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3 4456 0049243 B


I

Printed in the United States of America. Available from National Technical Information Service U S . Departrrient of Commerce 5285 Port Royal Road, Springfield, Virginia 22161 Price: Printed Copy $4.08; Microfiche $2.25 ~~

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 Administration, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any walranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness or usefulness of any information, apparatus, product or process disclosed, or lepiewnts that its use would not infringe piivately owned rights


UC-76

Contract

NO.

-

ORNL/ TM-48 94 Molten S a l t Reactor T e c h n o l o g y

W-7405- eng-26

CHENI CAI, TE CHTiOLOGY D I V I S I O N

ENGINEERING DEVELOPMEFT S'SIITDES FOR MOLTEN-SALT BREEDER REACTOR PROCESSING NO. 2 1

Compiled by:

J. R. H i g h t o w e r , Jr. Other C o n t r i b u t o r s :

C. H. Brown, Jr. E. M. Coimce X. 9. Lindauer

8. C.

Savage

MARCH 1976

NOTICE This document contains information of a preliminary nature and was prepared primarily for internal use a t the Oak Ridge National Laboratory. It

IS subject

to revision or correction and therefore does

opemted by 3 4 4 5 6 0049243 8 UNION CARBIDE COREORATION for the ENERGY RESEARCH AND DEVELOFMENT ADMINISTRATION


ii

R e p o ~ t spreviously i s s u e d i n t h i s s e r i e s a r e as follows:

ORNL-TM-3053

Period endi.ng December 1968

ORNL-TM- 3137

Period ending March 1969

0RNT;-TM-3138

Period endi.ng June 1969

ORNL-TM-3139

Period ending September 1969

ON?L -4T4- 314 0

Period ending December 1.369

ORNL-'L'M-32$7

Period endi-ng June 1970

ORNL-TM-3141

ORNL-TM-3258

Period ending March 1970 Period ending September

1970

ORNL-TM-3259

Period endi-ng December 19'90

OIUL-TM-33 52

Period end-ing March 197'1

0RN~-'1~-469 8

Period January through June 1974

ORNL-I'M-4 ORNL-'PTUI-

863

4 870

Period. J u l y through September 1974

Pejriod October through Decenber 1974


iii CONTENTS

SUMMBRLES.. 1. INTRODUCTION 2.

............ ......... ........................ c

t

.

.

,

4.

v 1

COIUINUOUS FLUORITWTOR DEVELOPMENT : AUTORESIS'L'MVCE HEATING TEST AHT-4

1

2.1

2

.......................... Decontamination o f AHT-3 Test Vessel. . . , . . . . . .

2.2 Design of Equipment for Autoresistsnee Heating Test AHT-4

3.

Page

.......,.. Status of Metal Transfer Experinlent MTE-3B. . . . . . . ,

2

DEYELOPMENT OF TKE KETAL TWVSFER PROCESS.

10

3.1

LO

S,LVI'L"-METP.L CONTACTOR DEVELOPiXENT : EXFEHIMENTS WITH 4 blECKPNICALLY AGTTYl-TED, NONDISPEnSING CONTACTOR IX THE SALTBISfjrUTIZ F'L OWTIIfiOUGd FAClL1TY

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

4.1 Preparation rs1m-9,.

for

.....

Transfer Fkperiments TSMC-8and

r d h s s e

.

4.2 Experhen-La1Operation.

4.3

~ s s sTransfer R c s - d t s

e

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

12

13

13

14

5. SA.LT-~VEL'AL CONTACTOR DEVELOPMENT :

EXI'EFiIbEMTS IrllTIi. A PECHILN1CAI;LY AGITATED, NONDISPERSING CONTACTOR USING WATER AJiD MENCURY a

5.1 5.2

Run:: a t Elevated Temperatures with the Lead Ion-Zinc

Amalgarri S y s t e m .

.......... .. ....... a

P o l a r o g r a p h i c D e t e r m i n a t i o n of Mass T r a n s f e r Coefficients

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

5.2.1 Theory . Experimental equipment 5.2 3 Experimental results

5.2,2 e

6.

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

FUEL RECONSTITUTION DEVELOPMENT: INS'I'ALLATIONOF' EQUIPMErJT FOR A FUEL RECONSTITIJTION E3GINEERIXG EXPERLiMXNT ,

.. .... 6.1. Gas Supply Systems. . . . . . . . . . , . . . . . . . 6 . 2 Eyuiprnent Installation. . . . . . . . . . . . . . . . . 6.3 Hz-HF Treatment of Salt from Autoresistance Heating Tests

'I.

REFERENCES

21

22 2% 22

24 24 26 27

28 35


CONTIWOUS FLUORiNATOR DEVELO-WNT :

HEATING TEST AHT-4

AUTORE SISTANCE

After completion of the third autoresistance heating test (AHT-3),

the system was dismantled and the test vessel in the next test, RHT-4.

was

decontaminated f o r use

Design and fabrication for the other vessels

to be used in AHT-4 were completed and installation was begun. DEVELOFNENT OF THX METAL TRANSFER PROCESS

Engineering experiments to study the steps in the metal transfer

process for removing rare-earth fission products from a molten-salt breeder reactor fuel salt will be continued-in experiment MTE- 3B.

During

this report period, we completed preoperational testing of Yne facility; charging of the salt and bismuth phase to the process vessels is in

progress.

SALT-METAL CONTACTOH DEXELOFNEI'T": EXPERIMENTS WITH A MECHANICALLY AGITATED, WOlVDISPERSiNG CONTACTOH In THE SALT-BISMUTH FLOWTHROUGH FACILITY

The eighth and ninth tracer runs (TSMC-8 and -9) were completed in

the mild steel contactor installed in the salt-bismuth flowthrough

facility in Bldg. 3592.

The agitator drive assembly failed to operate

properly during run TSMC-8,

The assembly was dismantled, repaired, and reassembled, with resultant satisfactory operation. Run TSMC-9 was made at a high agitator speed (244 rpm) to determine both the mass transfer coefficient m d e T conditions in which s a l t is dispersed into the bismuth, and if large amounts of bismuth and salt are entrained in the other phase. The mass transfer coefficient was 0.121 IO.108 cm/sec, which is 178% of the Lewis correlation. A11 the data suggest that when the phases are not dispersed, the effect of agitator speed on the mass transfer coefficient is less than that predicted by the Lewis correlation.


vi SALT-mTAL CONTACTOR DELTI,OPMElNI : FXPlCl{IMEIVTS WlTH A MECHANTCALLY AGTTATED, NONDISPhKdlNG CONTACTOR USING WA'L'EH AND MERCUlIY Mass t r a n s f e r r a t e s between water and. mercury have been measured i n

a mechanically a g i t a t e d contactor using . h e r e a c t i o n : Pb2+(Q0)

+

Zn(Hg) -., Z%?(H,O)

f

Pb(Hg)

,

which was assumed t o be instantaneous, irj?eversibl.e, and occurring e n t i r e l y a t the wa ter-mercury i n t e r f a c e .

Several. rims were made i n t h e water-mercury coiltactor at an elevated

temperature (- 40째C) t o t e s t the v a l i d i t y o f t h e assumption t h a t t h e

i n t e r f a c i a l r e a c t i o n given above i s instantaneous.

runs were inconclusive.

Results from thcse

I n v e s t l g a t i o n was i n i t i a t e d t o determine i f polarography i s a via,ble a l t e r n a t e method for measuring mass ti-ansfer rates i n a 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 using mercury and an aqueous e k c ' t r o l y t e solution.

Several

e l e c t r o l y t e s o l u t i o n s were investigated, but none were found t o be

e n t i r e l y i n m t t o mercury. t h a t a Fe"-Fe"+

Informat?.on foimd i n t h e l i t e r a t u r e suggested

redox couple (using i r o n corn-plexed wfth o x a l a t e i o n s )

may be s u i t a b l e as an e l e c ' t r o l y t e f o r o u r a p p l i c a t i o n .

Fui-t'ler t e s t s

w i l l be p e r f o m e d to determine i f the i r o n e l e c t r o l y t e w i l l produce s u i t a b l e polarograms

.

