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Extended Storage-in-Place of MSRE Fuel Salt and Flush Salt Karl J. Notz

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This report was prepared as an account of work sponsored by an agency of the UnitedStatesGovernment. NeithertheUnitedStatesGovernment norany agency thereof, nor any of their employees, makes any warranty, 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 represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of theunited States Government or any agency thereof.

ORNL/TM--9 7 5 6 DE86 001720

Nuclear and Chemical Waste Programs

EXTENDED STORAGE-IN-PLACE OF MSRE FUEL SALT AND FLUSH SALT

Karl J. Notz Chemical Technology D i v i s i o n

With c o n t r i b u t i o n s from: R. C. A s h l i n e , Chemical Technology D i v i s i o n D. W. Byerly, U n i v e r s i t y of Tennessee L. R. Dole, Chemical Technology D i v i s i o n D. Macdonald, Martin Marietta Energy Systems, I n c . , Engineering T. E. Myrick, Operations D i v i s i o n F. J. P e r e t z , Martin Marietta Energy Systems, Inc., Engineering L. P. Pugh, O p e r a t i o n s D i v i s i o n A. C. Williamson, Martin Marietta Energy Systems, Inc., Engineering

Date Published:

September 1985

NOTICE This document contains information of a preliminary nature. It is subject to revision or correction and therefore does not represent a final report.

Work Sponsored by U.S. Department of Energy S u r p l u s F a c i l i t i e s Management Program

OAK RIDGE NATIONAL LABORATORY Oak Ridge. Tennessee 37831 o p e r a t e d by MARTIN MARIETTA ENERGY SYSTEMS, INC. for the U.S. DEPARTMENT OF ENERGY under C o n t r a c t No. DE-AC05-840R21400 "

'4t

5.s: i u

iii CONTENTS

ABSTRACT.

EXECUTIVE SUMMARY 1.1 HISTORY 1.2 PROJECTIONS 1.3 CONCLUSIONS

INTRODUCTION.

HISTORY 3.1 DESCRIPTION 3.2 SURVEILLANCE AND MAINTENANCE 3.3 PRIOR STUDIES e 3.4 OPTIONS.

. . . . rn

CONCLUSIONS e EVALUATION OF OPTIONS 5.2 SELECTION OF PLAN

Appendix Appendix Appendix Appendix Appendix Appendix

A. B. C. D. E.

9 9 16 17 18

. e

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

PROJECTIONS 4.1 RADIOACTIVITY e e 4.2 RADIOLYSIS 4.2.1 P r e s s u r e Rise 4.2.2 C o r r o s i o n Rates Use of Getters 4.2.3 4.3 INTEGRITY OF THE FACILITY C e l l Penetrations 4.3.1 Water C o n t r o l 4.3.2 4.3.3 Secondary Containment e GEOLOGY AND HYDROLOGY 4.4 e 4.5 ENTOMBMENT 4.6 UTILIZATION FINAL DISPOSAL 4.7 4.7.1 WIPP. Commercial S p e n t F u e l R e p o s i t o r y 4.7.2 Greater Confinement D i s p o s a l 4.7.3 4.8 IN-CELL ALTERATIONS CONTINGENCY PLANNING 4.9

5.1

3 3 4 5

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

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

BIBLIOGRAPHY AND REFERENCES SEMIQUANTITATIVE EVALUATION OF SIX MSRE OPTIONS WIPP WASTE ACCEPTANCE CRITERIA ANALYSIS OF MSRE CELL PENETRATIONS BUILDING 7503 DRAINAGE SYSTEMS GEOLOGIC INVESTIGATIONS RELATIVE TO MOLTEN SALT REACTOR DECOMMISSIONING

27 27 45 46 50 52 54 55 60 62 62 63 64 65 66 66 67 67 68 71 71 73 75 79 85 93 111 125

EXTENDED STORAGE-IN-PLACE: OF MSRE FUEL SALT AND FLUSH SALT

Karl J. Notz ABSTRACT

The s o l i d i f i e d f u e l s a l t and f l u s h s a l t from t h e Molten S a l t Reactor Experiment (MSRE) have been s t o r e d a t t h e Oak Ridge N a t i o n a l Laboratory (ORNL) si.nce t h e r e a c t o r w a s s h u t down i n 1969.

The f l u o r i d e s a l t e u t e c t i c , c o n t a i n i n g 37 kg of

uranium p l u s plutonium and f i s s i o n p r o d u c t s , i s s a f e l y cont a i n e d i n t h r e e heavy-walled Hastel.loy t a n k s , which a r e l o c a t e d i n s i d e a reinforced concrete cell.

Kemoval of t h e s e s a l t s t o a

remote l o c a t i o n i s n o t f e a s i b l e u n t i l an a p p r o p r i a t e r e p o s i t o r y h a s been i d e n t i f i e d , b u i l t , and placed i n o p e r a t i o n . t h i s may t a k e many y e a r s , extended s t o r a g e - i n - p l a c e c a l l y evaluated.

Since

was c r i t i -

The e v a l u a t i o n , which involved a p r e l i m i n a r y

assessment of s e v e r a l o p t i o n s f o r enhancing t h e i n t e g r i t y of i n - p l a c e s t o r a g e , i n c l u d i n g containment improvement, t h e addit i o n of chemical g e t t e r s and n e u t r o n p o i s o n s , and entombment i n c o n c r e t e , showed t h a t t h i s approach was a r a t i o n a l and s a f e s o l u t i o n t o t h e problem f o r t h e s h o r t t e r m .

Entombment i s

e s s e n t i a l l y n o n r e v e r s i b l e , b u t t h e o t h e r o p t i o n s a r e openended; t h e y do n o t l i m i t t h e f u t u r e s e l e c t i o n of a f i n a l dispo-

sal option.

S p e c i f i c a c t i o n s and improvements t h a t would

enhance s a f e containment d u r i n g extended s t o r a g e and would a l s o b e of f u t u r e b e n e f i t , r e g a r d l e s s of which d i s p o s a l o p t i o n i s f i n a l l y s e l e c t e d , were i d e n t i f i e d .

1. 1.1

EXECUTIVE SUMMARY

HISTORY The Molten Salt Reactor Experiment (MSRE) w a s concluded i n 1969

a f t e r s e v e r a l y e a r s of well-planned and h i g h l y s u c c e s s f u l work.

This

homogeneous r e a c t o r concept w a s based on t h e thoriunrU-233 f u e l c y c l e and used a molten f l u o r i d e e u t e c t i c as t h e o p e r a t i n g medium.

This work

i s thoroughly documented. A t shutdown, t h e f u e l s a l t c o n t a i n i n g most of t h e uranium and

f i s s i o n p r o d u c t s w a s d i v i d e d and d r a i n e d i n t o two s e p a r a t e t a n k s , t h u s ensuring c r i t i c a l i t y safety.

The f l u s h s a l t , c o n t a i n i n g 1 t o 2 % of t h e

uranium and f i s s i o n p r o d u c t s , w a s d r a i n e d i n t o a t h i r d tank.

The s a l t s

were allowed t o c o o l and f r e e z e , t h e r e b y p r e c l u d i n g any l e a k a g e and d e c r e a s i n g f u r t h e r t h e already-low c o r r o s i o n rate.

The d r a i n t a n k s are

made of heavy-walled H a s t e l l o y N, a s p e c i a l a l l o y c r e a t e d f o r t h e program, which h a s s u p e r i o r s t r e n g t h a t h i g h t e m p e r a t u r e s and o u t s t a n d i n g c o r r o s i o n r e s i s t a n c e toward t h e e u t e c t i c f l u o r i d e system used f o r t h e MSRE.

These t a n k s a r e c o n t a i n e d w i t h i n a h e r m e t i c a l l y

s e a l e d , s t a i n l e s s steel-lined,

reinforced-concrete hot c e l l , located

below g r a d e except f o r a double s e t of roof p l u g s . A s u r v e i l l a n c e and monitoring program, which i n c l u d e s d a i l y and

monthly measurements, h a s been i n f o r c e s i n c e shutdown.

There i s a l s o

a n a n n u a l r e h e a t ( b u t n o t h o t enough t o r e m e l t ) t o recombine any f l u o r i n e t h a t might have formed from r a d i o l y s i s by (a,n) r e a c t i o n s on the fluoride salt.

There have been no a d v e r s e i n c i d e n t s o r releases of

r a d i o a c t i v i t y s i n c e t h e r e a c t o r w a s s h u t down 16 y e a r s ago.

Several

p r i o r s t u d i e s have been made of decontamination and decommissioning (D&D) o f t h e f a c i l i t y , based on removal and r e p r o c e s s i n g of t h e s a l t s and on t h e assumption t h a t a s i t e o r r e p o s i t o r y would be a v a i l a b l e t o a c c e p t t h i s material.

In f a c t , t h e r e i s no such s i t e o r r e p o s i t o r y a t p r e s e n t .

Nor i s i t f e a s i b l e t o r e p r o c e s s t h e s a l t s without major c o n s t r u c t i o n of s u c h c a p a b i l i t y , whlch would be v e r y c o s t l y and would i n t r o d u c e a f i n i t e p r o b a b i l i t y of r a d i d t i o n exposure o r release.

The p r e s e n t s t u d y focused on extended s t o r a g e and any enhancements t o t h e s t o r a g e mode t h a t would b e n e f i t t h e s t o r a g e p e r i o d and a l s o be b e n e f i c i a l i n view of e v e n t u a l f i n a l d i s p o s a l .

T i m e frames of 1 t o 20

years ( s h o r t t e r m ) , 20 t o 100 y e a r s ( n e a r t e r m ) , 100 t o 1000 y e a r s (midterm), and more t h a n 1000 y e a r s ( l o n g term) were considered.

1.2

PROJECTIONS The most important of t h e s e i s t h e r a d i o a c t i v i t y p r o j e c t i o n , which

w a s c a r r i e d out t o 1 m i l l i o n years

by u s i n g t h e ORIGEN2 code.

p r o j e c t i o n s were t r u n c a t e d a t 5 and 20 y e a r s . ) two major a s p e c t s :

(Prior

This p r o j e c t i o n showed

decay of f i s s i o n product (FP) a c t i v i t y , as a n t i c i -

p a t e d ; and decay/ingrowth/decay of a c t i n i d e a c t i v i t y , which i s somewhat unusual and d e r i v e s from t h e s l o w ingrowth of t h e U-233 decay chain.

The

FP a c t i v i t y h a s d e c l i n e d by a f a c t o r of 50 s i n c e d i s c h a r g e , w i l l d e c l i n e

by a n o t h e r f a c t o r of 8 a t 100 y e a r s a f t e r d i s c h a r g e , and w i l l e s s e n t i a l l y d i s a p p e a r a t 1000 y e a r s .

The f i s s i o n p r o d u c t s are t h e major s o u r c e of

b e t a and gamma a c t i v i t y .

The a c t i n i d e a c t i v i t y w i l l i n i t i a l l y decay by a

f a c t o r of 4 a t 1000 y e a r s b u t w i l l t h e n grow back i n t o about i t s o r i g i n a l l e v e l a t 40,000 y e a r s b e f o r e commencing f i n a l decay. The a c t i n i d e behavior i s t h e n e t r e s u l t of U-232

( h a l f - l i f e of 7 2

y e a r s ) and plutonium decay, a l o n g w i t h U-233 ( h a l f - l i f e ingrowth and t h e n decay.

of 158,000 y e a r s )

Each a c t i n i d e decay spawns a n a d d i t i o n a l f i v e

o r s i x a l p h a decays ( a l o n g w i t h some beta-gamma a c t i v i t y ) . a c t i v i t y i s important f o r s e v e r a l r e a s o n s : n e u t r o n s from ( a , n ) r e a c t i o n s on Be-9,

F-19,

The a l p h a

i t i s a long-term s o u r c e of

and Li-7,

which are major

components of t h e f l u o r i d e e u t e c t i c , and i t c o n t r i b u t e s about 50 W of decay energy f o r a v e r y l o n g t i m e .

The n e u t r o n s must be c o n s i d e r e d i n

s h i e l d i n g c a l c u l a t i o n s b u t do n o t pose a n undue problem.

The decay

energy i s , i n d i r e c t l y , a problem, n o t because of h e a t b u t because of radiolysis.

5 I

R a d i o l y s i s of f l u o r i d e y i e l d s f l u o r i n e p l u s f r e e metal.

At slightly

e l e v a t e d t e m p e r a t u r e s (>150째F) recombination i s r a p i d enough t o p r e c l u d e

a b u i l d u p of f l u o r i n e ; however, a t lower t e m p e r a t u r e s , f r e e f l u o r i n e w i l l

e v e n t u a l l y form ( a f t e r an i n c u b a t i o n p e r i o d of >5 y e a r s ) and w i l l t h e n c o n t i n u e t o be produced.

IJnless t h e r a d i o l y s i s problem i s brought under

c o n t r o l , d i s p o s a l of t h e salts i n t h e f l u o r i d e form w i l l p r e s e n t a s i g n i f i c a n t problem.

One p o s s i b l e way t o l i n t i t t h e f o r m a t i o n of f r e e f l u o r i n e

i s by t h e a d d i t i o n of a g e t t e r

an acti.ve metal t h a t reacts r e a d i l y w i t h

fluorine. The p h y s i c a l i n t e g r i t y of t h e d r a i n t a n k s and c e l l i s of obvious importance.

This f a c t o r w a s considered i n terms of p e n e t r a t i o n s and

c o n t r o l of water.

No d e f i c i e n c i e s t h a t would j e o p a r d i z e extended s t o r a g e

a r e e v i d e n t a t t h i s t i m e i n e i t h e r area, but some a d d i t i o n a l work i n t h e s e areas would be b e n e f i c i a l .

1.3

CONCLUSIONS

A t t h i s t i m e , extended s t o r a g e of t h e s o l i d i f i e d f u e l s a l t s i s t h e

most prudent and r a t i o n a l course.

Actions t h a t can be e a s i l y t a k e n out-

o f - c e l l t o enhance s t o r a g e should be implemented.

An e v e n t u a l d e c i s i o n

t o remove t h e f u e l s a l t s t o a f i n a l d i s p o s a l s i t e w i l l be tempered by s i t e a v a i l a b i l i t y i n 20 y e a r s o r so.

A f u t u r e d e c i s i o n concerning

whether t o r e p r o c e s s o r n o t w i l l be c o n t r o l l e d by t h e a b i l i t y t o l i m i t r a d i o l y s i s , which i s an open q u e s t i o n a t t h i s t i m e b u t m u s t be r e s o l v e d i n the interim.

INTRODUCTION

The MSRE was a graphit.e-moderated, homogeneous-fueled

reactor b u i l t

t o i n v e s t i g a t e t h e p r a c t i c a l i t y of t h e m o l t e n - s a l t r e a c t o r concept f o r It w a s o p e r a t e d from June 1965 t o

a p p l i c a t i o n t o c e n t r a l power s t a t i o n s .

December 1969 a t a nominal full-power l e v e l of 8.0 MW.

The c i r c u l a t i n g

f u e l s o l u t i o n w a s a e u t e c t i c mixture of Lithium and b e r y l l i u m f l u o r i d e s c o n t a i n i n g uranium f l u o r i d e as t h e f u e l and zirconium f l u o r i d e as a chem i c a l stabilizer.

The i n i t i a l f u e l charge w a s h i g h l y e n r i c h e d 235U,

which w a s l a t e r r e p l a c e d w i t h a charge oE 233U.

Processing c a p a b i l i t i e s

were i n c l u d e d as p a r t of t h e f a c i l i t y f o r on-line f u e l a d d i t i o n s , removal o f i m p u r i t i e s , and uranium recovery. l a t e d i n t h e two phases of o p e r a t i o n .

A Rota1 of 105,737 MWh w a s accumu-

Following r e a c t o r shutdown, t h e

f u e l s a l t was d r a i n e d i n t o two c r i t i c a l l y s a f e s t o r a g e t a n k s and i s o l a t e d i n a sealed hot c e l l , along with a t h i r d tank containing t h e f l u s h salt. When t h e r e a c t o r was f i r s t s h u t down, t h e assumption w a s made t h a t t h e f a c i l i t y and t h e f u e l and f l u s h s a l t s would probably be u t i l i z e d a g a i n a t some l a t e r d a t e .

Therefore, t h e shutdown procedure was essen-

t i a l l y a m o t h b a l l i n g o p e r a t i o n followed by s u r v e i l l a n c e and maintenance (S&M) procedures.

These procedures were designed t o e n s u r e s a f e t e m -

p o r a r y s t o r a g e and t o m a i n t a i n t h e o p e r a t i o n a l c a p a b i l i t y of t h e f a c i l i t y . Some y e a r s l a t e r , i t became e v i d e n t t h a t t h e f a c i l i t y would n o t be r e s t a r t e d , a t least n o t as a molten-salt

reactor.

A decommissioning

s t u d y w a s done i n which two o p t i o n s were c o n s i d e r e d :

(1) removal of t h e

f u e l and f l u s h s a l t s , followed by complete d i s m a n t l i n g of t h e h o t c e l l s ; and ( 2 ) removal of t h e f u e l and f l u s h s a l t s , followed by entombment of t h e s t r u c t u r a l components w i t h i n t h e r e a c t o r and f u e l d r a i n cells.

The

second o p t i o n i s f a r less c o s t l y t h a n t h e f i r s t , b u t both are q u i t e e x p e n s i v e because of t h e removal of t h e r a d i o a c t i v e s a l t s , which must be processed and repackaged.

Obviously, b o t h o p t i o n s r e q u i r e a r e p o s i t o r y

which w i l l a c c e p t t h e processed and repackaged s a l t s .

No such r e p o s i t o r y

c u r r e n t l y e x i s t s ; n o r i s t h e r e any a s s u r a n c e t h a t one w i l l be a v a i l a b l e i n

t h e r e a s o n a b l y n e a r f u t u r e , even though t h e r e are s e v e r a l p o s s i b i l i t i e s . T h e r e f o r e , our t a s k i s t o determine what s t e p s should be t a k e n t o extend t h e s t o r a g e p e r i o d s a f e l y and what measures, i f any, should be adopted t o enhance t h e p r e s e n t s t o r a g e c o n d i t i o n s . I n d e a l i n g w i t h t h e s e q u e s t i o n s , t h e r e are s e v e r a l t i m e frames t h a t represent various operational l i m i t s .

These can be d e f i n e d and d e s c r i b e d

as follows: 1.

Short t e r m :

1 t o 20 years.

This i s t h e p e r i o d d u r i n g which i n - c e l l

o p e r a t i o n s can s t i l l be c a r r i e d o u t w i t h confidence.

Final disposal

o p t i o n s w i l l be more c l e a r l y d e f i n e d a t t h e end of t h i s p e r i o d . During t h i s t i m e span, t h e f i s s i o n product a c t i v i t i e s w i l l decay t o about two-thirds of t h e i r p r e s e n t l e v e l .

20 t o 100 y e a r s .

Near term:

During t h i s p e r i o d , i n s t i t u t i o n a l

c o n t r o l can be maintained; t h e r e f o r e , i t i s t h e l o g i c a l t i m e t o t r a n s f e r t h e f u e l (and f l u s h ) s a l t s t o t h e f i n a l r e p o s i t o r y .

The

f i s s i o n product a c t i v i t i e s w i l l decay t o about 15% of t h e i r p r e s e n t l e v e l d u r i n g t h i s t i m e span.

Midterm:

100 t o 1000 y e a r s .

man-made c o n c r e t e s t r u c t u r e .

This i s a r e a s o n a b l e l i f e t i m e f o r a During t h i s t i m e , t h e f i s s i o n product

a c t i v i t i e s w i l l decay t o e s s e n t i a l l y z e r o , w h i l e t h e U-232 and plutonium a c t i v i t i e s w i l l decay t o about 3% of t h e i r p r e s e n t l e v e l ; however, t h e U-233 a c t i v i t y w i l l grow i n t o about 180% of i t s present level.

Long term:

1000 t o 1 m i l l i o n y e a r s .

c o n t r o l l i n g f a c t o r f o r t h i s period.

Geology w i l l be t h e During t h i s t i m e , o n l y t h e

U-233 decay c h a i n w i l l have any s i g n i f i c a n c e .

Its a c t i v i t y w i l l

peak a f t e r 40,000 y e a r s a t about 900% of t h e p r e s e n t l e v e l and w i l l t h e n decay permanently.

3.1

HISTORY

DESCRIPTION The primary r e a c t o r and d r a i n system components a r e c o n t a i n e d w i t h i n

t w o i n t e r c o n n e c t e d c e l l s ; t h e c o o l a n t and f u e l p r o c e s s i n g systems are l o c a t e d s e p a r a t e l y w i t h i n a d j o i n i n g c e l l s ( F i g s . 1 and 2).

The r e a c t o r

and d r a i n t a n k c e l l s are s e a l e d p r e s s u r e v e s s e l s t h a t s e r v e as secondary containment f o r t h e f u e l .

The r e a c t o r c e l l i s a 24-ft-diam

while t h e d r a i n tank c e l l i s a s t a i n l e s s steel-lined rectangular tank.

steel tank,

reinforced concrete

Each c e l l h a s removable roof beams and s h i e l d b l o c k s

w i t h a s t a i n l e s s s t e e l membrane seal t h a t must be c u t open f o r access. The c o o l a n t system and f u e l p r o c e s s systems are l o c a t e d w i t h i n s h i e l d e d

c e l l s t h a t are k e p t a t a s l i g h t l y n e g a t i v e p r e s s u r e and are swept by a Access I s gained v i a removable t o p

containment v e n t i l a t i o n system. s h i e l d plugs.

The a s s o c i a t e d equipment i s housed i n a s t e e l - c o n c r e t e

t r a n s i t e s t r u c t u r e t h a t h a s containment f e a t u r e s .

Both t h e containment

c e l l s and t h e high-bay area are maintained under n e g a t i v e p r e s s u r e , w i t h a n a c t i v e v e n t i l a t i o n system c o n s i s t i n g of c e n t r i f u g a l f a n s and roughing and HEPA f i l t e r s t h a t exhaust through a 100-ft s t e e l d i s c h a r g e s t a c k . The r e a c t o r h e a t d i s s i p a t i o n system i n c l u d e d a s a l t - t o - a i r

radiator

e x h a u s t i n g through a s t e e l s t a c k and a d r a i n t a n k f o r s t o r a g e of t h e c o o l a n t s a l t , where t h i s material now r e s i d e s .

i s e s s e n t i a l l y nonradioactive.

This s t o r e d c o o l a n t s a l t

Ancillary f a c i l i t i e s a t the s i t e include

a n o f f i c e b u i l d i n g , a d i e s e l g e n e r a t o r house, a u t i l i t y b u i l d i n g , a blower house, a cooling-water tower, and a vapor condensing system. These f a c i l i t i e s have been d e s c r i b e d i n d e t a i l i n o t h e r r e p o r t s . 4 , 5 , 1 5 s 1 8 The t h r e e c e l l s of most concern t o t h i s s t u d y ( r e a c t o r , d r a i n , and proc e s s i n g ) are d e s c r i b e d i n terms of p e n e t r a t i o n s and "containment envel o p e s " i n Sect. 4.3

p r o p e r t i e s and t h e

j o r components of t h e material of c o n s t r u c t i o n ,

Hastelloy N (also c

l e d INOR-8),

The p r e s e n c e o

A f u e l - s a l t d r a i n t a n k i s shown i n Fig. 3; t h e

are l i s t e d i n Table 1.15

t h e s o l i d i f i e d , s t o r e d f u e l and f l u s h s a l t s i s t h e

most s i g n i f i c a n t a s p e c t of t h e MSRE.

More t h a n 4600 kg of f u e l s a l t and

4300 kg of f l u s h s a l t , c o n t a i n i n g about 37 kg of uranium ( p r i m a r i l y U-233)

oi c

FUEL SALT SYSTEM FILL AND DRAIN LINE

TANK FILL LINE

MSR Primary Drain and Fill Tank Fig. 3.

Fuel-salt d r a i n tank.

13 Table 1.

Composition and p r o p e r t i e s of INOR-8 ( a l s o known as H a s t e l l o y N )

Chemical compositon, %

66-7 1 15-18 6-8 5 0.04-0.08 0.5 0.02 1.0 1.0 1.0 0.35 0.01 0.5 0.015 0.2

Ni Mo Cr F e , max C T i + A l , max S , max

max max max max B, max W , max P, max Co, max Mn, Mn, Si, Cu,

Physical properties: Density, l b / i n . Melting p o i n t ,

0.317 2470-25 55

O F

Thermal c o n d u c t i v i t y , B t u / ( h * f t * O F ) a t 1300째F

12.7

Modulus of e l a s t i c i t y a t -1300"F, p s i

24.8 x lo6

S p e c i f i c h e a t , Btu/lb*'F a t 1300'F

0.138

Mean c o e f f i c i e n t of thermal expansion, 70 t o 1300'F r a n g e , in./in.*OF

8.0 x 10-6.

Mechanical p r o p e r t i e s : Maximum a l l o w a b l e stress,a p s i

1000째F 1100째F 1 200째F 1300'F a

17,000 13,000 6,000 3,500

ASME B o i l e r and P r e s s u r e Vessel Code, Case 1315.

