ORNL-TM-4863

Page 1


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This report was prepared as an account of work sponsored by the United States Government. Neither the United States nor the Energy Research and Development P.dniinistration, nor any of their employees, nor any of their contractors. subcontractors, or their employees, wakes any warranty, express or implied, or assurries any legal liability or responsibility for the accuracy, completeness or usefulness of any infomiation, apparatus, product or process disclosed, C)I- represents that i t s use would not infringe privately owned rights.


UC-76

C o n t r a c t No.

OWL-TM-4863 -Molten S a l t R e a c t o r T e c h n o l o g y

W-7405-eng-26

CHEMICAL TECHNOLOGY D I V I S I O N

ENGINEERING DEVELOPMENT S T U D I E S FOR MOLTEN-SALT BREEDER REACTOR PROCESSING NO. 1 9

Compiled by: J. R.

H i g h t o w e r , Jr.

Other Contributors: C. W.

H. L. R. M. J . A. H. C.

Brown, J r . Carter Counce

Klein

Savage

JULY 1975

NOTICE This document contains information of a preliminary nature

and was prepared primarily for internal use a t the Oak Ridge National Laboratory. I t is subject to revision or correction and therefore does not represent a final report.

OAK RIDGE NATIONAL LABORATORY Oak R i d g e ,

T e n n e s s e e 37830

operated by

UNION CARBIDE CORPORATION

for the

ENERGY RESEARCH AND DEVELOPMENT ADMINISTRATION

3 445b 0550621, 7


ii

Reports previously i s s u e d i n t h i s series are as follows:

OWL-TM-3053

P e r i o d e n d i n g December 1968

OKNL-TM-3138

P e r i o d e n d i n g J u n e 1969

ORNL- Tlvl-3140

P e r i o d e n d i n g December 1969

ORNL-TM-3137

ORNL-TM-3139

P e r i o d e n d i n g March 1969

P e r i o d e n d i n g September 1969

ORNL-TM- 3141

P e r i o d e n d i n g March 1970

ORNL-TM-3258

P e r i o d e n d i n g September 1990

ORNL-TM-3257

P e r i o d e n d i n g J u n e 1970

ORNL-TM-3259

P e r i o d e n d i n g December 1970

ORNL-TM-- 33 52

ORNL-TM-4 698

P e r i o d e n d i n g March 1971

P e r i o d J a n u a r y through J u n e 1974


iii CON TENTS Page

............................ 1 . INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . 2 . DEVELOPMENT OF THE METAL TRANSFER PROCESS . . . . . . . . . . . . 2 . 1 E x a m i n a t i o n of MTE-3 E q u i p m e n t and Materials . . . . . . . . SUMMARIES

3

.

4

.

5

.

6

.

2.2

I n s t a l l a t i o n of Metal Transfer E x p e r i m e n t MTE-3B

2.3

D e s i g n of t h e Metal T r a n s f e r P r o c e s s F a c i l i t y

......

.......

v

1 1 2 6 9

SALT-METAL CONTACTOR DEVELOPMENT: EXPERIMENTS WITH A MECHANICALLY AGITATED. NONDISPERSING CONTACTOR USING WATER AND MERCURY 11

....

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

3.1

Theory

3.2

Experimental Apparatus

3.3

R e s u l t s and C o n c l u s i o n s

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

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

11 18

18

SALT-METAL CONTACTOR DEVELCPMENT: EXPERIMENTS WITH A MECHANICALLY AGITATED. NONDISPERSING CONTACTOR I N THE SALT-BISMUTH FLOWTHROUGH FACILITY 21

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

FUEL RECONSTITUTION DEVELOPMENT: ENGINEERING EXPERIMENT

DESIGN OF A FUEL RECONSTITUTION

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

REFERENCES

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

38

43



V

SUMMARIES DEVELOPMENT O F THE METAL TRANSFER PROCESS W e h a v e c o n t i n u e d f a b r i c a t i o n a n d assembly of the new c a r b o n s t e e l

v e s s e l s f o r metal t r a n s f e r e x p e r i m e n t MTE-3B; d u r i n g t h i s r e p o r t p e r i o d , t h e v e s s e l s were co m p l e t e d a n d i n s t a l l e d i n the metal t r a n s f e r e x p e r i m e n t f a c i l i t y i n Bldg.

3541.

The v e s s e l s p r e v i o u s l y u s e d i n e x p e r i m e n t MTE-3,

a l o n g w i t h t h e s a l t s and b i s m u t h t h e y c o n t a i n e d , were removed and s e n t t o t h e b u r i a l ground â‚Źor d i s p o s a l .

W e are renovating t h e metal t r a n s f e r

hood t o improve operating a c c e s s i b i l i t y and a s s u r e t h a t a l l equipment

i s i n good o p e r a t i n g c o n d i t i o n . E x a m i n at i o n of t h e v e s s e l s a n d a n a l y s e s of t h e s a l t and m e t a l p h a s e s

from t h e p r e v i o u s l y o p e r a t e d e x p e r i m e n t MTE-3 h a v e been c o m p l e t e d . L i m i t e d v i s u a l e x a m i n a t i o n i n d i c a t e d t h a t t h e i n t e r n a l s u r f a c e s exposed t o s a l t s a n d b i s m u t h were i n e x c e l l e n t c o n d i t i o n .

F a i l u r e of t h e

o x i d a t i o n - r e s i s t a n t p r o t e c t i v e c o a t i n g on t h e e x t e r n a l s u r f a c e s a l l o w e d s i g n i f i c a n t o x i d a t i o n o f t h e s e s u r f a c e s a t t h e 6 5 O o C o p e r a t i n g tempera-

t u r e , b u t w a s n o t e x t e n s i v e enough t o a f f e c t t h e vessel i n t e g r i t y .

A

d i f f e r e n t p r o t e c t i v e coating with superior air-oxidation r e s i s t a n c e w a s applied t o t h e MTE-3B v e s s e l s . X-ray

f l u o r e s c e n c e a n a l y s e s of t h e L i - B i p h a s e from t h e r a r e - e a r t h

s t r i p p e r a t t h e LiCl--Li-Bi i r o n an d t h o r i u m .

i n t e r f a c e c o n t a i n e d s i g n i f i c a n t amounts o f

S c a n n i n g e l e c t r o n p h o t o m i c r o g r a p h s of t h i s i n t e r f a c e

a t m a g n i f i c a t i o n o f 2 0 , 1 0 0 , 500, and 2000X w e r e t a k e n .

No identifiable

f i l m o r f o r e i g n m a t e r i a l c a n be s e e n a t t h e i n t e r f a c e .

Review of t h e d e s i g n c r i t e r i a for t h e Metal T r a n s f e r Process F a c i l i t y h a s been i n i t i a t e d .

site).

T h i s f a c i l i t y i s t o be l o c a t e d i n Bldg. 7503 (MSRE


vi

SALT-METAL CONTACTOR DEVELOPMENl' : EXPERIMENYS WITH A MECHANICALLY A G I T A T E D , N O N D I S P E R S I N G CONTACTOR U S I N G WATER AND MERCURY

F i v e r u n s were nlade i n t h e 5- by 7 - i n . - P l e x i y l a s

c o n t a c t o r w i t h phase

volumes, a g i t a t o r s p e e d , and i n i t i a l mercury-phase z i n c c o n c e n t r a t i o n s h e l d c o n s t a n t a t 1 . 8 l i t e r s , 1 5 0 rpm, and 0 . 1

E,

respectively.

The i n i -

E

t i a l aqueous-phase l e a d c o n c e n t r a t i o n w a s v a r i e d from 0 . 0 2 M t o 0 . 1 0 I

t o d e t e r m i n e which p h a s e c o n t a i n s t h e l i m i t i n g r e s i s t a n c e t o mass t r a n s f e r and t h e c o n c e n t r a t i o n o f l e a d i o n s i n t h e aqueous p h a s e a t which t h e coiit r o l o f mass t r a n s f e r changes from one p h a s e t o t h e o t h e r . A model w a s d e v el o p e d f o r t h i s s y s t e m under t h e a s s u m p t i o n t h a t t h e

r e a c t i o n t a k e s place e n t i r e l y a t t h e water-mercury i n s t a n t a n e o u s and i r r e v e r s i b l e .

i n t e r f a c e and i s

I tr w a s found t h a t for t h e c o n d i t i o n s

under which t h e s e and a l l p r e v i o u s r u n s were perEormed, t h e r e s i s t a n c e t o mass t r a n s f e r w a s n o t i n t h e mercury p h a s e as w a s p r e v i o u s l y b e l i e v e d . S ALT-METAL

A 6-in.

CONTACTOR BEVELOPMENT : EXPE RIMEN'I'S W I'm A MECHANICALLY A G I T A T E D , N O N D I S P E R S I N G CONTACTOR IN THE SALT-BISMUTH FLOWTHROUGH F A C I L I T Y

diam low-carbon s t e e l s t i r r e d i n t e r f a c e c o n t a c t o r h a s been

i n s t a l l e d i n t h e Sal t -B i s m u t h Flowthrough Faci.3.j.ty i n Bldg. 3592, which was p r e v i o u s l y u s e d t o s-tudy s a l t - b i s m u t h f l o w i n packed columns.

Six

t r a c e r r u n s have been completed t o d a t e u s i n g 9 7 Z r and 237U tracers.

The

s t i r r e r r a t e w a s v a r i e d from 121 r p m to 205 rpm, R e s u l t s from t h e f i r s t six r u n s i n d i c a t e t h a t t h e s a l t - p h a s e m a s s

t r a n s f e r c o e f f i c i e n t b as e d on 237U c o u n t i n g dat-a i s 37 + 3% of the v a l u e p r e d i c t e d by t h e Lewis c o r r e l a t i o n f o r r u n s 1, 2 , 3 , and 5 , and i s 1 1 6

+ 10% o f t h e L e w i s v a l u e f o r r u n s 4 and 6. The r e l a t i v e l y h i g h v a l u e s for t h e l a t t e r two r c n s are p r o b a b l y due t o d i s p e r s a l . of s a l t i n t o t h e

bis muth.

Experiments w i t h water-mercury and water-methylene bromide

s ys tems s u p p o r t t h i s b e l i e f . 97Zr

The inass t r a n s f e r c o e f f i c i e n t s b a s e d on

c o u n t i n g d a t a a r e f e l t t o be l e s s r e l i a b l e t h a n t h o s e based on

237u

becaus e of t h e i n a b i l i t y t o c o r r e c t f u r s e l f a b s o r p t i o n of t h e 7 4 3 . 3 7 keV $ - i n t h e s o l i d bismuth samples.


vii FUEL RECONSTITUTION DEVELOPMENT: DESIGN O F A FUEL RECONSTITUTION ENGINEERING EXPERIMENT

We are beginning engineering studies of fuel reconstitution.

ment is described for carrying out the reaction o f gaseous UF

6

Equip-

with UF4

dissolved in molten salt and the subsequent reduction with hydrogen of the resultant UF

T h e experiment w i l l be a flowthrough operation, and 5' the main vessels will consist o f a 36-liter feed tank, a UF6 absorption

vessel, a hydrogen reduction column, and a receiver vessel.



1.

INTRODUCTION

A molten-salt breeder reactor

(MSBK) w i l l be f u e l e d w i t h a m o l t e n

f l u o r i d e m i x t u r e t h a t w i l l c i r c u l a t e t h r o u g h t h e b l a n k e t a n d core r e g i o n s of t h e r s a c t o r an d t h r o u g h the p r i m a r y h e a t e x c h a n g e r s .

W e are d e v e l o p i n g

p r o c e s s i n g methods f o r u s e i n a c l o s e - c o u p l e d f a c i l i t y f o r removing f i s s i o n p r o d u c t s , c o r r o s i o n p r o d u c t s , a n d f i s s i l e materials from t h e molten f l u o r i d e mixture. S e v e r a l o p e r a t i o n s a s s o c i a t e d w i t h MSBR p r o c e s s i n g a r e u n d e r s t u d y . The r e m a i n i n g p a r t s of t h i s r e p o r t d i s c u s s : r e s u l t s o f i n s p e c t i o n o f equipment u s e d i n e x p e r i m e n t MTE-3 f o r d e m o n s t r a t i n g t h e metal t r a n s f e r p r o c e s s €or removal o f r a r e e a r t h s from NSBR f u e l c a r r i e r s a l t ,

s t a t u s o f t h e i n s t a l l a t i o n of e q u i p m e n t f o r metal t r a n s f e r e x p e r i m e n t MTE-3B, r e s u l t s of s t u d i e s w i t h mechanically a g i t a t e d , nondisp e r s i n g c o n t a c t o r s u s i n g water and m e r c u r y , r e s u l t s of s t u d i e s w i t h m e c h a n i c a l l y a g i t a t e d , n o n d i s p e r s i n g c o n t a c t o r s u s i n g m o l t e n s a l t and b i s m u t h , and

a d e s c r i p t i o n of e q u i p m e n t b e i n g f a b r i c a t e d €or a f u e l . r e c o n s t i t u t i o n engineering experiment. T h i s work w a s p e r f o r m e d i n t h e Chemical Technology D i v i s i o n d u r i n g t h e p e r i o d J u n e t h r o u g h September 1 9 7 4 .

2.

DEVELOPMENT OF THE METAL TRANSFER PROCESS H.

C. Savage a n d W.

I,. C a r t e r

W e p l a n t o c o n t i n u e s t u d y i n g t h e steps i n t h e metal t r a n s f e r p r o c e s s f o r removing rare e a r t h s from m o l t e n - s a l t b r e e d e r reactor f u e l s a l t .

In

t h i s p r o c e s s , f u e l s a l t , which i s f r e e o f uranium a n d p r o t a c t i n i u m b u t c o n t a i n s t h e rare e a r t h s , i s c o n t a c t e d w i t h b i s m u t h c o n t a i n i n g r e d u c t a n t

t o e x t r a c t t h e rare e a r t h s i n t o b i s m u t h .

The b i s m u t h p h a s e , which con-

t a i n s t h e r a r e e a r t h s a n d t h o r i u m , is t h e n c o n t a c t e d w i t h l i t h i u m c h l o r i d e Because of f a v o r a b l e d i s t r i b u t i o n c o e f f i c i e n t s , s i g n i f i z a n t f r a c t i o n s of


t h e r a r e e a r t h s t r a n s f e r t o t h e l i t h i u m c h l o r i d e along with a n e g l i g i b l e amount o f t h o ri u m .

'The f i n a l s t e p s of t h e p r o c e s s e x t r a c t t h e r a r e e a r t h s

from t h e l i t h i u m c h l o r i d e by c o n t a c t w i t h bismuth having l i t h i u m concent r a t i o n s of 5 and 50 a t . %. 'The c u r r e n t ex p e ri m e n t s

11ti Ii. ze

mechanically a g i t a t e d contactors a s

an a l t e r n a t i v e t o packed columns â‚Ź o r t h e m e t a l t r a n s f e r p r o c e s s .

' I 2

The

Lewis-type c o n t a c t o r a p p e a r s t o have t h e p o t e n t i a l â‚Źor a c h i e v i n g accept.-a b l e r a r e - e a r t h m a s s t r a n s f e r r a t e s w i t h minimum d i s p e r s a l of t h e s a l t and bismuth p h a s e s . 3'4

T h i s i s an i m p o r t a n t f a c t o r , s i n c e e n t r a i n m e n t

of bismuth i n t o p r o c e s s e d f u e l s a l t t h a t i s r e t u r n e d t o t h e r e a c t o r dann o t be t o l e r a t e d .