PVET, m C O N S T i T U T T O N DEVELOFMENT : 1NSTALLATlON OF EQUIPPFBT FOR A F T L RECONSTITUTlON HNGIIWERTNG EXPERTMENT

S a l t used 5.n experi-ment ART-3 was t r e a t e d with & and KF t o remove

oxides.

ments.

This s a l t will be used i.n t h e f i . r s t f u e l r e c o n s t i t u t i o n e x p m i -

I n s t a l l a t i o n o f t h e f u e l recons'Litution expeyimental equipment

i s continuing.


1

1. IT\PTKOIIUCTION A molten-salt breeder r e a c t o r (MSBR) w i l l be f u e l e d d t h a, molten

f l u o r i d e mixture t h a t will c i r c u l a t e through t h e blanket and core regions

of' t h e r e a c t o r and through t h e primary h e a t exchangers. We a r e developing processing methods for use i n a close-coupled f a c i l i t y for removing f i s s i o n products, c o r r o s i o n products, and f i s s i l e m a t e r i a l s from t h e

molten f l u o r i d e mixture.

Several operations a s s o c i a t e d with MSBR processing a r e under study. The remaining p a r t s of t h i s r e p o r t discuss: decontamination of t h e t e s t v e s s e l used i n a u t o r e s i s t a n c e h e a t i n g t e s t AHT-3,

and t h e design o f equipment for auto-

r e s i s t a n c e h e a t i n g t e s t ANT-4;

progress on i n s t a l l a t i o n of metal t r a n s f e r experiment IJTE-3B; measurements of mass t r a n s f e r of

2 3 7 ~and 97

Z r from MSBR fuel

c a r r i e r s a l t t o molten bismuth i n a mechanically a g i t a t e d

cont ac t o r ; results of an i n v e s t i g a t i o n t o determine i f polarography i s a

s u i t a b l e method f o r measuring water-side mass t r a n s f e r c o e f f i -

c i e n t s i n a mechanically a g i t a t e d c o n t a c t o r operating w i t h water and mercury; and d e s c r i p t i o n of equipment to be used i n engineering s t u d i e s o f

fuel reconstitution. 2'his work was performed i n t h e Chemical Technology Dtvision during t h e pes5od January through March 2.

1975.

CONTINUOUS FLUORINATOR DEVELOPI4EXV AUTORESISTANCE â‚Ź E A T I N G TEST AHT-4

R. B. Lindauer After completion of t h e t h i r d a u t o r e s i s t a n c e h e a t i n g t e s t (RHT-3),

t h e system w a s dismantled and t h e t e s t v e s s e l was decontaminated f o r

use i n t h e next t e s t , AHT-4.

Design and f a b r i c a t i o n f o r t h e o t h e r ves-

sels t o be used i n AHT-4 were completed and j n s t a l l a t i o n w a s 'begun.


2

2.1

Decontanination of AW-3 Test Vessel

The t e s t v e s s e l was cleaned by t r e a t i n g i.t with hot oxalic: a c i d i n an open steam-heated vat.

(%

6%

200'F)

I n o r d e r t o submerge t h e v e s s e l

completely i n t h e lit- t o 20-in. depth of solution, it was f i r s t necessary t o c u t the v e s s e l below t h e e l e c t r o d e s i d e arm, since 'chis s i d e arm and t'ne g a s - i n l e t s i d e arm a r e not i n t h e same plane. which contained a 2-in.

'The bottom o f .the vessel,

salt heel, was removed before immersion.

3 days, the s o l u t i o n was drained and t h e vessel. was inspected.

After

Salt

remained below t h e g a s - i n l e t side am, and t h e el.ectrode was still s e c w e d i n t h e s i d e arm by some r e s i d u a l salt.

Evidently t h e s a l t had contained

s u f f i c i e n t : c r u d t o prevent complete drainage through tize side-arm d r a i n \

o f Ync m a t e r i a l taken from below t h e gas in7.e-t contained.

A sa&e

line.

58% thorium. The v e s s e l was t r e a t e d for an. a d d i t i o n a l 3 d.a.ys i n a second o x a l i c

a c i d bath.

It was t h e n possib3.e t o remove the e l e c t r o d e and c h i p o u t the

remaining s a l t i n t h e side arme

able transferable activity.

A survey of t h e v e s s e l revealed. consider-

The v a t w a s cleaned and t h e v e s s e l was t r e a t e d

with a s o l u t i o n of' ammonium o x a l a t e and Versene.

A f t e r t h i s treatment, t h e

metal surface had a shiny m e t a l l i c appearance, compared W i t h the d u l l , powdery look on t h e surface a f t e r Vne o x a l i c acid treatment,s, o x a l a t e treatment was made followed by wet sand b l a s t i n g , showed

2.2

<

A Ynird

A f i n a l survey

200 dpm o f transfera,ble a c t i v i t y .

Design of Equipment f o r Autoresistance Heating Test AIiT-4

The next t e s t o f a u t o r e s i s t a n c e h e a t i n g f o r t h e frozen w a l l f l u o r i n a t o r w i l l use a c i r c u l a t i n g s a l t system t o h e l p prevent complete f r e e z i n g i n tine L

L e s t

vessel.

e"'

flowsheet f o r t h i s t e s t is shown in. Fig. 1.

S a l t flows

from t h e surge tank t o tine gas-1.iqui.d s e p a r a t o r by means o f an aygon gas lift.

The s a l t then

flows by g r a v i t y t o t h e test v e s s e l wliere it e n t e r s

through a s p e c i a l i n s u l a t e d f l a n g e and t h e electi*ode.

'The s a l t leaves

t h e bottom of' the t e s t v e s s e l and passes through a h e a t flowmeter before being returned t o t h e surge t a n k tnrough anot'nel- i n s u l a t e d flange.

The

i n s u l a t e d flanges are water-cooled t o permit %he use o f Teflon gaskets.

The b o l t s a r e i n s u l a t e d by a &&elite sleeve and Teflon washers, a s shown


z 0

w NW

w2 . _ I

-4 N A

3

v)

3

U W

w

i-


4 i n Fig. 2.

The r e t u r n l i n e has a d e f l e c t o r a t the point a t which 5 - t e n t e r s

t h e surge tarilk t o prevent s h o r t - c i r c u i t i n g across the l i q u i d stream (Fig. 3). 'The surge tank and separator aze, .therefore, a t t h e same e l e c t r i c a l poten-

t i a l as t h e e l e c t r o d e and must be irisul-ated from k h e equi.prnent supports. Gas l i n e s t o t h e s e two v e s s e l s have i n s u l a t e d sections.

An air-cooled

f r e e z e valve i s l o c a t e d i n t h e l i n e between t h e szparator and t h e t e s t v e s s e l t o make it p o s s i b l e t o t r a n s f e r t h e molten s a l t from the t e s t

v e s s e l t o t'ne surge tank a f t e r a rim bo determine t h e film thickness. The i n d i v i d u a l equipment pieces a r e described below. Test v e s s e l .

The t e s t v e s s e l i s the same one used i n AHT-3.

After

draining s a l t from t h e l a s t run, iiispection o f t h e vessel. revealed about

11 l i t e r s o f m a t e r i a l khich f a i l e d t o drain.

This was due p a r t l y t o

ruinback, but was p r i m a r i l y caused by p.l.u.gging of t h e side-arm d r a i n l i n e

with impwitlies (oxides and s t r u e t w - a l metal f l u o r i d e s ) which had accumulated over the past 2 years.

The bottom 6-1/2 in. o f the v e s s e l

was f i l l e d wlith s a l t and was c u t o f f .

Another c u t was made below t h e

e l e c t r o d e s i d e a m t o allow subm-ergelice i n an open vat.

The t e s t v e s s e l

w a s t r e a t e d w i t ' ? a hot (- 200째F) 6% o x a l i c a c i d s o l u t i o n f o r '-1 days, and h o t arrmonium oxal-ate f o r 2 days. t h e cleaning.

The s o l u t i o n was changed twice during

Cleaning w a s complicated by t h e s a l t remaining i n t h e

e l e c t r o d e s i d e a m which prevented removal o f t h e e l e c t r o d e and flange. 'This a l s o prevented c i r c u l a t i o n of the oxaI.ic a c i d t'nrough t h e s i d e arm.