14 and 743 g of plutonium ( p r i m a r i l y Pu-239) are p r e s e n t i n t h e d r a i n t a n k s . C a l c u l a t e d f i s s i o n product a c t i v i t i e s (mainly beta-gamma) decayed t o 1985, t o t a l about 32,000 C i .

of t h e s e s a l t s ,

The a l p h a a c t i v i t y from t r a n -

s u r a n i c i s o t o p e s and t h e i r d a u g h t e r s amounts t o about 2000 C i .

These

i s o t o p e s are d i v i d e d roughly 99% i n t h e f u e l s a l t and 1%i n t h e f l u s h

salt.

The t o t a l a l p h a a c t i v i t y of t h e f u e l s a l t i s v e r y h i g h , about

400,000 nCi/g, w h i l e t h a t of t h e f l u s h s a l t i s about 6000 nCi/g.

The

t o t a l decay h e a t a t p r e s e n t i s about 200 W, w i t h t h r e e - f o u r t h s coming from t h e beta-gamma component and t h e remainder from t h e a l p h a emissions. The compositions of t h e f u e l , f l u s h , a n d c o o l a n t s a l t s a r e g i v e n i n Table

The l a t t e r s a l t , which s e r v e d as a secondary c o o l a n t , i s n o t radioac-

t i v e and i s s t o r e d i n t h e c o o l a n t c e l l .

It i s of i n t e r e s t p r i m a r i l y

because i t c o n t a i n s 338 kg of h i g h - p u r i t y Li-7. As expected, t h e r a d i a t i o n hazards associated with t h e s t o r e d f u e l

are significant.

Gamma and n e u t r o n dose r a t e s w i t h i n t h e r e a c t o r and

s t o r a g e c e l l s are i n t h e l o 3 r a d / h range.

Some of t h i s r a d i a t i o n

r e s u l t s from (ct,n) r e a c t i o n s w i t h t h e e u t e c t i c s a l t base.

The h i g h

r a d i a t i o n f i e l d a l s o c a u s e s t h e g e n e r a t i o n of some f r e e f l u o r i n e , which s l o w l y accumulates.

Since recombination ( w i t h t h e metal s i m u l t a n e o u s l y

s e t f r e e i n t h e r a d i o l y s i s ) i s a c c e l e r a t e d by i n c r e a s e d t e m p e r a t u r e , t h e s a l t i s r e h e a t e d p e r i o d i c a l l y ; however, i t i s n o t melted.

The s t o r e d

s a l t s are i n a s t a b l e , n o n c o r r o s i v e s t a t e , as d r y f r o z e n s o l i d s . I n a d d i t i o n t o t h e s t o r e d f u e l , t h e p r i n c i p a l areas of concern a t t h e MSRE a r e t h e r e a c t o r components and p r o c e s s equipment remaining i n t h e below-grade containment c e l l s .

These components are i n t e r n a l l y con-

taminated and, i n some cases, h i g h l y n e u t r o n a c t i v a t e d .

Exposure r a t e s

o f up t o 2200 R/h have been measured i n t h e r e a c t o r v e s s e l , a t t r i b u t e d p r i m a r i l y t o Co-60.

The i n v e n t o r y of r e s i d u a l r a d i o a c t i v e materials i n

t h e r e a c t o r and f u e l p r o c e s s i n g c e l l s i s e s t i m a t e d t o be s e v e r a l thousand c u r i e s , w i t h t h e m a j o r i t y of t h a t a c t i v i t y being a s s o c i a t e d w i t h f i s s i o n and a c t i v a t i o n p r o d u c t s .

The remaining c e l l s , p r o c e s s p i p i n g , and asso-

c i a t e d o p e r a t i n g areas are known t o be s l i g h t l y contaminated.

The

r e a d i l y a c c e s s i b l e areas of t h e r e a c t o r b u i l d i n g ( i n c l u d i n g t h e r e a c t o r bay and o f f i c e a r e a s ) are g e n e r a l l y uncontaminated and are being used f o r l a b o r a t o r y and o f f i c e s p a c e , as w e l l as f o r s t o r a g e of v a r i o u s materials.

T a b l e 2.

S t o r e d MSKE s a l t s

Fuel salt

T o t a l mass, kg volume, f t 3 a t room t emp e r a t u r e D e n s i t y , g/cm3 Composition, mol % L iF

Flush salta

4290

4650 66.4

2.47

69.9 2.17

64.5

66b

BeF2

30.3

34b

ZrF4

5.0

---

0.13

UF 4 Uranium c o n t e n t , kg U-232 U-233 U-234 U-235 U-236 U-238 Total Plutonium c o n t e n t , g Pu-2 3 9 Pu-240 O t h e r Pu To t a l Lithium composition, % Li-6 Li-7

Coolant s a l t a

30.82 2.74 0.85 0.04 2.01

0.19 0.02 0.09 0.00 0.19

36.46 657 69 2

0.49

13 2 0

728

0.009d 99.991d

aTrace-element a n a l y s e s of 39 b a t c h e s used f o r b o t h s a l t s gave 1 6 ppm C r , 39 ppm N i , and 121 ppm Fe. Tbelve o t h e r a n a l y s e s of t h e f l u s h s a l t g a v e 38, 22, and 118 ppm, r e s p e c t i v e l y . (Note: Could t h e C r and N i have been i n t e r c h a n g e d ? ) I n a n o t h e r s e r i e s of 22 b a t c h e s , t h e c o r r e s p o n d i n g v a l u e s were 19, 25, and 166 ppm. bReported v a l u e s . A n a l y t i c a l d a t a f o r b a t c h e s 1 1 6 1 6 1 gave 6 3 and 37%, c a l c u l a t e d from r e p o r t e d v a l u e s of 12.95 w t % L i , 9.75 w t % B e , and 77.1 w t % F. For b a t c h e s 101-130, t h e c a l c u l a t e d c o m p o s i t i o n w a s 64.3 and 35.7%. C P r e s e n t a t 220 ppm, IJ-basis. d F o r b a t c h e s 116-142. The v a l u e s a r e 0.0065/99.9935 f o r b a t c h e s 143161.

16 The MSRE f a c i l i t y a p p e a r s t o be s t r u c t u r a l l y sound and c a p a b l e of r e t a i n i n g t h e c u r r e n t radionuclide inventory.

No s i g n i f i c a n t s p r e a d of

contamination o r personnel exposure h a s occurred s i n c e f a c i l i t y

s hut down.

3 . 2 SURVEILLANCE AND MAINTENANCE A comprehensive maintenance and s u r v e i l l a n c e program i s provided t o

e n s u r e adequate containment of t h e r e s i d u a l r a d i o a c t i v i t y a t t h e MSRE. Routine i n s p e c t i o n s of t h e containment systems and b u i l d i n g s e r v i c e s , r a d i o l o g i c a l s u r v e i l l a n c e of o p e r a t i n g areas and v e n t i l a t i o n e x h a u s t , stored-salt

monitoring ( t e m p e r a t u r e and p r e s s u r e ) , and p e r i o d i c t e s t i n g

o f s a f e t y systems a r e performed as p a r t of t h i s program.

In a d d i t i o n ,

t h e f u e l and f l u s h s a l t are r e h e a t e d i n o r d e r t o a l l o w recombination of f l u o r i n e , a n d t h e containment c e l l s are s u b j e c t e d t o a l e a k t e s t , b o t h on an annual b a s i s .

F a c i l i t y maintenance i n c l u d e s g e n e r a l r e p a i r s ,

e x h a u s t d u c t f i l t e r changes, and i n s t r u m e n t a t i o n and c o n t r o l s maintenance.

C o n s o l i d a t i o n of t h e s u r v e i l l a n c e i n s t r u m e n t a t i o n and p e r i o d i c

h e a t e r and c o n t r o l s tests are planned as major improvements t o t h e c u r r e n t program. The s a l t s t o r a g e c e l l s have been under a planned program of r e g u l a r s u r v e i l l a n c e and maintenance s i n c e t h e r e a c t o r w a s s h u t down i n l a t e 1969.

This program i n c l u d e s d a i l y o b s e r v a t i o n s of c e r t a i n parameters by

t h e Waste C o n t r o l Operations Center and monthly o b s e r v a t i o n s by t h e Reactor Operations Group.

The d a i l y o b s e r v a t i o n s i n c l u d e measurements of

i n t e r n a l c e l l temperature, building-air

radioactivity, pressure differen-

t i a l s of t h e c e l l v e n t i l a t i o n system, and s t a c k off-gas r a d i o a c t i v i t y l e v e l s i n terms of a l p h a , beta-gamma,

and r a d i o i o d i n e .

These obser-

v a t i o n s are recorded on l o g s h e e t s ( t h e l o g s have been k e p t s i n c e 1969). The r a d i o a c t i v i t y d a t a are now a l s o computerized and c o o r d i n a t e d through t h e c e n t r a l Waste C o n t r o l Operations Center.

A primary i n p u t p o i n t t o

t h e Center i s l o c a t e d i n t h e c o n t r o l room i n 7503. The monthly c h e c k l i s t i n v o l v e s a complete walk-through i n s p e c t i o n o f t h e e n t i r e f a c i l i t y p l u s r e c o r d i n g s of i n - c e l l t e m p e r a t u r e s and sump l e v e l s a t seven l o c a t i o n s .

Any n e c e s s a r y maintenance items are noted and

added t o t h e l i s t of work t o be scheduled. k e p t s i n c e 1969.)

(These l o g s have a l s o been

17 On an a n n u a l b a s i s , t h e t h r e e f u e l and f l u s h s a l t t a n k s are r e h e a t e d t o recombine any e l e m e n t a l f l u o r i n e t h a t may have formed from radiolysis.

The a c c e p t a b l e temperature range f o r t h e r e h e a t i n g i s

>300째F ( t o e n s u r e t h a t t h e d i f f u s i o n rate i s f a s t enough) but <500째F ( w e l l below t h e m e l t i n g p o i n t of t h e s a l t s ) .

The r e a c t o r and d r a i n t a n k

c e l l s are a l s o l e a k - t e s t e d a n n u a l l y , and a check i s made of about 40 equipment i t e m s .

In a d d i t i o n , s p e c i a l checks are made of t h e ven-

t i l a t i o n system, two of t h e sump pumps, and t h e DOP e f f i c i e n c y of t h e ventilation filter. During t h e c o u r s e of t h i s s t u d y , i t became a p p a r e n t t h a t d a t a on b u i l d i n g groundwater were needed. added t o t h e S&M procedures:

Therefore, two a d d i t i o n a l i t e m s were

a p e r i o d i c check of t h e r a d i o a c t i v i t y of

t h e b u i l d i n g sump d i s c h a r g e , and a p e r i o d i c check of t h e o p e r a t i n g f r e quency of t h e b u i l d i n g sump pump.

The r a d i o a c t i v i t y measurements, which

were i n i t i a t e d i n June, have c o n s i s t e n t l y shown no a c t i v i t y above background.

The sump pump monitoring was s t a r t e d on August 19, and

d a i l y r e a d i n g s show an o p e r a t i n g c y c l e of about 1 h/d. t h e p e r i o d w a s g r e a t e r t h a n normal. gal/min.

R a i n f a l l during

The pump c a p a c i t y i s about 35

These measurements w i l l be continued f o r a t least 1 y e a r i n

o r d e r t o e s t a b l i s h a d a t a base t h a t c o v e r s one complete a n n u a l weather cycle.

3.3

PRIOR STUDIES

Decommissioning of t h e MSRE p r e s e n t s some unique problems because of t h e p r e s e n c e of t h e f u e l and f l u s h s a l t s ,

Plans f o r s i t e decommissioning

w i l l f i r s t have t o a d d r e s s t h e i s s u e of d i s p o s i t i o n of t h e f u e l .

In t h e

e a r l y s t u d i e s , i t was g e n e r a l l y assumed t h a t t h e s t o r e d f u e l would be removed from t h e MSRE c e l l s , w i t h o r w i t h o u t r e p r o c e s s i n g ( f l u o r i n a t i o n ) t o s t r i p o u t t h e uranium and some of t h e f i s s i o n p r o d u c t s , and t h e n s e n t t o a f i n a l r e p o s i t o r y o r t o r e t r i e v a b l e s t o r a g e ; however, t h e s e o p e r a t i o n s

are complex and p o t e n t i a l l y hazardous and, t h e r e f o r e , expensive. 3 , 5,16, Thus f a r , no need f o r t h e r e c o v e r a b l e U-233 o r f o r t h e c e l l s p a c e h a s been e s t a b l i s h e d .

Therefore, t h e r e h a s been no i n c e n t i v e from t h a t

d i r e c t i o n t o proceed w i t h decommissioning.

F u r t h e r , t h e r e i s no known

s i t e t h a t w i l l accept the fluoride f u e l salt f o r disposal i n i t s present c o n d i t i o n , e i t h e r now o r i n t h e n e a r f u t u r e .

Consequently, i t a p p e a r s

t h a t t h e s o l i d i f i e d s a l t s must c o n t i n u e t o be s t o r e d i n t h e i r p r e s e n t mode and l o c a t i o n , r e g a r d l e s s of f u t u r e p o s s i b i l i t i e s , needs, o r decisions.

F o r t u n a t e l y , t h i s i s p o s s i b l e because t h e s a l t s , t h e i r c o n t a i n -

ment, and t h e f a c i l i t y are i n e x c e l l e n t c o n d i t i o n .

However, i t i s

e s s e n t i a l t o a d d r e s s two i s s u e s n o t d i r e c t l y c o n s i d e r e d i n p r i o r studies:

Is i t r a t i o n a l t o c o n t i n u e s t o r i n g t h e s e s a l t s i n t h e i r p r e s e n t s i t u a t i o n and, i f so, what g u i d e l i n e s should be followed t o enhance t h i s s t o r a g e i n terms of s a f e t y and s t a b i l i t y f o r an extended p e r i o d of t i m e ?

What o t h e r o p t i o n s e x i s t f o r t h e f u t u r e , and what s t e p s s h o u l d be t a k e n i n t h e n e a r term t o f a c i l i t a t e f u t u r e decision-making? T h i s s t u d y g i v e s a n a f f i r m a t i v e answer t o t h e f i r s t q u e s t i o n and

i d e n t i f i e s s p e c i f i c areas where improvements s h o u l d be made.

It a l s o

p i n p o i n t s needs t h a t should be a d d r e s s e d i n t h e s h o r t term t o p r o v i d e n e c e s s a r y i n f o r m a t i o n f o r f u t u r e s e l e c t i o n among a v a i l a b l e o p t i o n s . F i n a l l y , a p r e l i m i n a r y work p l a n i s o u t l i n e d t o a c h i e v e t h e above

o b j ec t i v e s

3.4

OPTIONS

P r i o r s t u d i e s of MSRE decommissioning have focused on t h e f i n a l d i s p o s i t i o n of b o t h t h e s a l t s and t h e f a c i l i t y .

S e l e c t i o n among o p t i o n s

involved many p o s s i b l e d e c i s i o n p o i n t s , i n c l u d i n g t h e f o l l o w i n g :

Should t h e s a l t be c h e m i c a l l y processed t o s e p a r a t e t h e uranium (and some f i s s i o n p r o d u c t s ) from t h e bulk of t h e f l u o r i d e

salts? B.

Should t h e f l u o r i d e s a l t s be c h e m i c a l l y converted t o a n o t h e r form?

Should t h e s a l t s ( w i t h o r without p r o c e s s i n g a n d / o r conversion) be packaged and s e n t t o an o f f - s i t e r e p o s i t o r y o r an o n - s i t e s t o r a g e / d i s p o s a l area, o r should t h e y be d i s p o s e d of i n t h e MSRE f a c i l i t y i t s e l f ?

Should t h e MSRE f a c i l i t y be t o t a l l y o r p a r t i a l l y d i s m a n t l e d and p o r t i o n s of i t entombed i n c o n c r e t e ?

A t p r e s e n t , t h e r e i s no f i r m b a s i s f o r s e l e c t i n g among t h e s e

options.

Options A o r B, i f e x e r c i s e d , would r e q u i r e s o p h i s t i c a t e d chem-

i c a l p r o c e s s i n g of h i g h l y r a d i o a c t i v e materials; new f l o w s h e e t s and

19 p r o c e s s i n g equipment would a l s o be needed (and t h e equipment would u l t i m a t e l y have t o be d i s p o s e d o f ) .

The t o t a l c o s t of p r o c e s s i n g might be

a s h i g h as $10 t o $20 m i l l i o n .

No c h o i c e can be e x e r c i s e d on o p t i o n (C)

a t t h i s t i m e because t h e r e i s no o f f - s i t e o r o n - s i t e l o c a t i o n t h a t can accept t h i s material a t p r e s e n t , and w e do n o t have an adequate b a s i s a t p r e s e n t t o recommend permanent d i s p o s a l i n t h e MSKE f a c i l i t y i t s e l f . Option D c o u l d c o s t as much as $10 m i l l i o n and r e q u i r e s a p r i o r d e c i s i o n on o p t i o n s A , B, and C. In s h o r t , w e need t o d e f e r a f i n a l d e c i s i o n .

Continued s t o r a g e of

t h e f u e l and f l u s h s a l t s i s f o r c e d upon us by e x t e r n a l c o n d i t i o n s .

The

i s s u e s of concern, t h e n , r e v o l v e around t h r e e q u e s t i o n s t h a t need t o be considered :

Is i s r e a s o n a b l e and s a f e t o p l a n continued storage-in-place

f o r up

t o 20 y e a r s o r so?

Before d e l i b e r a t e l y embarking on such extended s t o r a g e , what, i f a n y t h i n g , should be done t o enhance t h e s t o r a g e environment?

During t h i s s t o r a g e p e r i o d , o r p r i o r t o i t , what should be done t o f a c i l i t a t e a f u t u r e d e c i s i o n of a f i n a l n a t u r e ?

I n o r d e r t o g a i n a s e n s e of p e r s p e c t i v e , i t i s i n s t r u c t i v e t o d e f i n e a range of o p t i o n s and s y s t e m a t i c a l l y e v a l u a t e them a g a i n s t various criteria.

The s i x o p t i o n s t h a t have been t r e a t e d t h i s way as

p a r t of t h e e v a l u a t i o n are l i s t e d and d e f i n e d i n Table 3.

(Option 0,

w h i c h i s e s s e n t i a l l y t o c o n t i n u e t h e p r e s e n t p r a c t i c e , i s n o t acceptable

f o r an extended p e r i o d of time.)

Options 1, 2, and 3 focus on t h e f i n a l

d e c i s i o n and b r a c k e t a wide range of p o s s i b i l i t i e s ; t h i s p r o v i d e s a broad, long-term p e r s p e c t i v e .

Options 4 , 5 , and 6 f o c u s on t h r e e

v a r i a t i o n s of enhanced storage-in-place near-term needs i n t o view.

i n o r d e r t o b r i n g short-term and

The s t e p s used f o r a s s e s s i n g e a c h o p t i o n are

as follows:

L i s t t h e p r o c e s s o p e r a t i o n s involved and compare them q u a l i t a t i -

vely.

E v a l u a t e them s e m i q u a n t i t a t i v e l y on t h e b a s e s of ( a ) p r o c e s s r e a d i n e s s , ( b ) economics, ( c ) short-term h a z a r d , ( d ) long-term h a z a r d , and ( e ) c o n s e r v a t i o n ( i . e . , and c o n t a i n e d m a t e r i a l s ) .

b e n e f i c i a l u t i l i z a t i o n of t h e b u i l d i n g s

Table 3 .

Options f o r t h e Decontamination and Decommissioning of t h e MSRE

Option 0

Action t o Be Taken Continue as i s , w i t h no d e c i s i o n .

Requires continued

s u r v e i l l a n c e and maintenance, i n t r o d u c e s maximum uncert a i n t y , and e v e n t u a l l y s t i l l needs a d e c i s i o n between t h e

"real" o p t i o n s o u t l i n e d below.

Complete dismantlement of h o t c e l l s f o l l o w i n g removal of f u e l and f l u s h s a l t s .

Entombment of r e a c t o r and d r a i n t a n k c e l l s f o l l o w i n g remov a l of f u e l and f l u s h s a l t s .

Entombment of r e a c t o r and d r a i n t a n k c e l l s , w i t h f u e l and f l u s h s a l t s in-place.

Enhanced near-term s t o r a g e of s o l i d i f i e d s a l t s (which s t i l l leaves a l l other options available).

Enhanced s t o r a g e i n - p l a c e ,

i n c l u d i n g remelt and a d d i t i o n

o f g e t t e r s (which s t i l l l e a v e s o p t i o n s 1, 2 , 3 , and 6 available).

Enhanced s t o r a g e i n - p l a c e ,

i n c l u d i n g remelt, a d d i t i o n of

g e t t e r s , and repackaging (which s t i l l l e a v e s o p t i o n s 1, 2, and 3 a v a i l a b l e ) .

Identify the limiting factor(s).

Of n e c e s s i t y , t h e s e e v a l u a t i o n s a r e s u b j e c t i v e and o n l y s e m i q u a n t i t a t i v e a t t h i s stage.

The f i r s t e v a l u a t i o n (Table 4 ) l i s t s t h e major p r o c e s s s t e p s t h a t would be r e q u i r e d f o r t h e v a r i o u s o p t i o n s and i n d i c a t e s which s t e p s are r e q u i r e d i n e a c h case. r e p r e s e n t s a more-or-less

The s t e p s were d e f i n e d i n such a way t h a t each equivalent e f f o r t o r cost.

Evaluation then

simply r e q u i r e s c o u n t i n g t h e number of s t e p s f o r t h e p a r t i c u l a r o p t i o n i n question.

C l e a r l y , from t h i s p o i n t of view, o p t i o n s 1 and 2 are pro-

h i b i t i v e l y complex (and c o s t l y ) and would n o t be s e l e c t e d u n l e s s t h e r e

were a n o v e r r i d i n g r e a s o n f o r doing so. The second e v a l u a t i o n i n v o l v e s " s c o r i n g " each o p t i o n f o r e v e r y a p p l i c a b l e p r o c e s s s t e p , as i d e n t i f i e d i n Table 4. t a b u l a t e d i n Appendix B.

These r e s u l t s a r e

Scoring, which w a s done on f i v e d i f f e r e n t

b a s e s , w a s s e t up s o t h a t a low s c o r e i s more f a v o r a b l e t h a n a h i g h score.

The a v a i l a b l e s c o r i n g ranges were s e l e c t e d t o b a l a n c e t h e rela-

t i v e importance of each of t h e f i v e f a c t o r s , on t h e assumption t h a t near-term h a z a r d , long-term hazard, and c o n s e r v a t i o n were each about

twice as i m p o r t a n t as e i t h e r p r o c e s s r e a d i n e s s o r economics. e a c h c r i t e r i o n , as w e l l as t o t a l s , a r e summarized i n Table 5.

Scores f o r The

t o t a l s were converted t o a more normal s c a l e of 0 t o 100, w i t h a high s c o r e more f a v o r a b l e , by t a k i n g r e c i p r o c a l s of e a c h t o t a l and t h e n norm a l i z i n g by d i v i d i n g by t h e l a r g e s t v a l u e ( t h e 0.0161) by 100.

and m u l t i p l y i n g

On t h i s b a s i s , Options 3, 4 , and 5 are d i s t i n c t l y s u p e r i o r t o

Options 1, 2, and 6. The t h i r d e v a l u a t i o n ( T a b l e 6 ) i d e n t i f i e s l i m i t i n g f a c t o r s t h a t would d i s q u a l i f y a n o p t i o n from f u r t h e r c o n s i d e r a t i o n a t p r e s e n t .

While

t h i s evaluation i s the least quantitative, i t is, nonetheless, highly s i g n i f i c a n t because i t s e e k s t o i d e n t i f y c o n t r o l l i n g f a c t o r s .

The

l i m i t i n g f a c t o r s are t h o s e which, i f n o t w i t h i n an a c c e p t a b l e r a n g e , would e l i m i n a t e t h a t o p t i o n no matter how f a v o r a b l e t h e o t h e r aspects might be.

Thus, i n terms of t h e f i v e c r i t e r i a a l r e a d y e s t a b l i s h e d ,

Options 1 and 2 should n o t be considered f u r t h e r a t t h i s t i m e .

When two

a d d i t i o n a l c r i t e r i a were i n t r o d u c e d , based on a n t i c i p a t e d p u b l i c react i o n and on r e v e r s i b i l i t y r e g a r d i n g f u t u r e c h o i c e of o p t i o n s ; Option 3

w a s a l s o removed from c o n s i d e r a t i o n .

Table 4.

Process s t e p s r e q u i r e d f o r MSRE o p t i o n s Option

Process s t e p

Melt s a l t s (and add g e t t e r s )

Remove s a l t s

Build s a l t p r o c e s s f a c i l i t y

P r o c e s s o r c o n v e r t salts/U

Package s a l t s (and U)

D i smant l e / d i s p o s e of f a c i l i t y

T r a n s p o r t packaged p r o d u c t s

S t o r e / i s o l a te p r o d u c t s

Decontaminate c e l l s / e q u i p m e n t

Dispose of l i q u i d LLW

Remove equipment

Dispose of s o l i d LLW

Dismantle c e l l s t r u c t u r e

Dispose of s o l i d LLWIrubble

R e s t o r e area

Seal pipes/ penetrations

I n t e r n a l entombment

External structures S t a b i l i z e drain-tank c e l l Continue s u r v e i l l a n c e Number of more-or-less equal process s t e p s involved

Table 5.