The c o n t a c t o r h a s two a g i t a t o r s - - o n e

and one i n t h e bismuth phase--that: bismuth i n t e r f a c e .

i n t h e s a l t phase

a r e l o c a t e d well away from t h e s a l t -

These a g i t a t o r s a r e o p e r a t e d i n s u c h a manner t h a t t h e

p h a s e s are mixed a s v i g o r o u s l y as p o s s i b l e w i t h o u t d i s p e r s i n g one p h a s e into the other. An e n g i n e e r i n g ex p e ri m e n t (MTE-3)

i n which t h e s a l t flow r a t e w a s

about 1%of t h a t r e q u i r e d f o r p r o c e s s i n g t h e f u e l s a l t from a 1000 MW(e) MSBR was o p e r a t e d d u r i n g 1 9 7 2 t o measure r a r e - e a r t h mass t r a n s f e r r a t e s 5 across the salt-bismuth i n t e r f a c e s . These e x p e r i m e n t s w i l l h e c o n t i n u e d

i n a new e x p e r i m e n t , d e s i g n a t e d M'rE-313,

t h a t w i l l u s e new process v e s s e l s ,

s a l t s , and b i s m u t h . 2.1

Examination of MTE-3 Equipment and M a t e r i a l s

We completed t h e e x am i n a t i o n of t h e v e s s e l s and removal of samples of t h e s a l t and bismuth p h a s e s from v a r i o u s l o c a t i o n s i n t h e c o n t a c t o r and stripper vessels.

The v e s s e l s , a l o n g w i t h t h e s a l t and b i s m u t h c o n t a i n e d

i n them, were removed from t h e hood i n Bldg. 3 5 4 1 and were s e n t t o t h e b u r i a l ground f o r d i s p o s a l . A s previously reported'

samples of t h e Bi-Th, m e t a l interfaces.

Li-Bi,

s i g n i f i c a n t amounts of i r o n were found i n and L i C l p h a s e s t a k e n a t o r n e a r the s a l t -

A d d i t i o n a l samples of t h e Bi-Th,

Li-Bi,

and L i C l w e r e

t a k e n at_ v a r i o u s d i s t a n c e s from t h e i n t e r f a c e s and a n a l y z e d For i r o n content,

Tne samples w e r e o b t a i n e d by d r i l l i n g t h r o u g h t h e t a n k w a l l s w i t h


3

a l -i n . -d i am

h o l e s a w , and were g e n e r a l l y t a k e n from m a t e r i a l a p p r o x i -

m a t e l y 1/2 i n . from t h e i n s i d e - w a l l s u r f a c e .

are shown i n T ab l e 1.

R e s u l t s of i r o n a n a l y s e s

A s seen i n t h i s t a b l e , i r o n c o n c e n t r a t i o n s i n

samples t a k e n some d i s t a n c e ( 2 t o 8 i n . ) from t h e i n t e r f a c e s a r e s i g n i f i I

c a n t l y lower t h a n t h o s e a t o r n e a r t h e i n t e r f a c e . A section of the Li-Bi--LiCl

a c r o s s t h e i n t e r f a c i a l area i n t h e

s t r i p p e r w a s examined by s c a n n i n g e l e c t r o n microscopy.

Scanning e l e c t r o n

phot o m i c ro g rap h s a t m a g n i f i c a t i o n s of 2 0 , 100, 500, and 200OX were t a k e n

of t h i s i n t e r f a c e , and a r e shown i n F i g . 1.

These p h o t o g r a p h s w e r e t a k e n

of t h e ro u g h , u n p o l i s h e d s u r f a c e , and no i d e n t i f i a b l e f i l m o r f o r e i g n

material i s v i s i b l e .

(From a v i s u a l e x a m i n a t i o n o f t h e as-removed s e c t i o n

of t h i s i n t e r f a c e , t h e r e a p p e a r e d t o b e a l a y e r of material

?,

1/32 i n .

t h i c k of a d i f f e r e n t s t r u c t u r e t h a n t h e L i C l phase o r t h e L i - B i p h a s e . )

Analyses by X-ray f l u o r e s c e n c e were made a t f i v e l o c a t i o n s a c r o s s t h i s i n t e r f a c e , which a r e i d e n t i f i e d a s 1, 2 , 3 , 4 , and 5 on t h e 20X photomicrograph of F i g . 1.

R e s u l t s a r e g i v e n below:

I n t h e L i C l some d i s t a n c e from t h e B i - L i C 1 boundary, some t h o ri u m and a s m a l l amount of bismuth and lanthanum w e r e detected.

I n t h e L i C l n e a r t h e B i - L i C 1 boundary, a v e r y s m a l l amount of t h o r i u m , i r o n , and bismuth w a s d e t e c t e d . On t h e B i - L i C 1 b o u n d a r y , t h o r i u m and i r o n , as w e l l as bismuth and c h l o r i n e , were d e t e c t e d .

I n t h e bismuth a r e a n e a r t h e B i - L i C 1 boundary, l a r g e amounts of t h o r i u m , i r o n , and c h l o r i n e , a s well. as t h e b i s m u t h , were d e t e c t e d . I n t h e bismuth area some d i s t a n c e from t h e B i - L i C l boundary, o n l y bismuth w a s d e t e c t e d . The p r e s e n c e of i r o n (or i r o n o x i d e s ) a t o r n e a r t h e i n t e r f a c e i s 3 c o n s i s t e n t w i t h t h e r e l a t i v e d e n s i t i e s o f bismuth ( 9 . 6 y/cm ) and i r o n 3 3 ( 7 . 6 g/cm o r p o s s i b l y i r o n o x i d e s (% 5.5 g/cm ) t h a t would be e x p e c t e d t o p r e c i p i t a t e on c o o l i n g of t h e b i s m u t h p h a s e .

I r o n might be e x p e c t e d

t o c o n c e n t r a t e a t t h e i n t e r f a c e s due t o t h e d e n s i t i e s of t h e i r o n and 3

i r o n o x i d e s (Q 5 t o 5 . 5 g/cm )

,

and t h e s a l t and bismuth p h a s e s (% 3 . 5


4 I r o n c o n t e n t i n samples of metal and s a l t p h a s e s f r o m metal t r a n s f e r e x p e r i m e n t f4TE-3 a t v a r i o u s d i s t a n c e s from t h e metal-salt i n t e r f a c e s

T a b l e 1.

Contactor, L i C l s i d e Bi-Th

% %

%

1/8 i n . f r o m i n t e r f a c e 2 i n . from i n t e r f a c e 4-1/2 i n . from i n t e r f a c e

2500 18 17

Contactor, f l u o r i d e s a l t s i d e Bi-Th

% % %

1100 37 9

1/4 i n . from i n t e r f a c e 2 i n . from i n t e r f a c e 4 i n . from i n t e r f a c e

Str i p z z g .

< 1/8 i n . from i n t e r f a c e

Li-Bi

%

'L

1400 108

2 i n . from i n t e r f a c e 5 i n . from i n t e r f a c e

7

Stripper LiCl

'L % % %

1/2 i n . from i n t e r f a c e 1 i n . from i n t e r f a c e 6-3/4 i n . from i n t e r f a c e 8-3/4 i n . from i n t e r f a c e

650 200

115 35

Contac t o r

_ _ _ 1 -

LiF-BeF2-ThF4 (72-16-12 mole %)

a

320, 88a

1/8 i n . from i n t e r f a c e

Results o f t w o d i f f e r e n t s a m p l e s .

All o t h e r r e s u l t s a r e for one sample.

g/cm3 â‚Ź o r f l u o r i d e s a l t , 1 . 5 g/cm3 f o r L i C 1 , and

'L

9.6 g/cm3 â‚Źor b i s -

muth). When s a m p l i n g t h e L i C l i n t h e s t r i p p e r about 1 i n . above t h e L i C 1 - Li-Bi

i n t e r f a c e , a s m a l l amount of b l a c k material was s e e n .

W e w e r e able

t o s e p a r a t e some o f t h i s black m a t e r i a l (5 1 / 2 g ) from t h e s a l t f o r chemical a n a l y s e s . 5 2 . 7 ; Th - 1 8 . 7 ;

The f o l l o w i n g r e s u l t s w e r e r e p o r t e d

C1 - 4 . 1 ; L i - 2 . 8 ;

F

- 2.4;

Fe

-

0.26:

(wt % ) : Be

ai -

- 1 ppm.


5

O R N L D W G . 74-10116

MAG: 5 0 0 X

MAG: 2000X

M A G : 20x

r INTERFACE I

Fig. 1. Scanning electron photomicrographs of the interface between LiCl and Li-Bi in the stripper from experiment MTE-3. Unpolished.


6

These c o n s t i t u e n t s t o t a l 81%, l e a v i n g 1 9 % u n a c c o u n t e d f o r .

No other

e l e m e n t s , e x c e p t p o s s i b l y t h o s e i n t r o d u c e d by oxygen o r water contaminat i o n , are known t o be p r e s e n t i n t h e s y s t e m .

I f i t i s assumed t h a t t h e

r e m a i n d e r i s p r e d o m i n a n t l y oxygen, t h i s would be s u f f i c i e n t t o form o x i d e s and/or h y d r o x i d e s o f a l l of t h e c a t i o n i c s p e c i e s ( b i s m u t h , t h o r i u m , l i t h i u m , an d i r o n ) .

The gram e q u i v a l e n t of t h e s e s p e c i e s i s

Q

0.015,

w h i l e t h e anion-gram e q u i v a l e n t of f l u o r i n e and c h l o r i n e i s o n l y 0.0025. F o r 1 9 w t % oxygen i n t h e m a t e r i a l , t h e oxygen g a s e q u i v a l e n t i s 0.024,

o r 0.011 o f h y d r o x i d e . I t i s n o t now possible t o draw f i r m c o n c l u s i o n s a b o u t t h e r e l a t i o n -

s h i p of o u r c u r r e n t o b s e r v a t i o n s t o t h e low m a s s t r a n s f e r r a t e s s e e n i n e x p e r i m e n t MTE-3.

The t r a n s f e r o f f l u o r i d e s a l t i n t o t h e c h l o r i d e s a l t

j u s t p r i o r t o shutdown, and t h e l e n g t h of t i m e between shutdown and i n s p e c t i o n (from F e b r u a r y 1973 t o F e b r u a r y 1 9 7 4 ) , have c a u s e d much u n c e r t a i n t y i n t h e i n t e r p r e t a t i o n of t h e analyses. A d d i t i o n a l samples o f f l u o r i d e s a l t , LiC1--Bi-Th,

and L i B i from i n t e r -

f a c i a l s u r f a c e s i n t h e c o n t a c t o r and s t r i p p e r have been submitted f o r

x-

r a y d i f f r a c t i o n a n a l y s e s i n a n attempt t o i d e n t i f y compounds which m i g h t (No t h i n g o t h e r t h a n b e r y l l i u m w a s i d e n t i f i e d on o n e sample

be p r e s e n t .

of L i - B i from t h e s t r i p p e r p r e v i o u s l y examined by X-ray d i f f r a c t i o n . ) 2.2

I n s t a l l a t i o n o f Metal T r a n s f e r E x p e r i m e n t MTE-3B

F a b r i c a t i o n and a s s em b l y o f new carbon s t e e l vessels w e r e c o m p l e t e d d u r i n g t h i s report period. (MEW0 N o .

P443-10,

Q

An o x i d a t i o n - r e s i s t a n t protective c o a t i n g

0.015 i n . t h i c k ) w a s a p p l i e d t o t h e o u t s i d e s u r f a c e s

o f t h e c a r b o n s t e e l vessels and i n t e r c o n n e c t i n g l i n e s t o p r e v e n t a i r o x i d a t i o n a t t h e o p e r a t i n g t e m p e r a t u r e of 650OC.

A new pump f o r t r a n s f e r r i n g

f u e l c a r r i e r s a l t between t h e s a l t r e s e r v o i r and contactor w a s f a b r i c a t e d

and i n s t a l l e d .

New molybdenum a g i t a t o r s h a f t s and b l a d e s have a l s o b e e n

o b t a i n e d , a n d t h e a g i t a t o r assemblies were i n s t a l l e d i n t h e c o n t a c t o r a n d

stripper. The vessels an d t h e i r c o n t e n t s ( f u e l c a r r i e r s a l t , l i t h i u m c h l o r i d e , and b i s m u t h ) p r e v i o u s l y u s e d i n e x p e r i m e n t MTE-3 were removed from B l d g .

.


7

The new vessels have

3541 and s e n t t o t h e b u r i a l ground f o r d i s p o s a l .

been i n s t a l l e d , and t h e e x p e r i m e n t a l a r e a i n which t h e m e t a l t r a n s f e r experiment i s l o c a t e d i s being renovated.

T h i s i n c l u d e s r e r o u t i n g some

of t h e s e r v i c e l i n e s t o improve a c c e s s t o s a m p l i n g s t a t i o n s , r e l o c a t i o n of some p r e s s u r e g a g e s , f l o w m e t e r s , and v a l v e s € o r b e t t e r v i s i b i l i t y and a c c e s s , c a l i b r a t i o n and r e p l a c e m e n t (where r e q u i r e d ) of p r e s s u r e g a g e s , f l o w m e t e r s , and s o l e n o i d v a l v e s , and r e c a l i b r a t i o n of t e m p e r a t u r e c o n t r o l l e r s and r e c o r d e r s . We have completed t e s t s on two d i f f e r e n t o x i d a t i o n - r e s i s t a n t p r o t e c t i v e c o a t i n g s u s i n g a d i f f e r e n t method of a p p l i c a t i o n € o r e a c h t y p e of coating.

The c o a t i n g s were a p p l i e d t o t e s t s e c t i o n s made from L o n g i t u d i n a l

h a l f - s e c t i o n s of 6 - i n .

sched 40 mild s t e e l p i p e .

c o a t e d on all exposed s u r f a c e s .

The t e s t s e c t i o n s were

One t e s t p i e c e was c o a t e d w i t h t h e n i c k e l

alumide m a t e r i a l (METCO N o . M405-10 w i r e ) by flame s p r a y i n g w i t h a w i r e gun t o o b t a i n a c o a t i n g t h i c k n e s s of c o a t i n g used on t h e MTE-3 v e s s e l s .

0.010 i n . ,

thereby duplicating the

The s e c o n d t e s t p i e c e w a s c o a t e d w i t h

a n i c k e l chromium alloy c o n t a i n i n g 6% aluminum (METCO N o . P443-10 powder) a p p l i e d w i t h a plasma s p r a y gun t o a t h i c k n e s s of mended by t h e m a n u f a c t u r e r .

Q

0 . 0 1 0 i n . , a s recom-

The two p i e c e s were p l a c e d on f i r e b r i c k s

i n s i d e a f u r n a c e and h e a t e d t o t h e t e s t t e m p e r a t u r e .

During t h e t e s t ,

t h e p i e c e s were t h e r m a l l y c y c l e d s e v e r a l times by a l t e r n a t e l y c o o l i n g t h e furnace t o

%

1 0 0 ° C and r e t u r n i n g i t t o t h e t e s t t e m p e r a t u r e .