A f t e r t h e e l e c t r o d e was broken loose, t h e r e s i d u a l s a l t was broken up

manually and decontamination was completed.

New h e a t e r s and cooling c o i l s

have now been i n s t a l l e d . on t h e t e s t v e s s e l f o r b e t t e r c o n t r o l o f temperature.

The electrode, Fig. 4, i s sj-mil-ar t o t h a t used i n AHT-3, but with

an open-end pipe f o r s a l t flow.

6).

Fluoride-salt surge tank (Figs. 5 and

This i s a dual diameter

v e s s e l with a lower s e c t i o n o f G i n . sched ),LO n i c k e l pipe, 46-i.n. long; t h e upper s e c t i o n i s 1/8-in-tliick nickel, high.

24

in. i n diameter by I.l-in.

The long 6-in. s e c t i o n provides ample submergence for t h e gas

l i f t , while t h e l a r g e diameter upper s e c t i o n provicies sufficien'i capacity

t o contain t'ne s a l t from t h e e n t i r e system.

R s e n s i t i v e (0.20 ?.ne o f

water) l i q u i d - l e v e l 5.zistrument i n the l.arge diameter s e c t i o n w i l l iiidica,te


5

L P

-


6

k 0

(H

d


PHOTO 004675

F i g . 4. Electrode to be used in test vessel of autoresistance heating test AHT-4.


CD

Lo h I

m

0 0 I-

0

8 n

8

I

k 0


9


10 any unusual buildup of s a l t a t t h e t o p of t h e t e s t v e s s e l o r separator, a s well as providing a means f o r measuring t h e volume of t h e frozen s a l t f i l m a f t e r a t e s t run.

Gas-liquid separator.

This i s an 8-in.-diam

by 12-ln.-high

cone-

bottom n i c k e l v e s s e l containing an 8-in. -deep demister of n i c k e l Yorkmesh.

Two b a f f l e p l a t e s a r e l o c a t e d below t h e Yorkmesh f o r s e p a r a t i o n

o f t h e bulk of t h e argon and s a l t from t h e gas l i f t .

A differential

pressure instrument w i l l d e t e c t any l i q u i d buildup i n t h e bottom o r any excessive pressure drop across t h e separator.

A thermowell i s l o c a t e d

i n t h e Yorkmesh which w i l l be maintained above t h e melting p o i n t o f t h e salt. Heat flowmeter. a 28-in.

The s a l t leaving t h e t e s t v e s s e l passes through

s e c t i o n o f 2-in.

n i c k e l pipe containing a c a r t r i d g e h e a t e r .

Heat loss from t h e flowmeter (Fig. 7) w i l l be balanced by e x t e r n a l

heaters.

The i n t e r n a l h e a t e r can be operated on e i t h e r 120 V (750 W)

o r 240 V (3000 W),

depending on t h e s a l t flow r a t e .

A temperature r i s e

of about 1 0 째 C through t h e flowmeter w i l l i n d i c a t e a s a l t flow r a t e of e i t h e r 0.9 o r 3.6 l i t e r s l m i n , depending on whether t h e voltage applied t o t h e c a r t r i d g e h e a t e r i s 120 V o r 240 V.

3.

DEVELOPMENT O F THE METAL TRANSFER PROCESS H. C. Savage

Engineering experiments t o study t h e s t e p s i n t h e metal t r a n s f e r process f o r removing r a r e - e a r t h f i s s i o n products from a molten-salt breeder r e a c t o r f u e l s a l t will be continued i n experiment MTE-3B.

1

During t h i s r e p o r t period, we completed p r e o p e r a t i o n a l t e s t i n g of t h e f a c i l i t y , and t h e charging o f t h e s a l t and bismuth phases t o t h e process v e s s e l s i s i n progress.

3.1

Status of Metal Transfer Experiment MTE-3B

A r t e r i n s t a l l a t i o n , t h e t h r e e process v e s s e l s ( f l u o r i d e f i e 1 salt

r e s e r v o i r s , contactor, and s t r i p p e r ) were heated t o t h e design operating

6 5 0 " ~under an i n e r t gas (argon) atmosphere, and were pressure t e s t e d a t 15 psig. The carbon s t e e l v e s s e l s were t h e n hydrogen temperatures o f


PHOTO 0043-75 -

Fig. 7 .

Heat flowmeter used i n a u t o r e s i s t a n c e h e a t i n g t e s t AHT-4.


12 treated for surfaces.

-7

h r s while a t 6 5 0 " ~t o remove oxides from t h e i n t e r n a l

Addition of t h e s a l t and bismuth phases t o t h e process v e s s e l s

w a s then begun.

A l l a d d i t i o n s were made from a u x i l i a r y charging tanks,

and c a r e was taken t o prevent contamination of t h e m a t e r i a l s before and during t r a n s f e r i n t o t h e process vessels.

Finally, a l l s a l t s and bismuth

were f i l t e r e d through a s i n t e r e d molybdenum f r i t (- 30-11 mean pore diameter)

as t h e y were t r a n s f e r r e d from t h e charging v e s s e l s i n t o t h e process v e s s e l s t o remove any p a r t i c u l a t e s (such a s oxides). To date, we have completed t h e following a d d i t i o n s t o t h e MTE-3B process v e s s e l s :

(1) (2)

61.7

The bismuth was

kg of bismuth t o t h e c o n t a c t o r v e s s e l .

hydrogen t r e a t e d a t 650"c t o remove oxides.

110.6 kg of f u e l c a r r i e r s a l t (72-16-12mole % LiF-BeF,-ThF4)

t o t h e c o n t a c t o r and t h e f u e l - s a l t r e s e r v o i r .

Before being

added t o t h e system, t h e f u e l s a l t was sparged i n t h e charging v e s s e l with argon f o r 42 h r while i n contact with bismuth which contained thorium. The charging v e s s e l used for t h e bismuth and f u e l - c a r r i e r s a l t

A new charging v e s s e l i s being i n s t a l l e d

a d d i t i o n s has been removed.

t o f a c i l i t a t e t h e a d d i t i o n of a m i x t u r e of bismuth containing 5 a t .

%

of l i t h i u m t o t h e s t r i p p i n g vessel, and t h e l i t h i u m c h l o r i d e a d d i t i o n t o t h e contactor and s t r i p p e r .

4. SALT-METAL CONTACTOR DEVELOPMENT EXPERIMEXTS W I T H A MECHANICALLY AGITATED, NONDISPERSING CONTACTOR I N THE SALT-BISMUTH FLOWTHROUGH FACILITY C.

H. Qrovn, Jr.

Ve have continued operation of a f m i l i t y i n vhich mass t r a n s f e r

r a t e s between molten LiF-BeF,-ThF,

(72-16-12mole %)

and molten bismuth

can be measured i n a mechanically a g i t a t e d , nondispersing c o n t a c t o r of t h e "Lewis" type.' t o date.

A t o t a l of nine experimental runs have been completed

Results from t h e f i r s t seven runs have been previously reported. 394

Preparation f o r and results obtained from t h e e i g h t h and n i n t h runs, TSMC-8

and -9, r e s p e c t i v e l y , a r e discussed i n t h e following sections.


14.1

Preparation Tor Mass Transfer Experiments TSMC-8 and TSMC-9

__i n preparation f o r each o f t h e r i m s made during 'cinis re-port period, i.t was necessary t o :

(1)add beryllium t o t h e s a l t t o afiju-st t h e uranium

d i s t r i b u t i o n c o e f f i c j e n t ; ( 2 ) contact t h e s a l t and bi.smu.th by passing

both phases through the mi1.d s t e e l contzctor to ensure t h a t chemical equilibrium was achieved between t h e s a l t and bismuth; and

( 3 ) add a

s u f f i c i e n t q u a n t i t y of' a37U t r a c e r t o t h e salt while it was i n t h e salt

feed tank.

The experimental procedure t h a t was fo1l.owed i.n t h e f i r s t

s i x ~ u n shas been previously m - p r t e d , 3 and was followed i n th.e l a s t

tl1ree

'TUlS.