Summary of semiquantitative evaluation Option

Factor

A. Process readiness

B. Economics

C . Near-term hazard

D. Long-term hazard

To t a1

185

147

Reciprocal

0.0054

0.0068

0.0161

0.0145

0.0128

0.0102

Conservation

Normalized

100

Table 6 .

L i m i t i n g f a c t o r s f o r MSKE o p t i o n s 1

k c i s i o n nowa

XXX

xxx

D e c i s i o n i n 5-20 y e a r s

???

Factor

Process readiness

Economics

XXX

xxx

Near-term h a z a r d

xxx

I>.

Long-term h a z a r d Minimal f o r a l l o p t i o n s

xxx

Conservation

Institutional perception of anticipated public reaction D e c i s i o n now D e c i s i o n in 5-20

xxx ???

yearsb

Keversibility/future c h o i c e of o p t i o n s

xxx

amere i s no i d e n t i f i e d l o c a t i o n a t t h i s t i m e w h e r e t h e removed s a l t s c o u l d be t a k e n . b P u b l i c r e a c t i o n may become more r a t i o n a l w i t h time, o r i n s t i t u t i o n a l l e a d e r s may r e g a i n p u b l i c c o n f i d e n c e .

The r e s u l t s of a l l t h r e e e v a l u a t i o n s are c o n s o l i d a t e d i n Table 7.

In summary, i n terms of t h e s e t h r e e e v a l u a t i o n s , and a t t h i s t i m e : 1.

Options 1 and 2 are r e j e c t e d on t h e b a s i s of e a c h e v a l u a t i o n .

Option 3 i s r e j e c t e d , based on l i m i t i n g f a c t o r s but r e c o g n i z i n g t h a t p u b l i c r e a c t i o n may change in f u t u r e y e a r s , and t h a t l a c k

of r e v e r s i b i l i t y may n o t be d e t r i m e n t a l when judged a g a i n s t more d e f i n i t i v e criteria. 3.

Option 6 d e s e r v e s f u r t h e r c o n s i d e r a t i o n based on t h e semiquant i t a t i v e evaluation.

This l e a v e s Options 4 and 5, and p o s s i b l y Option 6 , a v a i l a b l e f o r short-term s e l e c t i o n .

These o p t i o n s are addressed i n S e c t s . 4 and 5.

Some t o p i c s r e l e v a n t t o t h e o t h e r o p t i o n s a r e a l s o a d d r e s s e d ; however, much of t h e i n f o r m a t i o n p r e s e n t e d i s of broad and g e n e r a l a p p l i c a b i l i t y , and i s germane t o a l l o p t i o n s .

26 Table 7.

Options and e v a l u a t i o n s f o r d e c o n t a m i n a t i o n and decommissioning Scorea

Opt i o n

Description

C o n t i n u e as i s , w i t h no d e c i s i o n . R e q u i r e s cont inued s u r v e i l l a n c e and maintenance, i n t r o d u c e s maxiinum u n c e r t a i n t y , a n d e v e n t u a l l y s t i l l n e e d s a d e c i s i o n between t h e "real" o p t i o n s o u t l i n e d below.

Kemoval of f u e l a n d f l u s h s a l t s ; c o m p l e t e d i s mantlement of hot cells.

185

Removal of f u e l a n d f l u s h s a l t s ; entombment o f r e a c t o r and d r a i n t a n k c e l l s .

147

Entombment o f d r a i n t a n k c e l l , w i t h f u e l a n d f l u s h salts in-place.

Enhanced n e a r - t e r m s t o r a g e of s o l i d i f i e d s a l t s (which s t i l l leaves a l l o t h e r options a v a i l a b l e ) .

Enhanced s t o r a g e i n - p l a c e , i n c l u d i n g remelt a n d a d d i t i o n of getters (which s t i l l leaves Options 1 , 2 , 3, a n d 6 a v a i l a b l e ) .

E n h a n c e d s t o r a g e i n - p l a c e , i n c l u d i n g remelt, a d d i t i o n of g e t t e r s , a n d r e p a c k a g i n g ( w h i c h s t i l l l e a v e s Options 1, 2 , and 3 d v a i l a b l e ) .

a l l cases, a low s c o r e i s s u p e r i o r . bNumber o â&#x201A;Ź p r o c e s s s t e p s i n v o l v e d . CSemiquantitative rating of process steps. dNumber of l i m i t i n g f a c t o r s .

4. 4.1

PROJECTIONS

RADIOACTIVITY

The o r i g i n a l decay c a l c u l a t i o n s , made u s i n g ORIGEN and MSRE-specific i n p u t d a t a , were t r u n c a t e d a t 5 years.â&#x20AC;&#x2122; been e x t r a p o l a t e d t o t h e year 2000. l 6

Subsequently, t h e s e d a t a have However, any d e c i s i o n s r e g a r d i n g

permanent emplacement r e q u i r e decay d a t a o u t t o a m i l l i o n y e a r s , as w e l l

a s a d e t a i l e d knowledge of r a d i o l o g i c a l p r o p e r t i e s i n t h e 10- t o 10,000y e a r t i m e span.

I d e a l l y , t h e e n t i r e c a l c u l a t i o n ( g e n e r a t i o n and deple-

t i o n ) should be r e p e a t e d u s i n g ORIGEN2, t h e updated and improved v e r s i o n o f ORIGEN.

However, ORIGEN2 does n o t have a molten s a l t r e a c t o r model,

and c o n s t r u c t i o n of such a model would be p r o h i b i t i v e l y expensive. T h e r e f o r e , t h e approach was t o t a k e t h e o l d ORIGEN o u t p u t d a t a a t d i s c h a r g e and t h e n make t h e decay c a l c u l a t i o n s w i t h ORIGEN2.

When t h e s e

two s e t s of d a t a a t 5 y e a r s a f t e r d i s c h a r g e were cross-checked,

only

i n c o n s e q u e n t i a l o r r e a d i l y e x p l a i n a b l e d i f f e r e n c e s were noted.

This

g i v e s us c o n f i d e n c e i n u s i n g t h e ORIGEN-generated

r e s u l t s as our s t a r t i n g

point. The t r u n c a t e d ORIGEN d a t a were p r e s e n t e d i n f o u r groupings:

fission

p r o d u c t s i n both grams and c u r i e s , and a c t i n i d e s i n b o t h grams and curies.

A t l e a s t one a c t i v a t i o n product (Zr-93,

mixture) w a s i n c l u d e d i n t h e o l d ORIGEN runs.

from t h e f l u o r i d e s a l t The two sets of l i s t s

(grams and c u r i e s ) were g e n e r a l l y m u t u a l l y e x c l u s i v e ; t h a t i s , i s o t o p e s l i s t e d on t h e grams o u t p u t ( b e c a u s e t h e y were p r e s e n t i n a q u a n t i t y g r e a t e r t h a n 0.1% of t h e t o t a l mass) were g e n e r a l l y n o t i n c l u d e d on t h e c u r i e s o u t p u t (where t h e y appeared i f c o n t r i b u t i n g g r e a t e r t h a n 0.1% of the t o t a l radioactivity).

By combining t h e s e two sets of l i s t s , w e

b e l i e v e t h a t t h e i n p u t d a t a f o r our ORIGEN2 c a l c u l a t i o n s were a c c e p t a b l y

c ompl e t e. The summary r e s u l t s are g i v e n i n Tables 8 through 11 ( f i s s i o n prod u c t s and a c t i n i d e s ; grams and c u r i e s ) f o r t h e s e t i m e s :

Table 8. ORIGEN2 o u t p u t f o r MSRE s a l t s : grams of f i s s i o n p r o d u c t s and d a u g h t e r s SUHBARY TABLE: DISCHARGE RE SR SR SR

87 88 89 90 Y 89 Y 91 ZR 90 Z R 91 Z R 92 Z R 93 Z R 94 Z R 95 ZB 96 NB 93 N B 95 50 95 110 97 lY0 98 110100 TC 90 a 0 99 R0101 RUlO2 RU103 RU104 XU106 RH103 PD105 PD106 PD107 AG107 SB125 TE125 TE127H TE128 ?E12911 TE130 I127 I129 XE129 CS137 EA137 EA138 LA139 CE140 CE141 CE142 CE144 PRlUl YD143 ND144 ND145

8.480E+00 5.640E+00 5.5733+00 9.893E+01 6.660E+Ol 7.458E+OO 4.440E+00 9.730E+Ol 1.100E+02 lS190E+02 l.l802+02 9.306E+00 1.140E+02 0.0 4.397E+00 2.4403+01 3.250E+01 3.160E+01 2.850 E+O 1 2.990ElOl

0.0 1.950E+01 1.560E+01 2.292E+00 7.880E+00 2.238E+00 5.07 O E + O 1 1.820E+01 U.61 O E + O O 5.640E+00 0.0 6.176.~-01 0.0 4.175E-01 9.46 O E + O O 8.859E-01 2.090E+01 0.0 1.490E+01 0.0 1.287E+02 5.560E+00 7.440E+01 1.700E+02 1.890E+02 1.439E+01 1.730E+02 3.979E+01 1.700E+02 1.6702+02 1.130E+02 1.070E+02

CONCENTRATIONS, GRABS E N T I R E CORE (HSRE WITH 0-233 POEL) 1.OYR 1O.OYR 100.OYR 1.OKY

8.480E+00 5.6UOE+00 3.705E-02 9.6603+01 7.214E+01 9.8462-02 6.7683+00 1.047E+02 1.1003+02 1.190E+02 1.180E+02 1.779E-01 1.14OE+O2 3.9793-06 2.19422-01 3.7722+01 3.250E+01 3.160E+01 2.8 5OE+ 01 2.380E+01 9.6971-05 1.950E+01 1.560E+01 3.6593-03 7.8802+00 1.125E+00 5.299E+O 1 1.82OE+O1 5.723E+00 5,64OE+00 6.018E-07 4.8093-01 1.40UE-01 4.0923-02 9.460E+00 4.731.E-04 2.090E+01 3.889E-01 1.579E+01 6 . 9 7 2 ~0 7 1.2583+02 8.500E+00 7.440E+01 1.700E+02 1.890E+02 5.972E-03 1.730E+02 1.633E+01 1.844E+02 1.670E402 1.365E+02 1.070E+02

8.480E+00 5.64OE+00 9.390E-22 7.798E+Ol 7.217E+01 1.201E-18 2.540E+01 1 .OUSE+02 1.100E+02 1.190E+02 1.18OE+O2 6.0803-17 l.lUOE+02 1.379 E-04 7.416E-17 3.812E+01 3.250E+Ol 3.160E+01 2.850E+ 0 1 2.980E+01 9.6932-04 1.950E+01 1.560E+01 2.357E-28 7.8802+00 2.309E-03 5.299E+0 1 1.820E+01 6.846E+00 5.6402+00 6.018E-06 5.057E-02 5-7673-01 3.418E-11 9.460E+00 1.6731-33 2.090E+01 4 -299E-0 1 1.579E+01 6.972 E- 06 l.O21E+O2 3.211E+01 7.440E+01 1.700E+02 1.890E+02 2.183E-33 1.730E+02 5.395E-03 1.844E+02 1.670E+02 1.528E402 1.070E+02

10.0KY

10O.OKY

1.3RY

8.48 OE+OO 8.U80E+00 8.4803+00 8 .U80E400 5.640E+00 5.640E+00 5 . 6 4 0 2 + 0 0 5.640E+00 0.0 0.0 0.0 0.0 9.1543+00 4-5523-09 0.0 0.0 7.2173+01 7 , 2 1 7 3 + 0 1 7.2173+01 7.2173+01 0.0 0.0 0.0 0.0 9.42UE+01 1 . 0 3 4 3 + 0 2 1.03UE+02 1.034E+02 1.048E+02 1.048E+02 1.048E+02 1 .O48E+02 1.100E+02 1 - 1 0 0 E + 0 2 1.100E+02 1.100E+02 1-190E+02 1 - 1 8 9 3 + 0 2 1.185E+02 14137E+02 1.180E+02 1-180E+02 1.180E+02 1,18OE+02 0.0 0.0 0.0 0.0 l.lUOE+02 l.lUOE+02 1.140E+02 1.140E+02 4.39 3E-03 5,290E-02 5.3693-01 5.270E+00 0.0 0-0 0.0 0.0 3,812E401 3.812E+01 3 . 8 1 2 2 + 0 1 3.812E+01 3 . 2 5 0 3 + 0 1 3.2503+01 3.250E+Ol 3.250E+01 3.160E+01 3.160E+01 3.160E+01 3.160E+01 2.85 OE+ 01 2.8 50E+O 1 2.8 50E+ 01 2 - 8 5 OE+ 01 2,975E+G1 2,37OE+Oi i.8&5fi+l)l Z . l S L E + O l 9.69613-03 9.681E-02 9.541E-01 8.277E+00 1.950E+01 1.950E+01 1.950E+01 1.950E+01 1.560E+01 1.560E+01 1 . 5 6 0 2 + 0 1 1.560E+01 0.0 0.0 0.0 0.0 7.8802+00 7,88OE+00 7.880E+00 7.880E400 0.0 0.0 3.060E-30 0.0 5.29 9E+01 5.299 E+O 1 5.299E+0 1 5.299E+01 1.820!?+01 1.820E+01 1.820E+C1 1.820E+01 6.848E+00 6.848E+00 6.848E+00 6.848E+00 5.6UOE+OO 5.639E+00 5.634E+OO 5.580E+00 6.018E-05 6.018E-04 6.015E-03 5.9863-02 Oh0 8.368E-12 0.0 0.0 6.2803-01 6,280E-01 6.280E-01 6.280E-01 0.0 0.0 0.0 0.0 9.450E+00 9.460E+00 9.460E+00 9 .U60E+00 0.0 0.0 0.0 0.0 2.090E+01 2.090E+01 2.090E+01 2.090E+01 4 - 2 9 9E-01 4.2 99E-0 1 4 - 2 99E- 01 4 - 2 99E-01 1.579E+01 1.579E+01 1.578E401 1.572E+01 6 .97 2 E-05 6.9 7 2 E-0 4 6.971 E- 03 6.957 E-02 1.277E+Ol 1.1883-08 3.0 0.0 1.215E+02 1.343E+02 1.343E+02 1.343E+02 7.UUOE+O1 7.440E+01 7.440E+01 7.4403+01 1.700E+02 1.700E+02 1.700E+02 1.700E+02 1.890E+02 1.890E+02 1.890E+02 1.890E+02 0.0 0.0 0.0 0 .o 1.730E+02 1.7303+02 1.730E+02 1.730E+02 0.0 0.0 8.319E-38 0.0 1.8U4E+02 1.84UE+02 1.844E+02 1.844E+02 1.670E+02 1 . 6 7 0 E + 0 2 1.670E+02 1.670E+02 1.528E+02 1.528E+02 1.528E+02 1 . 5 2 8 E + 0 2 1.070E+02 1.070E+02 1.070E+02 1.070E+02

8.480!?+00 5.640E+00

0.0 0.0 7.217E+01 0.0 1.034E+02 1.048E+02 1.100E+02 7.564E+Ol 1.180E+02 0.0 1.140E+02 4.335E+Ol 0.0 3.812E+01 3.250F+01 3.160E+01 2.8 5 J E + 0 1 1.151E+00 2.865E+01 1.950E+01 1.560E+01 0.0

7.8803+00 0.0 5.299E+0 1 1.820E+01 6.848!?+00 5.069E+00 5.708E-01

0.0 6.280E-01

0.0 9.460E+00 0.0 2.090E+01 4.295 E-0 1 1.511f+01 6.8 21 E- 0 1 0.0 1.343E402 7.440E+01 1.700~+02 1.8902+02 0.0 1.730E402 0.0

1.8443+02 1.670~+02 1.528E+02 1.070E+02

DISCHARGE

Table 8.

(continued)

SUHNARS! TABLE: CONCENT2ATIONS. GRAMS E N T I R E CORE (NSRE H I T H U-233 FUEL) 1.OYR 1O.OYR 100.OYR 1.OKP

ND146 ND148 ND150 PB147 2B1483 SHl47 SM148 SHl5O SH151 Sa152 EU151 E0152 EU153 EU154 EU155 GD154 GD155 SUMTOT

8.410E+01 4.630E+Ol 1.900E+01 4.01 1E+01 4.9123-02 2.390E+01 0.0 2.710E+01 5.5853+00 1.460E+01

8.410E+01 4.63OE+Ol 1.900E+01 3.080E+01 1.069E-04 3.3213+01 4.901E-02 2.710E+01 5.5423+00 1. U60E+01 0.0 4.285E-02 2.955E-02 3.11OE-02 5.450E+00 5.45OE+00 1.303E-01 1.202E-01 7.629E-01 6.634E-01 0.0 1.009E-02 0.0 9.951E-02 2 . 7 0 9 3 + 0 3 2.7091+03

8.410E+01 4.630E+01 1 .900E+01 2.8563+00 1.1663-28 6.115E+01 4.912E-02 2.710E+01 5.171E+00 1.461E+O 1 4.140E-01 1.868E-02 5.450E+00 5.8203-02 1.8863-01 7.21OE-02 5.743E-01 2.7093+03

8,41OE+01 r(.630E+Ol 1.900E+01 1.3451-10 0.0 6,40lE+01 4.912E-02 2.710E+01 2S85E+00 1-46 2E+Ol 3.000E+00 1.9033-04 5.450E+00 4.118E-05 6.453E-07 1.303E-01 7.629E-01 2,7093+03

TOTAL

2.709 E+03 2.709E+03

2.709 E + O i 2.709E+03

100.OKY

1 .OBY

8.41OE+01 8.410E+01 8.410E+01 4 . 6 3 0 2 + 0 1 4.630E+Ol 4.630E+Ol 1 - 9 0 0 E + 0 1 1.9COE+01 l . Y O O E + O l 0.0 0.0 0.0 0.0 0.0 0.0 6.401E+01 6.401E+01 6.401E+01 4.912E-02 4-912E-02 4.9121-02 2.710E+01 2.710E+01 2.710E+01 2 - 5 2 4 3 - 0 3 1.982E-33 0.0 1.462E+01 1.462E+01 1 . 4 6 2 3 + 0 1 5.582E+00 5.585E+00 5.585E+00 2.286E-24 0.0 0.0 5.450E+00 5.450E+00 5.4503+00 1.294E-36 0.0 0.0 0.0 0.0 0.0 1.303E-01 1.3038-01 1.303E-01 7.629E-01 7.629E-01 7.629E-01 2.7098+03 2.709E+03 2.709E+03

8.410E+01 U.o30E+01 1.9UOE+01 0.0 0.0 6.401E+01 9.9125-02 2.710E+01 0.0 1 .U625+01 5.585E+00 0.0 5.450E+00 0.0

1O.OKY

2-7 0 9 E + 0 3 2 - 7 09E+ 03 2.709E+03

0.0 1.303E-01 7.62YE-01 2.709E+03 2.7 0 9 E + 0 3

30 Table 9. ORIGEN2 output f o r MSRE s a l t s : c u r i e s of f i s s i o n products and daughters sunmm DI SCH ABGE 1.620E+05 1.350E+04 1.360E+04 1.830E+05 2.99lE-01 2.000E+05 0.0 1.720E+05 4.1U9E+03 5.054E-01 7.400E+04 7.4913+03 7.401E+O4 8.949E+03 2.902~03 1.390E+02 6,3803+02 1.870E+02 3.279E+04 3.940E+03 9.790E+04 2.670E+O4 2.631E-03

TABLE: RADIOACTIVITY, CURIES ENTIRE CORE (MSRE WITH U-233 FUEL) 1.OYR 1O.OYR 100.OYR 1.OKY

SR 89 SR 90 P 90 Y 91 ZR 93 ZR 95 N B 9311 N B 95 N E 95n TC 99 RU103 RU106 RH103M RH106 PD107 SN123M SB125 TE125M TE127 TE127M TE129 TE129M I129 CS134 CS137 BA137M CE141 CE142 CE144 PR144 PR14411 PM147 P n148n SM151 EU152 EU154 EU155 S UMTOT

1.120E+04 1.050E+04 4.101E+05 4.15 3E- 06 1.2703+05 1.28OE+05 3.0 3.720E+04 1.050E+03 l.U70E+02 5.380E+00 3.519E+01 3.550E+02 1.800E+06

TOTAL

1.800E+06 2.068E+05

5.519B+00

1.077E+03 1.318E+04 1.319E+04 2,416E+03 2.991E-01 3.82UE+03 1- 4 1 273-02 8.5843+03 2.837E+01 5.054E-01 1.181E+02 3.766E+03 1.065E+02 3.7668+03 2.902E-03 0.0 4.967E+02 1.2163+02 3.782E+02 3.8623+02 9.282E+00 1.426E+01 2.7892-03 3.9443+00 1.094E+04 1.035E+O4 1.702E+02 4.153E- 06 5.211E+04 5.211E+04 6,2543+02 2.856E+04 2.2863+00 l.459E+02 5. 1133+00 3.246E+01 3.087E+02 2.068E+05

2-7293-17 1.064E+04 1.0643+04 2.948E-14 2-991E-01 1 -307E-12 1 1 3 5E-0 1 2.9013-12 9.694E-15 5.0542-01 7.611E-24 7.730E+00 6.86lE-24 7.730E+00 2.9028-03

.o n y

1OO.OKP

1O.OKY

5.224E+01 1.275E+Ol 3.160E-07 3.226E-07 3.2RlE-29 5.0413-29 2.789E-03 1.91UE-01 8.8893+03 8.4093+03 6.220E-29 4 -1 53 E- 06 1.722E+01 1.7222+01 2.066E-01 2,649E+03 2.492E-24 1.361E+02 3.232E+00 1.5722+01 8.773E+01 4.159E+04

0.0 1.249E+03 1.249E+03 0.0 2.9911-01 0.0 2 82 4 2-0 1 0.0 0-0 5.0522-01 0.0 1.0243-26 0.0 1.0243-26 2.902E-03 0.0 8.6443-09 2.109E-09 0.0 0.0 0.0 0.0 2.789E-03 1.389B-14 1.11 1E+03 1.051E+03 0.0 4.15 3E- 06 2.655E-34 2.6553-34 3.186E-36 1.247E-07 0.0 6.804E+01 3.2922-02 1.11 22-02 3.0022-04 4.730E+03

0.0

0.0 0.0 0.0 4.1 53 E- 06 0.0

0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 6.643E-02 5.217E-32 3.9553-22 0.0 3.495E-34 0.0 0.0 0.0 1-159E+00 lS076E+00

0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 9.28 1E-01

0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3.9562-01

4.159E+04

4.730E+03

1.1 59E+00 1.076E+00

9.281E-01

3.956E-01

0 .o

0.0 0.0 6.212E-07 0.0 6.214E-07 0.0 0.0 0.0 2-990E-01 2.9783-01 0.0 0.0 2 8 U 0 E-0 1 2.8 29 E-01 0.0 0.0 0.0 0.0 5-038E-01 4-8923-01 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.9023-03 2.899E-03 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.3 2.C 0.0 0.0 2.7893-03 2.788E-03

0.0 0.0 0.0 0.0 2.8593-01 0.0 2.7 1 6 E-0 1 0.0 0.0 3.6501-01 0.0 0.0 0.0 0.0 2 -871 E-03 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.776E-03

0.0 0.0 0.0 0.0 2.668E-03

0.0

1.034E-06 0.0 9.783E-07 0.0

0.0 0.0 0.0 0.0 0.0 4 1 533-06 4.153 E-06 4 15 3 E-06

0.0

0.0 0.0 0.0 0.0 1.90

E-01 0.0 1.8 06 E- 0 1 0.0

0.0 1.952E-02 0.0 0.0 0.0 0.0 2.608E-03 0.0 0.0

0.0

31 Table 10. ORIGEN2 o u t p u t f o r MSRE s a l t s : grams of a c t i n i d e s and d a u g h t e r s

DISCHARGE

SUMNARY TABLE: CONCENTRATIONS, GRAMS E N T I R E CORE (MSRE Y I T A U-233 FUEL) 1.OYR 1O.OYR 100.OYR 1.OKY

1O.OKY

100.OKY

1 .any

HE 4 P B206 PB207 PB208 81209 B A22 6 TH229 TH230 TH232 0232 U233 0234 U235 U236 U238 NP237 PU239 PO240 PU241 Ai9241 S UNTOT

0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 7.846E+00 3.2323+04 2.911E+03 9.860E+02 6.800 E+O 1 2.3703+03 0.0 6.2232+02 7.501E+01 8.742E+ 00 2.7933-01 3.9378+04