The i n i t i a l t e s t t e m p e r a t u r e was 7OOOC.

After

%

400 h r a t 7 O O O C w i t h

e i g h t t h e r m a l c y c l e s , t h e p i e c e s were examined, weighed, and p h o t o g r a p h e d The M405-10 c o a t i n g w a s c o v e r e d e x t e n s i v e l y w i t h a r u s t - c o l o r e d

(Fig. 2),,

o x i d a t i o n p r o d u c t , b u t t h e r e was no s i g n of s p a l l i n g o f t h e c o a t i n g , whereas t h e p i e c e c o a t e d w i t h P443-10 had a much b e t t e r a p p e a r a n c e w i t h o n l y one edge showing a r u s t c o l o r . t e s t p i e c e was a b o u t 7 . 3 rng/cm2 1 0 . 3 mq/cm

2

.

,

Weight g a i n of t h e P443-10 c o a t e d

w h i l e t h e M405-10 c o a t i n g g a i n e d a b o u t

The t e s t t e m p e r a t u r e was t h e n i n c r e a s e d t o 5 1 S ° C and w a s continued

f o r 520 h r w i t h e i g h t t h e r m a l c y c l e s t o 1 O O O C . examined, weighed, and ph o t o g r a p h e d

(Fig. 2 ) .

The t e s t p i e c e s were a g a i n The M40.5-LO c o a t i n g had


ORNL DWG. 74-10117

Fig. 2. Ph o t o g ra p h s of 6 - i n . s c h e d 40 m i l d s t e e l p i p e w i t h o x i d a t i o n r e s i s t a n t protective coatings: ( a ) a f t e r 400 h r a t 7 O O O C i n a i r , (b) a f t e r 500 a d d i t i o n a l h r a t 8 1 5 째 C i n a i r .


9

d e t e r i o r a t e d t o t h e p o i n t where s p a l l i n g had o c c u r r e d , w h i l e t h e P443-10 c o a t i n g had no s p a l l i n g e x c e p t a l o n g one edge where t h e r e w a s some r u s t T o t a l w e i g h t g a i n of t h e

c o l o r e d o x i d a t i o n p r o d u c t and some s p a l l i n g . M405-10-coated

t e s t p i e c e w a s 69.2 mg/cm2, and 20.5 mg/cm2 f o r t h e

P443-10 t e s t p i e c e . M e t a l l o g r a p h i c e x a m i n a t i o n s w e r e made o f t h e b e s t and w o r s t a p p e a r i n g

areas of t h e two specimens.

I n t h e b e s t appearing areas, both coatings

were a d h e r e n t , b u t a t h i n l a y e r of o x i d e formed a t t h e m e t a l - c o a t i n g i n t e r f a c e of t h e specimen c o a t e d w i t h METCO M405-10; t h i s i n d i c a t e s t h a t oxygen i s d i f f u s i n g t h ro u g h t h e c o a t i n g .

The m e t a l - c o a t i n g i n t e r f a c e of

t h e specimen c o a t e d w i t h METCO P443-10 w a s f r e e o f v i s i b l e o x i d e , i n d i c a t i n g t h a t i t i s a good b a r r i e r t o oxygen d i f f u s i o n .

For t h e w o r s t

areas o f b o t h c o a t i n g s , o x i d e a t t h e m e t a l - c o a t i n g i n t e r f a c e s caused some s p a l l i n g where t h e c o a t i n g may n o t have been t h i c k enough t o p r e v e n t oxygen d i f f u s i o n t h ro u g h t h e c o a t i n g s .

The o x i d e formed u n d e r n e a t h t h e

P443-10 c o a t i n g ( i n a s p a l l e d area o c c u r r i n g o n l y a l o n g one e d g e ) a p p e a r e d

t o b e more d e n s e and p r o t e c t i v e t h a n t h a t formed on t h e M405-10-coated specimen.

T h i s i n d i c a t e s t h a t some o f t h e e l e m e n t s i n t h e P443-10 c o a t i n g

may have d i f f u s e d i n t o t h e b a s e metal and i m p a r t e d a measure of p r o t e c t i o n , even though t h e c o a t i n g had s e p a r a t e d i n t h i s area. T h i s l i m i t e d t e s t c l e a r l y d e m o n s t r a t e d t h e s u p e r i o r i t y of t h e plasma s p r a y P443-10 c o a t i n g o v e r t h e M405-10-wire

gun s p r a y e d material pr e v -

i o u s l y used f o r t h e MTE-3 v e s s e l ; t h e r e f o r e , t h e plasma s p r a y c o a t i n g h a s been a p p l i e d t o t h e e x t e r n a l s u r f a c e s of t h e MTE-3B v e s s e l s t h a t w i l l operate a t elevated temperatures. 2.3

Design of t h e Metal T r a n s f e r P r o c e s s F a c i l i t y

Design o f t h e metal t r a n s f e r p r o c e s s f a c i l i t y (MTPF) i n which t h e f o u r t h metal t r a n s f e r e x p e r i m e n t (MTE-4) w i l l be c a r r i e d o u t w a s underway when t h e MSR program w a s t e r m i n a t e d i n 1973.6

B r i e f l y r e v i e w e d , MTE-4 i s

an e n g i n e e r i n g ex p e ri m e n t t h a t w i l l u s e s a l t f l o w r a t e s t h a t a r e 5 t o 1 0 % o f t h o s e r e q u i r e d f o r p r o c e s s i n g a 1000-MW(e) MSBR.

Conceptual d e s i g n s

o f t h e t h r e e - s t a g e salt-metal c o n t a c t o r , made o f g r a p h i t e , and i t s


10 containment vessel were completed.'

The primary purposes of MTE-4 are :

demonstration of the removal of rare-earth fission products from MSBR fuel carrier salt, and accumulation of these materials in a lithium-bismuth solution in equipment of a significant size, determination of mass transfer coefficients between mechanically agitated salt and bismuth phases, determination of the rate of removal of rare earths from the fluoride salt in multistage equipment, evaluation of potential materials of construction, particularly graphite, testing of mechanical devices, such as pumps and agitators, that will be required in a processing plant, and development of instrumentation for measurement and control of process variables, such as salt-metal interface location, salt flow rate, and salt or bismuth liquid level. We are currently reviewing the design of metal transfer experiment

MTE-4.

A mathematical model of the system has been devised, and a com-

puter program (METTRAN) has been written to simulate transient operation of the experiment.

Computations can be made to determine the concentra-

tion of each nuclide being transferred at each stage and at the feed and

receiving vessels as a function of operating time.

The program allows the

experimenter to make parametric studies for such design features as inter-

facial area, number of stages, flow rates, agitator speed, and inventories

of materials.

METTRAN is being used to analyze the MTE-4 experiment to

ascertain the significance of various design features on metal transfer

rates in order to fix optimal design conditions.

Due to space limitations in Bldg. 4505, we are planning to locate

MTE-4 and several of the engineering experiments on molten-salt processing in the MSRe Building (7503).

General cleanup and checkout of existing

building services (electrical circuits, ventilation, and air-filtration systems) is underway.

A 480-V, 3-phase, 60-Hz, 300-kW diesel generator

set and necessary controls will be installed in the existing generator


11

.

b u i l d i n g a t t h e MSRE s i t e .

This will p r o v i d e emergency power f o r main-

t a i n i n g p o r t i o n s o f e n g i n e e r i n g e x p e r i m e n t s which c o n t a i n s a l t o r b i s m u t h

a t t e m p e r a t u r e s above t h e l i q u i d u s t e m p e r a t u r e s .

A purchase order f o r t h e

g e n e r a t o r s e t h a s been i s s u e d , and t h e s y s t e m d e s i g n h a s been c o m p l e t e d . 3.

SALT-METAL CONTACTOR DEVELOPMENT :

EXPERIftEN'rS

WITH A MECHANICALLY AGITATED, NONDISPERSING CONTACTOR U S I N G WATER AND MERCURY C. H . Brown, Jr.

A c r i t i c a l p a r t of t h e p r o p o s e d MSBR p r o c e s s i n g p l a n t is t h e e x t r a c -

t i o n o f r a r e e a r t h s from t h e f l u o r i d e fuel. c a r r i e r s a l t t o a n i n t e r m e d i a t e bis m u t h stream.

One d e v i c e b e i n g c o n s i d e r e d f o r p e r f o r m i n g t h i s e x t r a c -

t i o n i s a m e c h a n i c a l l y a g i t a t e d , n o n d i s p e r s i n g c o n t a c t o r i n which b i s m u t h and f l u o r i d e s a l t p h a s e s are a g i t a t e d t o e n h a n c e t h e mass t r a n s f e r r a t e o f rare e a r t h s a c r o s s t h e salt-bismuth i n t c r f a c e P r e v i o u s r e p o r t s 2,718 I

ha v e shown t h a t t h e folLowing r e a c t i o n i n t h e w a t e r - m e r c u r y syst.em i s s u i t a b l e f o r s i m u l a t i n g a n d s t u d y i n g m a s s transfer rdtes i n s y s t e m s w i t h high d e n s i t y diâ‚Źferences:

Pb2*[H201

+

%n[Hgl

+=

Zn

24

[H20]

+ Pb[Hg]

.

A l a r g e amount of d a t a h a v e b e e n r e p o r t e d

'7

f o r t h e water-mercury

system i n

which i t was assumed that; t h e l i m i t i n g r e s i s t a n c e t o mass t r a n s f e r e x i s t e d e n t i r e l y i n t h e mercury p h a s e , as s u g g e s t e d by l i t e r a t u r e c o r r e l a t i o n s . During t h i s r e p o r t p e r i o d , a s e r i e s of e x p e r i m e n t s was p e r f o r m e d i n t h e water-mercury

c o n t a c t o r t o d e t e r m i n e which p h a s e a c t u a l l y c o n t r o l s t h e

r a t e of m a s s t r a n s f e r a n d , also, t h e c o n c e n t r a t i o n of pb2+ a t which t h e control of mass t r a n s f e r c h a n g e s f r o m one p h a s e t o the o t h e r . 3.1

Theory

T h e r e a c t i o n u n d er c o n s i d e r a t i o n , Eq, (11, i s a l i q u i d - p h a s e

r e a c t i o n t h a t o c c u r s e n t i r e l y at t h e mercury-water

ionic

interface; this is

b e c a u s e z i n c m e t a l and lead m e t a l a r e i n s o l u b l e i n w a t e r and t h e r e c a n


12

b e no i o n i c lead o r z i n c i n t h e m e r c u r y .

Since t h i s is a t y p i c a l ionic

r e a c t i o n , i t i s assumed t o be e s s e n t i a l l y i n s t a n t a n e o u s and i r r e v e r s i b l e .

The e q u i l i b r i u m c o n s t a n t f o r t h e r e a c t i o n i s g i v e n by t h e f o l l o w i n g equation:

where K

‘Pb Cpb2+ ‘Zn ‘Zn2+

=

equilibrium constant,

=

c o n c e n t r a t i o n o f P b metal i n m e r c u r y , g - i n o l e / l i t e r ,

=

c o n c e n t r a t i o n o f Pb i o n s i n w a t e r , g - m o l e / l i t e r ,

=

c o n c e n t r a t i o n of Zn m e t a l i n m e r c u r y , g - m o l e / l i t e r

=

c o n c e n t r a t i o n o f zn i o n s i n w a t e r , g - m o l e / l i t e r .

,

The e q u i l i b r i u m c o n s t a n t i s v e r y l a r g e , i m p l y i n g t h a t at: e q u i l i b r i u m t h e i o n i c l e a d an d m e t a l l i c z i n c c a n n o t c o e x i s t a t a p p r e c i a b l e c o n c e n t r a t i o n s

a t the interface.

S i n c e i t i s assumed t o be a n e x t r e m e l y f a s t r e a c t i o n ,

t h e e q u i l i b r i u m r e l a t i o n n e a r t h e i n t e r f a c e must be s a t i s f i e d a t a l l

times For t h e instantaneous i r r e v e r s i b l e r e a c t i o n d i s c u s s e d p r e v i o u s l y , two s i t u a t i o n s c o u l d o c c u r n e a r t-he l i q u i d - l i q u i d

interface

,

d e p e n d i n g on

t h e r e l a t i v e m a g n i t u d es of the i n d i v i d u a l - p h a s e mass t r a n s f e r c o e f f i c i e n t s and t h e b u l k -p h a s e c o n c e n t r a t i o n s o f t h e t r a n s f e r r i n g s p e c i e s i n each phase.

F i g u r e 3 i l l u s t r a t e s t h e s e two c o n d i t i o n s .

I n F i g . 3 ( a ) , t h e l i m i t i n g r e s i s t a n c e t o mass t r a n s f e r i s assumed t o o c c u r i n t h e mercury p h a s e .

I t c a n b,s shown t h a t t h e p r o d u c t o f t h e b u l k

p h a s e c o n c e n t r a t i o n o f r e a c t a n t a n d t h e i n d i v i d u a l - p h a s e mass t r a n s f e r c o e f f i c i e n t i n the p h a s e where t h e l i m i t a t i o n o c c u r s must be l e s s t h a n t h e p r o d u c t of t h e b u l k -p h a s e c o n c e n t r a t i o n o f t h e o t h e r r e a c t a n t and t h e i n d i v i d u a l - p h a s e mass t r a n s f e r c o e f f i c i e n t i n t h e o t h e r p h a s e .

The

c o n c e n t r a t i o n of z i n c i n mercury n e a r t h e i n t e r f a c e d e c r e a s e s from the


13

ORML DWG. 74-10110

I I) )

I

I I

/.

cPb

24"

,B

WATER

INTER FAG1A L FILMS POSTULATED BY LEWIS AND WHIT I

I I

I

I

F i g . 3. I n t e r f a c i a l b e h a v i o r f o r a n i n s t a n t a n e o u s irreversible r e a c t i o n o c c u r r i n g between two l i q u i d phases. (a) Mercury-phase cont r o l l i n g mass t r a n s f e r . (b) Water-phase c o n t r o l l i n g mass t r a n s f e r .


14 b u l k c o n c e n t r a t i o n t o n e a r z e r o a t t h e mercury-water

interface.

The con-

c e n t r a t i o n a t t h e i n t e r f a c e i s v e r y s m a l l because of t h e i n s t a n t a n e o u s A t the inkerface i n i r r e v e r s i b l e reaction t h a t occurs a t t h e interface. 2+ h a s a f i n i t e v a l u e and t h e w a t e r p h a s e , t h e c o n c e n t r a t i o n of Pb

i n c r e a s e s through t h e i n t e r f a c i a l f i l m t o t h e bulk phase value. F i g . 3 ( b ) i l l u s t r a t e s t h e c o n d i t i o n i n which t h e l i m i t i n g r e s i s t a n c e

t o m a s s t r a n s f e r i s assumed t o o c c u r i n t h e water p h a s e .

