-18.

h t h e addition of two new glove boxes and two fumehoods in t h e apace

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cleared it i s a n t i c i p a t e d that the devslapment work on reprocessing could be i n i t i a t e d .

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Process Chemht-T Apparatus

It has been reporte

by

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cmLt h a t

r€duative extr=tion

of

P l u t d u m , uranium and protactinium i n t o l i q u i d bismuth could be c a r r i e d out e i t h e r in low carbon s t e e l o r melybdenum apparatus. 'The use of de&

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containers f o r holding s a l t and bismuth i s . , p r e f e m d as mild

is m o s -suceptible t o corrosion by fused salt. I n view of t h i s .a molybdenum crucible has been fabricated using 20 mil molybdemun sheet by eleotron bean welding.

A s p e c i a l graphite former has been f a b r i c a t

t o hold the p l a t e i n the form of crucible and ease of welding i n t h e e l e c t r o n beam welding u n i t a v a i l a b l e with Atonic Fuels Mvision. The e x t r a c t i o n s t u d i e s would be i n i t i a t e d as soon as lithium and bismuth becom available.

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3.3

Servicss Most of t h e high temp&atm equipment used f o r t h e E B R

development work and reprocessing s t u d i e s reguj re continuous water c o o l i w while the experiments are i n progress f o r days together.

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In

order t o ensure continuous supply of cooling water i n t h e event of 1

s h o r t supply of water from the.municipa1 mains as overhead tank of 1000 gallons capacity i s being erected and the necessary piping work t o the

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experimental assemblies are i n progress.

It is a n t i c i p a t e d t h a t this would c a t e r t o the need sf a l l water cooling systems f3r a period Cf 8 t o 10 hours i n the event of water supply f a i l u r e .

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. t

& .- I

temperature.

Ths Least square l i n e drawn i n fig. 1 f i t s the equation 1

log s

(do)

= 2.677

- 2.201

where S(m/o) i s t h e s o l u b i l i t y of ArF

1 0 3 ~

(1)

0 . ; .

i n mole percent. The apparent heat m f solution of PuF has bsen calculated t o be I O kcal from the

3

3

r e l a t i on s2

-

&(T~-T,)

log s1

2.303 T,T2

Ilecently ORNL group ham reported the s o l u b i l i t y of PuF i n

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LiF-BeF2-W (72-16-12 m/o) i n the temperature range of 54OoC to

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690째C.

Their data was found t o f i t t h e equation 2 log S (m/o)

=

3.01

- 2.41

x 103D

-.-.

with an apparent heat of s o l u t i o n of 11,008f?37 cal/mole

(2 1

Using the

above equation t h e s o l u b i l i t y values f o r three temperatures have been calculatcd and plotted i n f i g . 1.

The 0iW-L group have determined the s o l u b i l i t y values only i n

a temperaturs range of 150째C whereas the prssent experiment covers a range of 280OC. The conposition of the base s d t used by these workers i s d s o d i f f e r e n t from t h a t of the present work. If t h e analozy of s o l u b i l i t y behaviour

qf

CeF ( 8 ) i s applicable i n t h e case of FuF

.3

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both i n binary LiF - B F

and ternary LiF-BeF -ThF mixtures, then 2 2 4 s o l u b i l i t y should be prsdominently governed by t h e empirical paraneter

u =

1ThF4J

b =

[Li.F-2BEF23ThF4

[ThEi

+

i c h is the 'free' LiF contsnt, basis the s o l u b i l i t y of PuF3

determined by O l W workers should l i e very close t o FuF s o l u b i l i t y o b t d n e d by us in t h e pressnt experiment.

However, the

a r e higher than t h e present experiment by about 25"b.

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values

It may be

because of considerable s c a t t e r i n t h e analytical d a t a of ORNL emup

respectively a n d t h a t

9f

the OFINL composition is 0.43

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4.

m L z im m lT A L Details of the experimental determinatim of s o l u b i l i t y i f

h F have been described i n the previous qu&erly

rep&.

the present experiment a total of eleven samples have been withdrawn i n t h e

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temperature

of 510" t o 787°C both i n the cooling and heating cycle.

Out of these eleven samples eight hEve been withdrawn us-

10 micron

Porosity f i l t e r f r i t s , one using' 15' micron porosity f i l t e r frit while two were duplicate samples a t temperatures of 570" and 787°C takcn with

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15 micron porosity.

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The composition of LiF-BeF24hF 4 used i n t h e present experiment was 71.3-15.5-13.2m/~on the basis of chemical analysis f o r

Li,

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€!e m d Th

from samples withdrawn f r o m the equilibrated melts.

RJ~S-UUCSA" DISCUSSIONS

The r e s u l t s of the s o l u b i l i t y of PuF3 i n LiF-&F2-ThF4

(71.3,

15.5, 11.2 m/o) i n the t e m p e r a t u r e ' r w e of 510" t r 7C7"C obtained by chemical analysis and alpha cofinting are given i n Table I.

The r e s u l t s show t h a t t h e r e i s good agreement between two s e t s of r e s u l t s . The duplicate samplss withdrawn at 570°C and 787°C using 15 micron f i l t e r

frits sh?w Yh higher and 6.3% lower thcn the -.,orresponding s o l u b i l i t y values obtained using 10 micron porosity f i l t e r frits. This trend i n i

the a n a l y t i c a l values supgests t'nat the experimentally detemined s d u b i 1 i t y T a l u e s a r e true r a t h e r than due t o p a r t i c l e s entering i n t o t h e f i l t e r

f r i t s while sampling.