1.0453-02 9.7893-15 8.4 14E- 1 4 6.277E-02 5.3963-06 3.587E-08 1.389E-01 8.lllE-03 1.9793-06 7.771E+00 3.232E+04 2.911E+03 9.860E+02 6.8 0 1E+Ol 2.370E+03 7.7613-04 6.2232+02 7.500E+01 8.33 1 E + 0 0 6.8943-01 3.9373+04

1.051E-01 3.171E-10 8 -777E- 11 6.4353-01 5.926E-04 3.5829-06 1.388E+00 8.111E-02 1 98073-05 7.1263+00 3.232E+04 2.911E+03 9.8623+02 6 808E+01 2.370E+03 3.2733-02 6.2212+02 7.493E+01 5.40 2 E+OO 3.586E+00 3.9373+04

8.3543-01 2.170E-06 5.077E- 08 4.417E+00 5 - 9 6 1E-02 3.53 512-04 1.382E+Ol 8.107E-01 1.99 OE-04 2.996E+00 3.231E+O4 2.910E+03 9.878E+02 6 8 7 8E+Ol 2.370E+03 1.0652+00 6.205E+02 7.422E+Ol 7.096 E-02 7.868E+00 3.937E+04

4.487E+00 4.084E-03 8.7 27 E-06 7.207E+OO 5.794E+00 3.108E-02 1.323E+02 8.0643+00 2.089 E-03 5.161E-04 3.218E+O4 2.9032+03 1.003E+03 7.5 42 E+O 1 2.370E+03 7.028E+00 6-046E+02 6.7463+01 1 .O 85 E-2 0 1.875E+00 3.9372+04

7.195E+01 2.036E+00 8.8 9 3 E-04 7.207E+00 4.4C5E+02 1.217E+00 8.765E+02 7.647E+Ol 2.802E-02 1.207E-41 3.0943+04 2.830E+03 1.139E+03 1.1623+02 2.370E+03 8.847E+00 4.666E+02 2.598E+01 0.0 1.015E-06 3.937E+04

1.1423+03 2.208E+02 6.8 0 7 E-02 7.207E+00 9.361E+03 9.393E+00 9.958E+02 4.560E+02 3.9 17E-01 0.0 2.087E+04 2.193E+03 1.563E+03 1.4 1 4 E + 0 2 2.370E+03 8.593E+00 3.492E+01 1.866E-03 0.0 0.0 3.937E+04

3.6 1 9 E + 0 3 2.352E+03 1.3 03E+00 7.207E+00 2.861E+04 1.576E+00 1.947E+01 7.712E+01 4.0 4 5 E + 0 0 0.0 4.0813+02 1.711E+02 1.596E403 1.3 76 E+O2 2.370E+03 6.420E+00 1.925E-10 0.0 0.0 0.0 3.938E+04

TOTAL

3.9372+04

3.937E+04

3.9373+04

3.9372+04

3.937E+O4

3.937E+04

3.938El.04

3.938E+04

. . )

32 Table 11. ORIGEN2 o u t p u t for MSRE s a l t s : c u r i e s of a c t i n i d e s and d a u g h t e r s

DISCHARGE

0.0 5.491E+Ol 0.0 0.0 0.0 0.0 1.530E+02 0.0 0.0 0.0 1.530E+02 0.0

SUNMARY TABLE: RADIOACTIVITY, CURIES E N T I R E CORE (MSRE WITH 0 - 2 3 3 FUEL) 1.OYR 1O.OYR 100.OYR 1.OKY 3.144E-06 2.36 8E+01 6.354E- 02 2 - 9 4 2 E+OO 1.94 1E-04 3.153E-06 6.590E+01 3.4953-04 1.941E-04 3.1533-06 6.5903+01 2.942E+00 3 .U9 5E- 04 1.941E-04 4.2223+01 2.8783+00 3.495E-04 3.15 3E- 06 6.59 0 E+01 3.4963-04 2.942E+00 3.1533-06 6.590E+01 3.496E-04 2.942E+00 3.153E-06 6.590E+01 2.94 2 E + 0 0 3 - 0 9 6 E- 04 2 - 9 4 2E+OO 3.1533-06 3.110E-06 6.590E+01 2.9922+00 1.637E-02 2.136E-03 7.97 1E-04 4.51 1E-06 7.508E-04 7.97 1 E- 04 6.415E+01 3.1295+02 1.819E+01 2.136E-03 0.4523-03 7.97 12-01) 7 -50 8E-04 5.108E-01 3 85 9 E+01 1.6923+01 7,3132+00 2.701E+01

S UNTOT

0.0 0.3 0.0 0.0 0.0 1.680E+02 3.130E+02 1.820E+01 2.132E-03 4.4013-03 7.97 12-04 0.0 l.OOOE+OO 3.87 0 E+O 1 1.710E401 9.010E+02 9.59OE-01 2.450E+01 2.5532+03

7.084E-10 5.672E+01 6.3853-04 2.9 563-02 3.591E-10 7. 104E-10 1.5793+02 3.547E-08 3.591E-10 7.104E-10 1.579E+02 2.956E-02 3.547E- 08 1.16UE-10 1.011E+02 2.892E-02 3.546E-08 7.104E- 1 0 lI579E+O2 3.5483-08 2.9563-02 7.104E-10 1.579E+02 3.548E-08 2.9563-02 7. IOUE-10 1.579E+02 2.9563- 02 3.54 62-08 2.956E-02 7.10473-10 7.006E-10 1.5732+02 2.9563-02 1.6383-04 2.1323-03 7.971E-04 4.511E-08 5.473E-07 7.97 1E- 0 4 1.66UE+02 3.130E+02 1.820E+01 2.132E-03 4.402E-03 7.971E-04 5.473E- 07 1.090E+00 3.870E+O 1 1.710E+01 8.586E+02 2.367E+00 5.193E+00 2.525E+03

6.467E-08 5.618E+01 6.3822-03 2.955~3-01 3.395E-07 6.4863-08 1.564E+02 3.5423-06 3.396E-07 6.4863-08 1.564E+02 2.9552-01 3 -542E- 06 3.3963-07 1.002E+02 2.8913-01 3.542E-06 6.4 8 6 E- 08 1.564 E+02 3.543E-06 2.955E-01 6.486E-08 1.564E+02 3.543E-06 2.955E-01 6.486.E-08 1.5642+02 2 -9553- 01 3 - 5 4 3E-06 2.955E-01 6.482E-08 6.3963-08 1.562E+02 2,9553-01 1.638E-03 2.1332-03 7.9712-04 4.51433-07 2.308E-05 7.97 1 E- 0 4 1.526E+02 3.130E+02 1.82OE+Ol 2.133E-03 4,406E-03 7.971 E-04 2.3 08E- 0 5 1.040E+00 3.86 9 E+01 1.708E+01 5.567E+02 1.231E+01 4.511E-06 2.206E+03

TOTAL

2.5533+03

2.525E+03

2 . 2 0 6 E + 0 3 9.734E+02

TL207 TL208 TL209 PB209 PB2lO PB211 P B212 PB214 BIZ10 81211 BIZ12 B1213 BI21U PO210 PO212 PO213 PO214 PO21 5 PO216 PO218 AT217 RN219 RN220 EN222 F A22 1 R A223 RA224 88225 RA226 AC225 AC227 T A227 TH228 TH229 TH230 TH231 T H23U PA231 PA233 PA234N 0232 0233 0234 U235 U23 6 02 38 NP237 20238 PO239 10240 PU241 ~n24i (311242 ~

0.0

0.0 9.7603+01 0.0 0.0 0.0 1.530 E+O 2 0.0 0.0 0.0 1.530E+02 0.0 0.0 0.0 1.530E+02 0.0 0.0 0.0 0.0 0.0 1.530E+02 0.0 0.0

0.0

9.704E+02

1O.OKY

U.396E-04 1.1052-09 4.029E+00 1.8653+02 1.204E+00 4.409E-04 3.074E-09 1.204E+00 1.20UE+00 4.409E-04 3.07UE-09 1.865E+02 1 2 OUE+OO 1.2CUE+00 1.9703-09 1.825E+02 1.204E+00 4 - 4 09 E-04 3.074 E-09 1.204E+00 1.865E+02 4.4093-04 3.07YE-09 1.204E+00 1.865E+02 4.409.E-04 3.07UE-09 1.865E+02 1.2 0UE+ 00 1.8653+02 4.409E-04 4-348E-04 3.074E-09 1.865E+02 1.544E+00 2-4632-03 7 . 9 7 1 E-04 4.407E-04 6.2393-03 7.97 1 3-04 2.584E-40 2.996E+02 1.769E+01 2.463E-03 7.520E-03 7.971E-04 6.2 39 E-03 5.5412-35 2 9 01 E+ 0 1 5.922E+00 0.0 3.4872-06 0.0 1.857E+03

6.149E+02

1.8573+03 2.006E+03

1.0rlY

100.OKY

U.492E-05 4.086E-03 6 - 0 7 9 E-0 1 2.8 15E+O 1 3.0733-02 4.504E-05 1.137E-02 3.074E-02 3.0733-02 4.5043-05 1.1373-02 2.8 1 5 E + 0 1 3.074 E-0 2 3.073E-02 7.286E-03 2.7543+01 3.0733-02 4.5 04 E-05 1 1 3 7 E-0 2 3.0743-02 2.815E+01 4.5043-05 1.137E-02 3.074E-02 2.815E+01 4.504E-05 1-1372-02 2.8 1 5 E + 0 1 3.074 E-0 2 2.8 1 5 E + 0 1 4.504E-05 4.442E-05 1.137E-02 2.815E+Ol 1.628E-01 2.17OE-03 7.971 E-04 4.503E-05 4.956E-03 7.9 71 E-04 1.105E-02 3.116E+02 1.815E+01 2.170E-03 4-881E-03 7.971E-04 4.9563-03 4.173E-04 3.7 6 0 E+O 1 1.5388+01 1.1 18E-18 6.4395+00 0.0 6.149E+02

2.7953-03 1.544E-08 4.577E+00 2 . 1 1 9E+02 9.287E+00 2.803E-03 4.298E-08 9.289E+00 9.2873+00 2.8033-03 4.298E-08 2.119E+02 9 28 9 E + O O 9.287E+00 2.7543-08 2.0733+02 9.2873+00 2 - 8 033- 0 3 4 - 2 9 8E-08 9.291E+00 2.1 19E+02 2.803E-03 4.298E-08 9.291E+00 2.119E+02 2.803.E-03 4.2982-08 2.11 9E+02 9 . 2 9 1 E+OO 2.11 9E+02 2.803E-03 2-7643-03 U.298E-08 2.119E+02 9.208E+00 3.381E-03 7 . 9 7 1 E-04 2.803E-03 6.0603-03 7.97 1 E-04 0.0 2.021E+O2 1.371E+01 3.381E-03 9.149E-03 7 . 9 7 1E-04 6.060E-03 0.3 2.17 1 E+OO 4.254E-04 0.0 0.0 0.0 2.006E+03

3.442E-03 1.595E-07 8.9 511-02 4.1 U4E+00 1.558E+00 3.452E-03 4.438E-07 1.558E+00 1.558E+00 3.452E-03 0.4383-07 U.l44E+00 1.5 58 1+00 1.558E+00 2.8445-07 4.055E+00 1.558E+00 3.4 52E- 0 3 4 . 4 38 E- 07 1.559E+00 4.144E+00 3.452E-03 4.438E-07 1.559E+00 4.144E+00 3.4522-03 4.4383-07 4. 1 U U E + O O 1.5 59 E + 00 4.1443+00 3.452E-03 3.404E-03 4.438E-07 4.1 U4E+00 1.557E+00 3.452.E-03 7.970E-04 3.452E-03 4.527Z-03 7.9 70 E-04 0.0 3.9523+00 1.0b9E+00 3.452E-03 8.909E-03 7.970E-0U 4.5 27 E-03 0.0 1 . 1 9 7 E- 1 1 0.0 0.0

0.0 0.3 5.382E+01 5.3829+01

33 Discharge ( t h e s e ' a r e t h e i n p u t d a t a , as t a k e n from ORIGEN)

1 year 10 years 100 y e a r s 1000 y e a r s 10,000 y e a r s 100,000 y e a r s

1 million years Data were a l s o c a l c u l a t e d f o r t h o s e times used i n t h e o r i g i n a l ORIGEN runs:

384 d ( 1 y e a r and 19 d, corresponding t o J a n u a r y 1, 1971; used i n t h e o l d ORIGEN c a l c u l a t i o n s ) 749 d ( 2 y e a r s and 19 d) 1115 d ( 3 y e a r s and 19 d) 1480 d ( 4 y e a r s and 1 9 d ) 1845 d (5 y e a r s and 19 d) Agreement between t h e two o u t p u t s w a s checked a t t h e 1845-d o u t p u t and found t o be e x c e l l e n t , w i t h minor e x c e p t i o n s . g i v e n i n Tables 12 through 15.

A detailed l i s t i n g is

In summary, t h e e x c e p t i o n s are as

follows : 0

Of a t o t a l of 45 i s o t o p e s , 31 a g r e e d

F i s s i o n p r o d u c t s ( i n grams):

e x a c t l y and t h e o t h e r 14 d i f f e r e d by no more t h a n 4%.

The t o t a l FP

m a s s was 2710 g in both cases. 0

Of a t o t a l of 29 i s o t o p e s , 7 a g r e e d

F i s s i o n products ( i n c u r i e s ) :

e x a c t l y , 6 d i f f e r e d by minor amounts (1 t o 4 % ) , 3 d i f f e r e d s i g n i f i c a n t l y (17% l e s s , 50% less, and 250% more), and 13 d i f f e r e d by l a r g e f a c t o r s (20 t o 800).

A l l of t h e l a r g e d i f f e r e n c e s were i n minor

i s o t o p e s t h a t c o n t r i b u t e d less t h a n 0.1% of t h e t o t a l a c t i v i t y , which agreed v e r y w e l l (5.70

l o 4 v s 5.71 x l o 4 C i ) .

t h e s e d i s c r e p a n c i e s are twofold:

revised half-lives,

The c a u s e s of and a numeri-

c a l e r r o r i n ORIGEN f o r t h e v e r y low a c t i v i t i e s . 0

A c t i n i d e s ( i n grams):

E x c e l l e n t agreement f o r a l l n i n e i s o t o p e s ;

two a g r e e d e x a c t l y , f i v e were w i t h i n 1%, one minor c o n s t i t u e n t (Pu-241)

was w i t h i n 14%, and t h e major c o n t r i b u t o r (U-233) was

w i t h i n 2%.

The d i f f e r e n c e f o r U-233 w a s t r a c e d t o a r e v i s i o n i n t h e

34 Table 12. R e c o n c i l i a t i o n of ORIGEN/ORIGEN2 R e s u l t s I:

A c t i n i d e s and Daughters, i n C u r i e s

Curies a f t e r 5 y r Comments

Isotope

Half-life

ORIGEN

T1-208 Pb-212 Bi-212 Po-212 PO-216 Rn-220 Ra-224 Th-228 U-232 U-233 U-234 Pu-238 Pu- 23 9 PU-240 Pu-241 Am-241

3.05 min 10.6 h r 60.6 min 0.3 usec 0.15 s e c 55.6 sec 3.64 d 1.91 y r 72 y r 158 E3 y r 245 E3 y r 88 y r 24.1 E3 y r 6540 y r 14.4 y r 432 y r

5.82 1.62 1.62 1.03 1.62 1.62 1.62 1.62 1.60 3.13 1.82 1.09 3.87 1.71 6.88 6.97

Cm-242

163 d

3.81 E-2

0.97 E-2

ORIGEN used h a l f - l i f e of 13.0 y r Daughter of Pu-241; ORIGEN h a l f - l i f e w a s 470 y r Assumed O R I G I N i n c l u d e d a p r e c u r s o r d

Subt o t a1

2.37 E3

2.40 E3

D i f f e r e n c e due mainly t o Pu-241

Total

2.38 E3b

2.40 E 3

D i f f e r e n c e due mainly t o Pu-241

El E2 E2 E2 E2 E2 E2 E2 E2 E2 El EO El El E2 EO

ORIGENZ

a a 1.04 E2

In In In In

a a

In In

1.61 a a a 1.08 a a 7.07 7.40

secular secular secular secular secular secular secular secular

equilibrium equilibrium equilibrium equilibrium equilibrium equilibrium equilibrium equilibrium

with with with with with with with with

U-23ZC U-232 U-232 U-23ZC U-232 U-232 U-232 U-232

E2 EO

aSarce v a l u e a s ORIGEN. bThis t o t a l i n c l u d e s some minor c o n t r i b u t o r s n o t i n c l u d e d i n t h e s u b t o t a l . CBranching decay p r o d u c t of Bi-212. dAm-242 m (152 y r ) ; 0.04 C i a t d i s c h a r g e would e x p l a i n t h e d i f f e r e n c e .

35 Table 13. R e c o n c i l i a t i o n of ORIGEN/ORIGEN2 R e s u l t s 11:

A c t i n i d e s and Daughters, i n Grams

Grams a f t e r 5 y r Isotope

Half-life

ORIGEN

ORIGEN2

U-232 U-233 U-234 U-235 U-236 U-238 Pu-239 Pu-240 Pu-241

72.0 y r 158 E3 y r 245 E3 y r 704 E6 y r 23.4 E6 y r 4.47 E9 y r 24.1 E3 y r 6540 y r 14.4 y r

7.49 3.30 2.94 9.86 6.80 2.37 6.31 7.74 6.03

7.47 3.23 2.91 a 6.81 a 6.22 7.50 6.86

EO E4 E3 E2 E1 E3 E2 El EO

EO E4 E3 El E2 El EO

Comments -

ORIGEN ORIGEN ORIGEN ORIGEN ORIGEN ORIGEN ORIGEN ORIGEN

used used used used used used used used

half-life half-life half-life half-life half-life half-life half-life half-life

of of of of of of of of

162 E3 y r 247 E3 y r 711 E6 y r 23.9 E6 y r 4.51 E9 y r 24.4 E 3 y r 6758 y r 13.0 y r

Subtotal

4.01 E4

3.94 E4

D i f f e r e n c e due mainly t o U-233

Total

4.01 E 4

3.94 E4

M f f e r e n c e due mainly t o U-233

aSame v a l u e a s ORIGEN.

36 Table 14. R e c o n c i l i a t i o n of ORIGEN/ORIGENZ X e s u l t s 111: F i s s i o n P r o d u c t s , i n C u r i e s

Curies a f t e r 5 y r Isotope

Half-life

ORIGEN

ORIGEN2

Comments Numerical e r r o r in O R I G I N b

Sr-89 Sr-90 Y-90 Y-91 Z r - 95 Nb-95 m Nb- 95 Ru-103 Rh-103 m Ru-106 Rh-106 Sn-123 m Sb-125 Te-125 m

50.5 day 29.1 y r 64 h r 58.5 day 64.0 day 87 h r 35 day 3 9 day 56 min 368 day 30 sec 40 min 2.77 y r 5 8 day

8.67 1.19 1.19 8.43 7.31 7.76 8.56 1.79 8.94 2.30 2.30 7.99 1.83 8.70

E-4 E4 E4 E-3 E-2 E-4 E-2 E-7 E-8 E2 E2 E-2 E2 El

.016 E-4 a a .059 E-3 .042 E-2 .031 E-4 .096 E-2 .005 E-7 .049 E-8 2.32 E2 2.32 E2 0 1.80 E2 4.4 E l

Te-127 m Te-127 Te-129 m Te-129 Cs-134 Cs-137 Ba-137 m Ce-141 Ce-144 Pr- 144

109 day 9.35 h r 33.6 day 69.6 min 2.06 y r 30.0 y r 2.55 min 32.5 day 284 day 17.3 min

1.09 5.39 6.40 2.05 1.00 9.95 9.30 1.52 1.41 1.41

EO E-1 E-10 E-10 EO E3 E3 E-9 E3 E3

.032 EO .31 E-1 .008 E-10 .005 E-10 a a 9.43 E3 .003 E-9 a a

Numerical e r r o r i n O R I G I N b Numerical e r r o r i n O R I G I N b Numerical e r r o r i n ORIGINC Numerical e r r o r i n O R I G I N b Numerical e r r o r i n O R I G I N b Numerical e r r o r i n ORIGINC O R I G I N used h a l f - l i f e of 366 days In s e c u l a r e q u i l i b r i u m w i t h Ru-106 O R I G I N used h a l f - l i f e of 129 daysd O R I G I N used h a l f - l i f e of 2.70 y r e Daughter of Sb-125 r e v i s e d branching r a t i o Numerical e r r o r i n O R I G I N b Numerical e r r o r i n O R I G I N C Numerical e r r o r i n ORIGINb Numerical e r r o r i n ORIGINC

Numerical e r r o r i n O R I G I N b

37 Table 14.

(continued)

R e c o n c i l i a t i o n of OKIGEN/ORIGENZ R e s u l t s 111:

F i s s i o n h - o d u c t s , i n C u r i e s (Concluded)

Curies a f t e r 5 y r Isotope

Half-life

ORIGEN

ORIGENZ

Pm-147 Pm-148 m Sm-151 Eu-152 Eu-154 Eu-155 Gd-162 Tb-162 m

2.62 y r 41.3 day 90 y r 13.6 y r 8.6 y r 4.96 y r 8.6 min 7.6 min

1.02 1.61 1.42 4.02 2.83 5.14 8.27 8.27

.98 -004

E4 E-8 E2 EO El. E1

4.16 2.34 17.52

E-2 E-2

E4 E-8 a EO E El 0 0

Subt o t a1

5.71 E4

5.70

Total

5.71 E4

5.70

Comments Numerical e r r o r i n ORIGENb used h a l f - l i f e of used h a l f - l i f e of used h a l f - l i f e of used h a l f - l i f e o f In t r a n s i e n t e q u i l i b r i u m

OKIGEN ORIGEN ORIGEN ORIGEN

12 y r 16 y r 1.8 y r 1.00 y r g w i t h Gd-162

aSame v a l u e as ORIGEN. b A l l of t h e s e had h a l f - l i v e s of 32 t o 109 days. ORIGEN gave t h e c o r r e c t v a l u e s a t 1 y r , but t h e n changed t o a l o n g e r h a l f - l i f e ( a b o u t 50% l o n g e r ) . Later v e r s i o n s of ORIGEN do n o t have t h i s e r r o r . CDaughter of a p r e c u r s o r t h a t s u f f e r s from t h e e r r o r d e s c r i b e d in f f "b". dORIGEN r e v e r s e d t h e h a l f - l i v e s of Sn-123 and Sn-123 m. eORIGEN used a l o n g e r h a l f - l i f e d u r i n g t h e f i r s t y e a r . fORIGEN used 47%; l a t e r v a l u e i s 23%. g T h i s i s a n e r r o n e o u s v a l u e used by ORIGEN. L a t e r v e r s i o n s of ORIGEN used 10.4 min, b e f o r e going t o 8.6 min.

Table 15. R e c o n c i l i a t i o n of ORIGEN/ORIGENZ R e s u l t s F i s s i o n P r o d u c t s , i n Grams

IV:

Grams a f t e r 5 y r Isotope

Half-life

ORIGEN

ORIGEN2

Comments

Rb-87 Sr-88 Y-89 Sr-90 Z r - 90 Z r - 91 Zr-92 Zr-93 Zr-94 Mo- 95 Zr-96 Mo- 97 Mo- 98 Tc- 99 Mo- 100 Ru-101 Ru- 102 Rh-103 Ru- 104 Pd-105 Pd- 106 Pd-107 Te-128 1-129 Te-130 CS-137 Ba-137

4.7 E10 y r stable stable 29.1 y r stable stable stable 1.5 E6 y r stable stable stable stable stable 2.1 E5 y r

8.48 5.64 7.24 8.44 1.57 1.05 1.10 1.19 1.18 3.97 1.14 3.25 3.16 2.99

a a 7.22 E l 8.77 E l a a a a a 3.81 E l

O R I G I N used h a l f - l i f e o f 5.0 E10 y r b

stable

2.85 E l

stable stable stable stable stable stable 6.5 E6 y r stable 1.57 E7 y r stable 30.0 y r stable

1.95 1.56 5.30 7.88 1.82 6.77 5.64 9.47 1.58 2.09 1.14 1.97

a a a a

EO EO El El El E2 E2 E2 E2 El E2 El El El

El El El EO El EO EO EO El El E2 El

O R I G I N used h a l f - l i f e of 28.1 y r

a a a 2.98 E l

a 6.78 EO a 9.46 EO a a 1.15 E2 a

O R I G I N used h a l f - l i f e o f 7.0 E6 y r b O R I G I N used h a l f - l i f e of 1.70 E7 y r b

Table 15.