The e x p l a n a t i o n

of t h e c o n c e n t r a t i o n g r a d i e n t s i n t h e i n t e r f a c i a l f i l m s i s e n t i r e l y analogous t o t h e case e x p l a i n e d a b o v e . t h e mer cury , Zn

2+

The c o n c e n t r a t i o n p r o f i l e s o f l e a d i n

i n t h e w a t e r , and NO

-

3

( t h e a n i o n ) i n t h e water a r e n o t

shown i n F i g . 3 . S e v e r a l c o r r e l a t i o n s have been d e v e l o p e d and p r e s e n t e d i n t h e l i t e r a t u r e f o r p r e d i c t i n g i n d i v i d u a l - p h a s e mass t r a n s f e r c o e f f i c i e n t s i n n o n d i s p e r s i n g stirred i n t e r f a c e c o n t a c t o r s .

For t h e mercury-water

system, all.

o f t h e s e c o r r e l a t i o n s p r e d i c t t h a t t h e mercury-phase m a s s t r a n s f e r c o e f f i -

c i e n t would be smaller t h a n t h e w a t e r - p h a s e c o e f f i c i e n t . I n a l l p r e v i o u s work p erfor m e d w i t h t h e mercury-water t h e c o n c e n t r a t i o n s of t h e r e a c t a n t s were e q u a l .

s y s t e m , 2,7,8

T h i s c o n d i t i o n , coupled

w i t h t h e f a c t t h a t t h e mercury-phase mass t r a n s f e r c o e f f i c i e n t was pred i c t e d t o be s i g n i f i c a n t l y smaller t h a n t h e w a t e r - p h a s e c o e f f i c i e n t ?

i n d i c a t e d t h a t t h e l i m i t i n g r e s i s t a n c e t o m a s s t r a n s f e r should occur i n t h e mercury p h a s e . I n order t o t e s t t h e a s s u m p t i o n t h a t mass t r a n s f e r i s c o n t r o l l e d by t h e mercury p h a s e , w e c an w r i t e t h e f o l l o w i n g r e l a t i o n s f o r t r a n s f e r o f t h e r e a c t a n t s from t h e b u l k p h a s e t o t h e i n t e r f a c e where t h e y r e a c t , b a s e d

on t h e two -fi l m r e p r e s e n t a t i o n shown i n F i g . 3 :

where

k

=

i n d i v i d u a l - p h a s e mass t r a n s f e r c o e f f i c i e n t , cm/sec,


15

N

=

r a t e of mass t r a n s f e r t o t h e i n t e r f a c e , g / s e c ,

A

=

i n t e r f a c i a l a r e a , cm

C

=

concentration,

2

,

(B d e n o t e s b u l k - p h a s e 3

i n t e r f a c i a l c o n c e n t r a t i o n ) , g/cm'

,

concentration, i denotes

and

s u b s c r i p t s Hg and 1-1 0 r e f e r t o t h e p h a s e b e i n g c o n s i d e r e d . 2

As stated

above, we assumed t h a t t h e rate a t which r e a c t i o n (1) p r o c e e d s i s cont r o l l e d by t h e r a t e o f t r a n s f e r of z i n c t h r o u g h t h e mercury p h a s e t o t h e The n e c e s s a r y c o n d i t i o n s for t h i s a s s u m p t i o n t o b e v a l i d a r e :

interface.

(1) The e q u i l i b r i u m c o n s t a n t f o r t h e r e a c t i o n must h e l a r g e ( i . e . , t h e r e a c t i o n sholild be i r r e v e r s i b l e ) . (2)

The p r o d u c t of t h e mass t r a n s f e r c o e f f i c i e n t : t i m t ? s t h e b u l k c o n c e n t r a t i o n of r e a c t a n t i n t h e p h a s e where t h e r a t e of mass t r a n s f e r i s l i m i t i n g must be less t h a n t h e product i n t h e other phase.

S i n c e 1 mole o f z i n c i s e q u i v a l e n t t o 1 mole o f Ph

2+

a c c o r d i n g t o Ey. (l),

S u b s t i t u t i n g Eqs. ( 3 ) and ( 4 ) i n t o t h i s e x p r e s s i o n , and Zn * assuming t h a t t h e c o n t r o l l i n g r e s i s t a n c e i s i n t h e mercury p h a s e , t h e

N

Pb

2 + = N

f o l l o w i n g e x p r e s s i o n i s o b t a i n e d for t h e a p p a r e n t mercury-phase mass transfer coefficient:

kH20 (CPb 2+ , B - CPb2+

,1)

where

k

IIg ,A

k

H2째

=

t h e a p p a r e n t i n d i v i d u a l - p h a s e mass t r a n s f e r c o e f f i c i e n t f o r t h e mercury p h a s e , cm/sec,

=

the t r u e individual-phase m a s s t r a n s f e r coeffi-cient f o r the water phase,

I n t h e above e q u a t i o n , t h e a c t u a l . m a s s t r a n s f e r c o e f f i c i e n t d i f f e r s from t h e a p p a r e n t mass t r a n s f e r c o e f f i c i e n t o n l y i f t h e mercury p h a s e d o e s n o t c o n t r o l t h e r a t e of m a s s t r a n s f e r .

The t r a n s i e n t method used t o d e t e r m i n e

t h e m a s s t r a n s f e r c o e f f i c i e n t h a s been d e s c r i b e d p r e v i o u s l y . 8


By a n argument s i m i l a r t o t h a t which l e d t o t h e development o f E q . ( 5 ) , an e q u a t i o n f o r t h e a p p a r e n t aqueous-phase mass t r a n s f e r c o e f f i c i e n t

c a n be w r i t t e n for t h e case where t h e l i m i t i n g r e s i s t a n c e i s i n t h e w a t e r . The c o n c e n t r a t i o n of Pb2+ i n t h e water below which t h e l i m i t i n g res'is-

t a n c e t o mass t r a n s f e r i s i n t h e w a t e r ( a t a f i x e d c o n c e n t r a t i o n of z i n c i n t h e mercu ry ) c a n be d e t e r m i n e d a s f o l l o w s :

I f t h e Pb2+ c o n c e n t r a t i o n

i s s u f f i c i e n t l y h i g h , t h e l i m i t i n g r e s i s t a n c e t o mass t r a n s f e r w i l l be i n t h e mer cury , a n d t h e i n t e r f a c i a l c o n c e n t r a t i o n of Pb

a f i n i t e value.

2+

,

CPb2.tli

w i l l have

i s lowered by a n amount A ( n o t l a r g e enough t o ,B c a u s e t h e l i m i t i n g r e s i s t a n c e t o change p h a s e s ) , E q . ( 5 ) t h e n i n d i c a t e s t h a t CPb2+ e n c e Cpb2+

,i ,B

I f CPb2+

must a l s o d e c r e a s e by t h e same amount A , k e e p i n g t h e d i f f e r -

- Cpb2+,i

constant.

The w a t e r - p h a s e m a s s t r a n s f e r c o e f f i -

c i e n t i s assumed t o remain c o n s t a n t ( a l t h o u g h o f unknown v a l u e ) . CPb2+,B i s re d u ce d s u f f i c i e n t l y , Cpb2+

is f u r t h e r reduced, C

2+

w i l l d r o p t o z e r o ; i f Cpb2+

t i

,B'

,R

w i l l remain z e r o , and t h e l i m i t i n g r e s i s t a n c e

Pb , i w i l l change from t h e mercury p h a s e t o t h e w a t e r p h a s e . of Cpb2+

If

A t high values

t h e a p p a r e n t mercury-phase mass t r a n s f e r c o e f f i c i e n t w i l l

remain c o n s t a n t as CPh2+IB i s lowered t o t h e p o i n t where t h e l i m i t i n g r e s i s t a n c e moves i n t o t h e water p h a s e .

A s Cpb2+

,B

i s f u r t h e r reduced,

2+ . w i l l b e z e r o o x v e r y n e a r z e r o . E q u a t i o n ( 5 ) shows t h a t t h e Pb ,I a p p a r e n t mercury-phase mass t r a n s f e r c o e f f i c i e n t w i l l v a r y d i r e c t l y w i t h

C

Cpb2+,B ( s i n c e C

zn ,B

i s f i x e d , and t h e t r u e w a t e r - p h a s e mass t r a n s f e r

c o e f f i c i e n t i s assumed t o b e c o n s t a n t ) .

T h i s dependence of t h e a p p a r e n t

mercury-phase mass t r a n s f e r c o e f f i c i e n t on t h e c o n c e n t r a t i o n o f Pb t h e water i s shown i n F i g a 4 .

2+

in

The dependence of t h e a n a l o g o u s l y d e f i n e d

a p p a r e n t wa t er-p h a s e mass t r a n s f e r c o e f f i c i e n t i s also shown.

Thus, by

c a l c u l a t i n g t h e a p p a r e n t mercury-phase m a s s t r a n s f e r c o e f f i c i e n t as a f u n c t i o n o f t h e i n i t i a l aqueous-phase

lead concentration €OK a s i n g l e

a g i t a t o r speed, t h e t r a n s i t i o n f r o m mercury-phase

c o n t r o l l i n g t o aqueous-

p h a s e c o n t r o l l i n g s h o u l d be i d e n t i f i a b l e by a l i n e - s l o p e change d e t e r m i n e d by p l o t t i n g t h e a p p a r e n t mercury-phase mass t r a n s f e r c o e f f i c i e n t v s t h e i n i t i a l aqueous-phase

lead concentration.


TRANSFER COEFFICIENT

APPARENT INDIVIDUAL-PHASE MASS


18 3.2

Experimental Apparatus

A series o f mass t r a n s f e r e x p e r i m e n t s was p e r f o r m e d i n a mercury-

w a t e r c o n t a c t o r t o d e t e r m i n e t h e p o i n t a t which c o n t r o l . o f mass t r a n s f e r changes f r o m t h e mercury p h a s e t o t h e aqueous p h a s e .

The e x p e r i m e n t a l

a p p a r a t u s u s ed i n t h i s s t u d y i s shown s c h e m a t i c a l l y i n F i g . 5. ment c o n s i s t s of a 5- by 7-in.

The e y u i p -

Plexiglas vessel, 10 i n . high, containiny

t w o p h a s e s , e a c h of which i s 3 i n . d e e p .

An a g i t a t o r s h a f t t o which two

f o u r - v a n e d , f l a t p a d d l e s a r e a t t a c h e d i s suspended from a v a r i a b l e speed motor .

The p a d d l e s are p o s i t i o n e d a t t h e m i d p o i n t o f e a c h p h a s e .

In

t h i s s t u d y , t h e t w o p h a s e s w e r e 1 . 8 l i t e r s of c l e a n mercury c o n t a i n i n g 0.1

g Zn, and 1 . 8 l i t e r s o f d i s t i l l e d water c o n t a i n i n g from

0.02 t o 0.10

- P b( N03 )2 . M 3.3

R e s u l t s and C o n c l u s i o n s

F i v e e x p e r i m e n t s were r u n t o measure t h e a p p a r e n t mercury-phase mass t r a n s f e r c o e f f i c i e n t as a f u n c t i o n of t h e i n i t i a l aqueous-phase concentration.

The i n i t i a l mercury-phase

constant a t 0.1

E.

lead

z i n c c o n c e n t r a t i o n was h e l d

Ph as e volumes and a g i t a t o r s p e e d w e r e a l s o h e l d

c o n s t a n t a t 1 . 8 l i t e r s an d

%

150 rpm, r e s p e c t i v e l y .

The e x p e r i m e n t a l r e s u l t s a r e p r e s e n t e d g r a p h i c a l l y i n F i g . 6 .

The

a p p a r e n t mercury-phase mass t r a n s f e r c o e f f i c i e n t d e c r e a s e d f o r a l l i n i t i a l l e a d c o n c e n t r a t i o n s less than i n previous experiments.

This i n d i c a t e s

t h a t u n d e r t h e s p e c i f i e d c o n d i t i o n s , t h e l i m i t i n g r e s i s t a n c e t o mass t r a n s f e r i s a p p a r e n t l y n o t i n t h e mercury p h a s e . one p o i n t a t t h e lowest Pb

2+

However, b a s e d on t h e

c o n c e n t r a t i o n , t h e a p p a r e n t aqueous-phase

mass t r a n s f e r c o e f f i c i e n t d o e s n o t seem t o remain a c o n s t a n t as would be p r e d i c t e d by t h e model d e s c r i b e d above.

T h i s p o i n t must be c l a r i f i e d by

additional data. From t h e s e r e s u l t s , t h e f o l l o w i n g c o n c l u s i o n c a n be drawn:

For t h e

c o n d i t i o n s u n d er which t h e s e a n d a l l o t h e r r u n s w e r e p e r f o r m e d , t h e r e s i s t a n c e t o mass t r a n s f e r w a s n o t i n t h e mercury p h a s e a s w a s p r e v i o u s l y believed.

F u r t h e r s t u d i e s a r e needed t o t e s t o t h e r a s s u m p t i o n s employed

i n a n a l y z i n g r e s u l t s from t h e t r a n s i e n t m a s s t r a n s f e r e q u i p m e n t .


19

QRNL DWG. 74-10112

VARIABLE

,--ROTATING

SPEED DRIVE

MorOR

AGITATOR

SHAtFT

A G I TAT0R PADDLES (CENTERED IN EACH PHASE 1

PLEXiGL AS CTOR

Fig. 5 . mercury-water

S c h e m a t i c diagram of t h e Plexiglas c o n t a c t o r u s e d f o r the s y s t em .


20

$E

0RNL DWG. 74-10109 I

I

0

t-

z

-

W 0

I

V - APPARENT

MERCURY PHASE MASS TRANSFER COEFFICIENT' 0- APPARENT AQUEQUSPHASE M A S S TRANS f ER COEFFICIENT

0.010

u

1

0.008

LL

L W

0 0

a: 0.006 W LL U J

z a a

I-

0.004

II)

UJ

a

2 0

w

QI I)

0.002

UJ

Q:

w E

0.o 0.0

0.02

0.04

INITIAL AQUEOUS -PHASE

0.06

Q.Q8

LEAD CONCENTRATION

0.10

(m) moles

F i g . 6. E x p eri m en t a l r e s u l t s showing t h e a p p a r e n t mercury-phase mass t r a n s f e r c o e f f i c i e n t s a s a f u n c t i o n of t h e i n i t i a l a q u e o u s - l e a d c o n c e n t r a t i o n a t c o n s t a n t a g i t a t o r speed.


4.

SALT-METAL CONTACTOR DEVELOPMENT

EXPERIMENTS W I T H

:

A MECHANICALLY A G I T A T E D , NONDISPERSING CONTACTOR I N THE SALT-BISMUTH FLOW’1’HROUGH F A C I L I T Y

J . A.

K l e i n , C . H . Brown, J r . , and J. R. Hightowerr, Jr.

M ec h an i c al l y a g i t a t e d , n o n d i s p e r s i n g c o n t a c t o r s a r e being c o r l s i d e r e d f o r e x t r a c t i n g p r o t a c t i n i u m and t h e r a r e - e a r t h f i s s i o n p r o d u c t s from t h e f u e l c a r r i e r s a l t of a m o l t e n - s a l t b r e e d e r r e a c t o r i n t o m o l t e n bismuth containing dissolved reductant.

Mass t r a n s f e r r a t e s were measured i n a m i l d s t e e l c o n t a c t o r which was f a b r i c a t e d and i n s t a l l e d i n t h e S a l t - B i s m u t h Flowthrough F a c i l i t y .