4.2

Experimental Operation

Rim TSMC-8 w a s performed with s a l t and bismuth flow r a t e s o f 1 5 2 c c /

min and 164 cclmin, r e s p e c t i v e l y .e ' T

uranium d i s t r i b u t i o n c o e f f i c i e n t

was m a i n t a h e d a t a high l e v e l (> 140) f o r t h i s rim, whi.ch, a s has been

previously discussed, i s g r e a t e r than t'ne minimum d e s i r e d value o f 20.

%he a g i t a t o r was thought t o have been operated a t 241. rpm, which i s high

enough t o produce mild d i s p e r s i o n of t h e phases i n t h e contactor and,

therefore, r e s v J t s in a 'high measlured mass t r a n s f e r r a t e .

Results from

thi.s run, howe-ver, i n d i c a t e d t h a t -fery l i t t l e (-- 2576) o f t h e ' " U

was a c t u a l l y t r a n s f e r r e d from t h e salt t o t h e bisrnixtln.

tracer

'inspection o f t h e

magnetically coupled a g i t a t o r d r i v e assembly i n d i c a t e d t h a t an acciaiulation of

c2 highly

viscous, carbonaceous R a t e r i a l between t h e upper carbon bearing

and t h e a g i t a t o r d r i v e shaft had prevented proper r o t a t i o n of" ?ne s h a f t . The d r i v e assembly operated s a t i s f a c t o r i l y af'ter it was cleaned o f all.

â&#x201A;Źoreign m a t e r i a l and. reassembled. The n i n t h tracer rim, TSMC-9, TW..

w a s performed as a, repeat o f t h e eighth

169 ec/min and 161t cclmin, at 244 rym d.uring t h i s run.. A

S a l t and bismuth flow m t e s were s e t at

respectively.

The a g i t a t o r vas operated

high s t j - r r e r r a t e was maintained i n order t o determine t h e e f f e c t s of

d i s p e r s a l of one phase i n t h e o t h e r on t h e mass t r a n s f e r r a t e , and t o

determine i f l a r g e amounts o f bismuth and s a l t a r e e n t r a i n e d i n t h e o t h e r

phase a f t e r gassing through t h e s m a l l s e t t l i n g chamber i n t h e contactor

eff"luent l i n e .

The uranium 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 g r e a t e r than

47


14 during t h i s run.

No systematic probl.ems weye encountered and t h e run

was performed smooth1.y.

IC. 3 F4ass Transfer Results The samples taken during both r u n s were analyzed by f i r s t counting t h e sample capsules f o r t h e a c t i v i t y of 237U

(207.95 keV p-).

The

m a t e r i a l i n t h e sample capsules w a s then dissolved, and t‘ne , z c t i v i t y o f

“37U was counted agaix.

The counting d a t a obta.ined i n t h i s manner f o r

runs TSMC-8 and TSMC-9 a r e shown in ‘Tables 1 am?. 2, respectively. Operating condi.t,i-ons and mass t r a n s f e r resid-ts f o r runs TSMC-8 and

-9, and

t h e r e s u l t s from runs TSMC-2 through

-‘I

a r e summarized i n Table 3.

‘i‘he sa.1.t-phase mass t r a n s f e r c o e f f i c i e n t was c a l c u l a t e d us?-ng t h r e e

d i f f e r e n t equations derived frov an o v e r a l l mass balance around the

contactor.’

The average measured mass t r a n s f e r c o e f f i c i e n t , wit2n t h e

corresponding standard deviation, i s reported i n Table 3. A s previously discussed, t h e agi-tator f a i l e d t o operate properly i n

run TSMC-8, which explains t h e r a t h e r l o w mass tramsfer r a t e measured

during t h i s run, 0.0022 i 0.0010 cm/sec.

The measured mass t r a n s f e r

c o e f f i c i e n t obtained i n r u n TSMC-9 i s 0.121 & 0.1.08 cm/sec, which

corresponds to

178% of t h e Lewis c o r r e l a t i o n .

A s shown by t h e high value

f o r t h e standard deviation, t h e t h r e e determinations f o r t h e mass t r a n s f e r coefficient d i f f e r greatly.

One possi.bl.e explanation f o r t h i s i s t h a t

t h e 237U t r a c e r balance around. t h e c o n t a c t o r showed c l o s u r e .to within

only 5%.

A Lewis p l o t o f t h e r e s u l t s from the six runs which have produced

meaningful. r e s u l t s i s shown i n Fig. 8. is:

k

=

v Re

= =

“he nomenclature used i n Fig. 8

individual phase m a s s transrer c o e f f i c i e n t , cm/sec, 2

kinematic v i s c o s j t y , em /see, Iieynolds Number (ND2 /v), dimensionless,

D = s t i r r e r diameter, em, N

=

s t i r r e r r a t e , l/sec,

s u b s c r i p t s 1, 2 = phase being considered.


Table 1. Counting data o b t a i n e d from r u n TSKC-8 ~~

Sample

code&

358-3-5 35943-5 362-~-1 363-3-1

Solid a n a l y s i s for 237u

i counts/ g)

< 1.7

-< 1.4

1.27 1.25

103 103

lo3

lo3

Solution analysis

for 237s

(counts/g)

Sample codea

Samples t a k e n prior to run

4.18 4.33 4.51 4.06

103 103 103

103

35643-5 357-s-5 360-S-3 301-5-3

Solid a n a l y s i s f o r 2 3 7~ Ccounts/g1

<

3.8

74.8 -

< 4.7 c 4.8

-

x

for 2 3 7 ~ (counts/ g)

lo3

103

x 103

103

Samples taken p r i o r to run b u t after a d d i t i o n of t r a c e r

364-5-3 365-5-3

Solution analysis

2.35 x. 106 2.41 x

lo6

2-89 x 106 2.91 x l o 6

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

366-B-FS 367-B-FS 368-B-FS 369-B-FS 370-B-FS 371-B-FS 372-B-FS ~~o-B-I

381-E-I.

382-B-2 383-B-2

388-B-5 389-E-5

2.74 x 103 9.18 lo3 2.66 x l o 4 2.43 104

2.36 x lo4 2.99 io4 3.06 x 10"

4-78 1 0 3 4.81 x lo3

1.51

104

1.56 x l o 4

1 . 2 2 x 105

1.39

105

LOO 3.21

io4 io4 lo4

8.69 x

io4 lo4

8,88 x 8.03 x 9.59

1.06 x

104

105

373-S-FS 374-s-FS 375-S-FS 376-S-FS 377-S -FS 378-S-FS 379-s-Fs

3.04 x 105 9.45 105 1.76 x l o 6 2.08 x 1 0 6 1.94 x l o 6 1.90 x l o 6 2.43 x 1 0 6

Samples t a k e n a f t e r run

1.57 x 104

1.48 x 5.22

4.07

104 104

104 3.19 x los 3.66 x I O 5

384-s-3 385-S -3 386-S-4 387-S-4 390-5-5 391-S 5

-

2.28 x 106 2.19 x 106 1.77 x 106

1.80 x 1 0 6 < 1.0 x 104 < 1.2 x 1 0 4

-

3.73 x 10s

1.02 x 1 0 6 2.14 x l o 6 2.29 x l o 6

1.90 x

2.18 x

lo6 lo6

2.34 x 106

2.67 x 1 0 6 2.48 x 106

2.15 x 106

2,35 x

lo6

< 2.4 x 104 < 2.4 x 104

a Each sample i s 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 to A - 3 4 , where A = sample number; B = material i n sample ( E = b i s m u t h , S = s a l t ) ; and C = sample o r i g i n : 1 = T1, 2 = T2, 3 = T 3 , 4 = T4, 5 = T5, FS = f l o w i n g stream sample.


Table 2 .