The s c a t t e r i n the data may be due t o t h e small

varictions tbt may be occurring i n thc porosity of the frits duke Welding.

If t h i s were the case, it i s very d i f f i c u l t t o estimate the

v a r i a t i o n i n porosity of the frit d u m fabrication. Hpwever, it may be mentioned t h a t such f i l t e r frit was individually checked by s t a t i c pressure t e s t bsfors using end those showing the maximum uniformity were only selected f o r sampling

t

The d a t a obtained from measurements on samples taken during

cooling and heating cycles together with those of the duplicate samples

are plotted i n Fig.1 i n terms *f m/o of FuF3 vs the reciprocal absolute 4

w

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and a l s o t h e temperature range covered being narrower. I n any case t h e i r r e s u l t s show t h he PuF s o l u b i l i t ues as higher comparsd

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t o our r e s u l t s which i s q u i t e s a t i s f a c t o r y from the point of view of

BBR(Pu) f e a s i b i l i t y .

I n the naxt experiment, it i s proposed to determine the s o l u b i l i t y of PuF i n the base salt composition of

t

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m/o). This should make it possible t o m a k s d i r e c t Comparison between CMNJJ values and values obtained hy us f o r LiF-&F2-ThF4(72-16-12

the same salt composition.

about

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The lithium and bismuth ordered a r e expected t o a r r i v e i n month's t i m . supply position of nickel, inconel e t c . a l s o

appear t o have improved m d order f o r these materials a r e being placed f o r e a r l i e s t delivery of materials.

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AN.ALYSIS

The s d t sanplss were analysed by alpha counting and by potentionetric methods f o r plutonium , a f t e r dissolution 70b perchloric a q i d . The base salt wcs Estimated f o r L i , Ik and Th a f t e r removal of plutonium by an anion cxchmge method i n corc. EC1 medium.

Details

of the procedur;. f o r a a l y s i s have been given i n prscseding quarterly

reports.

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SXJNImY The s o l u b i l i t y of PuF3 i n LiF-BeF2-ThF 4 mixture of com-

position I

71.3, 15.5, 13.2 m/o has been determined i n t h e temperature

of 510" t o 7 8 7 O C m d t h e values have been found t o vary between at 510째C and 4 m 787째C. The duplicate s o l u b i l i t y values deternined using 15 micron f i l t e r frits a t 570 and 787째C confirms t h a t the s o l u b i l i t y values m e t r u e within t h e experimental e r r o r s . The limited s c a t t e r of the d a t a obtained using d i f f e r e n t f i l t e r f r i t s 5

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he samples by the

s of experiment c o n f i r m the preliminaqr

hese values a r e corns o l u b i l i t y required t o j u s t l f y a

t i a l of ~ E ~ ( P U concept ),

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T

at i s required XIS s t o r e s requiresubmitted a f t u r year work programme with personnel ment. '

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3.

Progress %port on molten salt breeder reactor project f o r

half yea: endire July 31, 1969, E i R C i n t s r n a l communication.

Progress eport on nolten s a l t breeder reactor project for half y e w sndiig January 31, 1970, hBC i n t e r n a l communication. t no1tr.n salt breeder reactor f c r t h e period Progress * ~ g o r on

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ending Ap;<l 30, 1970, BAC i n t e r n a l cornmication.

Progress :-;port on n d t e r ? salt breedsr r e a c t w f o r t h e period endJu:y 31, 1970, BARC i n t e x a l comunication.

5.

Progress iepo;.t on mclten sal: breeder r e a c t o r tnc: period ending October 3.0, 1970, E A C i n t e r n a l comnunicatlon.

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Progress i*spc.rt on moltcn salt breeder r s a o t o r fqr t h e period endin5 Jan~cry31, 1971, BLRC i n t a r n d compicat~-o;l.

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Holten Salt Reactnr Program-Semi-annual pGogress report f o r t h e 2Eriod ending ilugust 31, 7970 - OWL 4622 pp 91-92.

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Barton, .':JI Eredig, L.O. Inorg. Chcm. 9, 307 (1970).

C.J.

Gtlpatraick and J.L.

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FredricksGn,

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Solubility of PuF3 i n LiF-â&#x201A;ŹkF,-!PhF4(71.3,

15.5, 13.2 m/o)

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S.No.

Temp.

OC

l/P OK

w/o

w/n

Ii 1

0.70

0.73

4.277

0.99

0.99

5.020 4 834 7 0480

1 018

1.17

1.12

1.?3

1.75

1.'8

8 076

1.88

1.93

70.43

24 6

2.55

12.40

13e28

0,970

13 *53

13-385

0.943

14 64

14-74

0.943

73-44

73.89

3 -08 3e39 3 e37 3 031

3 032 3 94: 34 9 3w q 3

1a277

545

1.221

"570

1.186

570

1.186

62 5

1.113 1.076

7

656 677

1.052

10.09

8

72 8

0.999

9

"757 Y87 787

6

10 11

Q/O

Chemical

3 177

3 .@7 4249 5 e048 4.786 7.345 7 0857

510

4 5

m/0

Chemical Fbdiochsmical

counting

.

f

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CHEMICAL is ‘4 0 Q - - ----

f+?EI 6995

ANALYSIS HEATING COOLING - COUNTING HEATING COOLING

LEAST .SBUARE LINES ORNL LEAST SQUARE UNI

I . SOLUBILITY OF PuF3 IN LIF-BsF2 t-( Pl*3, IS*!5 ,I302 m/o) , H-(68*2,. 20.3;, q*3 mm , l-045

Ia95

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I.145

103/ 1 (‘It)

8

I.195

-ThF4 I I *24S

I*295