T h i s e x p e r i m e n t a l s y s t e m a l l o w s ( a ) p e r i o d i c p u r i f i c a t i o n of t h e f e e d s a l t and metal,

(b) removal o f s u r f a c e c o n t a m i n a t i o n from t h e salt-metal i n t e r -

f a c e , and ( c ) v a r y i n g of t h e d i s t r i b u t i o n r a t i o of t h e m a t e r i a l . of i n t e r -

e s t between t h e s a l t and b i s m u t h . The new s t i r r e d i n t e r f a c e c o n t a c t o r makes u s e of t h e e x i s t i n g p i p i n g equipment and i n s t r u m e n t a t i o n i n t h e S a l t - B i s m u t h Flowthrough F a c i l i t y 10-1.4 A t h a t were used f o r s t u d y i n g s a l t - b i s m u t h f l o w i n packed columns. s i m p l i f i e d fl o w diagram o f t h e f a c i l i t y i s shown i n F i g . 7 .

The f a c i l i t y

c o n t a i n s f i v e v e s s e l s , t h e a s s o c i a t e d p i p i n g , and t h e c o n t a c t o r a s s e m b l y . The v e s s e l s are a s a l t - f e e d t a n k , a s a l t - c o l l e c t i o n t a n k , a b i s m u t h - f e e d t a n k , a b i s m u t h - c o l l e c t i o n t a n k , and a t r e a t m e n t v e s s e l ( T 5 ) f o r s p a r g i n g b o t h s a l t and m e t a l w i t h m i x t u r e s of HF and

13

2’

To c o n s e r v e s p a c e , f e e d

and c o l l e c t i o n t a n k s f o r b o t h s a l t and m e t a l are c o n c e n t r i c . c o l l e c t i o n t a n k s and p i p i n g are made o f low c a r b o n s t e e l .

Feed and

The t r e a t m e n t

v e s s e l i s made of s t a i n l e s s s t e e l w i t h a g r a p h i t e l i n e r . A diagram o f t h e c o n t a c t o r i s shown i n F i g .

o f a 6-in.-diam

cal. b a f f l e s .

8.

The c o n t a c t o r i s made

low-carbon s t e e l vessel c o n t a i n i n g f o u r 1-in.-wide

The a g i t a t o r c o n s i s t s of two 2-7/8-in.-diam

f o u r 3/4-in.-wide

n o n ca n t e d b l a d e s .

A 3/4-in.-diam

verti-

s t i r r e r s with

o v e r f l o w a t the

i n t e r f a c e a l l o w s t h e removal of i n t e r f a c i a l f i l m s w i t h t h e s a l t and m e t a l e f f l u e n t streams.

S a l t and bismuth a r e f e d i n t h e c o n t a c % s r below t h e

s u r f a c e o f t h e r e s p e c t i v e p h a s e , and b o t h p h a s e s w e r e e q u i l i b r a t e d p r i o r t o an e x p e r i m e n t .

The s y s t e m w a s o p e r a t e d i n e s s e n t i a l l y t h e same manner


ORNL DWG 74-694R1

n

CONTACTOR

METAL FEED AND COLLECTION TANK

SALT FEED AND COLLECTION TANK

SALT AND METAL TREATMENT VESSEL

F i g . 7. Flow d i a g r a m of t h e S a l t - B i s m u t h F l o w t h r o u g h F a c i l i t y w i t h t h e mechanically agitated c o n t a c t o r i n s t a l l e d .


23

Q R N L DWG 7 4 - 1 0 0 7 3

A-Bismuth inlet B-Salt inlet C-Four I-in. b a f f l e s D-2-7/8-in. x 3/4-in. blades E-Gas- salt interface F- Bismuth-salt interfoce G - Interface removal H-Salt effluent I- Bisrnut h effluent Fig. 8. Diagram of the mechanically agitated, nondispersing contactor installed in the Salt-Bismuth FlowtArough Facility.


24

as w a s employed w i t h t h e packed column. 10-14

After t r a n s f e r of t h e s a l t

a n d metal p h a s e s t o t h e feed t a n k s , 9 7 Z r and 237U t r a c e r s were added t o With t h i s t e c h n i q u e , t h e r a t e s a t which z i r c o n i u m and uranium

the salt.

t r a c e r s t r a n s f e r from t h e s a l t t o t h e b i s m u t h c o u l d be measured i n a s y s t e m t h a t was o t h e r w i s e a t chemical. e q u i l i b r i u m . The e x p e r i m e n t a l l y d e t e r m i n e d d a t a f r o m t h e s y s t e m a r e s u f f i c i e n t

t o a l l o w t h r e e i n d e p e n d e n t e x p r e s s i o n s f o r t h e o v e r a l l mass t r a n s f e r c o e f f i c i e n t t o b e d e r i v e d â‚Ź o r t h e c o n t a c t o r i n t h e S a l t - B i s m u t h Flowt h r o u g h F a c i l i t y from s t e a d y - s t a t e material b a l a n c e r e l a t i o n s h i p s .

7

These e x p r e s s i o n s f o r t h e o v e r a l l m a s s t r a n s f e r c o e f f i c i e n t are g i v e n below i n terms o f t h e measured q u a n t i t i e s C1 r C s r Cmr F i r F 2 r Dr and A:

F 1(1

-

5) C

c

where F1

=

3 f l o w r a t e o f salt, c m / s e c ,

F

=

f l o w r a t e o f m e t a l , c m /sec,

=

tracer c o n c e n t r a t i o n i n s a l t inflow, units/cm

2

C1

3

3

,


25

3

,

cS

=

tracer concentration in salt outflowl units/cm

cm

=

tracer concentration in metal outflow, unit:;/cm 3 ,

A

=

interfacial area, cmL , and

D

=

distribution coefficient

=

ratio of concentraction in metal.

phase to concentration in salt phase at; equilibrium, 3 mo les/cm moles/cm3 The subscripts 1, 2, and 3 on K

S

indicate the equation used to evaluate

the overall mass transfer coefficient, K

S

.

The overall mass transfer

coefficient is related to the mass transfer coefficients in the individual

phases through the following relation: l/Ks

I/kS + l/Dkm,

=

where K

S

ks

=

overall mass transfer coefficient based on salt-phase concentrations, cm/sec,

=

km =

individual mass transfer coefficient in salt phase, cm/sec,

and

individual mass transfer coefficient phase in metal, cm/sec.

Within experimental error, the distribution coefficient, D, can be set as desired.

In order to minimize effects of uncertainties i n the

value of D on the calculated value of the overall mass transfer coefficient, it is desirable to make D Eairly large. F o r the values of concentrations and flow rates used in these experiments, the terms containing D in E q s .

( 6 ) - ( 8 )are less than 5% of the values o f the other

terms for values o f D greater than 20, and can be disregarded with l i t t l e error.

Assuming that the terms containing D can be omitted,

Eqs. (6)-(8) reduce to


26

Ks

2

-

F

2 -

, and

A

uncertainties in the distribution coefficient do not affect the accuracy of the overall mass transfer coefficient. However, as shown by Eq. (91,

when D

i s

very large, the overall mass transfer coefficient is essentially

the individual salt-phase coefficient, since resistance to mass transfer in the metal phase is negligible in comparison. Six runs have been completed to date. 7

Four runs (TSMC-1 through -4)

have been discussed previously, and two runs (TSMC-5 and -6) were completed during this report period.

We have recalculated results for a l l

runs and will discuss them together in this report.

All runs were performed using the same procedure. While the fluoride

salt and bismuth are in contact in T5 (the treatment vessel), sufficient

beryllium is added to the salt electrolytically to produce the desired

distribution coefficient, D. Since it is impossible to completely exclude oxidants, addition of beryllium must be carried out periodically in order

to maintain a relatively high distribution coefficient. Periodic transfer of

salt and bismuth throughout the system are also performed to keep the

system in equilibrium.

Prior to a run, the salt and bismuth phases are separated by pressur-

izing the salt-bismuth purification vessel and transferring salt arid


27

bism u t h t o t h e i r r e s p e c t i v e feed t a n k s .

97

Approximately 7 m C i of 9 7 Z r -

Nb

0 are allowed t o d i s s o l v e i n t h e s a l t phase 3 8 about 2 h r p r i o r t o an experiment.

and 50 t o 100 m C i o f 237U

S a l t a n d b i s m u t h strems a r e p a s s e d t h r o u g h t h e c o n t a c t o r v e s s e l a t t h e d e s i r e d f l o w r a t e s by c o n t r o l l e d p r e s s u r i z a t i o n o f t h e s a l t and b i s The c o n t a c t o r i s m a i n t a i n e d a t a p p r o x i m a t e l y 59O OC f o r

muth f e e d t a n k s . a l l runs.

Both p h a s e s e x i t t h r o u g h a common o v e r f l o w l i n e , separate,

and r e t u r n t o t h e s a l t and b i s m u t h c a t c h v e s s e l s .

P e r i o d i c s a m p l i n g of

b o t h e x i t streams i s ac c o m p l i s h e d by means o f f l o w i n g - s t r e a m samplers i n s t a l l e d i n t h e e x i t l i n e s from t h e c o n t a c t o r . Sample a n a l y s i s w a s a c c o m p l i s h e d by f i r s t c o u n t i n g t h e sample cap-

s u l e s â‚Źor t h e a c t i v i t y of 97Nb

237u

( 2 0 7 . 9 5 k e v 6-1 and the a c t i v i t y of 97Zr-

(743.37 keV and 658.18 keV R - ,

respectively) a f t e r secular equilib-

rium w a s r e a c h e d between 9 7 Z r a n d i t s d a u g h t e r 97Nb.

The m a t e r i a l i n 237u wa s t h e sample c a p s u l e s w a s t h e n d i s s o l v e d , a n d t h e a c t i v i t y o f

cou n t e d a g a i n a f t e r t h e 9 7 Z r - 9 7 N b

a c t i v i t y had d e c a y e d t o a v e r y P o w

l e v e l ; t h i s w a s done t o c o r r e c t f o r s e l f - a b s o r p t i o n

i n t h e s o l i d samples.

Mass t r a n s f e r r a t e s were t h e n c a l c u l a t e d from t:he r a t i o s of t r a c e r conc e n t r a t i o n s as d i s c u s s e d p r e v i o u s l y .

The c o u n t i n g d a t a o b t a i n e d d u r i n g r u n s TSMC-2 t h r o u g h -6 a r e shown i n T a b l e s 2-6.

C o u n t i n g d a t a a r e g i v e n â‚Ź o r 237U

(207.45 keV f3-)

and

972 r (743.37 keV 6-1 i n t h e s o l i d s a l t and b i s m u t h s a m p l e s , and f o r a f t e r t h e samples were d i s s o l v e d .

237u

A l l t h e r e s u l t s are given i n t e r m s of

c o u n t s per gram of p h a s e . R e s u l t s o f measurements o f o v e r a l l mass t r a n s f e r c o e f f i c i e n t s a r e shown i n Table 7 .

T h re e d i f f e r e n t e q u a t i o n s f o r c a l c u l a t i . n y m a s s t r a n s -

f e r c o e f f i c i e n t s were used. f o r c a l c u l a t i n g t h e r e s u l t s f o r any one r u n , and t h e r e s u l t s a r e p r e s e n t e d a s a n a v e r a g e o f t h r e e c a l c u l . a t e d v a l u e s with t h e standard deviation.

V a l u e s are g i v e n b o t h f o r r e s u l t s b a s e d

on t h e u ra n i u m c o u n t i n g d a t a and f o r r e s u l t s based on t h e z i r c o n i u m c o u n t i n g data.