Sample

codea

394 -B -5 395-E-5 398-3-1 399-B-1

Solid analysis f o r 2 3 7~ (counts/g)

< 7.8 x 102 < 8.2 x 1 0 2

7.64 x :O2 8.53 x 1 0 2

Counting data o b t a i n e d from r u n TSMC-9

Solution a n a l y s i s for 2 3 7 3

I co7cmt s / g i -< 3.2 - 2.6 < <

Sample cod@

Samples t a k e n p r i o r t o run 103

x io3 x 103

2.5 3.0

103

3924-5 3934-5 396-S-3 397-s-3

Solid a n a l y s i s f o r 2375 (comts/g)

< 6.8 < 6.8 < 5.7 < 6.9 -

Solution analysis for 2 3 7 ~

( c o u n t s/ g )

x lo3 x lo3 x 103 x lo3

SacqAes t a k e n p r i o r t o m a b u t a f t e r a d d i t i o n o f t r a c e r

400-5-3

h01-S-3

2.17 x 106 2.16 x l o 6

2.89 x 3.25 x 106

Saripies t a k e n d u r i n f f run

402-B-FS

40 3-3-FS 404 -B-FS Li 0 5-B-FS

40 6 4 - F ~

40 7-B-FS h 08-B-FS

3.35 3.15 2.96 2.78 3.31 2.88 2.92

x 105

5.20

4.74 6.35 5.29 4.36 5.71 5.94

105

x lo5

x 105 x lo5

x

lo5 105

409-S-FS

105 105

k10-S-FS

x lo5 x 105

412-S-FS 413-S-FS

x

io5

105

x lG5

411-S-FS

414-s-Fs b15-S-FS

Ssmples t a k e n a f t e r

416-B-1 417-E-1 41843-1 4 19 -B-2 4 24 -B-5 42 5-B - 5 a

8.55 102 9.25 x 10'

1.47 1.43

105

105

1.06 x io5 1.19 x 1 G 5

< < -

3.7 3.1 3.05 2.86

x 103 x LO3

4204-3

lo5

2.29 x 105 2.45 x 105

426-s-5 42 7-S- 5

x 105

105

io5

2.04 x 105

1.96

105 2.22 x 105

1.74 x l o 5 1.89 x 105

2.03 x

io5

2.95 105 1.79 105 1.88 x l o 5 1.65 i o 5

rsul

421-S-3 4224-4

x

2.17 2.06

423-5-4

6.89 7.12 x

105

lo5

1.51; x 1 0 5 1.54 1 0 5 < 7.1 x 103 < 6.L x 1 0 3

Each sample i s Clesignnated by EL code c o r r e s p o n d i n g t o A-B-C, w h e r s A = s m p l e number; E = material i n sample ( B = bismuth, S = s a l t ) ; and C = sarnpie or-igin: 1 = T1, 2 = T2, 3 = " 3 , 4 = Th, 5 = 'T5, FS = f l o w i a g stream s a p l e .


Table 3.

Run TSMC-2 TSMC-3

TSMC-L

Experimental r e s u l t s of mass t r a n s f e r measurements in t h e salt-bismuth contactor

S a l t flow (cc/min)

Bismuth flow (cc/min)

228

197 173

166

170 219

144

Stirrer rat e ( rpm 1

DU

'~r

121

0.94-34

0.96

162 205

--

> 172

> 24

0.78

24

0.35

43

124

206

185

TSMC-7

152

170

> 172

TSK 6

152

s o

> 40

TSMC-9

169

164

180 68

244

47

TSMC-6

-

%action

154

t r a c e r t r a n s f e r r e d = (1 - c

/c1).

0.17

> 34

175

TSMC-5

Fraction tracer transferred'

>

> 97

>

> 24

----

0.50

0.64 0.40

0.25

0.94

K~ (cm/sec) Based on U

0.0059

- 0.0092

2 0.003 0.054 2 0.02 0.0095 2 0.0013 0.039 2 0.005 0.0057 2 0.0012

Based on 2r 0.0083

0.012

0.0022 2 0.0010

0.121 2 0.108

2

---

0.0055

2 0.02 0.0163 2 0.0159

0.035

0.020 f. 0.01

-------

P

-4


18 Q R M L DWG 7 5 - 7 5 8 300 RUN-9

/

IO0

/

/

/

/

/

RUN-4

LEWIS CORRELATION

1

0

--.

-w /

/

IO

/ I

/

/

/ I

/

/

/

/

/

/'

/

RUN-6

UN-3

RUN-5

/

u

zr

I

I 1 I I I I I

I

I I I l l 1

F i g . 8. Mass t r a n s f e r results measured i n t h e salt-bismuth contactor with 237U and 97Zr t r a c e r s , compared t o tile values p r e d i c t e d by t h e Lewis correlation.


1-9 I n Fig. 8 it can be seen t h a t t h e mass t r a n s f e r group based on ura-

nium f o r runs 3, 5 , and 7 i s between 33% and 65% o f t h e L e w i s e o r r e l a t i o n , while t h a t same group f o r runs 4, 6 , and 9 i s g r e a t e r t h a n 100% of

the Lewis correlation. t h e a g i t a t o r drive.

R u n 8 w a s not shown because of t h e malfunction o f

I n a l l b u t one c a s e , t h e mass t r a n s f e r r e s u l t s

based on zirconium are c o n s i s t e n t l y slightLjr l e s s than t h e values based on uranium.

This discrepancy i s probably r e l a t e d t o t h e i n a b i l i t y t o

c o r r e c t f o r t h e self-absorption o f t h e 743.37 keV 6- from the 97Zr i n

t h e s o l i d bismuth samples.

Results from t h e runs performed i n t h e nondispersed regime, runs

TSMC-3, -5, and -7, suggest t h a t t h e dependence of t h e mass t r a n s f e r

group on t h e Reynolds number group i s s l i g h t l y l e s s t h a n t h a t 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 . to

The exponent appears t o be c l o s e r t o 1 . 0 t h a n

1.65. This i s c o n s i s t e n t w i t h t h e

L e w i s data which show t h a t f o r a

s i n g l e aqueous-organic system, t h e exponent on t h e Reynolds number group i s more n e a r l y 1 . 0 t h a n 1.65. 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 entrainment of s a l t i n t o t h e b i s -

muth begins t o occur a t a stirrer speed between 160 and 180 rpm.

The

apparent 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 o f an

i n c r e a s e i n t h e s u r f a c e area f o r m a s s t r a n s f e r due t o surface motion.

This e f f e c t i s v e r i f i e d by t h e high m a s s t r a n s f e r rates measured i n runs

4 , 6, and 9.

Experiments with water-mercury and water-methylene bromide

systems support t h e b e l i e f that phase d i s p e r s a l i s p r e s e n t a t a g i t a t o r speeds near 180 rpm.

It i s p o s s i b l e t h a t a t h i g h a g i t a t o r rates (> 170 r p m ) some salt o r bismuth i s e n t r a i n e d i n t h e o t h e r phase and i s c a r r i e d out of t h e contactor.

This e f f e c t i s d e t e c t a b l e i f s u f f i c i e n t s e t t l i n g time i s not

available between t h e t i m e s when t h e s a l t and bismuth e x i t from t h e con-

t a c t o r and when t h e flowing stream samples are taken.

Figure 9 shows

t h e results of a n a l y s i s f o r beryllium i n t h e bismuth flowing stream sam-

p l e s taken i n runs TSMC-5, - 6 , and - 9 , which w e r e performed a t 1 2 4 , 180, and 244 rpm, r e s p e c t i v e l y .


â&#x20AC;&#x2DC; p

8

8

20

I)

c

D

n

am

Q

F

N

6


It i s assuned t h a t any beryllium present i n the s a l t i s due to

entrainment of s a l t i n t h e bismuth phase.

From Fig.

9, i t i s seen t h a t

when d i s p e r s i o n i s suspected t h e r e i s more beryllium, and hence s a l t , p r e s e n t i n t h e bismuth stream, a t l e a s t near t h e beginning and near t h e end of

$3

run.

I n t h e middle of

8

I-un, a g i t a t o r speed does n o t seem t o

have ,ane f f e c t on t h e amount of beryllium i.n t h e bismuth.

The e f f e c t

o f s a l t entrainment i n t h e bismuth i s most s i g n i f i c a n t i n t h e metal

t r a n s f e r process where t h e presence o f f l u o r i d e ions i n t h e l i t h i u m c h l o r i d e has a d e l e t e r i o u s e f f e c t on t h e s e p a r a t i o n between t h e r a r e e a r t h s and thorium, Analyses o f bismuth i n t h e salt samples could n o t be obtained.

ibwever, no g r o s s amounts of bi.smuth were i n d i c a t e d f'rom t h e weights

o f t h e s a l t samples.