(continued)

R e c o n c i l i a t i o n of ORIGEN/ORIGENZ R e s u l t s IV:

F i s s i o n P r o d u c t s , i n G r a m s (Concluded) Grams after 5 y r

Isotope

Half-life

Ba-138 La-139 Ce- 140 h--141 Ce- 142 Nd-143 Ce-144 Nd- 144 Nd-145 Nd-146 Pm-147 Sm-147 Nd-148 Nd- 150 Sm- 150 Sm-151 Sm-152 Eu-153

stable stable stable stable stable stable 284 d 2 . 1 E15 y r stable stable 2.62 y r 1.06 E l l y r stable stable stable 90 y r stable stable

ORIGEN

7.44 1.70 1.90 1.84 1.73 1.73 4.41 1.52 1.07 8.41 1.10 5.46 4.63 1.90 2.71 5.21 1.46 5.49

EX E% E2 E2 E2 E2 E-1 E2 E2 EX El El El El El EO El EO

ORIGEN2

Comments

a a 1.89 E2 a a 1.67 E 2 4.43 E-1 a

a a 1.06 E l 5.35 E l

Assume ORIGEN i n c l u d e d a p r e c u r s o r C O R I G I N used h a l f - l i f e of

Assume ORIGEN i n c l u d e d a p r e c u r s o r d O R I G I N used h a l f - l i f e of m b r e

a a a 5.37 EO

O R I G I N used h a l f - l i f e of 87 y r

a 5.45 EO

Subtotal

2.71 E 3

Total

2.76 E3f

2.71 E3

%ame v a l u e a s ORIGEN. bFor v e r y l o n g - l i v e d i s o t o p e s t h e d i f f e r e n c e i n h a l f - l i v e s has no e f f e c t over a 5-yr period. CPr-143 (13.6 d a y s ) ; 6 grams a t d i s c h a r g e would e x p l a i n t h e d i f f e r e n c e . dNd-147 ( 1 1 d a y ) ; 1.6 grams a t d i s c h a r g e would e x p l a i n t h e d i f f e r e n c e . e O R I G I N had more p r e c u r s o r , Ra-147. f n i s t o t a l i n c l u d e s some minor c o n t r i b u t o r s n o t i n c l u d e d i n t h e s u b t o t a l .

40 h a l f - l i f e from 162,000 t o 158,000 y e a r s .

This a c c o u n t s f o r t h e

U-233 and a l s o f o r t h e small d i f f e r e n c e i n t h e t o t a l a c t i n i d e mass o f 4.01 x l o 4 g vs 3.94 x l o 4 g.

The d i f f e r e n c e f o r Pu-241,

a minor

c o n s t i t u e n t , a l s o r e s u l t s from a r e v i s e d h a l f - l i f e of 14.4 y e a r s vs t h e p r i o r v a l u e of 13 y e a r s . 0

Actinides ( i n curies):

E x c e l l e n t agreement; of a t o t a l of 1 7 i s o t o -

p e s , 11 agreed e x a c t l y , 5 were w i t h i n 6%, and an e x p l a n a t i o n w a s found f o r Cm-242,

a minor c o n s t i t u e n t where ORIGEN2 w a s 75% low.

minor p r e c u r s o r f o r Cm-242,

Am-242m (152-years h a l f - l i f e ) , would n o t

have been shown i n t h e summary ORIGEN p r i n t o u t because i t w a s below t h e 0.1% c u t o f f ; however, a f t e r 5 y e a r s , i t would c o n t r i b u t e t h e major p a r t of t h e t o t a l Cm-242,

which has a h a l f - l i f e of o n l y 163 d.

The o l d ORIGEN c a l c u l a t i o n s were q u i t e thorough, i n c l u d i n g allowance f o r a c t i v a t i o n of the e u t e c t i c s a l t and r a t h e r precise modeling of t h e U-235 and U-233 f u e l i n g s and o p e r a t i n g c y c l e s .

Allowance w a s made f o r

t h e continuous g a s s p a r g i n g , which r e s u l t e d i n p a r t i a l s t r i p p i n g of t r i -

t i u m and rare g a s e s ; a l s o , t h e f l u o r i n a t i o n p r o c e s s i n g a f t e r t h e U-235 o p e r a t i o n , which removed n o t o n l y U, b u t a l s o H, H e , S e , B r , K r , Nb, Mo, T c , Ru, T e , I, X e , and Np, w a s t a k e n i n t o c o n s i d e r a t i o n .

1-129,

Both Tc-99 and

of p o t e n t i a l concern f o r permanent emplacement, were i n t h e grams

printout.

W e were a b l e t o i d e n t i f y o n l y two f a c t o r s t h a t were n o t

included:

a c t i v a t i o n of c o r r o s i o n p r o d u c t s , and a c t i v a t i o n by n e u t r o n s

from ( a , n ) r e a c t i o n s on t h e Be-9 and F-19 i n t h e e u t e c t i c s a l t mixture. Both of t h e s e a r e v e r y minor c o n t r i b u t o r s . A h e l p f u l view of t h e ORIGEN2 r e s u l t s i s g i v e n i n F i g s . 4 and 5.

F i g u r e 4 shows t h e t o t a l FP a c t i v i t y and t h e major c o n t r i b u t o r s o u t t o 1 m i l l i o n years.

F i g u r e 5 shows t h e t o t a l a c t i n i d e a c t i v i t y and t h e major

c o n t r i b u t o r s , a l s o t o 1 m i l l i o n years.

same scale.

Both drawings were made t o t h e

The former i s e s s e n t i a l l y a l l beta-gamma c o n t r i b u t o r s , w h i l e

t h e l a t t e r i s mostly a l p h a emitters.

The a c t i n i d e decay c h a i n does

i n c l u d e T1-208 (from t h e U-232 c h a i n ) , which i s noteworthy because of a v e r y e n e r g e t i c (2.6 M e V ) gamma accompanying t h e b e t a decay t o *08Pb.

e a c h case, a r e l a t i v e l y few i s o t o p e s c o n t r i b u t e most of t h e a c t i v i t y o v e r

a r a t h e r d i s t i n c t i v e t i m e span. n o t ewo r t h y :

'Ibo o b s e r v a t i o n s are p a r t i c u l a r l y

ORNL DWG 85-438

106

TOTAL FISSION PRODUCTS AND

---

105

Ce-144/Pr-144 AND Pm-14 .......... Sr-90/Y-90 AND Cs - 1 37/ Ba - 137m Zr-.93/Nb-93m AND Tc-9

-----

-c) 104 n

(The Z r - 9 3 i s an activation product. )

I-

2 I-

103

o a

102

I 1

0 -

IO’

I oo

10” 1oo

10’

IO2

lo3

1o4

1o5

1 o6

TIME AFTER DISCHARGE ( y e a r s )

Fig. 4 .

F i s s i o n product a c t i v i t y of MSRE f u e l and f l u s h s a l t s .

ORNL DWG 85-439

105

104

TOTAL ACTINIDES AND DAUGHTERS

---

-.-

...........

-----

U - 2 3 2 CHAIN U-233 CHAIN Pu-239, P u - 2 4 0 , AND Pu -241/Am- 241

I-

5 -

103

102

E 1

I-

10’

loo

10’’

loo

10’

lo2

1 o3

I o4

1 o5

1 o6

TIME AFTER DISCHARGE ( y e a r s )

Fig. 5.

A c t i n i d e and d a u g h t e r a c t i v i t y of MSRE f u e l and f l u s h s a l t s ,

43 1.

F i s s i o n product a c t i v i t y dominates a t p r e s e n t , by a f a c t o r of 15, b u t w i l l d e c l i n e by a f a c t o r of 10 over t h e n e x t 100 y e a r s and be a t

a minimal l e v e l a f t e r 1000 y e a r s . 2.

A c t i n i d e a c t i v i t y , p r e s e n t l y controllled by plutonium and t h e U-232 c h a i n , is decaying s l o w l y , w h i l e t h e U-233 c h a i n i s v e r y s l o w l y growing i n .

The r e s u l t i s a minimum i n a l p h a a c t i v i t y a t 1000

y e a r s , a l o n g w i t h t h e d e p l e t i o n of t h e T1-208 gamma, followed by a maximum i n a l p h a a c t i v i t y a t about 40,000 y e a r s ; t h e r e f o r e , permanent decay o c c u r s . The t o t a l a c t i v i t y h a s decayed d r a m a t i c a l l y s i n c e d i s c h a r g e , from 1.8 m i l l i o n C i t o 34,000 C i . t i o n of s h o r t - l i v e d

Most of t h i s d e c l i n e stems from t h e deple-

f i s s i o n p r o d u c t s , which accounted f o r 200,000 C i a t 1

y e a r a f t e r d i s c h a r g e and now, a f t e r 1 5 years, amounts t o 32,000 C i .

The

a c t i n i d e s have decayed s l o w l y , from 2550 C i a t d i s c h a r g e , t o 2520 C i a f t e r 1 y e a r , t o 2000 C i a f t e r 1 5 y e a r s . It can be s e e n t h a t t h e gamma a c t i v i t y w i l l c o n t i n u e t o decay w i t h

h a l f - l i v e s of about 2, 30, and 7 2 y e a r s and w i l l e s s e n t i a l l y d i s a p p e a r a f t e r 1000 y e a r s , w h i l e t h e a l p h a a c t i v i t y w i l l f l u c t u a t e w i t h i n one o r d e r of magnitude f o r t h e next 500,000 y e a r s b e f o r e d e c l i n i n g permanently.

S i n c e a l p h a decay c o n t r i b u t e s about one-fourth of t h e decay

energy a t p r e s e n t , t h i s long-term a l p h a c o n t r i b u t i o n i s p e r t i n e n t concerning radiolysis t o yield fluorine. The n e u t r o n a c t i v i t y of t h e s a l t s f r o m ( a , n ) r e a c t i o n s i s much g r e a t e r t h a n normal because of t h e p r e s e n c e of Be-9, These i s o t o p e s , p a r t i c u l a r l y t h e Be-9 and F-19, (a,n) reactions.

F-19,

and Li-7.

are e x c e l l e n t t a r g e t s f o r

A t p r e s e n t ( 1 5 y e a r s a f t e r d i s c h a r g e ) , t h e r e are about

6 x l o 9 n e u t r o n s / s from t h i s source. tes some n e u t r o n a c t i v i t y . a c t i n i d e curve w i t h t i m e .

Spontaneous f i s s i o n a l s o c o n t r i b u -

These v a l u e s , l i s t e d i n Table 16, f o l l o w t h e

Less t h a n 1%of t h e a l p h a s are converted t o

neutrons. The t r a n s u r a n i c a l p h a a c t i v i t y of t h e s a l t s i s r e l a t i v e l y h i g h , about 70,000 nCi/g i n t h e f u e l s a l t and about 1,000 nCi/g i n t h e f l u s h

salt.

(The t o t a l a l p h a a c t i v i t y , i n c l u d i n g t h a t from a l l t h e d a u g h t e r s ,

i s about s i x t i m e s g r e a t e r . )

Removal of t h e uranium and neptunium by

44 Table 16.

Neutron a c t i v i t y of f u e l s a l t (a,n) neutrons/s

Time (years)

9Be

F '

7 ~ i

S.F.a

neutrons/s

Discharge

1.8 E9

4.7 E9

1.6 E7

1.86 E6

1.8 E9

4.7 E9

1.6 E7

1.75 E6

1.6 E9

4.1 E9

1.4 E7

1.69 E6

100

7 E8

1.8 E9

6 E6

9.30 E5

1000

4 E8

1.1 E9

4 E6

5.23 E5

10,000

1.3 E9

3.5 E9

1.2 E7

1.74 E6

100,000

1.4 E9

3.7 E9

1.3 E7

1.89 E6

1,000,000

4 E7

1 E8

0.4 E6

4.64 E4

aSpontaneous f i s s i o n .

45 f l u o r i n a t i o n could lower t h e a c t i v i t y of t h e f l u s h s a l t below t h e t h r e s h o l d l e v e l f o r TRU w a s t e , b u t t h e f u e l s a l t would s t i l l be a TKU

waste because of t h e plutonium c o n t e n t . 4.2

RADIOLYSIS One of t h e more s i n g u l a r s i d e e f f e c t s d e r i v i n g from t h e u s e of a

f l u o r i d e s a l t e u t e c t i c as t h e m a t r i x material f o r t h e MSRE f u e l i s t h e p r o d u c t i o n of f l u o r i n e i n t h e cooled s a l t a s a r e s u l t of r a d i o l y s i s . T h i s e f f e c t w a s f i r s t observed i n 1962 i n small t e s t c a p s u l e s , where a f l u o r i n e o v e r p r e s s u r e was noted a f t e r removal from a h e a t e d environment. Subsequent experiments have confirmed t h a t f l u o r i n e forms i n cooled f l u o r i d e s a l t s as a consequence of gamma r a d i a t i o n and r e c o i l from t h e reaction

radiation,

M F'2,-

radiation

followed by

M'F

F2.

A f t e r a n i n c u b a t i o n p e r i o d , gaseous F2 may be observed.

At elevated tem-

p e r a t u r e s , recombination ( t h e r e v e r s e r e a c t i o n ) i s f a s t enough t o p r e v e n t accumulation of F2.

The recombination r e a c t i o n i s t e m p e r a t u r e dependent

( a c t i v a t i o n energy of 19.4 kcal/mol) but r e l a t i v e l y independent of f l u o r i n e pressure.

This i s c o n s i s t e n t w i t h a s o l i d - s t a t e d i f f u s i o n

mechanism, which would account f o r t h e primary a s p e c t s of f l u o r i n e g e n e r a t i o n , t h e i n c u b a t i o n p e r i o d , and t h e r a t e - c o n t r o l l i n g

factors i n

t h e recombination r e a c t i o n . P r i o r a n a l y s e s suggested t h a t f o r t h e MSRE f u e l s a l t t h e p r o d u c t i o n

r a t e f o r r a d i o l y t i c f l u o r i n e ( i n 1984) would be about 26 cm3/h ( a t STP) and t h e i n d u c t i o n p e r i o d would be about 5

year^.^,^^

t h e a n n u a l r e h e a t w a s i n s t i t u t e d a f t e r shutdown.

350'F

For t h i s r e a s o n ,

A t e m p e r a t u r e of about

i s u t i l i z e d , which i s w e l l below t h e m e l t i n g p o i n t of t h e s a l t and

w e l l above t h e e s t i m a t e d t e m p e r a t u r e of 145'F where t h e recombination r a t e e q u a l s t h e f o r m a t i o n rate.

In any d i s c u s s i o n of extended s t o r a g e , f l u o r i n e p r o d u c t i o n i s of p o s s i b l e concern f o r two r e a s o n s :

p r e s s u r e r i s e , and c o r r o s i o n .

The

46 f o l l o w i n g a n a l y s e s show t h a t n e i t h e r i s a concern f o r extended s t o r a g e , b u t b o t h must be c o n s i d e r e d i n terms of permanent d i s p o s a l .

In t h e

l a t t e r case, m i t i g a t i o n can p o s s i b l y be achieved by t h e a d d i t i o n of a getter

an a c t i v e metal which w i l l react r e a d i l y w i t h e l e m e n t a l

fluorine. To calculate t h e e s t i m a t e d p r o d u c t i o n r a t e of F 2 , w e use Haubenreicb's d a t a 2 f o r t h e n e t y i e l d of F2 a t ambient temperature: 0.020 molecule/100 e V , o r 0.17 c m 3 (STP)/W-h. c a l c u l a t e d from:

3.0 x

The i n d u c t i o n p e r i o d i s

eV/g, o r 1.3 W-h/g.

Table 17 g i v e s t h e thermal power f o r a c t i n i d e s (and d a u g h t e r s ) and f o r f i s s i o n p r o d u c t s , as c a l c u l a t e d by ORIGEN2.

These r e s u l t s , which are

graphed i n Fig. 6, show t h a t t h e r e i s a r a p i d d e c l i n e i n thermal power d u r i n g t h e f i r s t 100 y e a r s and a c t i n i d e a c t i v i t y i s t h e c o n t r o l l i n g fact o r thereafter.

These c u r v e s are, of c o u r s e , an analogue t o t h e radioac-

t i v i t y c u r v e s shown p r e v i o u s l y , e x c e p t t h a t t h e a c t i n i d e c o n t r i b u t i o n i s r e l a t i v e l y g r e a t e r s i n c e t h e a v e r a g e energy p e r a l p h a decay i s g r e a t e r t h a n f o r beta-gamma decays. calculations.

This a l s o i n t r o d u c e s c o n s e r v a t i s m i n t h e

Haubenreich's d a t a 2 were o b t a i n e d f o r gamma r a d i a t i o n , b u t

a l p h a r a d i a t i o n has a much h i g h e r l i n e a r energy t r a n s f e r (LET). T h e r e f o r e , t h e f r e e r a d i c a l s produced by a l p h a decay w i l l be much c l o s e r t o g e t h e r , and recombination i s more probable.

The i n d u c t i o n p e r i o d s and

n e t f l u o r i n e y i e l d r a t e s were c a l c u l a t e d u s i n g Haubenreich's v a l u e s ; t h e s e v a l u e s a r e a l s o g i v e n i n Table 17.

(The a c t u a l F2 p r o d u c t i o n

r a t e s are about t w i c e t h e n e t y i e l d s , b u t some recombination i s o c c u r r i n g e v e n a t ambient temperature.) The d a t a i n Fig. 6 were i n t e r p o l a t e d t o estimate i n d u c t i o n p e r i o d s and F2 y i e l d rates d u r i n g t h e 10- t o 100-year p e r i o d ; t h e r e s u l t s are g i v e n i n Table 18.

In 35 y e a r s ( 5 0 y e a r s a f t e r d i s c h a r g e ) , t h e F2

y i e l d r a t e w i l l f a l l t o h a l f i t s p r e s e n t v a l u e and w i l l c o n t i n u e dropping u n t i l i t r e a c h e s a minimum a t about 1000 y e a r s .

It w i l l remain a t an

a v e r a g e v a l u e of about 8 cm3/h f o r t h e n e x t 500,000 y e a r s b e f o r e commencing a f i n a l d e c l i n e .

4.2.1

P r e s s u r e Rise The p r e s s u r e rise i n t h e f u e l s a l t d r a i n t a n k s can be c a l c u l a t e d

from t h e F2 y i e l d r a t e and t h e void volumes i n t h e t a n k s .

Each t a n k ( 5 0

i n . diam by 86 i n . h i g h ) has a c a p a c i t y of 80 f t 3 , and t h e volume of

Table 17.

Thermal power and c a l c u l a t e d f l u o r i n e y i e l d r a t e Thermal power (W) Induction period (years)

Fluorine yield (cm3/h)

Time (years)

A c tinides and d a u g h t e r s

Discharge

5,655

5,704

682

732

0.9

116

165

100

1,000

10,000

100,000

1,000,000

1.3

Fission products

Total

1.3

a S a l t i s molten; recombination i s v e r y f a s t .

530

a 124

0.2

ORNL

DWG M-1098

160

01 loo

/ACTINIDES

lo2

Thermal

power

10” TIME

DAUGHTERS

\/ \

10’

Fig.

AND

MSRE fuel

(years and flush

lo4

IO5

) salts.

lo6

49 Table 18.

R a d i o l y s i s d a t a f o r t h e 10- t o 100-year p e r i o d Induct i o n period (years)

Fluorine yield (cm3/h>

Time a f t e r dischargea (years)

Estimated thermal power

165

4.2

140

4.9

122

5.7

7.0

8.3

9.6

11.0

12.1

13.5

14.7

100

16.0

(W>

aThe r e a c t o r was s h u t down on December 1 2 , 1969.

50 s o l i d i f i e d f u e l s a l t i s 66.4

ft3.

Since t h e f u e l s a l t i s d i v i d e d between

two t a n k s , t h e void volume of e a c h t a n k i s 47 f t 3 .

This p r o v i d e s con-

Assuming t h a t t h e 1985 r e h e a t , completed

s i d e r a b l e room f o r expansion.

i n June-July of t h i s y e a r , i s t h e l a s t one, an i n c u b a t i o n p e r i o d of 5 y e a r s would y i e l d gaseous f l u o r i n e s t a r t i n g 20 y e a r s a f t e r d i s c h a r g e . The c a l c u l a t e d p r e s s u r e rise p e r y e a r i n t h e 20th year would be 2.0 p s i . T a b l e 19 g i v e s t h e c a l c u l a t e d v a l u e s o u t t o 100 y e a r s .

The a n n u a l

p r e s s u r e i n c r e a s e , a l t h o u g h q u i t e s m a l l , i s n o t i n s i g n i f i c a n t enough t o b e n e g l e c t e d over a p e r i o d of years. C o r r o s i o n Rates

4.2.2

C o r r o s i o n d a t a f o r INOR-8 have been o b t a i n e d o n l y a t t e m p e r a t u r e s above t h e m e l t i n g p o i n t of t h e s a l t because t h i s w a s t h e obvious area of i n t e r e s t f o r r e a c t o r operation.

Corrosion by t h e molten f l u o r i d e eutec-

t i c i s extremely slow and, below t h e m e l t i n g p o i n t , would be even slower. I n t h e s o l i d s t a t e , t h e c o r r o s i o n r a t e i s l i m i t e d by d i f f u s i o n p r o c e s s e s . I n a d d i t i o n , a s a c o r r o s i o n product b u i l d s up, i t s e r v e s as a d i f f u s i o n b a r r i e r and may a c t as a p r o t e c t i v e c o a t i n g .

Chromium i s t h e most

v u l n e r a b l e component, which w a s p r e d i c t e d t h e o r e t i c a l l y and confirmed experimentally.

A f t e r i n i t i a l r e a c t i o n w i t h any i m p u r i t i e s and o x i d e

f i l m s i s completed, t h e r e i s a v e r y slow r e a c t i o n w i t h UF4:

2UF4 -+ C r F 2

2 UF3

S e v e r a l y e a r s of MSRE o p e r a t i o n y i e l d e d a n e s t i m a t e d c o r r o s i o n r a t e of o n l y 0.1 m i l / y e a r a t o p e r a t i n g temperature ( 1 100-1400째F).

Corrosion by e l e m e n t a l f l u o r i n e , i n t h e molten s t a t e , i s f a r more severe.

During r e p r o c e s s i n g o p e r a t i o n s , which used F2 t o s t r i p o u t ura-

nium by c o n v e r s i o n t o W g , a c o r r o s i o n r a t e of 0.1 m i l / h was e s t i m a t e d w h i l e i n t h e molten c o n d i t i o n (50째F above t h e l i q u i d u s t e m p e r a t u r e o r about 80O0F) .6

Again, chromium i s t h e most v u l n e r a b l e component by v i r -

t u e of i t s l a r g e r n e g a t i v e f r e e energy of f o r m a t i o n f o r t h e f l u o r i d e

s a l t r e l a t i v e t o t h e o t h e r components of INOR-8.

The a t t a c k on n i c k e l

w a s e s t i m a t e d a t 0.04 m i l / h , w h i l e t h a t f o r chromium was 0.14 mil/h. T h i s s e l e c t i v e a t t a c k on t h e chromium i s i n keeping w i t h t h e chemical p r o p e r t i e s of t h e two metals.

51 Table 19.

C a l c u l a t e d p r e s s u r e rise i n f u e l s a l t d r a i n t a n k s , assuming l a s t r e h e a t was i n 1985

Time a f t e r dischargea (years)

P r e s s u r e rise rate (psi/year)

2.0

1.6

1.4

1.2

1.1

1.0

0.9

0.8

100

0.7

aThe r e a c t o r w a s s h u t down on December 12,

Total pressure buildup ( p s i )

1969.

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

This is

c l e a r l y evidenced by t h e f a c t t h a t f r e e f l u o r i n e can even be formed i n t h e s o l i d i f i e d s a l t s i n c e , f o r t h i s t o happen, e l e m e n t a l L i , Be, o r Z r A l l of t h e s e metals are more r e a c t i v e chemically

must a l s o be formed.

t h a n N i , Mo, Cr, o r Fe, t h e major components of INOR-8.

F u r t h e r , t h e y are

d i s p e r s e d throughout t h e s a l t on a molecular scale as a r e s u l t of t h e The i m p l i c a t i o n i s t h a t e l e m e n t a l f l u o r i n e i s q u i t e

r a d i o l y s i s process.

u n r e a c t i v e w i t h metals when s o l i d - s t a t e d i f f u s i o n i s t h e r a t e - c o n t r o l l i n g process.

Even i n t h e exposed p a r t s of t h e t a n k , where gaseous d i f f u s i o n

a l l o w s f r e e access by t h e l i b e r a t e d f l u o r i n e , any i n i t i a l a t t a c k would immediately b u i l d up a l a y e r of metal f l u o r i d e , a f t e r which s o l i d - s t a t e d i f f u s i o n would become r a t e c o n t r o l l i n g . 4.2.3

Use of Getters

The p r e c e d i n g d i s c u s s i o n s u g g e s t s t h a t r a d i o l y s i s can be regarded as

a minor f a c t o r over t h e n e x t 10 t o 20 y e a r s b u t must be c o n s i d e r e d f o r prolonged s t o r a g e .

The a d d i t i o n of c h e m i c a l l y a c t i v e metals, t o s e r v e as

g e t t e r s , h a s been proposed.

Comparison of t h e amount of F 2 t h a t might be

r e l e a s e d and t h e void s p a c e a v a i l a b l e i n e a c h t a n k f o r t h e a d d i t i o n of g e t t e r s shows t h e i d e a t o be f e a s i b l e .

Assuming an a v e r a g e F 2 y i e l d r a t e

o f 15 cm3/h (Table 1 8 ) , t h e c a l c u l a t e d p r o d u c t i o n o v e r t h e n e x t 80 y e a r s

i s 470 mol.