Table 2 .

~~~

C o u n t i n g d a t a o b t a i n e d from r u n TSYC-2

~

Solid analysis for 2 3 7 ~ (counts/ g)

Sample code"

Solution analysis for 2 3 7 ~ (counts / g)

Solid analysis for 9 7 ~ r (counts/g)

Sample codea

Solid analysis f o r 237u (counts/g)

Solution analysis for 2 3 7 ~ (counts/g)

Solid analysis for 9 7 ~ r ( c o u n t s/ g )

Samples t a k e n p r i o r t o r u n

< 3.3 3.2 -< 2 . 2

88-B-5 93-B-1 94-B-1

x 102 x 102 x 102

- 2.8 < 1.9 < 2.3 -

103 103 x lo3

< 6.37 x l o 1 < 1 . 0 3 x lo2 < 6 . 6 x lo1

86-S-5 874-5 89-s-3 90-S-3

< 8.5 < 6.8 < 2.9 < 5.6

x lo3 x lo3 103 104

<

4.5

< 7.7 -< 3.9 < 6.6 -

x 102

x 102 x 102 x lo2

Samples t a k e n p r i o r t o r u n , b u t a f t e r a d d i t i o n of tracers 91-S-3 92-S-3 Samples t a k e n d u r i n g r u n 9 3- B-FS 91-B-FS 95-B-FS 96-B-FS 97-B-FS 98-B-FS 99-B-FS

107-B-1 108-B-1 109-B-2 110- 8-2 115-13-5 116-B-5

1.80 1.46 1.91 2.24 2.15 1.86 x 3.21 x

104

5.05 4.iE 1.48 1.96 2.76 5.15

io3 lo3

x X

104

io4 io4 104

10'

io4

IO4

x 104

x

x

io4 io4

2.80 x 10'

2.01 1.69 2.00

104 104

3.87 3.91 5 . 0 1 x 10'

1.94 x 1.97 2.74

lo4 io4 io4

3.49 3.29

4.28

1.08 1.04 3.29 3.76 5.52 6.34

104

io4 io4 io4 io4

io4

x io4 x IO' x 10' x lU4

io4

2.10

io4

104

100-S-FS 101-S-FS 102-S-FS 103-S-FS 104-S-FS 105-S-FS 106-S-FS

Samples t a k e n a f t e r r u n 4.40 103 4.05 x 10'

1.61 1.83

104

io4

2 . 4 0 x 10'

2.54

io4

111-S-3 112-S-3 113-5-4 114-S-4 117-S-5 118-5-5

3.01 105 1.96 x I O 5 2.32 io5 2.41 105 2.44 x I O 5

--

2.65 x 2.74 x

2.91

lo5 lo5 105

5.00 x io5 5 . 1 4 s IO5

2.41 2.55 1.53 9.59

105 105 105

io4

aEach sample is d e s i g n a t e d by a c o d e c o r r e s p o n d i n g t o A-B-C, where A = sample number; B = inaterial i n sample C = sample o r i g i n ; 1 = "1; 2 = T2; 3 = T 3 ; 4 = T 4 ; 5 = T5; FS = f l o w i n g stream sample.

,

1.94 1.93 1.29 1.36 6.63 7.95

105

105 105

105

io4 io4

(B = b i s m u t h , S = s a l t ) ; and


29

T a b l e 3. ___- -

Sample codea

Solid analysis f o r 237u (counts/g)

141-B-5 142-B-5 1 47- 8- 5 148-B- 5

.<. 1 . 1 3 -< 1 . 6 4 (6.26 -< 1.00

x 10' x lo2 x lo1 x 102

C o u n t i n g d a t a o b t a i n e d f r o m r u n TSMC-3

Solution a n a l y s i s f o r 237u (counts/ g)

< 5.1 < 5.5 < 3.4

Sample codea

Samples t a k e n p r i o r t o r u n

-< 4 . 0

103

io3 io3 103

143-S-5 144-5-5 145-5-3 146-5-3

Solid a n a l y s i s for 2 3 7 ~ (counts / g)

< 3.3 < 3.2

103

io3 io3 io4

< 3.4

< 3.2

S o l u t i o n analysis for 2 3 7 ~ (counts/g)

-< 5.3

104

< 7.6 < 7.6 < 5.6

104

io4 io4

Samples t a k e n p r i o r t o r u n b u t a f t e r z d d i t i o n of tr-aLeL 149-S-3 150-S-3

io4

151-B-FS 152-B-FS 1 5 3- 8- FS 154-B-FS 155-B-FS 156-8-FS 157-8-FS

4.52 4.14 4.12 4.51 6.32 3.88 4.00

165-B-1 166-B-1 1 69- B-2 170-B-2 173-B-5 174-B-5

4 . 3 8 x lo2 6 . 5 3 x 10' 3.19 io4 io4 2.86 5.47 io4 5.24 io4

io4

io4 io4

io5 io4 io4

6.13 6.33

Samples t a k e n d u r i n g r u n 1.13 1.29 1.33 1.44 1.26 1.44 1.49

105

105 105 105

io5 io5 io5

158-S-FS 159-S-FS 160-S-FS 161-S-FS 162-S-FS 163-S-FS 164-S-FS

Samples t a k e n a f t e r run 4.8 103 4.7 io3 1 . 6 1 x lo5 9.56 io4 1.43 io5 1.44 io5

167-S-3 1 68- S- 3 1 7 1- S - 4 172-5-1, 175-S-5 176-5-5

3.48

--

2.96

3.08 x

3.02 3.19

--

105 105

9.37 9.29

io5

4.89

105

4.36 4.56 3.99 4.43

lo5 105

io5

105

--

1.19

2.64 x 10' 2.70 105 < 6.4 x l o 3 < 6.4 x l o 3

4.71 4.12 5 1.4 < 1.4

105 105 105

io5 _L

6 . 6 8 x lo5

--

105

--

105

105

io5 io5

105

io5

aEach s a m p l e is d e s i g n a t e d by a cqdde c o r r e s p o n d i n g t o A-B-C, w h e r e A = s a m p l e number; B = m a t e r i a l in sample (B = b i s m u t h , S = s a l t ) ; and C = s a m p l e o r i g i n ; 1 T 1 ; 2 = T2; 3 = T3; 4 = T4; 5 = T 5 ; FS = f l o w i n g stream s a m p l e .


T a b l e 4.

C o u n t i n g d a t a o b t a i n e d from r u n TSMC-4

~~

Sample codea

Solid analysis for 2 3 7 ~ (counts/g )

Solution analysis for 2 3 7 ~ (coun t s / g )

< 5.1 c 6.7 < 4.9 c 4.7

191-B-5 192-B-5 195-B-1 196- B- 1

io3 io3 io3 io3

Solid analysis for 9 7 ~ r (coun t s / g )

Sample code"

Samples t a k e n p r i o r t o r u n x 102 189-S-5 < 3 . 3 x 102 190-S-5 < 3.3 x 102 193-S-3 < 5.7 x 1 0 2 194-S-3

-< 4 . 4

Solid analysis f o r 237.0 (counts/g)

< 5.9 (4.0 2 4.7 2 4.3

x 103 x

x

x

lo3 lo3 lo3

Samples t a k e n p r i o r t o r u n b u t a f t e r a d d i t i o n o f t r a c e r s 197-S-3 1.22 x 106 198-S-3 1 . 2 1 x 106 199-E-FS 200-B-FS 2 01-B- FS 202-B-FS 203-B-FS 204-B-FS 205-B-FS

9.67 1.45 1.70 1.85

213-B-1 214-B-1 215-B-2 216-B-2 221-B-5 222-B-5

2.06 1.73 1.06 1.07 7.86 8.28

2.19

1.83 1.57

Solution analysis f o r 2 3 7ii (count s / g )

< 3.6 < 3.8 < 3.6

< 1.0

x lo4 x 1oq 104

104

x 105

2.97 105 3 . 2 3 x 105 2.88 105 5.01 x 1 0 5 3.34 105 3.10 105 3.14 105

103 103 105 105 104

8.7 x l o 3 7.7 103 2.84 io5 3.17 105 2.23 105 2.38 x l o 5

Samples t a k e n a f t e r r u n 217-5-3 1 . 9 x 10' 1.1 103 218-S-3 3.69 io4 219-S-4 3.68 io4 2 2 0-S -4 223-S-5 2.53 io4 2.62 io4 224-S-5

1 . 3 1 x lo6 1.25 x 106 2.29 105 2.38 105 8 . 3 x io4 8.0 io4

1.48 x 106 1 . 5 4 x lo6 2.61 105 2.71 105 c 4.7 104 < 4.9 104

io4

aEach sample is d e s i g n a t e d by a code c o r r e s p o n d i n g t o .4-B-C, where A = s a m p l e number; B = m a t e r i a l i n sample C = sample o r i g i n ; i = T I ; 2 = T2; 3 = T3; 4 = T4; 5 = T5; FS = f l o w i n g stream sample.

io5 io5

2.39 x l o 5 2.36 io5 4.88 io4 4.67 io4 < 2.2 103 < 3.9 103

i.46 2.64 2.98 2.97 2.76 2.63 2.52

lo5

103

x 102

4.58 io4 6 . 3 3 x 10' 4.61 x l o 4 6.07 io4 6.96 io4 8.48 io4 6.84 io4

Samples t a k e n d u r i n g r u n 3.63 104 206-S-FS 4.50 io4 207-S-FS 5 . 6 6 x lo4 208-S-FS 6.34 x 10' 209-S-FS 6.36 x loq 210-S-FS 6.43 io4 211-S-FS 212-S-FS 7.12 104

x 105 105 x IO5

< 1.4 < 9.5 -

x 103 x 10'

1.92 1.99

2.91 io5 3.57 io5 4.82 105 4.72 x 10' 5.01 ios 5.36 105 5.32 105

x

< 1.5 < 6.4 -

1 . 4 4 x 106 1 . 4 9 x 106

104 105 105 105 105 105 105

x lo5 x 105

Solid analysis for 9 7 ~ r ( c o u n ts / g )

(B

=

b i s m u t h , S = s a l t ) ; and

W

0


Table 5.

C o u n t i n g d a t a o b t a i n e d from run TSMC-5

~~

Sample codea

Solid analysis for 2 3 ’ ~ (counts/ g)

S o l u t i o n analysis for 23713 (counts/g)

Solid analysis for 9 7 ~ r ( c o u n t s / g)

Sample codea

Samples t a k e n p r i o r to run

227-B-5 2 2 8- 3-5 2 3 1-B- i 232-B-1

-< 5.64 x 102 8.49 x 102 c 4.83 x 102 < 5.91 x 1 0 2

-

x lo2 x 102 x 102 x 102

-< 1 . 4 < 2.2 < 1.1 < 1.0

--

--

---

225-S-5 226-S-5 229-5-3 230-S-3

Solid analysis

for 2 3 7 ~ (counts/g)

-< 7.4 5

6.9 (4.9 ( 6.0

103 x lo3 x lo3 x lo3

Samples t a k e n p r i o r t o run b u t after a d d i t i o n o f t r a c e r s 233-S-3 234-S-3

235-B-FS 236-B-FS 2 37-B-FS 238-8-P’S 2 3 9-8- FS 240-B-FS 2 41- B- FS

241)-B-1 250-B-1 25 1-B- 2 25 2- 3- 2 25 7-B-5 258- B-5

1.04 105 1.30 x 10’ 1.53 105 1.35 io5 1.35 .io5 1.67 io5 1.41 105

< 1.38

-< 1 . 0 5

io3

103 7.70 x lo4 1.00 io5 1.71 105 1.34 105

2.87 io5 4.13 x IO5 4 . 6 0 x 105 4 . 6 1 x lo5 4.83 io5 4.6; 105

5.31

105

---

---

---

S a m p l e s t a k e n d u r i n g run

1.85 io4 2.62 x l o 4 2-96 104 2.89 io4 2-78 104 3.04 104 2.92 x lo4

-< 4.0 < 3.5

1.95

1.80 2.47 2.00

242-S-FS 243-S-FS 244-S-FS 245-S-FS 246-5-FS 247-S-FS 245-S-FS

x lo2

io4 104

104 104

253-S-3 254-S-3 255-5-4 256-5-4 259-S-5 260-S-5

----

3.44 x 106 3.48 x 1 0 6

1.83 x lo6 1.64 x lo6 1.82 x lob

2.13 2.00 2.00 2.10 2.01 2.08

1.75 x lo6 1 . 9 6 x lo6 1.79 x lo6 5.40 x lo6 3.11 3.28 1.52 1.10 5 9.2

21.1 -

x

lo6

x lob x lob x 106 x 103 x IO‘

aEach sample is d e s i g a a t e d by a code c o r r e s p o n d i n g t o A-B-C, where A = sample number; 5 = material i n sample C = sample o r i g i n ; 1 = TI; 2 = T 2 ; 3 = T3; 4 = T 4 ; 5 = T5; FS = f l o w i n g stream sample.

Solid analysis for 9 7 ~ r ( c o u n t s J g)

--

2 . 5 4 x 106 2.57 x lo6

Samples t a k e n a f t e r r u n x 102

Solution analysis f o r 2 3 7~ ( c o u n t s / g)

2.10 105 2.20 x 105

lo6 x 106 x 106 x 106 x 106 x lo6

2.47 1.79 2.64 2.43 2.25 1.92 5.36

x

--

-----

---

x IO5

x IO5

105

x

x

105

lo5 IO4

105 105 1.19 105 1.37 105 < 2.6 x 103 < 3 . 5 x IO3 -

(5 = b i s m u t h , S = sal:);

2.96 3.19

io5

and

r W


C o u n t i n g d a t a u b t a i n e d from r u n TSMC-6

Table 6 .

Sample codea

261-B-5 262-B-5 265-B-1 266-B-1

Solid analysis for 2 3 7 ~ (counts/g)

1.75 2.37

1.95 1.99

104 104 104 104

Solution analysis for 2 3 7 ~ (countslg)

5.32

io4

5.55 io4 5 . 7 8 x 10’ 5.47 io4

Solid analysis f o r 9721(counts/g)

Sample codea

Solid analysis for 2 3 7 ~ (counts/g)

Solution analysis f o r 2371.1 (counts/g)

Samples t a k e n p r i o r t o r u n

--

2.51 103 8.96 10’ 9 . 4 8 x 10’

2 59-S- 5 260-S-5 263-S-3 264-S-3

< 6.2 < 6.1 < 1.3 < 5.6

103 103 x 10’ x lo3

< 1.3

104 104

< 1.3

104 104

< 1.4 < 1.4 -

Samples t a k e n p r i o r t o r u n b u t a f t e r a d d i t i o n of t r a c e r s 267-S-3 268-S-3

269-B-FS 2 7 0-B-FS 2 7 1-B-FS 2 72-B-FS 273-B-FS 274-E-FS 275-B-FS 2 a 3 - ~ -1 2 84-B-1 285-52 2 8 6 - ~ -2 291-B-5 292-B-5

7.69

1.13

104 105

1.25 io5 1 . 4 3 x io5

1.55 1.54

1.53

io5 io5 io5

2.28 x io4 2.51 104 1.07 105 1.13 io5 1.05 io5 1.33 105

2.39 io5 3.63 io5 4.16 xl105 4.17 x I O 5 4.36 x l o 5 4.27 io5 4.53 io5 6.79 io4 6.59 x I O 4 3.34 io5 3.11 io5 3.41 lo5 3.31 105

Solid analysis for 9’~r (counts/g)

< 2.2

< 1.3

< 1.6 < 2.1

103

x 103 x lo3 103

1 . 1 2 x 106 1.07 x l o 6

1 . 2 9 x 106 1.34 x l o 6

3.29 x 1 0 5 3 . 1 6 x 105

4.11 105 4.63 io5 4.59 105 4.03 x 105 5.00 105 4.83 s l o 5 4.63 x lo5

3.53 105 105 4.55 3.83 105 4 . 3 8 x 105 105 4.26 4.66 x l o 5 3.40 105

1.75 105 2.30 io5 2 . 1 1 x 105 2.16 105 1.85 io5 2.03 io5 2.07 x IO5

x 106

3.47 105 3 . 5 7 x 105 8.40 104 8.89 10‘ < 5.7 lo3

Samples t a k e n d u r i n g r u n

6.78 io4 6.70 x l o 4 7.54 104 8 . 0 1 x lo4 7.79 io4 9.01 io4 8.85 io4

276-S-FS 277-S-FS 278-s-n 279-S-FS 280-S-FS 281-S-FS 282-S-FS

Samples t a k e n a f t e r r u n 3.73 3.44 5.33 5.59 4.36 4.45

aEach sample i s d e s i g n a t e d by a c o d e c o r r e s p o n d i n g t o A-B-C, C = sample o r i g i n 1 = ‘71 2 = T2 3 = T 3 4 = T4 5 = T5

x 103 x 10’ x 104

io4 io4

x 10’)

287-s-3 288-5-3 289-s-4 290-5-4 293-S-5 294-5-5

1.32 x lo5 1 . 2 0 x 106 4.04 105 3.90 105 < 9.2 103 -

< 8.1

103

where A = s a m p l e number; B = material i n s a m p l e FS = f l o w i n g stream s a m p l e .

1.60 1.34 4.15 3.80 -< 1.8 < 1.7

(B

=

x 10: x lo3 x lo5 105 105

-< 5.0

b i s m u t h , S = s a l t ) ; and

io3

W N


io

k

N

d 0

2

:

3

c

0

x VI

a m

*r

N

n

I

In 0 0

ln 0

+

33

a

r-!

In

N 0 0

m

4- I

0

+I r-i

\o

I I I

m

In 0

0

0

0

1’1

0

a, 0

m N

0

cn

In

-t I

0

0

0

0 0

0

r-1

0

+I 0 0

0

+I -3 0

m

0

I cn 0

0

0

0 0

I n

N 4 0

r. 0

r-

In 0

co m m

0

I I

Kr

u

I

m

N

d

cn

4

P

In

-3 N 4

W

A

N

XP N A

cv

XP A

-3

rl

rf

In 0

A

A

N

m

N \o 4

Kr Kr rl

m

P

l--

0 In

0

4

0

v m

0

rl N P-4

a

i--

d

0 P d

\D u)

r-l

a, N

c\I

I

V

?.I

u

m I

u

P.1

5E-1 P5 B3 5E+


34

A p r e l i m i n a r y r u n , TSMC-1,

dure.

w a s p r i m a r i l y designed t o t e s t t h e proce-

S a l t and b i s m u t h f l o w s w e r e a p p r o x i m a t e l y 200 cc/min,

stirrer r a t e w a s 123 r p m .

and t h e

Unfortunately, t h e d i s t r i b u t i o n c o e f f i c i e n t

w a s t o o l o w t o e f f e c t any s i g n i f i c a n t mass t r a n s f e r ; t h u s , m a s s t r a n s f e r r a t e s c o u l d n o t be a c c u r a t e l y d e t e r m i n e d , and no r e s u l t s are shown â‚Źor t h i s run. O p e r a t i o n o f t h e equipment d u r i n g r u n TSMC-2 w a s v e r y smooth.

s a l t and b i s m u t h f l o w r a t e s w e r e 228 and 197 cc/min,

The

respectively.

The

d i s t r i b u t i o n c o e f f i c i e n t s were h i g h e r t h a n f o r t h e p r e v i o u s r u n but were

L o w e r t h a n d e s i r e d , and w i t h a c o n c o m i t a n t l a r g e d e g r e e o f u n c e r t a i n t y . S e v e r a l d e t e r m i n a t i o n s of D