T t i s p o s s i b l e t o take advantage of t h e increased

mass t r a n s f e r r a t e afforded by mild d i s p e r s a l o f t h e s a l t and bismuth

phases i n a s t i r r e d c o n t a c t o r without imposing any detrimental e f f e c t s

t o t h e r e a c t o r vessel, o r a,ddinp, a large burden t o t h e bismuth removal

step.

We plan t o m a k e a series of runs at high agitator speeds t o

i n v e s t i g a t e more c l o s e l y t h e magnitude o f entrainment e f f e c t s i n t h i s

type o f contactor.

5. SALT-PETAL CONTACTOR DEVELOPNElVY : EXI'EEIIMENTS WITH A MECHANICALLY AGITATED, NONDISPERSTNG COWTACTOR USING WA'IXK ANI) MERCURY C. H. Brown, Jr. We have continued development o f a two-phase nondispersing contactor using water and mercury t o simulate molten f l u o r i d e s a l t and bismuth. During t h i s r e p o r t period, s e v e r a l runs were made i n t h e watermercury system a t an elevated temperature t o determine i f t h e assumption t h a t t h e r e a c t i o n under consideration,

i s instantaneous.

We have a l s o i n i t i a t e d experiments to determine i f

polarography i s a v i a b l e a l t e r m t i v e method f o r determining i n d i v i d u a l


22 water-phase mass t r a n s f e r c o e f f i c i e n t s i n t h e nondispersing s t i r r e d interfa.ce contac t o r .

5.1

R u n s a t Elevated Temperatures wn'.th t h e Lead Ton-Zinc Amalgam System

Several rims were made i n which t h e temperature of t h e c o n t a c t o r and r e a c t a n t s was r a i s e d to approximately 40째C.

The r e s u l t s from t h e s e

t e s t s a r e inconclusive, because it was found t h a t a t t h i s e l e v a t e d temperature, hydrochloric acid, which was p r e s e n t i n Yne aqi-1eou.s phase t o prevent oxide formation a t t h e mercury surface, reacted. with zinc t o

form zinc chloride.

Tnis makes t h e mass t r a n s f e r a n a l y s t s more d i f f i c u l t

by intorducing a competing r e a c t i o n .

Also, d e p l e t i o n o f t h e a c i d c9,iised

formation of a spongy l e a d compound on t h e a g i t a t o r blades and a t t h e water-mercury- i n t e r f a c e . 5.2

Polarographic Determination o f Mass Transfer C o e f f i c i e n t s

Polarography has been suggested as an a l t e r n a , t e method f o r determining t h e water-phase 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 water-mercury contactor. The necessary experimental equipment has been assembled and preliminary t e s t s have been made t o deteruline:

(1)a s u i t a b l e redox couple, and ( 2 )

an e l . e c t r o l y t e which w i l l produce t h e d e s i r e d p o l a r i z a t i o n curve while being chemically i n e r t t o mercury. 5.2.1

Theory The polarographic technique f o r determining mass t r a n s f e r c o e f f i c i e n t s

involved oxidation o f a reduced species or reduction o f an oxidized s p e c i e s a t an e l e c t r o d e which i s a t a condition of concentration p o l a r i z a t i o n . One system t h a t has been s t u d i e d previously' ferricyanide ions at a polarized nickel electrode.

i s t h e reduction of

A s f e r r i c y a n i d e was

reduced a t t h e cathode, ferrocyanide was oxidized a t the anode.

There

w a s no n e t consumption of chemicals o r change i n t h e composition o f t h e

e l e c t r o l y t e solution. P o l a r i z a t i o n o f t h e cathode can be accomplished i n one o f t w o ways e i t h e r t h e cathode s u r f a c e a r e a i s made very large with respect t o t h e

--


anode surface area, or t h e concentration of t h e oxidized species i s made

v e r y small with r e s p e c t t o t h e reduced species.

The migration of an i o n i n both e l e c t r i c and concentration f i e l d s

i s described by t h e Nernst-Planck equation:

Q

=

ZCF D(VC + om), RT1

where

c

=

concentration of r e a c t i n g ion, m o l e s / l i t e r ,

Q

=

f l u x of t h e ion, moles ern

-2

see

-1

D = d i f f u s i o n c o e f f i c i e n t , cm2/sec,

2

=

valence change o f t h e t r a n s f e r r i n g ion,

R = gas constant,

T = absolute temperature, F = Faraday

@

=

constant,

OK,

"C/mole,

e l e c t r i c p o t e n t i a l , V.

The f i r s t term i n t h e expression r e p r e s e n t s t h e c o n t r i b u t i o n of ordinary d i f f u s i o n t o t h e flux, and t h e second term r e p r e s e n t s t h e c o n t r i b u t i o n of electromigration.

A l a r g e concentration ( r e l a t i v e t o t h a t o f t h e r e a c t i n g

i o n ) of an i n e r t e l e c t r o l y t e a l t e r s t h e d i e l e c t r i c p r o p e r t i e s of t h e s o l u t i o n such t h a t t h e p o t e n t i a l will decrease smoothly across t h e region between t h e electrodes, while t h e concentration drops sharply across t h e t h i n p o l a r i z e d l a y e r near t h e cathode.

Thus, t h e term containing t h e

e l e c t r i c p o t e n t i a l becomes r e l a t i v e l y small, and

Q = DvC.

(3)

The c u r r e n t flowing between t h e e l e c t r o d e s i s t h u s a measure of mass t r a n s f e r r a t e s governed by o r d i n a r y molecular d i f f u s i o n .

This c u r r e n t

i s sometimes c a l l e d t h e "diff'usion c u r r e n t . " T h e impressed c u r r e n t a c r o s s the cell i s proportional t o the m a s s

flw a c r o s s t h e stagnant layer between t h e bulk e l e c t r o l y t e and t h e

p o l a r i z e d cathode, and t h e mass t r a n s f e r c o e f f i c i e n t i s given by:


24

__

K =

i

(4)

(Z) (A) (F) (C,)'

where

mass t r a n s f e r coefficient through 'the f i l m , cm/sec,

k

:=

1

=

p o l a r i z a t i o n cwryent, A,

A

=

area of t h e polarized electrode, em2, and

C

B

=

concentration i n g-,mnoles/cm3 of t z ~ a n s f e r r i n gspecies i n t h e bulk l i q u i d .

IIence, it i s possible to determine mass t r a n s f e r rat?s from t h e bu3.k

e l e c t r o l y t e t o ti?e electrode surface using experimentzlly determined v a l . 1 ~ ~ f o r I, CB, and A.

5 . 2 " 2 Experimental- equipment The experimental apparatus which w i l l be used t o measi.ire mass ti-ans-

f e r rates i n t h e water-mercury skirred. c o n t a c t o r i s shown schematically

i n Fig. 1.0. !!%e equipment c o n s i s t s of t h e 5- by 7-in.

Plexiglas rtonLacLor

which was used i n previous Twork with t'ne water-mercury system.

The

mercury sixface i n t h e contactor a c t s as t h e cathode i n .the electrochemi.ca1 eel-1.

The cathode i s e l e c t r i c a l l y connected t o t h e r e s t o f t h e c i r c u i t

by a 1./8-in. -diam s t a i n l e s s s k e e l welding rod. which i s e l e c t r i c a l l y i n s u l a t e d from t h e e l e c t r o l y t e phase by a T e f l o n sheath.

The anode of

t h e ce1.l. i s suspended i n t h e aqueous el-ectrolyte phase, and c o n s i s t s o f a 1/8-in.-thick

piece of n i c k e l sheet which .i.s formed .to f i t t h e inner

perimeter of t h e Plexiglas c e l l .

The c u r r e n t through the cell i s i n f e r r e d

from t h e voltage drop across a 0.1 il f 0.5$, 1.0-rrJ p r e c i s i o n r e s i s t o r .

Ti?e

signal. produced across t h e resistor is recorded a s t h e y c o o r d i m t e on a.

Hew]-ett-Packard

)it

y plotter.

'The x coordinate on t h e p l o t t e r i s produced

by t h e vol-tage supplied to t h e c e l l , which i s a d i r e c t signal from t h e 0 t o LO

5.2.3

V, 0 t o 1 0 A Hewlett-Packard d i r e c t cu.rrent power supply.