A c t i v e metals t h a t are e a s i l y a v a i l a b l e are l i s t e d i n Table

20, along w i t h t h e r e a c t i o n s and t h e d e n s i t i e s of t h e metals.

The volume

o f metal r e q u i r e d t o react w i t h 470 m o l of F 2 was c a l c u l a t e d from t h i s and w a s found t o be q u i t e small.

Considering t h e d e c l i n i n g r a d i o l y s i s

r a t e , t h e r e i s enough void volume i n e a c h t a n k f o r metal t o consume t h e t o t a l F2 y i e l d o v e r t h e next 10,000 t o 100,000 y e a r s . A t 100 y e a r s , t h e c a l c u l a t e d 470 mol of F2 r e p r e s e n t about 0.6% of

t h e f l u o r i d e inventory i n t h e tanks. F2,

There would be about 3000 mol of

o r about 4 % of t h e t o t a l f l u o r i d e , a t 1000 y e a r s .

I n any e v e n t , as

f l u o r i n e i s consumed by r e a c t i o n w i t h g e t t e r , t h e c o n c e n t r a t i o n of unrecombined f r e e metal i n t h e body of t h e s o l i d s a l t would i n c r e a s e t o t h e

same d e g r e e and would, t h e r e f o r e , i n c r e a s e t h e r a t e of t h e recombination reaction.

Thus, a t i m e would come when recombination equaled p r o d u c t i o n

and t h e n e t F 2 y i e l d became zero.

53 Table 20.

Active metal

Potential fluorine g e t t e r s

React ions

D e n s i t y of metal ( g / cm

Volume of metal required, t o consume 470 mol of F 2 ( f t 3 )

F2 + IkF2

1.85

0.082

F2 + CaF2

1.55

0.43

2F2 + ZrFq

6.4

0.12

2F2 + T i F 4

4. 5

0.09

1.5F2

2.7

0.24

M g + F2

1.74

0.23

AlF3

MgF2

Other f a c t o r s t o c o n s i d e r are t h e manner and t h e d e g r e e of c o n t a c t between t h e s o l i d s a l t and t h e g e t t e r metal.

S i n c e t h e F 2 has found i t s

way t o where p r e s s u r e can be measured, simply adding metal f l a k e s , c h i p s , o r sponge t o t h e void s p a c e above t h e s a l t may be adequate.

If f i n e l y

d i v i d e d metal were a l s o added t o t h e bulk s a l t ( w h i l e i n a molten cond i t i o n and t h e n allowed t o f r e e z e ) , recombination w i t h i n t h e s o l i d s a l t Metal w i t h a d e n s i t y n e a r l y i d e n t i c a l t o t h a t of t h e

would be enhanced.

s a l t i s r e q u i r e d i n o r d e r t o a c h i e v e good d i s p e r s i o n throughout t h e s a l t . T h i s can be achieved by a l l o y i n g B e , Mg, o r Ca w i t h A l , Z r , o r T i i n s u i t a b l e proportions. Before t h e a d d i t i o n of g e t t e r s i s undertaken, a d d i t i o n a l d a t a are needed i n two areas:

t h e s t o r a g e t a n k s themselves, and t h e performance

o f c a n d i d a t e g e t t e r metals.

Concerning t h e former, a means f o r monitor-

i n g f o r F 2 release should be included.

This could be done e i t h e r v i a

measurements of p r e s s u r e r i s e i n t h e s e a l e d s t o r a g e t a n k s o r v i a p e r i o d i c analyses f o r F2 i n swept samples.

Meanwhile, t e s t s should be conducted

w i t h v a r i o u s metals t o determine t h e a c t u a l e f f i c a c y of e a c h i n r e a c t i n g w i t h F 2 a t ambient t e m p e r a t u r e and i n v a r i o u s c o n f i g u r a t i o n s .

4.3

INTEGRITY OF THE FACILITY

The a p p a r e n t i n t e g r i t y of t h e h o t c e l l and t h e c o n t a i n e d f u e l s a l t and f l u s h s a l t i s v e r y high.

In many ways, t h e f a c i l i t y a l r e a d y h a s t h e

c h a r a c t e r i s t i c s of an engineered r e p o s i t o r y .

The uranium i s i n a s o l i d

form and i s being h e l d i n a c o n f i g u r a t i o n t h a t i s s a f e a g a i n s t c r i t i c a l i ty.

The c o n t a i n e r s are made of heavy-walled H a s t e l l o y N (INOR-8),

i s h i g h l y r e s i s t a n t t o c o r r o s i o n by f l u o r i d e .

which

They a r e s t o r e d i n a

h e a v i l y s h i e l d e d h o t c e l l made of r e i n f o r c e d c o n c r e t e w i t h 3 - f t - t h i c k

walls ( l a r g e l y underground) and a double-layer 5 - f t - t h i c k c e l l , l i n e d w i t h a welded s k i n of 1/8-in. and l e a k - t e s t e d

a regular basis.

roof.

The

s t a i n l e s s steel, is gas t i g h t

a n n u a l l y ; i t i s monitored f o r t e m p e r a t u r e and p r e s s u r e on However, t h e f a c i l i t y w a s n o t designed f o r permanent o r

- c e l l penetracontainment - b e f o r e t h i s

extended emplacement, and t h r e e f a c t o r s need a t t e n t i o n t i o n s , c o n t r o l of groundwater, and secondary c a n be s e r i o u s l y considered. 4.3.1-4.3.3.

These f a c t o r s are a d d r e s s e d i n Sects.

55 4.3.1

C e l l Penetrations The h o t c e l l s were b u i l t f o r complex o p e r a t i o n s i n v o l v i n g material

t r a n s f e r s and e x t e n s i v e use of e l e c t r i c a l h e a t i n g .

A l l f u n c t i o n s were

f u l l y i n s t r u m e n t e d w i t h redundant power s u p p l i e s , c o n t r o l c i r c u i t s , t e m p e r a t u r e and p r e s s u r e r e a d o u t s , e t c .

T h e r e f o r e , t h e t h r e e main o p e r a t i n g

c e l l s ( r e a c t o r c e l l , d r a i n t a n k c e l l , and f u e l p r o c e s s i n g c e l l ) have numerous p e n e t r a t i o n s f o r e l e c t r i c a l s i g n a l s p l u s a l a r g e number of

material t r a n s f e r l i n e s through t h e o u t e r c e l l w a l l s . l a r g e cell-to-cell

openings:

a 36-in.

There a r e a l s o two

opening between t h e r e a c t o r and

d r a i n t a n k c e l l s , and a 14-.in. opening between t h e d r a i n t a n k and reprocessing cells ( t h e latter is sealed).

T h e s e openings c a r r y i n s u l a t e d ,

h e a t e d l i n e s f o r t h e t r a n s f e r of molten s a l t , p l u s o t h e r l i n e s t h a t almost f i l l t h e s e openings.

Tables 2 1 and 22 l i s t t h e p e n e t r a t i o n s f o r

t h e r e a c t o r c e l l and d r a i n t a n k c e l l , r e s p e c t i v e l y .

A more comprehensive

t a b u l a t i o n , i n c l u d i n g t h e p r o c e s s i n g c e l l , i s g i v e n as p a r t of Appendix D. I n summary, t h e s e p e n e t r a t i o n s can be grouped and d e s c r i b e d as f o l l o w s : Reactor C e l l Numbers I-XXIV: P e n e t r a t i o n s are from 4 t o 36 i n . i n diam (many 8 and 24 i n . ) ;

most

a r e f i t t e d w i t h m u l t i p l e l i n e s , f o r materials, e l e c t r i c a l , t h e r mocouples, and off-gas.

Only one i s a "spare;" f o u r carry d u a l

water l i n e s . Drain Tank C e l l Numbers 1-30: S i n g l e p e n e t r a t i o n s are from 3/4 t o 14 i n . in diam; t h e y are used t o move material [steam, water, helium, and molten s a l t ; n i n e were used by t h e Chemical Technology D i v i s i o n (Chem Tech) f o r r e p r o c e s s i n g ] and are l o c a t e d as f o l l o w s :

South w a l l :

18 l i n e s , mostly 1-in.;

West w a l l :

2-3/4-in.

North w a l l :

t h e n i n e used by Chem Tech and t h e 14-in.

lines;

salt

t r a n s f e r opening; e i g h t of t h e n i n e a r e 1-1/2-in., and one i s 4-in.

T a b l e 21. 1.G.

Type

Silbsets Usage

Cell Location

Ft-in. I iI 111 IV

v VI VI1 vi11 1X i XI 111 XI11 XIV IV S'iI YVII XVIll XlI

xi Iii l%iI ill11 XXIV

lluitiple Huitiple Hultiple flultiple Huitipie Open Open

llui t i pie lrlanted i n nul t i p i e nultipie Single Furnace Mtiple Hul t i p l e Huiklple Hultipie nul t i p i e Furnace Nul t i pi e

Huitipie Open Duct

tluitipie Open

Leak Detectors 836 44 Electrical 634 44 Electrical 836 60 Ther~ocouples 834 61) Instru~entation 836 647 Saapi er O f f gas Sampler 847 6 Fuel Purp Uux; Piping 636-9 Cell Neutron Instrument Tube E X 5 6 Fuel Pump Liquid Level 644-6 13 Fuel Pump Aux. Piping 836-9 I Component Coolant Air 629-10 840-10 1 Coolant S a l t t o HX 2 Water Lines 639-9 2 Spare 839-9 2 Mater Lines 839-9 2 Mater Lines 639-9 2 Water Lines 839-9 1 Coolant Salt t o Radiator 837 3 Offgas 839-9 7 Offgas â&#x201A;Ź59-9 1 Cell Exhaust Duct ai!-11) 3d Theraocoupie 636 Drain Tank Cell Intercon.625-? Suap? Bottoe 61J Reactor

MSRE r e a c t o r c e l l p e n e t r a t i o n l i s t Access k e a

Sire

, Degrees I5 io 45 60 75 1IG 115 125 145

155 I60 165 170

185 200 205 210 220 220

225 2;0 215

325 330 Center

Sub-unit sires

Reference Dra~ings

h e r a i : EGX!-40704,4 1487 41 489,4149O South ESA South ESA South ESA South ESA South ESA high icay High Bay Service Tunnel High Bay Special Eq. RP. Special Eq. Rn. Special Eq. AB. Coolant Cell Coolant Cell Coolant Cell Coolant Cell Coolant Cell Coolant Cell Coolant Cell Coolant Cell Coolant Cell CDT Tunnel k t Tunnel Drain Tank Cell

24'

24" 24" 24' 24' 4' 6'

18" 36'

4' 18" 6' 24"

8" 8' 8' 8'

8" 24" b' b"

50" 24"

36"

DKRD-40976 DKkP-40976 DRKD-40976 DkKD-40976 DKKD-4097b DKKD-40973 DKKD-40973 DKKD-40717 DYKD-40716 DKKD-40973 DKKD-40718 DKKD-40714 EKKD-4071 1 OW-40740 DKKD-40740 DKKD-40740 DKKD-40740 DKKD-40740 NED-40712 DI:I(D-?0740 DkKD-40740 DkkD-4G710 DfKD-40976 EkKD-40713 EEBZ-55493

EBBD-41863 EEBD-41863 EB6D-41863 EBBD-41663 EBBD-41663 DKkD-40974 DKKD-40974 EKKD-40735 EKKD-40715 DKKD-40975 EKKD-40737 EGGD-55411 EG62-5549B DELI)-40741 DEKD-40741 Di'KD-40711 DLKD-40741 DKKD-40741 E662-55498 DKKD-40741 DKKD-40741 EKKD-40749 EBBD-41863

EPBD-41664 EGBD-41864 EBBD-41864 E66D-41864 EBBD-41864

DJJD-55494 DJJD-40495 60 t 1/4" tubing EHHZ-56234 EflHZ-56246 6 i 1'1F5, 38 i JI4'IPS EMHZ-56230 EHH2-56246 6 i 1'IPS, 38 t 3/4"1PS 7t3/4',28t1/2",25t3/6'lPS DHHB-53567 DHH6-55567 60 3/8"IPS ( 2 f 1/2")

DBBC-41339 EHHA-41796 EGGD-55411 EJJD-55426 EG6D-55411

3*1/2', 4*3/4', l*l'lPS 10 Ion Chamber h i d e s 6 6 1/4' tubing 2 i l"lPS, 11 f 1/2'1PS

2 * 1" 2 i 2' 2 t ?-I/?' 2 * 2' 2 * 2" 3 * 1" 2 i 1-114" EBBD-41864 DHHB-55567

38 + 3/8"1PS

Table 22. 1.G.

Type

S 6

Single

I Steam from Dones

Single

I S t e a l from Dome: I Water t o Steam Domes 1 Vater t o Steam Doaes

Single Single Single Single

Single B 3

1!I !!

12 13

I4 15 15

l! 18 20 i? 21 27 2; 24 ^C

;b 27

;e 27 7..ii

A-i t o 8-1 te C-1 t o D-1 t o E-I t o R-17 t o B-37 t o C-3! !o E-1J t o

Subsets U s a l e

Single Single Single Single Si ngI e Single Single Single Single Single Single Single Single Single Single Single Single Singie Single Single Single Single Furnace .Z Bank 36 Bank I.6 Bank

3 Bank 36 Bank bb Bank bi:l Rank

6Q Bank bb Rani

1 Hater 1 Water

I Spare I Spve 1 I 1 I

I 1

I I 1 I 1

29 36 36 36 36 24 24 24 24

Helium Helium Heliur Helius Helium Helium Heliua Heliui Sump Discharge Sump Discharge kir t o Sump Bir t o Sump (Chetn. Tech.) (Chen. Tech.) (Chem. Tech. 1 (Chea. Tech.) (Chea. Tech, i (Chen. Tech.) Khen. Tech. 1 (Cher. Tech.) (Chen. Tech. 1 S a l t Transfer Instruoentation Instrumentation Thermoccuples Ther~ocouples Thermocouples Electrical Electrical Electrical Electrical

MSRE drain tank c e l l penetration l i s t

Cell Location Access

South Wail Sogth Wall South Hail South Wall South Wail South Wail South Wall South Wall South Wail South Wail South Wall South Wall South Wall South Wall South Wall South Wall South Wall South Wall West Wali West Wall North Wall North Wall North Wail North Wall North Wall North Wall North Wall North Wall North Wail North Wall East gall East Wall East Wail East Wall East Wall East Wd1 East Wall East Wall East NJli

fire2

South ESA

SoulC ES4 South ESA South ESR South E5b South ESB South ES4 South ESA South ES9 South ESR South ESA South ESA South ESR South ESA South ESA South ESR Waste Cell Waste Cell Yest of Bidq. West of Bldq. Fuel Proc. Cell Fuel Proc. Cell Fuel F'roc. Cell Fuel Proc. Cell Fuel Proc. Cell Fuel Proc. I:ell Fuel Froc. Cell Fuel Prcc. Cell Fuel Proc. Cell Fuel Proc. Cell North ESA North ESB North ESR North ish North ESA North ESA North ESk North ESA North ESB

Sire

Reference Drawings

3' in 4 " ;"i n 4'

OEK0-4W46 DDCD-405'46 DDi'D-4!1946 DXD-40948 LDCD-48948 DDKF-40948 DDKD-40948 BDKD-4OC49

I" 1' 1" 1' I'

112" in I" 112" in 1"

112" i n 1" l i 2 " in I' 112" i n I @ 3/4" 3/4"

â&#x201A;Ź660-55425 EEGE-55425 EGGD-55425 E6GO-554X FKKR-41253

DDkD-40948 DDID-40948 DDKD-40948 DDKD-40948 DDKD-40948 DDKD-49948 DKlrB-4 1 ?PO DKKB-41 28 1 DDKF-40948 DKKB-41280 DKKB-41281

;ii"

314" L-1/2' i-l/Z" 1-112" l-l/Zn 1-112" 4"

1-112'

DliKD-411949

DWD-40949 DKKD-40949

1-1/2"

1-1/2" 14" 514" 5/4n

I)I:K@-4i!947 PtiHB-55567

5116" i n 3 / 4 " WED-49947 EHNZ-51656

S u b - u n i t sizes

Table 22. ?4 Electrical 24 Electrical Spare Spare

hltiple

5 Cover Gas

F L fl N L! F

Q F:

Multiple liultiple Single Multiple llultiple hltiple

5 1 4 12 12

Spare Spare Spare CoRponent Coolant Air Component Cnolaet Air Corponent Coolant Air DP Cell Leak Detector Leak Detector

East EaEt East Eant East East East East East East East East East East

Wall Wail ia11 Wall

Wall id311 Mall

Wall Wall Wall Wall

Wall Wall

Hall

North North 1ic:th North North North North North North North North North

iSk E 3 i5d

ESA ESA ESA ESA ESR ESR ESR ESR ESR South ESA South ESR

(continued) J i l C " I n 314' Dt VP-4OY4? EM;?Z-;1656 ; / l b " in I/+''DiiFD-4:447 Ei(!f-51655 bU DYKD-4iiP47 bm EliKD-40?4!

;I 1i;'IPS

DJdA-41B79 DJJR-41860

DJJR-41979 DJJR-41RBO b" ha b"

3 3

* 3/4"1PS * !I4"1?3

DJJR-41 B i ? DJJA-418911 DKKD-40947 EGGE-41884 DJJR-41879 DJJR-418RO 4 * liZ"lP5 DKKD-40947 ERHD-4186.3 EBED-41863 DJJD-55494 DJJD-55495 12 l / 4 " tubing DKKD-4094! EBEB-41863 EEBD-41863 DJJD-55494 DJJD-55495 12 f 114" tubing

___________-____________________________-------------------------------

Banks A-1 t o -60, -36:

B-1

C-1 t o -36,

t o -60,

A l l are 3/4-in.

D-1 t o -36,

and E-1 t o

p e n e t r a t i o n s of t h e east w a l l and are used f o r

f o r i n s t r u m e n t s , thermocouples, and e l e c t r i c a l s u p p l i e s . Numbers 0-R:

All a r e 6-in.

p e n e t r a t i o n s of t h e east w a l l , most w i t h m u l t i p l e

l i n e s f o r cover g a s , c o o l i n g a i r , and l e a k d e t e c t o r s ; f i v e are "spares

Reprocessing C e l l Numbers 31-54: S p e c i f i c p e n e t r a t i o n s have n o t been i d e n t i f i e d , b u t t h e s e f u n c t i o n s

a r e provided :

H-series l i n e h e a t e r s :

equipment h e a t e r s :

material t r a n s f e r :

thermocouples:

a t l e a s t : 4 (HF, H2, F 2 , o f f - g a s ) ; 28;

57;

94;

l i m i t annunciators:

15.

These p e n e t r a t i o n s are well-engineered and have proven t o be r e l i a b l e through many y e a r s of o p e r a t i o n and monitored s t o r a g e .

They,

a l o n g w i t h t h e r e a c t o r and d r a i n t a n k c e l l s , were p r e s s u r e - t e s t e d p s i (gage) p r i o r t o p l a c i n g t h e MSRE i n t o h o t o p e r a t i o n .

t o 45

All external

p e n e t r a t i o n s are welded i n t o p l a c e and were o f f s e t o r s h i e l d e d t o minimize r a d i a t i o n leakage. a t installation.

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

The t r a n s f e r l i n e s are., o r can be, s e a l e d on b o t h s i d e s There i s no cause

o f t h e c e l l w a l l w i t h Gray-loc c l o s u r e s o r by welding.

f o r concern f o r t h e s h o r t term, b u t t h e s e p e n e t r a t i o n s should be reviewed from e n g i n e e r i n g and c o r r o s i o n a s p e c t s b e f o r e extended s t o r a g e i s adopted

a s a planned p o l i c y .

Some of t h e t r a n s f e r l i n e s probably should be

capped, r a t h e r t h a n j u s t being valved o f f .

Many of t h e e l e c t r i c a l

p e n e t r a t i o n s a r e of no f u r t h e r use and could a l s o be s e a l e d . s t r i n g e n t a n a l y s i s i s a p p r o p r i a t e f o r extended s t o r a g e . to-cell

A more

The l a r g e c e l l -

opening a l s o d e s e r v e s a s t r i n g e n t a n a l y s i s f o r long-term s t o r a g e

i f t h a t i s t o be pursued.

Again, f o r t h e short-term,

t h e two-cell system

a p p e a r s t o be more t h a n a d e q u a t e , b u t extended s t o r a g e might b e n e f i t from s p e c i f i c modifications.

An e n g i n e e r i n g s t u d y of t h e p e n e t r a t i o n s , c l o s u r e o p t i o n s , and

p o s s i b l e containment envelopes w a s s t a r t e d l a t e i n FY 1985 but could n o t b e completed w i t h t h e a v a i l a b l e funds; t h e r e s u l t s o b t a i n e d t h u s f a r have been r e p o r t e d and are i n c l u d e d as Appendix D.

It i s a n t i c i p a t e d t h a t

t h i s work w i l l be completed i n FY 1986, o r as soon as funding i s provided.

The important f e a t u r e s of t h i s s t u d y t o d a t e are:

A sequence of t h r e e p o s s i b l e containment envelopes w a s d e f i n e d , f o r

f u t u r e consideration:

the drain tank cell; the drain tank plus

r e a c t o r c e l l s ; and t h e d r a i n t a n k , r e a c t o r , and r e p r o c e s s i n g cells. 2.

Eight t y p e s of c e l l p e n e t r a t i o n s were i d e n t i f i e d and catalogued.

Three t y p e s of c l o s u r e o p t i o n s were i d e n t i f i e d f o r t h e s e e i g h t t y p e s of penetrations:

( 1 ) cappingjwelding of unneeded l i n e s t h a t emerge

from a m u l t i p l e p e n e t r a t i o n ; ( 2 ) t o t a l capping of a m u l t i p l e p e n e t r a t i o n w h e r e none of t h e i n d i v i d u a l l i n e s are needed anymore and are c u t o f f behind t h e new s e a l - p l a t e ;

and ( 3 ) use of a

t h r e a d e d , p r e s s u r e - t i g h t plug on e l e c t r i c a l l i n e s , as was done on t h e o r i g i n a l design with spare lines. 4.

I n d i v i d u a l p e n e t r a t i o n s w e r e c a t a l o g u e d i n t e r m s of containment envelope and c l o s u r e o p t i o n s .

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

u s e s f o r each of t h e p e n e t r a t i o n s was s t a r t e d b u t n o t completed. F i n a l l y , i t was s u g g e s t e d t h a t a v i s u a l i n s p e c t i o n be made of a l l a c c e s s i b l e p e n e t r a t i o n s t o determine t h e p r e s e n t c o n d i t i o n of each. T h i s w i l l be done as soon as p o s s i b l e because of t h e obvious implications 4.3.2

i f any p e n e t r a t i o n s were t o be found i n poor c o n d i t i o n .

Water C o n t r o l I f water should e n t e r t h e c e l l s , i t could cause major problems s u c h

as:

i n c r e a s e d c o r r o s i o n r a t e of t h e H a s t e l l o y t a n k s ;

slow r e a c t i o n w i t h t h e f l u o r i d e s a l t s o r r a p i d r e a c t i o n w i t h any f l u o r i n e (from r a d i o l y s i s ) t o y i e l d HF;

r a d i o l y t i c p r o d u c t i o n of H2 and 02, which i s an e x p l o s i v e m i x t u r e t h a t could cause p r e s s u r e b u i l d u p o r could i n c r e a s e o x i d a t i v e corros i o n ; and

movement of r a d i o a c t i v e m a t e r i a l along t r a n s p o r t p a t h s provided by

water.

Water e n t r y h a s never occurred o v e r t h e p a s t 20 y e a r s .

Each c e l l

does have a sump where any water would be c o l l e c t e d ( i f i t d i d e n t e r ) and c o u l d t h e n be pumped o u t o r j e t t e d o u t .

The c e l l s are l e a k - t e s t e d

a n n u a l l y and are known t o be l e a k t i g h t ; t h e r e f o r e , water e n t r y i s t h e o r e t i c a l l y n o t p o s s i b l e , even i f t h e l e v e l of t h e groundwater were t o

r i s e above t h a t of t h e c e l l f l o o r .

Even so, groundwater i s a long-term

concern s i n c e t h e water t a b l e i s n o t v e r y f a r down a t t h e MSRE s i t e . However, t h e b u i l d i n g w a s c o n s t r u c t e d w i t h French d r a i n s below t h e f o o t e r s and has a b u i l d i n g sump w i t h a minimum e l e v a t i o n of 812 f t .

The

lowest c e l l l e v e l i s t h e d r a i n t a n k cell., a t 814 f t f o r t h e c e l l f l o o r , which i s above t h e b u i l d i n g sump l e v e l . Although t h e b u i l d i n g sump pump i s known t o o p e r a t e o c c a s i o n a l l y , t h e frequency of o p e r a t i o n and t h e volume of water pumped have not been

As a p a r t of t h i s s t u d y , a pump monitor

recorded o r measured p r e v i o u s l y .

w a s r e c e n t l y i n s t a l l e d and h a s been i n o p e r a t i o n s i n c e August 19, 1985. Readings were t a k e n d a i l y , except on weekends.