w e r e made w i t h a r a n g e o f 0.94 t o 34; c o n s e U y u e n t l y , o n l y a r a n g e of p o s s i b l e v a l u e s f o r t h e o v e r a l l m a s s t r a n s f e r c o e f f i c i e n t c o u l d b e s t a t e d f o r t h e r e s u l t s b a s e d on uranium. mination of D

Zr

w a s made, i n d i c a t i n g t h a t D

Zr

was 0.96.

One d c t e r -

A value f o r

o v e r a l l mass t r a n s f e r c o e f f i c i e n t b a s e d on z i r c o n i u m i s g i v e n b a s e d on the value of t h i s d i s t r i b u t i o n coefficient, but since the value f o r D

zr

must be c o n s i d e r e d u n c e r t a i n , t h e r e i s a l a r g e r e r r o r i n t h e m a s s t r a n s f e r c o e f f i c i e n t t h a n i s i n d i c a t e d by t h e r e p o r t e d s t a n d a r d d e v i a t i o n g i v e n i n Table 7. I f i t i s assumed t h a t t h e r a t i o of s a l t - s i d e m a s s t r a n s f e r c o e f f i -

c i e n t t o b i s m u t h - s i d e m a s s t r a n s f e r c o e f f i c i e n t c a n be d e t e r m i n e d from t h e L e w i s c o r r e l a t i o n , t h e n t h e s a l t - s i d e mass t r a n s f e r c o e f f i c i e n t s f o r r u n TSMC-2 a r e h i g h e r t h a n t h e o v e r a l l mass t r a n s f e r c o e f f i c i e n t by a f a c t o r o f 1 . 5 5 f o r t h e r e s u l t s b a s e d on z i r c o n i u m . A bis m u t h l i n e l e a k o c c u r r e d i m m e d i a t e l y p r e c e d i n g r u n TSMC-3.

During t h e r e s u l t i n g d e l a y â‚Ź o r r e p a i r s , t h e 9 7 Z r d e c a y e d a n d o n l y t h e 237U

t r a c e r c o u l d be u s e d .

The r e m a i n d e r of t h e r u n went smoothly.

Salt

and bis m u t h f l o w r a t e s were 1 6 6 and 1 7 3 c c / m i n , a n d t h e s t i r r e r r a t e w a s 1 6 2 rpm.

run.

A high v a l u e for D

U

( g r e a t e r t h a n 34) w a s maintained f o r t h i s

I n r u n TSMC-4, f l o w r a t e s o f 1 7 0 and 144 cc/min were s e t f o r t h e s a l t and bis mu t h f l o w s , and a s t i r r e r r a t e of 205 r p m w a s m a i n t a i n e d .

The

d i s t r i b u t i o n c o e f f i c i e n t d e t e r m i n e d from s a m p l e s t a k e n b e f o r e , a f t e r , and


35 d u r i n g t h e r u n , were g r e a t e r t h a n 1 7 2 f o r D

W

a n d g r e a t e r t h a n 24 f o r D

T h i s v a l u e i s s u f f i c i e n t l y l a r g e so t h a t E q s .

( l 0 ) - ( 1 2 ) are v a l i d ,

zr .

Large

d i s t r i b u t i o n c o e f f i c i e n t s cannot b e determined p r e c i s e l y due t o t h e i n a b i l i t y to d e t e r m i n e v e r y small amounts o f uranium i n t h e s a l t p h a s e .

No

pr o b l em s arose d u r i n g t h i s r u n . Runs TSMC-5 and -6 w e r e p e r f o r m e d w i t h o u t i n c i d e n t .

The d i s t r i b u t i o n

c o e f f i c i e n t s were m a i n t a i n e d a t h i g h l e v e l s f o r b o t h r u n s .

TSMC-5 had a

s t i r r e r r a t e of 1 2 4 r p m l and s a l t and b i s m u t h flows o f 2 1 9 a n d 1 7 5 c c / m i n . TSMC-6 s a l t and b i s m u t h f l o w s were 206 and 185 cc/min,

respectively, with

a s t i r r e r r a t e o f 180 r p m . A s m en t i o n e d p r e v i o u s l y , when t h e d i s t r i b u t i o n c o e f f i c i e n t i s l a r g e ,

t h e overall m a s s transfer coefficient is essentially the individual saltphase m a s s t r a n s f e r c o e f f i c i e n t .

T h u s , r e s u l t s f o r r u n s TSMC-3 t h r o u g h

-6 c a n be compared d i r e c t l y t o t h e L e w i s c o r r e l a t i o n .

The L e w i s c o r r e l a -

t i o n 3 I 4 â‚Ź o r mass t r a n s f e r i n t h e n o n d i s p e r s i n y c o n t a c t o r i s

where

k

=

i n d i v i d u a l mass t r a n s f e r c o e f f i c i e n t , cm/sec,

v

=

k i n e m a t i c v i s c o s i t y (rl/p)

rl

=

viscosity, P,

p

=

d e n s i t y , g/cm

Re

=

nd /v,

d

=

a g i t a t o r d i a m e t e r , cm, and

n

=

a g i t a t o r speed, r p s .

2

3

I

2

c m /sec,

,

dimensionless,

The s u b s c r i p t s 1 and 2 r e f e r t o s a l t and b i s m u t h , r e s p e c t i v e l y .

Figure

9 shows a c o m p ari s o n o f t h e measured v a l u e s o f mass t r a n s f e r c o e f f i c i e n t

with t h e Lewis correlation.

The e f f e c t s of m a s s t r a n s f e r resistance i n


36

ORNL DWG 14-633iR3

10000

1000

-I

qr (D

100

EXPERIMENTAL VALUES FROM ORGANIC -WATER

e

A

1.0 IO

Fig.

3.

[

B A S E D ON U BASED ON Z r

100 1000 6 . 7 6 x IOm6] [ R e i + Re2 772 71

-1

1.65

10000

E x p e ri m e n t al r e s u l t s from t h e s a l t - b i s m u t h c o n t a c t o r .


37

t h e b i s m u t h p h a s e c a n n o t be a c c u r a t e l y a c c o u n t e d f o r i n t h e results of r u n TSMC-2;

h e n c e , t h e s e r e s u l t s a r e n o t i n c l u d e d in F i g . 9 .

F i g u r e 9 shows t h a t two r u n s produced v a l u e s of mass t r a n s f e r c o e f f i c i e n t t h a t were 30 t o 40% of t h e v a l u e s p r e d i c t e d by t h e Lewis c o r r e l a t i o n , w h i l e t h e r e were two r u n s t h a t produced v a l u e s which were s l i g h t l y g r e a t e r t h a n t h o s e p r e d i c t e d by t h e Lewis c o r r e l a t i o n . c o e f f i c i e n t s based on z i r c o n i u m a r e c o n s i s t e n t l y lower t h e v a l u e s b as e d on uranium.

The m a s s t r a n s f e r

( s l i g h t l y ) than

I t i s f e l t t h a t the mass t r a n s f e r c o e f f i -

c i e n t s b as e d on zirconiuin a r e l e s s r e l i a b l e t h a n t h o s e b a s e d on uranium; i n a l l r u n s , o n l y a b o u t 60% o f t h e z i r c o n i u m t r a c e r c o u l d be a c c o u n t e d

f o r , whereas more t h an 80% of t h e uranium c o u l d be a c c o u n t e d f o r .

This

d i s c r e p a n c y i s p r o b a b l y r e l a t e d t o s e l f a b s o r p t i o n of t h e 7 4 3 . 3 7 keV from 9 7 Z r i n t h e b i s m u t h s a m p l e s .

6-

We b e l i e v e t h a t t h e i n i t i a t i o n of s a l t e n t r a i n m e n t i n t o - t h e b is m u t h

b e g i n s t o o c c u r a t a s t i r r e r speed between 160 and 180 rpm.

The a p p a r e n t

i n c r e a s e i n mass t r a n s f e r c o e f f i c i e n t i s a m a n i f e s t a t i o n of an i n c r e a s e i n t h e s u r f a c e a r e a f o r mass t r a n s f e r c a u s e d by s u r f a c e motion.

Experi-

ments w i t h wa t er-m e rc u ry and w a t e r - m e t h y l e n e bromide s y s t e m s s u p p o r t thFs belief. I f , a s Fig.

9 seems t o i n d i c a t e , t h e mass t r a n s f e r e o e f f i - c i e n t s i n

the s a l t - b i s m u t h s y s t e m a r e lower by a f a c t o r o f a b o u t 0.35 t h a n p r e d i c t e d by t h e Lewis c o r r e l a t i o n , t h i s c o r r e c t e d c o r x - e l a t i o n c o u l d be used

t o e s t i m a t e t h e a r e a and bismuth f l o w r a t e r e q u i r e d i n t h e r a r e - e a r t h removal c o n t a c t o r i n t h e p r e s e n t f l o w s h e e t .

The L e w i s c o r r e l a t i o n p r e -

d i c t s t h a t mass t r a n s f e r c o e f f i c i e n t : ; a r e a p p r o x i m a t e l y p r o p o r t i o n a l t o 15 t h e a g i t a t o r d i a m e t e r , d, t o t h e 3.30 power. S i n c e it h a s been shown

t h a t t h e a l l o w a b l e a g i t a t o r s p e e d below which t h e r e i s no phase d i s p e r s a l

i s i n v e r s e l y p r o p o r t i o n a l t o t h e 1..43 power of t h e a g i t a t o r d i a m e t e r , a t s p e e d s slightly below t h e l i m i t i n g a g i t a t o r s p e e d t h e mass t r a n s f e r c o e f f i c i e n t w i l l a p p a r e n t l y be p r o p o r t i o n a l t o t h e a g i t a t o r diameter t o t h e 0.94 power.

These r e s u l t s were u s e d t o estimate the area required f o r

a s i n g l e - s t a g e c o n t a c t o r and the b i s m u t h f l o w r a t e t o remove c e r i u m , which

has t h e s h o r t e s t removal t i m e (16.6 d a y s ) o f the r a r e e a r t h s i n t h e


35

reference flowsheet.

Fo r a s a l t f l o w r a t e o f 0.88 gpm ( c o r r e s p o n d i n g

t o t h e 10-day c y c l e t i m e used i n t h e r e f e r e n c e process f l o w s h e e t ) and a d i s t r i b u t i o n c o e f f i c i e n t o f 0.062

( t h e d i s t r i b u t i o n c o e f f i c i e n t t h a t was

u s e d i n t h e r e f e r e n c e p r o c e s s i n g f l o w s h e e t ) , a n area f o r mass t r a n s f e r of 10 f t

2

w i l l a l l o w removal o f c e r i u m on a 16.6-day c y c l e i f t h e b i s m u t h

f low r a t e t h r o u g h t h e c o n t a c t o r i s 30 gpm and a 3 - f t - d i m used.

T h i s b i s m u t h f l o w r a t e i s o n l y a b o u t 2-1/2

agitator is

t i m e s t h e f l o w rate

s p e c i f i e d i n t h e p r o c e s s i n g p l a n t f l o w s h e e t on t h e b a s i s o f e q u i l i b r i u m calculations.

The u s e of a h i g h e r d i s t r i b u t i o n c o e f f i c i e n t , m u l t i p l e

s t a g e s , e t c . , c a n r e s u l t i n a r e d u c t i o n of e i t h e r t h e b i s m u t h f l o w r a t e or t h e mass t r a n s f e r area.

These c h a n g e s , however, w i l l r e s u l t i n

c h a n g e s i n o t h e r s e c t i o n s of t h e f l o w s h e e t , a n d more e x t e n s i v e c a l c u l a t i o n s are r e q u i r e d t o e v a l u a t e t h e s e e f f e c t s .

5.

FUEL RECONSTITUTION DEVELOPMENT: D E S I G N O F A FUEL RECONSTITUTION ENGTNEERXNG EXPERIMENT R. M.

Counce

The r e f e r e n c e f l o w s h e e t f o r p r o c e s s i n g t h e f u e l s a l t from a m o l t e n s a l t b r e e d e r reactor (MSBR) i s b a s e d upon removal of uranium by f l u o r i n a -

t i o n t o UF

as t h e f i r s t p r o c e s s i n g step. The uranium removed i n t h i s 6 s t e p must s u b s e q u e n t l y be r e t u r n e d t o t h e f u e l s a l t stream b e f o r e i t r e t u r n s t o the reactor.

The method f o r r e c o m b i n i n g t h e uranium w i t h t h e

f u e l c a r r i e r s a l t ( r e c o n s t i t u t i n g t h e f u e l s a l t ) i s t o absorb g a s e o u s UF

6

i n t o a r e c y c l e d f u e l s a l t stream c o n t a i n i n g d i s s o l v e d UF

t h e reaction:

The r e s u l t a n t U F

5

would be re d u c e d t o UF

vessel according t o t h e reaction:

4

4

by u t i l i z i n g

w i t h hydrogen i n a s e p a r a t e


39

We a r e b e g i n n i n g e n g i n e e r i n g s t u d i e s of t h e fuel r e c o n s t i t u t i o n s t e p

in order t o p r o v i d e t h e t e c h n o l o g y n e c e s s a r y f o r t h e d e s i g n o f l a r g e r equipment f o r wecombining [JF

6

generated i n f l u o r i n a t o r s i n t h e processing

p l a n t w i t h t h e p r o c e s s e d fuel- s a l t r e t u r n i n g t o t h e r e a c t o r .

Equi.pmt?nt

f o r s t u d y i n g t h e f u e l r e c o n s t i t u t i o n process has been d e s i g n e d d u r i n g t h i s r e p o r t p e r i o d , and i s d e s c r i b e d i n t h i s r e p o r t . A f l o w d i a g ra m of t h e Pquipment

t o IF

u s e d f o r the Fuel r e c o n s t i t u -

t i o n engineering e x p e r i m e n t (FREE) i s shown i n F i g . 10,

The equipmetit

for t h i s e x p eri m en t c o n s i s t s of a 3 6 - l i t e r feed t a n k , a UF

vessel, a H

2

6

absorption

r e d u c t i o n column, a n e f f l u e n t stream s a m p l e r , a 3 6 - l i t e r

r e c e i v e r , MaF t r a p s f o r c o l l e c t i n g excess U F s u p p l i e s â‚Ź o r a r g o n , h y d r o g e n , and U F

streams from t h e r e a c t i o n v e s s e l s .

6'

6

and d i s p o s i n g of H F , yrls

and rncdns f o r a n a l y z i n g t h e gas

T h e e x p e r i m e n t i s operated by p r e s s u r i z i n g t h e f e e d t a n k w i t h a r g o n

i.n o r d e r to d i s p l a c e s a l t from t h e f e e d tamk t o t h e UF a t rates from 5 0 t o 300 cc/min.

i s s i p h o n ed i n t o the W

2

From t h e UF

6

absorption tank 6 ahsorp-tion t a n k , the s a l t

r e d u c t i o n column, a n d t h e salt t h e n f l o w s by