"Ikperimental results Several d.ifferent e l e c t m l y t e solutf-ons have been evaluated on the

b a s i s t o two d i f f e r e n t c r i t e r i a :

(I) t h e e l e c t r o l y t e must be chemically

face wtth t h e given e l e c t r o l - y t e ,

The d i f f e r e n t e l e c t r o l y t e s t'nat have

ii1er.t to mercury, and ( 2 ) it must be p o s s i b l e t o pol-artze t h e mercury sur-


OANL DWG. ?5-813R1

PLOTTER

X ,Y

II

M

+-

+

II

Y

84

Lp-p- P-PJ

D C POWER SUPPLY 0-IOV 0-IOA

I

-I

V A R I A B L E SPEED DRIVE MOTOR

WATER-MERCURY ELECTROCHEMICAL CELL

Fig. 10. Schezatic diagraq of the e q u i p e r l t used to measure p o l a r i z a t i o n c u r r e n t s in the water-mercury electrochemical cell c o n t a c t o r .


26 been examined a r e :

(1)potassium f e r r o - and ferri.cyanid.e with a sodium

hydroxide supporting electrol.yte;

( 2 ) potassium f e r r o - and ferricyaiiide

( 3 ) potassium ferro- and f e r r i c y a n i d e s with a sod.ium n i t r a t e supporting e l e c t r o l y t e ; ( 4 ) f e r r o u s

w i - t h a sodium chloride supporting e l e c t r o l y t e ;

and f e r r i c s u l f a t e with a sod.ium hydroxide s u p p o r t h g e l e c t r o l y t e ; and

( 5 ) f c r r o u s and f e r r i c s u l f a t e w i t h s u l f u r i c a c i d a s t h e siippor'iing

e l e c t rol y t e

.

None o f 'ihe e l e c t r o l y t e s mentioned above met both o f t h e imposed

criteria.

The f e r r o u s and f e r r i c s u l f a t e system v i t h su.l.fu.ric a c i d as

t h e i n d i f f e r e n t e l e c t r o l y t e was the only cornbinati.on wh5.ch proved to be

It

chemically i n e r t t o t h e mercury cathode.

14-3s

found., however, t h a t

a t a voltage l.ess than s u f f i c i e n t t o polarize t h e mercury cathode, t h e

f e r r i c ions reacted. with t h e mercury cathode. previously reported i n the l i t e r a t w e . K o l t h a f f and Lingane

6

Tnis phenomenon has been

4 r e p o r t t h a t t'ne following r e a c t i o n occurs when

f e r r i c i o n s a r e con'iacted with mercury:

2 Fe3'

2 Hg = 2 Fe

2+

-k

2f

Hg2

;

(5)

therefore, t'ne half-wave p o t e n t i a l of f e r r i c ions cannot be measured directly. The r e v e r s i b l e oxidation and reduc'tiori o f f e r r o u s and f e r r i c ions

have been reported f e a s i b l e when t h e i r o n ions a r e complexed with excess oxal-ate ions.

'This system w i l l be examined i n d e t a i l and applied Lo -the

experiment under development.

6.

FUET, RECONSTITUTION DEVELOPMENT: INSTALLATION OF EQUIPMENT FOR A FUEL RECONSTITUTION ENGJPEERING EXPERIMENT

K. M. Counce The reference flowsheet f o r processing t h e f u e l salt from a molten

s a l t breeder r e a c t o r (MSBR) is based upon removal of iiranium by f l u o r i -

n a t i o n t o W g a s t h e f i r s t processing step.

The uranium removed i n t h i s

step must subsequen"c.y be returned t o t h e Cue1 s a l t stream before it


The UF5 for t h e f i x 1 r e c o n s t i t u t i o n engineeri2g e q e r i r r e n t is

avail-able in 5-in. -diam by $-in. -high c y l i n d e r s contain-ing up to

55 lb

wTl1 be supplied to this eqeri.ment by nmA-intain5.ng (g> the temperature of the Uklg cylinder a t ZZOOE', and a t a vapor pressure o f

o? UF6.

70 psia,.

The I F 6

?'his hea.ting id11 be aecomylished by use of 1.7.Z-psia steam..

The steam h e a t s t h e e,ylinders d i r e c t l y tlirough 3/8-in..

copper tubing,

which is coiled arouuid the e n t b e cylifider.. '!L?E I.ower 3.8 in. of tbe cylinder and tubing is covered w i t h a c o n d u ~ t l i v ecement to min5mize response time. The cylfnder and associated v-aLves a m then enclosed in a cabinet insulated with 2 in. o f F'iberglas Tnszdation.


P u r i f i e d argon w i l l . be used f o r a3.1 a p l i c a t i o n s r c q u t r i n g an i i i e r t

p e s s u r i z a t i o n o f tanks f o r transSerri.ng salt, dip.-lrt: bubblers

g a s (e.g.,

for l i q u i d ?eve1 measurements, purging or" equi-pr;lenl; and lines, e t c . ).

Cylinder argon i s passed throu.gh a bed o f t i t a n i u m sponge where water and oxygen are removed-

T h i s bed opera-Le.; a t 825째C.

Cylinder hydrogen i s pui"iti.ed suffi.cien-Lly by passing i t through a

Oeoxo u n i t , where oxygen i s conver'ied t o water.

No TniirLhcr pui-i.-iics-tion

o f the nitrogen i s needed, s i n c e it Is s u f f i c i e n t l y pure f o r use ia

ca,l.ibrating t h e gas d e n s i t y cells.

,6.2 Equipment T n s t a l l a t i o n The equi.pmeiit for- t h e f u e l recons-Litution e n g i n c e r i n g experiment i s

being i n s t a l l e d i n t h e n o r t h e a s t corner of the bay i n Building 7503. The experiment -is operated reliiot,ely from a c o n t m l room in t h ? b u i l d i n g , although .the gas f l o w c o n t r o l l e r s and some o t h e r equipment aye l o c a t e d i n t,he bay. ,'I7

ifle

experimental. equipmen-t f.s shown i n Fj.gs. 11-114-before t h e a d d i t i o n

of t h e m a 3 insulation.

Fig. 11 i s an ovej~al.1.sidev-iew of t h e equipneni;

showing t h e feed and r e c e i v e r tanks, t i t a n i u m s'pongq trap,

112

reducbioii

column and i t s j a c k l e g and sample pol-t, and t'ne h-F r,nd TJF6 t r a p s .

Ffgure 1 2 i s a n o v e r a l l f r o n t view of the cqeri:ment

c o n t m l panel feed and receri.ver tanks,

showing the gas

the t o p o f t h e UF6 absorption

vessel, and t h e 3 2 r e d u c t i o n c o l u ~ i i iand i J G s zffliient s t r e m sample p o r t . Figupe l3 shows a vieis of t h e lower por-Lion of t'ne E-I2 red.iic't.ion col.i.mn

and i t s jack3eg, and the i.nstruments for mer,siirring t h e depth of t%le feed and r e c e i v e r tanks.

A view o f t h e HI'and

m6 traps (packed b2ds o f NaF

pellets) and the i n - l i n e g a s densiky detec'iors i s shown i n Fi.g. 14.

The e l e c t r i c a l supply panel i s l o c a t e d in a remote contl-ol room, snd

i s shown i n F i g r n 15.

'Temperature i s cont-rolled by m n u a l adjusimciit o f

heater voltage and by ailtomatic on-off controllers. Figire

16 shows t h e temperature recorders and. temperature

f o r major vessels and t h e gas d e n s i t y c e l l s . flow recorders and c o n t r o l l e r s .

A l s o shown

controller=s

a r e l e v e l and

'Yhe instruments a t t h e right of t h e

c o n t r o l panel a r e recorders a s s o c i a t e d wri~ththe gas d e n s i t y cells.


29 ORNL-Photo 1153-75R1

P

d

t r r L U ~ N TS I KLHM SAMPLER

H2 HtUULTlON

ri

t

GAS SUPPLY

ARGON â&#x20AC;&#x2122;U R I F I CATION BEDr)

--

-

F i g . 11. Overall side view of equipment for Fuel Reconstitution Engineering Experiment before addition of thermal insulation.


30

IORNL-Photo 1148-75R1

rcII

P

b

iECElVER

TANK

I

I

Fig. 12. Overall front v i e w of Fuel Reconstitution Engineering Experiment showing gas control panel.