During t h e f i r s t t h r e e

weeks, t h e w e s t pump o p e r a t e d an average of 1.06 h / d , w i t h a d a i l y h i g h o f 1.5 h and a d a i l y low of 0.6 h. n o t come on d u r i n g t h i s period.

The east pump, a backup system, d i d

It i s planned t o c o n t i n u e g a t h e r i n g

t h e s e d a t a as p a r t of our ongoing S&M. Because of t h e importance of water c o n t r o l f o r extended s t o r a g e , a n e n g i n e e r i n g overview was prepared. e n t i r e t y a s Appendix E.

This r e p o r t i s a t t a c h e d i n i t s

The i n f o r m a t i o n c o n t a i n e d w i t h i n i t w a s o b t a i n e d

from e n g i n e e r i n g drawings and r e p o r t s ; h i g h l i g h t s from t h e r e p o r t include:

A d e s c r i p t i o n of t h e r a d i o a c t i v e l i q u i d waste system.

A d e s c r i p t i o n of t h e n o n r a d i o a c t i v e d r a i n a g e , which i n c l u d e s ground-

water c o l l e c t e d by t h e b u i l d i n g French d r a i n system and water e n t e r i n g f l o o r d r a i n s o u t s i d e t h e c e l l s , which i s t h e n r o u t e d t o t h e b u i l d i n g sump c i t e d earlier.

A d e s c r i p t i o n of t h e storm water system, which c o l l e c t s water from

roof d r a i n s and d i s c h a r g e s t o a separate c a t c h b a s i n . 4.

A d e s c r i p t i o n of t h e s a n i t a r y wastewater system, which i s d i s c h a r g e d t o a s e p t i c t a n k and d r a i n f i e l d system.

4.3.3

Secondary Containment

In c o n t e x t of t h i s d i s c u s s i o n , secondary containment r e f e r s t o t h e e x t e r n a l b u i l d i n g s t r u c t u r e surrounding t h e h o t c e l l s ( i . e . ,

t h e outer

s h e l l , t h e b u i l d i n g v e n t i l a t i o n system, t h e high-bay area and overhead c r a n e , and t h e c o n t r o l rooms).

This i s t h e containment t h a t i s r e l i e d on

d u r i n g open-cell maintenance o r i n t h e e v e n t of a release from one of t h e cells.

Secondary containment w i l l be r e q u i r e d and must be f u l l y

f u n c t i o n a l i n case i t should become n e c e s s a r y t o open one of t h e c e l l s f o r m o d i f i c a t i o n s , a d d i t i o n s , removal of e x t r a n e o u s equipment, o r treatment of t h e s a l t s .

Secondary containment i s n o t r e q u i r e d d u r i n g standby

mode, which i s t h e u s u a l c o n d i t i o n of t h e f a c i l i t y . The p r e s e n t s t a t u s of t h e secondary containment system i s f u n c t i o n a l . The high-bay area can be c l o s e d and v e n t i l a t e d through t h e c e l l v e n t i l a t i o n system, w h i l e m a i n t a i n i n g a n e g a t i v e p r e s s u r e i n s i d e t h e containment zone. The overhead c r a n e i s s t i l l o p e r a t i o n a l .

The remote maintenance c o n t r o l

room h a s d e t e r i o r a t e d somewhat, and t h e z i n c bromide viewing windows have been d r a i n e d ( b u t a r e s t i l l u s a b l e ) .

The main c o n t r o l room c o n t a i n s most

o f t h e i n s t r u m e n t a t i o n being used f o r monitoring and s u r v e i l l a n c e . The u s e f u l l i f e t i m e of t h e secondary containment system i s d e f i n i t e l y l i m i t e d i n t h e absence of a planned program t o m a i n t a i n t h i s c a p a b i l i t y . Any o p e r a t i o n s t h a t may need t o be done p r i o r t o committing t o extended s t o r a g e should be c a r r i e d o u t i n t h e r e a s o n a b l y n e a r f u t u r e .

In doing

s o , i t would be p o s s i b l e t o s t i l l u t i l i z e e x p e r i e n c e d p e r s o n n e l who have

a f i r s t h a n d knowledge of t h e f a c i l i t y from p r i o r e x p e r i e n c e when t h e MSRE w a s an a c t i v e p r o j e c t . 4.4

GEOLOGY AND HYDROLOGY

A g e o l o g i c and h y d r o l o g i c overview of t h e MSRE s i t e w a s prepared by

a consultant i n t h i s f i e l d .

F. 1.

A copy of h i s r e p o r t i s i n c l u d e d a s Appendix

The more s i g n i f i c a n t of h i s f i n d i n g s can be summarized as f o l l o w s : The g e n e r a l g e o l o g i c c o n d i t i o n s a t t h e MSRE s i t e are f a v o r a b l e f o r continued storage.

The area h a s a low seismic r i s k and h a s been

r e l a t i v e l y s t a b l e f o r m i l l i o n s of y e a r s .

Other waste s t o r a g e f a c i l i -

t i e s ( s o l i d LLW, TRU waste, h y d r o f r a c t u r e ) have been s i t e d i n Melton V a l l e y because of i t s s u i t a b i l i t y f o r s u c h a p p l i c a t i o n s .

63 2.

Water i s a s i g n i f i c a n t concern because t h e water t a b l e i s n o t f a r below t h e s u r f a c e and because water i s a p o t e n t i a l problem f o r two reasons:

i t can h a s t e n c o r r o s i o n , and i t can p r o v i d e a pathway o r

mechanism f o r movement; of any r e l e a s e d r a d i o a c t i v i t y . I n p l a n n i n g f o r t h e f u t u r e of MSRE and e v a l u a t i n g v a r i o u s o p t i o n s , t h e t i m e scale must be considered s i n c e e a c h t i m e frame h a s i t s own characteristics.

The v a r i o u s t i m e frames are d e f i n e d i n Sect. 1.

purposes o f t h i s e v a l u a t i o n , two key c h a r a c t e r i s t i c s are:

For

t h e t y p e s of

p h y s i c a l c o n t r o l t h a t can be a p p l i e d , and t h e n a t u r e of t h e r a d i o a c t i v e decay which i s o c c u r r i n g .

S e i s m i c f a c t o r s are of minor concern t o us through t h e n e a r term ( u p t o 100 y e a r s ) s i n c e t h e r e i n f o r c e d c o n c r e t e c e l l s and heavy-walled H a s t e l l o y t a n k s w i l l p r o v i d e ample s t r e n g t h d u r i n g t h e e a r l y y e a r s .

Water i n t r u s i o n , however, must be considered even f o r t h e s h o r t t e r m . Data are needed on water behavior i n t h e immediate environment.

l i s t e d i n t h e g e o l o g i s t ' s a n a l y s i s , d a t a a r e needed on t h e following:

( 1 ) c h a r a c t e r i z a t i o n of t h e e a r t h e n materials a t o r n e a r t h e s i t e ; ( 2 ) t h e s i t e d e s i g n i t s e l f , i n c l u d i n g a l l engineered improvements; and ( 3 )

s i t e hydrology.

4.5

ENTOMBMENT

Entombment i n c e m e n t i t i o u s material. has been surveyed by L. R. Dole o f t h i s L a b o r a t o r y , whose complete r e p o r t was g i v e n as Appendix E i n t h e e v a l u a t i o n s t u d y t h a t preceded t h i s r e p o r t . 2 o

His s u r v e y i d e n t i f i e s

s e v e r a l a s p e c t s of t h i s concept t h a t could be d e t r i m e n t a l , t h u s i n d i c a t i n g a need f o r c a u t i o n s i n c e entombment i s n o n r e v e r s i b l e f o r a l l prac-

t i c a l purposes.

It a l s o p o i n t s o u t t h e p o t e n t i a l l y harmful e f f e c t s of

water, which s u g g e s t r e s t r a i n t a t p r e s e n t and a l s o s u p p o r t t h e need f o r more d a t a i n t h i s area ( a s noted i n t h e p r e v i o u s s e c t i o n ) . While entombment i s v e r y a t t r a c t i v e and might, i n f a c t , become t h e o p t i o n of c h o i c e a t a f u t u r e t i m e , i t i s premature a t p r e s e n t because we

a r e n o t i n a p o s i t i o n t o make a permanent commitment.

This w i l l c o n t i n u e

t o be t h e case u n t i l we have d e f i n i t i v e d a t a concerning t h e r a d i o l y s i s of fluoride.

The n e g a t i v e a s p e c t s of entombment i n c l u d e t h e p r e c l u s i o n of

d i r e c t s u r v e i l l a n c e , t h e p o s s i b l e n e t weakening of t h e o v e r a l l s t r u c t u r e from s h r i n k a g e o r expansion mismatch, apd t h e i n t r o d u c t i o n of water from

t h e grout mixture i t s e l f .

In a d d i t i o n , t h e s o l i d i f i e d g r o u t c o u l d a c t as

a wick t o t r a n s p o r t m o i s t u r e t o metal s u r f a c e s and t h e r e b y i n c r e a s e corrosion.

It a l s o f i l l s up v o i d space t h a t might b e t t e r be used as a

s i n k f o r i n t r u d e d water o r as a r e s e r v o i r f o r a d e s i c c a n t (e.g.,

unslaked

l i m e o r P o r t l a n d cement). On t h e o t h e r hand, a p r o p e r l y engineered g r o u t could add s t r e n g t h

and provide a d i f f u s i o n b a r r i e r a g a i n s t t h e movement of water e i t h e r i n o r o u t of t h e c e l l .

The p r o j e c t e d l i f e t i m e of a g r o u t can be measured i n

m i l l e n n i a i n a d r y climate.

A more-detailed

s u r v e y i s r e q u i r e d t o iden-

t i f y any areas where s p e c i f i c d a t a need t o be g a t h e r e d , o r g e n e r a t e d , i n o r d e r t o have t h e n e c e s s a r y t e c h n i c a l b a s i s f o r a f u t u r e d e c i s i o n r e g a r d i n g entombment. R a d i o l y s i s of t h e water c o n t a i n e d i n g r o u t i s a l s o a p o s s i b l e drawback.

The r e s u l t i n g oxygen and hydrogen could l e a d t o e x c e s s i v e

p r e s s u r e o r an i n c r e a s e d c o r r o s i o n rate; however, i n h i b i t o r s o r c a t a l y t i c recombiners could be used t o m i t i g a t e t h i s e f f e c t . The u s e of o t h e r entombment materials, such as l e a d o r s u l f u r , h a s been s u g g e s t e d , b u t t h e s e materials have n o t been examined i n d e t a i l .

4.6

UTILIZATION The MSRE b u i l d i n g f a c i l i t i e s are being used e x t e n s i v e l y , par-

t i c u l a r l y t h e o f f i c e areas and t h e s t o r a g e space i n t h e high-bay and r e c e i v i n g areas.

Approximately 50 people from t h e H e a l t h and S a f e t y

Research D i v i s i o n a r e housed i n t h e o f f i c e complex, and t h i s number i s expected t o grow.

The h i s t o r y of t h e Laboratory c l e a r l y shows a n e v e r

i n c r e a s i n g need f o r o f f i c e space.

Therefore, t h e o f f i c e f a c i l i t i e s

s h o u l d be r e t a i n e d i n any e v e n t . The need f o r s t o r a g e s p a c e f o r low-level r a d i o a c t i v e samples and

materials has a l s o continued t o grow.

A t present, t h e building provides

s p a c e f o r s o i l s a m p l e s (about 100 55-gal drums) and Cs-137 s o u r c e s (about 260 i n 200-lb

l e a d p i g s ) , and m i s c e l l a n e o u s equipment (e.g.,

remote m a n i p u l a t o r s ) . retained.

about 20

These s t o r a g e f a c i l i t i e s d e f i n i t e l y need t o be

Even a c o n s e r v a t i v e estimate s u g g e s t s an a d d i t i o n a l 20-year

l i f e t i m e f o r t h e o f f i c e s and t h e s t o r a g e space.

This i s commensurate

w i t h t h e a n t i c i p a t e d short-term extended s t o r a g e of t h e f u e l and f l u s h

salts.

Looking beyond u t i l i z a t i o n a l r e a d y e x t a n t , t h e h o t c e l l s themselves

a r e a v a l u a b l e asset whose f u t u r e u t i 1 i t : y should be preserved.

Because

o f a c t i v a t i o n , t h e r e a c t o r , d r a i n , and p r o c e s s i n g c e l l s are l i k e l y cand i d a t e s f o r entombment u n l e s s a s u i t a b l e major p r o j e c t comes along.

Even

w i t h entombment of t h e s e t h r e e c e l l s , however, t h e y could f i r s t be f i l l e d w i t h waste removed from o t h e r c e l l s .

The remaining c e l l s could e a s i l y be

used f o r s t o r a g e purposes o r , w i t h m o d i f i c a t i o n , f o r a s u i t a b l e p r o j e c t .

4.7

FINAL DISPOSAL The long-term a l p h a a c t i v i t y of t h e U-233 decay c h a i n may r e q u i r e

e v e n t u a l removal of t h e f u e l and f l u s h s a l t s , even i f t h e r a d i o l y s i s problem can be c o n t r o l l e d w i t h g e t t e r s . possible

- and

highly desirable

- to

In t h e l a t t e r case, i t would be

leave the salts i n t h e i r present

H a s t e l l o y N t a n k s s i n c e t h e s e t a n k s should serve as e x c e l l e n t primary containers.

There are t h r e e p o s s i b l e o p t i o n s f o r permanent d i s p o s a l of

t h e t a n k s and c o n t e n t s :

t h e WlPP (Waste I s o l a t i o n P i l o t P l a n t ) , which i s now under c o n s t r u c t i o n i n New Mexico;

a s p e n t f u e l r e p o s i t o r y , which i s planned f o r a western l o c a t i o n ; o r

o n - s i t e g r e a t e r confinement d i s p o s a l ( i n t e r m e d i a t e - d e p t h b u r i a l ) , which h a s been c o n s i d e r e d f o r Oak Ridge.

These t h r e e o p t i o n s are d i s c u s s e d i n t h e f o l l o w i n g s e c t i o n s .

In t h e

e v e n t t h a t t h e r a d i o l y s i s problem cannot be c o n t r o l l e d w i t h g e t t e r s , t h u s making r e p r o c e s s i n g n e c e s s a r y , t h e s e p a r a t e d uranium and TRU waste would s t i l l be c a n d i d a t e s f o r t h e same t h r e e f i n a l o p t i o n s .

However, i n t h i s

case, w i t h t h e f l u o r i d e removed and t h e r e s i d u e repackaged, a c c e p t a n c e

c r i t e r i a should be easier t o meet.

It should be recognized t h a t , i n i -

t i a l l y , a l l d i s p o s a l s i t e s w i l l be c o n s e r v a t i v e i n s p e c i f y i n g t h e i r a c c e p t a n c e c r i t e r i a b u t t h a t , w i t h t h e passage of t i m e and accumulation o f e x p e r i e n c e , t h e p o t e n t i a l f o r some r e l a x a t i o n i n t h e s e c r i t e r i a i s v e r y r e a l , e s p e c i a l l y f o r a one-time i n t e r m e n t t h a t could be g i v e n addit i o n a l overpacks.

4.7.1

WIPP -

S i n c e t h e WIPP i s a c t u a l l y under c o n s t r u c t i o n and h a s been planned f o r many y e a r s , t h e waste a c c e p t a n c e c r i t e r i a (WAC) f o r WIPP have been t h e s u b j e c t of e x t e n s i v e s t u d y , review and comment, and r e v i s i o n s .

Even

s o , t h e s e WAC are n o t y e t f i n a l and, as a l r e a d y p o i n t e d o u t , t e n d t o be conservative.

Appendix C summarizes t h e WAC f o r remotely handled (RH)

waste, t h e C e r t i f i c a t i o n Compliance Requirements (CCR), and some g e n e r a l comments.

The WAC and CCR a r e n o t always i n agreement.

Those r e q u i r e -

ments t h a t concern t h e MSRE f u e l s a l t are b r i e f l y d i s c u s s e d below. Size l i m i t :

Diameter of t a n k s t o o l a r g e (50 vs 26 i n . ) but l e n g t h s a t i s f a c t o r y (86 v s 121 in.)

Weight:

Each t a n k (-1300 kg) p l u s s a l t (-2300

kg) i s j u s t

w i t h i n t h e l i m i t (3636 k g ) ; a d d i t i o n of g e t t e r would make them overweight. S u r f a c e dose:

S u r f a c e dose probably g r e a t e r t h a n t h e lOO-rem/h l i m i t ; a l s o , n e u t r o n dose much h i g h e r t h a n 75

mrem/h, a s l i m i t e d by t h e CCR ( a l t h o u g h t h e WAC r e q u i r e s o n l y t h a t n e u t r o n d o s e s >75 mrem/h be reported). Thermal power:

Well below t h e l i m i t of 300 W/package; d r a i n t a n k s

a r e about 100 W each. Criticality :

About 10 t i m e s t h e l i m i t of 1.9 g/L; a c t u a l l y , about 17 g/L.

Pu-239 equivalent :

Probably about t h e l i m i t of 1000 plutoniume q u i v a l e n t Ci/package.

4.7.2

Commercial Spent Fuel Repository T h i s o f f e r s some a t t r a c t i v e f e a t u r e s .

f l u s h s a l t s q u a l i f y i n a g e n e r i c sense.

C e r t a i n l y , t h e MSRE f u e l and

The MSRE D&D i s funded through

t h e commercial branch of t h e SFMP s i n c e t h e MSRE w a s i n t e n d e d f o r com-

mercial a p p l i c a t i o n .

The f u e l s a l t i s a s p e n t f u e l , and t h e f l u s h s a l t

c o n t a i n s some s p e n t f u e l .

Most of t h e WIPP r e s t r i c t i o n would n o t be

a p p l i c a b l e t o a s p e n t f u e l r e p o s i t o r y , which would be designed t o h a n d l e h i g h e r d o s e s , t h e r m a l power, c r i t i c a l i t y , and Pu-239 e q u i v a l e n t . p o s s i b l e problem i s t h e t a n k diameter.

One

A r e p o s i t o r y might n o t be

designed f o r a package d i a m e t e r of over 4 f t , even on a n e x c e p t i o n b a s i s .

4.7.3

Greater Confinement Disposal Every major DOE s i t e (Oak Ridge i n c l u d e d ) has p o t e n t i a l problems

TRU waste,

w i t h o v e r s i z e d , overweight, o r o t h e r w i s e o u t - o f - s p e c i f i c a t i o n f o r which i n t e r m e d i a t e - d e p t h d i s p o s a l i s being considered.

The MSRE f u e l

s a l t i s a n obvious c a n d i d a t e f o r such d i s p o s a l s i n c e t h e l a r g e t a n k d i a m e t e r would n o t be a problem i n t h i s s i t u a t i o n .

Shipment would a l s o

b e minimized i f a n Oak Ridge s i t e i s developed i n t h e f u t u r e .

4.8

IN-CELL ALTERATIONS A number of i n - c e l l a l t e r a t i o n s might be performed i n t h e s h o r t t e r m

( w i t h i n 10 t o 2 0 y e a r s ) t o enhance t h e c o n d i t i o n of t h e f u e l s a l t s d u r i n g extended s t o r a g e and a l s o t o h e l p s e t t h e s t a g e f o r e v e n t u a l removal.

a s t e p toward t h e e v e n t u a l removal of t h e s a l t s , i t would be h i g h l y d e s i r a b l e t o p l a c e t h e c e l l and t h e s a l t s i n t o a s u i t a b l e c o n d i t i o n d u r i n g t h e s h o r t t e r m s o t h a t t h e removal o p e r a t i o n can be c a r r i e d o u t as simply and e a s i l y as p o s s i b l e .

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

and t h e n e v a l u a t e d i n terms of b o t h enhanced s t o r a g e and e v e n t u a l removal :

removal of steam domes (and a d d i t i o n of n e u t r o n poison);

a d d i t i o n of f l u o r i n e g e t t e r , without r e m e l t i n g ;

r e m e l t i n g of s a l t , w i t h a d d i t i o n of f l u o r i n e g e t t e r ;

repackaging of s a l t i n t o s m a l l e r c o n t a i n e r s , a f t e r r e m e l t i n g w i t h

a d d i t i o n of f l u o r i n e g e t t e r ;

d i s c o n n e c t i o n of l i n e s t o and from t h e d r a i n t a n k s ; and

i n s t a l l a t i o n of a d d i t i o n a l i n s t r u m e n t a t i o n . It i s assumed t h a t t h e f u e l s a l t s w i l l e v e n t u a l l y have t o be removed

t o a more permanent l o c a t i o n because of t h e long-term a c t i v i t y from t h e

U-233 chain.

It i s a l s o assumed t h a t i t w i l l be f e a s i b l e t o do so w i t h

t h e s a l t s packaged i n t h e i r p r e s e n t c o n t a i n e r s .

With t h e s e assumptions,

i t i s clear t h a t t h e steam domes must be removed e v e n t u a l l y ; t h e r e f o r e ,

t h i s s h o u l d be done i n t h e s h o r t term w h i l e experienced p e r s o n n e l are

still available.

Once t h e steam domes w i t h a t t a c h e d bayonet t u b e s are

removed, t h e t h i m b l e s ( 3 2 p e r t a n k ) can be used t o i n s e r t n e u t r o n poisons.

These can be i n t h e form of Cd, B, o r G e metal r o d s .

The e a r l i e r d i s c u s s i o n on r a d i o l y s i s i s a s t r o n g argument f o r t h e a d d i t i o n of a f l u o r i n e g e t t e r .

In f a c t , i f an e f f e c t i v e g e t t e r i s n o t

added, d i s p o s a l of t h e f u e l s a l t as t h e f l u o r i d e w i l l probably n o t be acceptable.

The s i m p l e s t way t o i n c l u d e g e t t e r i s t o add i t t o t h e void

volume i n e a c h tank.

This might r e q u i r e c e l l e n t r y ; of c o u r s e , t h e pre-

f e r r e d method would be t o s u p p l y g e t t e r through t h e a d d i t i o n t u b e used p r e v i o u s l y f o r adding s a l t s .

If c o l d l a b o r a t o r y tests show t h a t t h e

g e t t e r must be d i s p e r s e d w i t h i n t h e s o l i d s a l t t o be e f f e c t i v e , t h e n r e m e l t i n g would be r e q u i r e d .

While t h i s o p e r a t i o n i s p o s s i b l e , i t might

cause some f u r t h e r c o r r o s i o n t o t h e t a n k s .

D i s p e r s a l of added g e t t e r

c o u l d be accomplished v i a s p a r g i n g w i t h d r y helium through t h e d i p t u b e s a l r e a d y provided f o r t h i s purpose. I n t h e e v e n t t h a t t h e s a l t needs t o be melted i n o r d e r t o add g e t t e r , t h i s would be t h e l o g i c a l t i m e t o repackage i n t o smaller cont a i n e r s ( i f t h i s s t e p i s needed).

However, t h e i n c e n t i v e t o repackage i s

s m a l l s i n c e t h e c o n t r o l l i n g f a c t o r i s r a d i o l y s i s and, if r a d i o l y s i s can

b e c o n t r o l l e d by t h e a d d i t i o n of g e t t e r , t h i s can be done j u s t as w e l l i n t h e present d r a i n tanks. The l i n e s f o r t h e v e s s e l should n o t be d i s c o n n e c t e d u n t i l t h e r e i s a s s u r a n c e t h a t t h e s a l t need not be repackaged o r r e p r o c e s s e d .

Such

a s s u r a n c e cannot be provided u n t i l a c t u a l d a t a are i n hand t o v e r i f y t h e a d d i t i o n of g e t t e r as a v i a b l e method f o r l i m i t i n g f l u o r i n e formation. T h i s may r e q u i r e t h e i n s t a l l a t i o n of a d d i t i o n a l i n s t r u m e n t a t i o n .

4.9

CONTINGENCY P L A N N I N G

The MSRE h a s had an e x c e p t i o n a l l y c l e a n h i s t o r y f o l l o w i n g shutdown o f t h e r e a c t o r i n December 1969.

Because of t h i s long p e r i o d of t r o u b l e -

f r e e s u r v e i l l a n c e and maintenance, formal contingency p l a n n i n g a n d / o r emergency planning h a s r e c e i v e d v i r t u a l l y no a t t e n t i o n .

However, s i n c e

i t i s now becoming clear t h a t extended s t o r a g e i n t h e p r e s e n t l o c a t i o n

w i l l be r e q u i r e d , such planning i s a p p r o p r i a t e i n t h e immediate f u t u r e . Obviously, no major c o n t i n g e n c i e s are expected; n o r are t h e y l i k e l y t o occur.

On t h e o t h e r hand, i t i s prudent t o c a r r y o u t a s t r u c t u r e d analy-

sis i n order t o systematically investigate the p o s s i b i l i t i e s , t o i d e n t i f y any weaknesses t h a t could o r should be remedied i n advance, and t o be prepared i n case t h e unexpected happens.