g r a v i t y t h r o u g h t h e e f f l u e n t stream sampler t o t h e r e c e i v e r . sa1.t will be LiF-BeF -ThF

4 taininc3 up t o 0.3-mole % UT 2

(72-16-12

The f e e d

mole 0 ) MSBR f u e l c a r r i e r s a l t con-

A b s o r p t i o n of [JF by r e a c t i o n with d i s 6 s o l v e d U F w i l l o c c u r i n t h e U F a b s o r p t i o n v e s s e l , and t h e r e s u l t a n t 4 6 IIF w i l l be re d u ce d w i t h hydrogen i n t h e I1 r e d u c t i o n c o l u m n . Uraniiim 5 2 h e x a f l i i o r i d e flow r a t e s from 60 t o 360 s c c / m i n , * and, H f l o w r a t e s from 4'

60 t o 7 2 0 scc/min w i l l b e u s e d .

2

The e f f l u e n t s a l t w i l l b e c o l l e c t e d i n

t h e r e c e i v e r f o r r e t u r n t o t h e f e e d t a n k a t t h e end of t h e r u n .

The o f f -

g a s from t h e a b s o r p t i o n v e s s e l and t h a r e d u c t i o n c o l u m n w i l l b e anal.yzed for UF

6

and HF, r e s p e c t i v e l y .

The s a l t i n t h e f e e d t a n k and s a l t samples

from t h e column e f f l u e n t s a l t w i l l be a n a l y z e d f o r uranium.

The p e r f o r -

mance o f t h e column w i l l b e d e t e r m i n e d from t h e s e a n a l y s e s .

The e f f l . u e n t

HF and any UF

p a s s i n g t h r o u g h t h e column w i l l be collected on t i l e NaF 6 trap's b e f o r e t h e gas i.s e x h a u s t e d t o t h e o f f - g a s s y s t e m ,

*

S t a n d a r d cubi-c c e n t i m e t e r s per m i n u t e .


40

1

ORNL DWG 74-11666

7

TRAP

ANALYSIS

Ar

-[

-

BUILD!NG OFF-GAS SYSTEM

EFFLUENT STREAM SAMPLER

uF6 ABSORPTION VESSEL

RECEIVER

FEED TANK

H2 REDUCTION COLUMN

Fig. 10. Flow diagram for equipment u s e d in fuel reconstitution engineering experiment.


41

The f u e l r e c o n s t i t u t i o n e n g i n e e r i n g e x p e r i m e n t w i l l b e i - n s t a l l e d i n t h e h i g h bay a r e a , Bldg. 7503 (MSRE: s i t e ) .

Scaffolding erected for a

previ-ous e x p e r i m e n t w i l l s e r v e t h e FREE equipment a d e q u a t d y

.

The s y s t e m ,

e x c e p t f o r t h e u p p er s e c t i o n of t h e column, wi1.1 b e e n c l o s e d hy a s p l a s h shield

e

The U F

a b s o r p t i o n v e s s e l w i l l have a n i n s i d e d i a m e t e r of 4 i n . and 6 a n i n s i d e h e i g h t of 11 i n . The v e s s e l w i l l be c o n s t r u c t e d from 4 - i n . s c h e d 4 0 n i c k e l p i p e mounted v e r t i c a l l y w i t h a 1 5 0 - l b s t a n d a r d Monel f l a n g e a t t h e t o p and a 0 . 2 5 - i n .

n i c k e l p l a t e bottom.

n o z z l e s p r o v i d e € o r s a l t f l o w i n and o u t of t h e v e s s e l . n o z z l e s p r o v i d e f o r UF,(g) 0

Two 1 / 2 - i n . Two .3/8-in.

f l o w i n a n d off-gas f l o w o u t of t h e t a n k .

r e d u c t i o n column w i l l h a v e a n o v e r a l l h e i g h t o f 1 1 5 i n . I t 2 i s c o n s t r u c t e d of l-1/2-in. s c h e d 4 0 n i c k e l p i p e mounted v e r t i c a l l y w i t h The I3

a 150-lb Monel f l a n g e on t h e u p p e r e n d , and a s c h e d 40 n i c k e l welded c a p a t t h e l o wer en d .

G a s e n t e r s through a 3/8-in.

a t t h e bottom, w h i l e 1/2-in.

and 3/8-in.

sched 40 n i c k e l s i d e a r m

n o z z l e s p r o v i d e for s a l t e n t r a n c e

and a n o f € - g a s e x i t . B ec au s e of t h e h i g h l y c o r r o s i v e n a t u r e of d i s s o l v e d UF m e r i t ex p o s e d t o s i g n i f i c a n t q u a n t i t i e s of UF

5'

a l l equip-

w i l l be g o l d or g o l d p l a t e d 5 a f t e r a s t a r t u p and d e m o n s t r a t i o n p e r i o d u s i n g t h e equipment. d e s c r i b e d

i n t h i s report. The 3 6 - l i t e r f e e d t a n k w i l l h a v e a n i n s i d e d i a m e t e r of 1 0 i n . and a n i n s i d e h e i g h t o f 33 i n .

I t will he a n i c k e l v e s s e l w i t h 0 . 2 5 - i n . - t h i c k

w a l l s , eq u i p p e d w i t h t w o l j 2 - i n .

two 3/8-in.

n o z z l e s €or s a l t e x i t and e n t r a n c e l i n e s ,

n o z z l e s f o r a r g o n s p a r g i n g a n d off-gas e x i t , and a 3/4-in.

samplitig p o r t .

T h e r e c e i v e r v e s s e l w i l l b e e s s e n t i a l l y i d e n t i c a l t o t:he

feed tank. A l l p i p i n g exposed t o t h e l i q u i d p h a s e

(MSBR c a r r i e r s a l t ) o r tempera-

t u r e i n e x c e s s of l00OC w i l l be n i c k e l pipe or t u b i n g . c a r r y i n g UF

6

or H F w i l l be n i c k e l t u b i n g .

copper tubing. tubing

(I

Off-gas l i n e s

A l l o t h e r g a s l i n e s w i l l bc

Off-gas l i n e s and l i q u i d p h a s e p i p i n g wi.l.1 be 1 / 2 - i n .


42

S t a n d a r d b r a s s v a l v e s ca n b e used t h r o u g h o u t t h e g a s s y s t e m , e x c e p t

or HF where n i c k e l b e l l o w s - s e a l v a l v e s a r e 6 S t a i n l e s s s t e e l , f u l l - b o r e b a l l v a l v e s w i l l b e used t o i n t r o -

on g a s l i n e s c a r r y i n g U F required.

d u c e t h e sample l a d l e s i n t o t h e f l o w i n g stream s a l t s a m p l e r . a b s o r p t i o n and f o r H F 6 These traps a r e i d e n t i c a l e x c e p t f o r t h e i . r l e n g t h s . The

Two sodium f l u o r i d e t r a p s a r e r e q u i r e d f o r U F absorption.

removal t r a p h a s a l e n g t h of 55-5/8 i n . , w h i l e t h e H F t r a p h a s a 6 l e n g t h o f 31-5/8 i n . The t r a p s a r e c o n s t r u c t e d o f 4 - i n . s c h e d 49 Monel

UF

p i p e mounted v e r t i c a l l y w i t h 1 5 0 - l b s t a n d a r d f l a n g e s a t b o t h e n d s for c h a r i n g a n d removing NaF p e l l e t s .

The g a s e n t e r s from l / 2 - i n .

nickel

t u b i n g t h r o u g h t h e f l a n g e d end and e x i t s t h r o u g h t h e lower f l a n g e d end. A 6-in.

s e c t i o n i n t h e lower end o f t h e t r a p c o n t a i n s 4-in.-diam

Monel

York mesh t o k ee p p e l l e t s from p l u g g i n g t h e e x i t . The e x p e r i m e n t w i l l be m o n i t o r e d by a n a l y z i n g t h e o f f - g a s from e a c h l e g of t h e column. for this.

GOW-MAC g a s d e n s i t y detectors are b e i n g c o n s i d e r e d

The d e t e c t o r e l e m e n t s of t h i s a n a l y s i s s y s t e m a r e n o t exposed

t o t h e measured g a s stream, which i n t h i s case i s c o r r o s i v e . The l i q u i d p h a s e w i l l be sampled p e r i o d i c a l l y by w i t h d r a w i n g e f f l u e n t -

stream s a l t s am p l e s from t h e hydrogen r e d u c t i o n column. v e r t i c a l l y mounted 3/4-in.

s c h e d 40 p i p e , 20-3/4

s t a i n l e s s s t e e l f u l l - b o r e v a l v e located 12-1/4

allow a c c e s s t o t h e f l o w i n g s a l t stream.

e n d , a g a i n u s i n g 1/2-in.

tubing.

s a l t f o r i n s e r t i o n of a s am p l e r .

i n . diam by 1 - i n . - l o n g low er end.

i n . i n length; it has a

i n . from t h e l o w e r end t o

The s a m p l e r i s v e n t e d t o t h e

o f f - g a s s y s t e m above and below t h e b a l l v a l v e .

lower end of t h e sampler from 1 / 2 - i n .

The s a m p l e r i s a

The s a l t f l o w s into the

t u b i n g and e x i t s 1-1/4

i n . from t h e

T h i s a s s u r e s a minimum of l / 4 i n . of The sampler i s a s t a i n l e s s s t e e l 0.250-

tube w i t h a 0.050-in.

I t i s connected t o a 1/16-in.

f r i t t e d metal f i l t e r on t h e

s t a i n l e s s s t e e l t u b e which i n

t u r n i s a t t a c h e d t o a vacuum pump. E n g i n e e r i n g s k e t c h e s â‚Źor a l l o f t h e equipment e x c e p t t h e U F have been completed.

supply 6 The s c a f f o l d i n g i n Bldg. 7503 i s b e i n g c l e a r e d t o

make room for t h i s e x p e r i m e n t .


43

6.

FSFERENCES

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H. C. Sa v ag e , E n g i n e e r i n g Development S t u d i e s f o r M o l t e n - S a l t B r e e d e r

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J . A. K l e i n e t al., MSR Program Semiannu. P r o g r . R e p t . Aug. 31, 1 9 7 2 , ORNL-4832, p . 1 7 1 .

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13. 0. Weeren e t al., E n g i n e e r i n g Development S t u d i e s f o r M o l t e n - S a l t B r e e d e r Reactor P r o c e s s i n g N o . 9 , ORNL-TM-3259 (December 1 9 7 2 ) r pp.

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.

p. 3 8 7 , Wiley, N e w Y O r k r

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W. K e e , and L . E . McNeese, E n g i n e e r i n g Development S t u d i e s f o r M o l t e n - S a l t B r e e d e r R e a c t o r P r o c e s s i n g N o . 8 , ORNL-TM3 2 5 9 (May 1 9 7 2 ) p , 6 4 .

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13. A. Han n a fo rd , C. W . K e e , and L. E. McNeese, Engineer-i.ng DevelopIr!& -S t u d i e s f o r M o l t e n - S a l t B r e e d e r Reactor P r o c e s s i n q N o . 9, ORNL-TM3 2 5 9 (December 1 9 7 2 1 , p . 158.

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W. 0. Weeren and L. E . McNeese, E n g i n e e r i n g Development S t u d i e s f o r M o l t e n - S a l t B r e e d e r R e a c t o r P r o c e s s i n g N o . 1 0 , ORNL-TM-3352 (December 1 9 7 2 ) , p. 53.

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Ha n n afo rd , E ri qi n e e r i n y Development S t u d i e s f o r M o l t;en-Salt Breeder R e a c t o r P r o c e s s i n g N o . 1 0 , ORNL-TM-3352 (December 1 9 7 2 ) , p . 1 2 .

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31, 1 9 7 2 ,



45

OKNL-TM-4863 UC-76 - Molten S a l t Reactor Technology INTERNAL DISTRIBUTION

1-2. 3. 4. 5. 6. 7. 8.

9. 10. 11. 12. 13.

14. 15. 16. 17. 18. 19. 20. 21.

22" 23. 24 25. 26. 27. 28.

29. 30.

31. 32. 33. 34.

35. 36. 37. 38 39. 40. 41-66, 67. e

MSW Director ' s O f f i c e C. F. B a e s , Jr. C. E . Bamberyer J . Beams M . Bender pa. R. B e n n e t t E. S. B e t t i s R. E. B l an c 0 J . 0. Blomeke E . G . Bohlmann

S

. Brauns t e i n

Bredig Briggs Bronstein Brooksbank Brown, ,Jr. Brown Brynestad C an t o r W Cardwell L. Carter H . Cook M . Counce L . Crow]-ey L. C u l l e r

M. A. R. B . H . R. R. E . C. H. K . B.

J.

S. D W. W. I

H.

3. F.

.

J. M.

Dale

F. L. Daley J . H . DeVan J. R. D i S t e f a n o W. P . Eatherly K . L . Eyli, ERDA-OSR J . R. Engel G . G. Fe e D. E . Fergiison I,. M. F e r r i s L. 0. G i l p a t r i c k J. C. Griess W. R. G r i m e s R. H . Guymon J . R. Hi g h t o we r, Jr. R . F. Hitch

68. 69.

70. 71. 72.

73. 74. 75. 76. 77. 73 79. 80. 81. s

82. 83 * 84. 85. 86 87.

R. W. C. A. J. W.

R. R.

W. H. A. C. A. R.

J.

K.

-

R. B. M. A.

88.

13.

90. 9 1* 92. 93

f

94. 95. 96. 97. 98. 99. 100. 101. 102. 103-105. 106 107-116 I

I

117.

c.

W. R. W.

Norton Huntley

Kee

D. K e l m e r s

Klein Laing Lindauer MacPhcrson C. McClain E. McCoy P . Malinauskas 1,. Matthews I EKDA-OSR S . Meyer T,. Moore P. Nichols J . Notz 0 . Payne Postma W. Rosenthal D . Ryon C . Savage D. S c o t t J . Skinner J . Smith P . Smith Spiewak G. S t e w a r t K . 'l'allcnt

A. R. B. E.

M. F. G. I. M. 0. L. M. D. B. W. E , J . R. M. K . R. G.

Toth

Trauger Unger Weir Wilkinson

Wymer

C e n t r a l Research L i b r a r y Document R e f e r e n c e S e c t i o n L a b o r a t o r y Records L s l m r a t o r y Records (OPJL-RC)


46

CONSULTANTS AND SUBCONTRACTORS 118. 119. 120. 121. 122.

J. C. J. W. R.

C. H.

Frye

Ice

J. K a t z

K. Davis B. R i c h a r d s

EXTERNAL DISTRIBUTION

123. 124. 125-126. 127-230.

R e s e a r c h and T e c h n i c a l S u p p o r t D i v i s i o n , ERDA, Oak Ridge Operat i o n s O f f i c e , P. 0. Box E , Oak Ridge, Tenn. 37830 Director, Reactor D i v i s i o n , ERDA, Oak Ridge O p e r a t i o n s O f f i c e , P . 0. Box E , O a k R i d g e , Tenn. 37830 Director, ERDA D i v i s i o n o f Reactor R e s e a r c h and Development, Washington, D. C. 20545 F o r d i s t r i b u t i o n as shown i n TID-4500 u n d e r IJC-76, Molten Salt R e a c t o r Technology


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