I I


31 OR N L- Phot 0 115 1- 75 R 1

I

S A M P L E PORT

I

.

701 l l M N JACK1 F G -

I

1

1 PURIFICATION BED nnuuix

\

Fig. 13. V i e w o f i n s t a l l e d feed tank and r e c e i v e r , t i t a n i u m sponge t r a p , and bottom o f hydrogenation column.


32

L

ORNL-Photo 115

1

L

t

Fig. 14. View of sodium f l u o r i d e t r a p s and i n - l i n e gas d e n s i t y

detectors.


33

.

__--

-

Fig. 15.

Experiment.

E l e c t r i c a l supply p a n e l for Fuel R e c o n s t i t u t i o n Engineering


34

r

E

PHOTO 1154-75

1

, -

Fig. 1 6 . Panelboard f o r F u e l Reconstitution Engineering Experiment temperature, l e v e l , and flow r e c o r d e r s and c o n t r o l l e r s .


35 H2-HF Treatment of S a l t from Autoresistance Heating Tests

6.3

The f i r s t s e r i e s of experiments w i l l use

86 kg o f f u e l s a l t , formerly

To remove oxides p r e s e n t i n t h e s a l t , i t was sparged with

used i n AHT-3.

3541.

a H2-HF mixture i n Bldg.

The metal oxides were removed! according t o

t h e following generalized reaction:

where (g)

=

gaseous

( d ) = dissolved

x

M

=

number of moles

=

metal species found i n s a l t .

The HF was d i l u t e d with H2 i n o r d e r t o prevent excessive a t t a c k on v e s s e l and piping.

The HF concentration i n t h e mixture was

nominal t o t a l flow r a t e was 15 scfh.*

33 vol

%.The

The HF flow was s e t by c o n t r o l l i n g

t h e pressure drop a c r o s s a c a p i l l a r y ; t h e H2 flow was s e t by use of a rotameter and was checked by a wet-test meter, The

HF u t i l i z a t i o n was determined by using an aqueous scrubber and

a small (0.05 f t 3 / r e v ) w e t - t e s t meter i n p a r a l l e l with t h e NaF t r a p f o r sampling t h e gas f e d t o t h e treatment v e s s e l o r leaving t h e v e s s e l . The concentration of HF i n t h e gas stream was determined by passing t h e

gas through 250 m l o f a

f t 3of

0.4 N NaOH s o l u t i o n i n t h e scrubber.

When 0.05

H2 had passed through t h e w e t - t e s t meter, t h e gas flow was stopped

and t h e s o l u t i o n was removed f o r a n a l y s i s .

The HF concentration i n t h e

gas was determined by t i t r a t i n g small samples of t h e scrubbing s o l u t i o n

N HC1. with 0.1 -

i n t h i s manner.

Both t h e feed and t h e discharge streams were monitored U t i l i z a t i o n of t h e HF was c a l c u l a t e d from t h e f e e d and

discharge concentrations.

The

HF u t i l i z a t i o n decreased from an i n i t i a l

value o f about 5% t o about 25% a f t e r 20 h r .

a t 25% f o r t h e l a s t 10 hr.

*

Standard cubic f e e t per hour.

The HF u t i l i z a t i o n remained


36 Reduction of corrosion product fluorides, principally NiF2, FeF2,

and CrF2, will proceed after verification of oxide removal. Of the corrosion products present in the salt, a hydrogen sparge will reduce

only NiF2 in a practical time period; thus, CrF2 and possibly FeF2 will

be reduced with T h metal.

After the reduction of the corrosion fluorides to their metallic

form, they will be filtered from the mixture as it is decanted into a

fuel reconstitution experiment vessel. Sufficient UF4 will be added to

bring the concentration in the salt to 0.0125 mole % after the salt has been transferred to the fbel reconstitution equipment.

7. RFFERFNCES 1. H. C. Savage, Engineering Development Studies for Molten-Salt Breeder Reactor Processing No. 20, ORNL-TM-4870 (in preparation). 2.

J. B. Lewis, Chem. Eng. Sci.

1, 248-59 (1954).

3. J. A. Klein, MSR Program Semiann. Progr. Rept. ORNL-5011.

4.

Aug. 31,

1974,

C. H. Brown, Jr., MSR Program Semiann. Progr. Rept. Feb. 28, 1975, ORNL-5047.

5. J. S. Watson, "A Study of Detached Turbulence Promoters f o r Increasing Mass Transfer Rates in Aqueous Chemical Flow, of Tennessee (1967).

6.

Ph. D. Thesis, University

I. M. Kolthoff and J. J. Lingane, Polarography, 1st ed., Interscience, New York, 1946.

7. R.

M. Counce, Engineering Development Studies for Molten-Salt Breeder Reactor Processing No. 20, ORNL-TM-4870 (in preparation).


37

UC-76

ORNL/IpM-4894 Reactor Technology

- Molten S a l t

INTEWAL DISTRIBUTION

1-2, MSfiP Director’s Office 3. C, F. Baes, Jr. 4. C. E. Bmberger 5 . J. Beams 6. M. Bender 7. M. R. Bennett 8. E. S. B e t t i s 9. R. E. Blanc0 10. J. 0. Blomelre 11. E. G. BohLmann 1 2 . J. Braunstein 13. M. A. Zcredig 14. R. R . Briggs 15. E. R. Bronstein 16. R. E. Broolfsbaiik 17. C. H. Brown, Jr, 18. K. B . Brown 19. J. Brynestad 20. s . Cmtor 21. D. W. Cardwell 22. w. L. Carter 23. W. H. Cook 24. R. M. Counce 25.

J. L . Crawley

26. F. L. Culler

J’, M. Dale F’. L. Daley J. H. DeVan 30. J. R. DiStefano 31. W. P. Eatherly 32. R. L. Egli, AEC-OSR 33. J. R. Engel 34. G. G. Fee 35. D. E. Ferguson 27. 28. 29.

3G. L. M. 37. L. 0 . 38. W. S . 39. S . C .

Ferris Gilpatrick Groenier Griess

40.

W. R. Grimes

41. R. If. J. 52. B. 53. R. 54. W. 55. V. 56. C. 57. A. 58. W. 59. H.

42-51.

60.

61.

Gu;nnon 8. Ilightower, Jr.

F. H i t c h W. Hoa-ton R. FPmtIey

A. Jacobs

W. Kee

D. Kelmers R. Laing

B. Lindauer R. E. M E K P ~ W S O ~

W. C. McCLrzin

62. H. E.

McCoy

A. P. l h l i n a u s k a s 64. C . L. Matthews 65. R. L. Moore 63.

66. J. P. Nichols 67. E. Postma ha. M. w. Nosent’nal. 69. E. C. SaTTage 7 0 . W. F. S c h a f f e r , 71. C. D. S c o t t 72. M. J, Skinner 73.

‘74. 75. 76. 77.

78.

79. 80. 81. 82.

83-84. 85. 86-88. 89.

,Jr.

F. J. S m i t h

G . P . Smith I. S p i e w a 0 . K. T a l l e n t L. M. Tot41 D. B. Trauger W. E. IJager J. E. Weir M. K. Wilkinson R . G. ITyiner C e n t r a l Researcl? Library Document Xefer.ence S e c t i o n

Laboratory

R ~ C O T ~ ~

Laboratory Records (JXB-RC)


38 CONSULTANTS AZVD SUBCONTRACTORS 90.

91.

92.

93. 94. 95.

J. C . Frye c. K. I c e J . J. Katz E . A. Mason Ken Davis R . B . Richards

EXTERNAL DISTRIBUTION

96.

Research and Technical Support Division, ERDA, Oak iiidge Operations O f f i c e , P. 0. Box E, O a k Ridge, Tenn. 37830 97. D i r e c t o r , Reactor Division, ERDA, O a k Ridge Operations O f f i c e , P. 0. Box E , O a k Ridge, Tem. 37830 98-99. Director, ERDA Division of Reactor Reseaxch and Development, Washington, D . C. 20545 100-201. For d i s t r i b u t i o n as shown i n TID-4500 under UC-76, Molten S a l t Reactor Technology

ir US. GOVERNMENT PRINTING OFFICE: 1976-748-189/275


ORNL-TM-4894