A p r e l i m i n a r y l i s t of p o s s i b l e

e v e n t s i n c l u d e s , b u t i s n o t n e c e s s a r i l y l i m i t e d t o , t h e f o l l o w i n g items:

71 5. 5.1

CONCLUSIONS

EVALUATION OF OPTIONS

E v a l u a t i o n of t h e o p t i o n s , d a t a , and c o n s t r a i n t s d i s c u s s e d i n t h e body and appendixes of t h i s r e p o r t l e d t o t h e f o l l o w i n g c o n c l u s i o n s :

Extended s t o r a g e i s n o t o n l y feasib:Le b u t p r e f e r a b l e a t t h i s t i m e because :

a. t h e f u e l s a l t i s p r e s e n t l y i n a s a f e p l a c e ; b.

t h e r e i s no a v a i l a b l e r e p o s i t o r y o r d i s p o s a l s i t e t o t a k e i t i f i t

were removed, e i t h e r w i t h o r without r e p r o c e s s i n g , a t t h i s t i m e ; C.

t h e f u l l range of f u t u r e disposall o p t i o n s o r l o c a t i o n s i s n o t y e t known ;

d. any enhancement a c t i o n s t a k e n a t t h i s t i m e would probably b e n e f i t whichever o p t i o n i s f i n a l l y e x e r c i s e d ; and

e. extended s t o r a g e would p r o v i d e t i m e t o c o l l e c t a d d i t i o n a l d a t a t h a t would be of d i r e c t h e l p i n s e l e c t i n g a f i n a l o p t i o n a t a f u t u r e date.

Entombment s h o u l d be d e f e r r e d because:

a. s u c h a c t i o n i s n o t n e c e s s a r y a t t h i s t i m e ; b. i t i s e s s e n t i a l l y n o n r e v e r s i b l e and would be premature a t t h i s

t i m e ; and C.

a d d i t i o n a l t e c h n i c a l d a t a are needed b e f o r e such a d e c i s i o n could be supported.

Some enhancements i n d i r e c t s u p p o r t of extended s t o r a g e s h o u l d be evaluated i n the near future.

For example:

a. c e l l p e n e t r a t i o n s should be reviewed by Energy Systems E n g i n e e r i n g , i n s p e c t e d by t h e Operations D i v i s i o n and, where cons i d e r e d n e c e s s a r y , s e a l e d permanently; b. c e l l i n t e r n a l s should be reviewed t o i d e n t i f y i n t e r f e r i n g s t r u c t u r e s , i f any, and p l a n s made f o r t h e i r removal; C.

r e m e l t i n g of t h e f u e l s a l t , w i t h p o s s i b l e a d d i t i o n of a f l u o r i n e g e t t e r (and p o s s i b l y a n e u t r o n poison) should be e v a l u a t e d f o r implementation s i n c e t h i s would e l i m i n a t e both t h e need f o r a n n u a l r e h e a t i n g and long-term concerns about r a d i o l y s i s - p r o d u c e d f l u o r i n e ;

d. repackaging ( i f needed, i t should be done i n c o n j u n c t i o n w i t h r e m e l t i n g ) should a l s o be e v a l u a t e d ;

e. enhancements seem prudent s i n c e t h e a l p h a a c t i v i t y (and t h e r e s u l t i n g n e u t r o n s from a,n r e a c t i o n s ) w i l l d e c l i n e o n l y s l i g h t l y i n f u t u r e y e a r s , even though t h e gamma a c t i v i t y w i l l d r o p s i g n i f i c a n t 1y ;

f . t h e s e enhancements would n o t i n t e r f e r e w i t h t h e e x e r c i s e of o p t i o n s a t a l a t e r d a t e and would, i n t h e i n t e r i m , improve on t h e a l r e a d y sound and s e c u r e c o n d i t i o n of t h e f a c i l i t y ; and g. t h e s e enhancements, w h i l e n o t n e c e s s a r y f o r continued short-term s t o r a g e , should be made p r i o r t o i n i t i a t i n g extended s t o r a g e w h i l e t h e a s s u r e d c a p a b i l i t y t o do s o s t i l l e x i s t s , i n terms of b o t h p e o p l e w i t h f i r s t h a n d knowledge and equipment t h a t i s s t i l l funct ional.

The f o l l o w i n g p e r t i n e n t d a t a ( o r s t u d i e s ) should be o b t a i n e d ( o r made) over t h e n e x t few y e a r s :

a. o b s e r v a t i o n s of groundwater l e v e l s around t h e s i t e ; b. p o s s i b l e improvements of a c i v i l e n g i n e e r i n g n a t u r e , t o lower t h e groundwater l e v e l ;

c. H a s t e l l o y N c o r r o s i o n behavior i n t h e p r e s e n c e of m o i s t u r e p l u s a l k a l i , f l u o r i d e , o r both; d. s u i t a b i l i t y of c a n d i d a t e materials f o r u s e as a f l u o r i n e g e t t e r , i n - c e l l d e s i c c a n t , t a i l o r e d g r o u t , and n e u t r o n poison; and

e. contingency p l a n s developed, a l o n g w i t h a review and update of S&M procedures.

B e n e f i c i a l u t i l i z a t i o n of t h e f a c i l i t y should be encouraged and a i d e d f o r t h e f o l l o w i n g reasons:

a. t o h e l p f i l l d i r e c t l y o u r own f a c i l i t y r e q u i r e m e n t s ; b. o f f i c e s p a c e a t t h e s i t e i s f u l l y u t i l i z e d today, and t h i s need i s e x p e c t e d t o grow; c. t h e high-bay area i s being used t o s t o r e bulky, m i l d l y r a d i o a c t i v e samples,and t h i s need i s expected t o c o n t i n u e ; d. t h e t h r e e more a c t i v e h o t c e l l s ( r e a c t o r , d r a i n t a n k , and reproc e s s i n g ) could be used f o r s t o r a g e of o t h e r r a d i o a c t i v e wastes;

e. t h e remaining c e l l s could be used f o r h o t o p e r a t i o n s o r r a d i o a c t i v e waste s t o r a g e ; and

69 (1) v e n t i l a t i o n f a i l u r e ; ( 2 ) extended power f a i l u r e ; ( 3 ) water i n g r e s s from l e a k a g e ; ( 4 ) e l e c t r i c h e a t e r f a i l u r e ; ( 5 ) thermocouple f a i l u r e ;

( 6 ) o v e r h e a t i n g d u r i n g annual r e h e a t ; (7) loss of i n s t r u m e n t a i r ; (8) a c a t a s t r o p h i c e v e n t s u c h a s a tornado, e a r t h q u a k e , p l a n e c r a s h , o r f l o o d ; ( 9 ) s a b o t a g e o r t e r r o r i s t a c t i o n ; (10) p o s s i b l e r a d i a t i o n exposure v i a

plume o r i n g e s t i o n ; and (11) p o s s i b l e r a d i a t i o n exposure t o s i t e operators.

In a d d i t i o n t o t h e above i n c i d e n t s , a contingency a n a l y s i s should

a l s o cover t h r e e broad c a t e g o r i e s :

(1) i n f o r m a t i o n s o u r c e s , ( 2 ) iden-

t i f i c a t i o n of equipment, and ( 3 ) p h y s i c a l c o n d i t i o n of components. I n t h e e v e n t of a contingency, needed i n f o r m a t i o n must be e a s i l y and quickly available.

A c o n c i s e "contingency p l a n , " w i t h r e a d i l y a v a i l a b l e

backup i n f o r m a t i o n i n v a r i o u s s p e c i f i c areas, i s probably a p p r o p r i a t e . I n a d d i t i o n , e a s y and p o s i t i v e i d e n t i f i c a t i o n of components, c o n t r o l s ,

e t c . , may be e s s e n t i a l .

The r e c e n t l y completed c o l o r coding scheme i s a

significant s t e p i n t h i s direction.

The coding employed i s p i n k f o r

r o u t i n e maintenance and s u r v e i l l a n c e , whether d a i l y , monthly, o r a n n u a l , and yellow f o r p o s s i b l e f u t u r e use i n r e m e l t i n g , t r a n s f e r r i n g , etc.

(If

t h e s e c o l o r s seem unusual, t h e y were chosen t o match t h e markup of drawings used t o do t h i s work.) I n t h e e v e n t of a s e r i o u s contingency, i t might be of c o n s i d e r a b l e b e n e f i t i f t h e f r o z e n f u e l were i n a c o n d i t i o n whereby i t could e i t h e r be s e a l e d o f f and l e f t i n p l a c e f o r a long t i m e o r , a l t e r n a t i v e l y , t r a n s p o r t e d elsewhere.

These f a c t o r s would, of c o u r s e , be enhanced if

t h e f u e l had p r e v i o u s l y been remelted and g e t t e r s added, o r remelted and repackaged, o r i f i n t e r f e r i n g s t r u c t u r e s (e.g.,

steam domes) had been

removed. A t t h i s t i m e , work i s scheduled f o r t h e n e x t f i s c a l year on a con-

t i n g e n c y p l a n , a l o n g w i t h a review and update of S&M procedures.

f . t h e LL-7

c o n t e n t of t h e c o o l i n g s a l t i s n o n r a d i o a c t i v e and may

have enough v a l u e t o j u s t i f y recovery.

5.2

SELECTION OF PLAN

Based on t h e above c o n s i d e r a t i o n s , an o u t l i n e d p l a n and approxi-

mate s c h e d u l e are proposed: 1.

1986 - complete -

( o r expand on) work i n p r o g r e s s :

a. p e n e t r a t i o n s

complete t h e e n g i n e e r i n g e v a l u a t i o n and p r o v i d e

r ecommend a t i o n s ; b. groundwater

c o n t i n u e d a t a c o l l e c t i o n on r a d i o a c t i v i t y and sump

pump o p e r a t i o n ; complete a n o n - s i t e s u r v e y and i n s p e c t i o n of d r a i n a g e system and components;

c. r a d i o l y s i s

conduct a peer review of t h e o v e r a l l problem and

p o t e n t i a l s o l u t i o n ; prepare a technical plan f o r pressure o r f l u o r i n e " s n i f f e r " measurements on t h e two d r a i n t a n k s ; make a d e c i s i o n i f r e h e a t i n g i s t o be d i s c o n t i n u e d ( i n o r d e r t o o b t a i n d i r e c t d a t a on r a d i o l y s i s ) ; and conduct p r e l i m i n a r y l a b o r a t o r y -

scale t e s t s w i t h p o t e n t i a l f l u o r i n e g e t t e r s ; d. review and update t h e S&M procedures and p r e p a r e a contingency plan. 2.

1987 - upgrade -

f a c i l i t y and p r e p a r e f o r new work:

a . s e a l o r improve c e l l p e n e t r a t i o n s , as a p p r o p r i a t e ;

b. i n s t a l l f l u o r i n e r a d i o l y s i s t e s t equipment; and

c. p r e p a r e a t e c h n i c a l p l a n f o r removal of steam dome and o t h e r i n t e r n a l s i n o r d e r t o e v a l u a t e t h e work involved.

1988-95

- collect

data:

a. f l u o r i n e r a d i o l y s i s i n t h e d r a i n t a n k s ; and b. l a b o r a t o r y - s c a l e

1996 -Make -

tests on f l u o r i n e g e t t e r s .

t h e following decisions:

a. t o remelt and add g e t t e r , o r n o t ; b. t o remove steam dome and i n t e r n a l s , o r n o t ; C.

t o reprocess, or not;

d. t o repackage, o r n o t ; and

e. s e l e c t i o n of f i n a l d i s p o s a l s i t e , based on i n f o r m a t i o n a v a i l a b l e at that time.

Appendix A.

BIBLIOGRAPHY AND REFERENCES

Appendix A.

BIBLIOGRAPHY AND REFERENCES

The MSRE P r o j e c t i s e x t e n s i v e l y and t h o r o u g h l y documented by r e p o r t s , drawings, photographs, and m i s c e l l a n e o u s documents.

A com-

p u t e r i z e d l i s t i n g of t h e s e has been prepared by Park Owen and Nancy b o x , o f t h e ORNL Remedial Action Program Information Center.

There are

approximately 1450 e n t r i e s i n t h i s f i l e , c a t e g o r i z e d as f o l l o w s : Type of e n t r y

No. of e n t r i e s

Progress report

-140

Technical r e p o r t CF memo

-370

TM r e p o r t

-240 Q7 0

ORNL r e p o r t Miscellaneous

Journal article

Drawing

Pâ&#x20AC;&#x2122;n o t og r a ph

-500

Patent

Conference paper

Q50

Correspondence

Total

-1450

Copies of most of t h e s e documents are i n t h e MSRE f i l e , which i s s t o r e d i n t h e basement of B u i l d i n g 7503. h a s c o p i e s of many of t h e r e p o r t s .

The I n f o r m a t i o n Center a l s o

These documents are a merger of

f i l e s p r e v i o u s l y maintained by i n d i v i d u a l s who were c l o s e l y a s s o c i a t e d with the project. o v e r t h e years.)

( U n f o r t u n a t e l y , s e v e r a l e x t e n s i v e f i l e s have been l o s t Most of t h e photographs were s u p p l i e d by Luther Pugh.

There i s a l s o a n e x c e l l e n t c o l l e c t i o n of c o n s t r u c t i o n drawings maint a i n e d by Martin Marietta Energy Systems, I n c . ,

Engineering on f i l e i n

Bui Id i n g 1000.

A r e l a t i v e l y small number of r e p o r t s have provided a l l t h e background i n f o r m a t i o n used f o r t h i s study.

A l i s t i n g , i n chronolo-

g i c a l o r d e r , i s provided on t h e f o l l o w i n g pages.

The c h r o n o l o g i c a l num-

b e r s are used as r e f e r e n c e c a l l - o u t s i n t h e main body of t h e r e p o r t .

77 1.

Ruth S l u s h e r , H. F. McDuffie, and W. L. M a r s h a l l , Some Chemical A s p e c t s of Molten-Salt

Reactor Safety:

(1) D i s s o l u t i o n of Coolant

and Fuel M i x t u r e s i n H70, ( 2 ) A P o r t i o n of t h e System LiF-BeF?-H?O a t 25, 60 and Near 100째C, ORNL-TM-458,

P. N.

Haubenreich, I n h e r e n t Neutron S o u r c e s i n Clean MSKE F u e l Salt, August 27, 1963.

ORNL-TM-611, 3.

J. R. Engel and B.

P r i n c e , C r i t i c a l i t y F a c t o r s i n MSRE F u e l

S t o r a g e and D r a i n Tanks, ORNL-TM-759,

December 14, 1962.

September 14, 1964.

R o b e r t s o n , MSRE Design and O p e r a t i o n s R e p o r t -

D e s c r i p t i o n of R e a c t o r Design, ORNL-TM-728,

J a n u a r y 1965.

L i n d a u e r , MSRE Design and O p e r a t i o n s Report

Part I

F u e l Handling and R e p r o c e s s i n g P l a n t , ORNL-TM-907R,

Part V I 1

December 28,

1967. 6.

R. B. L i n d a u e r , P r o c e s s i n g of t h e MSKE F l u s h and Fuel S a l t s , ORNL-TM-2578,

August 1969.

S t e f f y , Jr.,

F u e l , ORNL-TM-2685, 8.

I n h e r e n t Neutron Source i n MSRE w i t h Clean U-233 August 10, 1969.

W. R. G r i m e s , "Molten-Salt

R e a c t o r Chemistry", N u c l e a r A p p l i c a t i o n s &

Technology 8 , 137, F e b r u a r y 1970. 9.

J. B e l l , C a l c u l a t e d R a d i o a c t i v i t y of MSRE F u e l S a l t , ORNL-TM-2970,

May 1970. 10.

P. N.

H a u b e n r e i c h , F l u o r i n e P r o d u c t i o n and Recombination i n Frozen

MSK S a l t s a f t e r R e a c t o r O p e r a t i o n , OWL-TM-3144,

11.

R. H.

1970.

Guymon, MSRE P r o c e d u r e s f o r t h e P e r i o d Between Examination and

U l t i m a t e D i s p o s a l , ORNL-TM-3253,

12.

September 30,

F e b r u a r y 10, 1971.

Roy E. Thoma, Chemical A s p e c t s of MSRE O p e r a t i o n s , ORNL-4658, December 197 1.

13.

P. N. Haubenreich and R. B. L i n d a u e r , C o n s i d e r a t i o n of P o s s i b l e Methods of D i s p o s a l of MSRE S a l t s , ORNL/CF-72-1-1,

14.

E. L. Compere e t a l . ,

F i s s i o n P r o d u c t Behavior i n t h e Molten S a l t

R e a c t o r Experiment, ORNL-4865, 15.

C. D.

October 1975.

Cagle and L. P. Pugh, Decommissioning Study f o r t h e ORNL

Molten-Salt 1977.

J a n u a r y 28, 1972.

Reactor Experiment (MSRE) , ORNL/CF-77/391, August 25,

78 16.

EBASCO S e r v i c e s , Inc.,

Technical Report

F e a s i b i l i t y Study:

D i s p o s a l of MSRE Fuel and Flush S a l t s , Letter Report (unnumber), October 1980.

17.

D. R. Simpson, P r e l i m i n a r y R a d i o l o g i c a l C h a r a c t e r i z a t i o n of t h e Molten S a l t Reactor Ekperiment (MSRE), ORNL/CF-84/92,

September 20,

1984.

18.

F. J. P e r e t z , P r e l i m i n a r y Decommissioning Study Reports

- Volume 5 :

Molten S a l t Reactor Experiment, X-OE-231, Vol. 5 , September 1984. 19.

T. E. Myrick, The ORNL S u r p l u s F a c i l i t i e s Management Program LongRange Plan, ORNL/TM-8957,

20.

September 1984.

J. Notz, F e a s i b i l i t y E v a l u a t i o n of Extended Storage-in-Place

MSRE Fuel S a l t and Flush S a l t , ORNL/CF-85/71,

March 1985.

Appendix B.

SEMIQUANTITATIVE EVALUATION OF SIX MSRE OPTIONS

Table No.

E v a l u a t i o n Basis

B. 1

I’r oces s R e a d i n e s s

B. 2

Ec onomi c s

Be3

Short-Term Hazard

B. 4

Long-Term Hazard

B. 5

Co n s e r v a t i o n

Table B . l .

S e m i q u a n t i t a t i v e e v a l u a t i o n of MSKE o p t i o n s : A. Process r e a d i n e s s a Opt i o n

Process s t e p

Melt s a l t s (and add g e t t e r )

Remove s a l t s

Build s a l t p r o c e s s f a c i l i t ?

P r o c e s s o r c o n v e r t salts/Ua

Package s a l t s (and U)

Dismantle/dispose of f a c i l i t y

T r a n s p o r t packaged p r o d u c t s

S t o r e / i s o l a t e productsb

D e contaminate c e l l s / equipment

Dispose of l i q u i d LLW

Remove equipment

Dispose of s o l i d LLW

Dismantle c e l l s t r u c t u r e

Dispose of s o l i d LLW/rubble

R e s t o r e area

Seal pipes/penetrations I n t e r n a l entombment External s t r u c t u r e s S t a b i l i z e drain-tank c e l l Continue s u r v e i l l a n c e

Total

aRange: 0 t o 5. ( A low s c o r e i s s u p e r i o r . ) The r a t i n g c o n s i d e r s t h e c o s t of developing t h e p r o c e s s , as w e l l as t h e u n c e r t a i n t y of successThe t i m e d e l a y involved i s n o t a p a r t of t h e r a t i n g f u l development. s i n c e a m p l e t i m e i s presumably a v a i l a b l e . bNo p r o c e s s f l o w s h e e t h a s been d e f i n e d a t t h i s t i m e . cNo f a c i l i t y which w i l l a c c e p t t h e packaged p r o d u c t s h a s been ident i f i e d at t h i s t i m e .

81 Table B.2.

S e m i q u a n t i t a t i v e e v a l u a t i o n of MSRE o p t i o n s : B Economicsa Option ~~

Process s t e p

Melt s a l t s (and add g e t t e r s )

Remove s a l t s

Build s a l t p r o c e s s f a c i l i t y

P r o c e s s o r c o n v e r t salts/U

Package s a l t s (and IJ)

D i smant l e / d i s p o s e of f a c i l i t y

T r a n s p o r t packaged p r o d u c t s

S t o r e / i s o l a t e products

Decontaminate c e l l s / e q u i p m e n t

Dispose of l i q u i d LLW

Remove equipment

Dispose of s o l i d LLW

Dismantle c e l l s t r u c t u r e

Dispose of s o l i d LLW/rubble

R e s t o r e area

Seal pipes/penet rations

S t a b i l i z e drain-tank c e l l

Continue s u r v e i l l a n c e

I n t e r n a l entombment External s t r u c t u r e s

Total

aRange: 0 t o 5. ( A low s c o r e i s s u p e r i o r . ) r e l a t i v e c o s t of each process.

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

Table B.3.

S e m i q u a n t i t a t i v e e v a l u a t i o n of MSRE o p t i o n s : C. Short-Term hazarda Opt i o n

Process s t e p

Melt s a l t s (and add g e t t e r s )

Remove s a l t s

Build s a l t p r o c e s s f a c i l i t y

Package s a l t s (and U)

Dismantle/dispose of f a c i l i t y

T r a n s p o r t packaged p r o d u c t s

S t o r e / i s o l a t e products

Decontaminate c e l l s / e q u i p m e n t

Dispose of l i q u i d LLW

Kemove equipment

Dispose of s o l i d LLW

Dismantle c e l l s t r u c t u r e

Dispose of s o l i d LLW/rubble

R e s t o r e area

Seal pipes/penetrations

I n t e r n a l entombment

External structures

S t a b i l i z e drain-tank c e l l

Continue s u r v e i l l a n c e

P r o c e s s o r c o n v e r t salts/U

Total

aRange: 0 t o 10. ( A low s c o r e i s s u p e r i o r ) . The r a t i n g c o n s i d e r s t h e expected o p e r a t o r exposure, p u b l i c exposure, p r o b a b i l i t y of a n a d v e r s e release, and p o s s i b i l i t y of s a b o t a g e o n - s i t e , d u r i n g t r a n s p o r t , o r i n t h e f i n a l location. Short term means less t h a n 100 y e a r s , nominally 5 t o 20 years.

83 Table B.4.

S e m i q u a n t i t a t i v e e v a l u a t i o n of MSRE o p t i o n s : D. Long-Term hazarda Option

Process s t e p

Melt s a l t s (and add g e t t e r s )

Remove s a l t s Build s a l t p r o c e s s f a c i l i t y P r o c e s s o r c o n v e r t salts/U Package s a l t s (and U) Dismantle/ d i s p o s e of f a c i l i t y T r a n s p o r t packaged p r o d u c t s S t o r e / i s o l a t e products Decontaminate c e l l s / e q u i p m e n t Dispose of l i q u i d LLW Remove equipment Dispose of s o l i d LLW Dismantle c e l l s t r u c t u r e Dispose of s o l i d LLW/rubble R e s t o r e area Se a1 p i p e s / p e n e t r a t i o n s I n t e r n a l entombment

Ex t e r n a l s t r u c t u r e s S t a b i l i z e drain-tank c e l l Continue s u r v e i l l a n c e

To t a l

Range: 0 t o 10. ( A low s c o r e i s s u p e r i o r . ) The r a t i n g c o n s i d e r s t h e expected p u b l i c exposure, p r o b a b i l i t y of an a d v e r s e release, and p o s s i b i l i t y of i n a d v e r t e n t i n t r u s i o n . Long t e r m means g r e a t e r t h a n 100 y e a r s , nominally 1000 y e a r s o r l o n g e r . bNot r e a l l y a v i a b l e long-term o p t i o n ; would e v e n t u a l l y have t o be s u p p l a n t e d by one of t h e o t h e r o p t i o n s .

Table B.5.

S e m i q u a n t i t a t i v e e v a l u a t i o n o f MSRE o p t i o n s : E Conservationa

Process s t e p

Melt s a l t s (and add g e t t e r s ) Remove s a l t s Build s a l t p r o c e s s f a c i l i t y P r o c e s s or c o n v e r t salts/U Package s a l t s (and U) D i s m a n t l e f d i s p o s e of f a c i l i t y T r a n s p o r t packaged p r o d u c t s S t o r e / i s o l a t e products Decontaminate cells/equipment

Dispose of l i q u i d LLW Remove equipment Dispose of s o l i d LLW Dismantle c e l l s t r u c t u r e Dispose of s o l i d LLW/rubble R e s t o r e area ( l a n d ) Seal pipeslpenetrations I n t e r n a l entombment External s t r u c t u r e s (buildings) S t a b i l i z e drain-tank c e l l Continue s u r v e i l l a n c e

Total

The r a t i n g c o n s i d e r s Range 0 t o 10. ( A low s c o r e i s s u p e r i o r . ) near-term u t i l i z a t i o n of t h e b u i l d i n g s and long-term u t i l i z a t i o n of t h e 1and.

A p p e n d i x C.

WIPP WASTE ACCEPTANCE C R I T E R I A

c.1.

WIPP WASTE ACCEPTANCE CRITERIA

C.2.

W I P P CEKTIFICATION COMPLIANCE REQUIREMENTS

C.3.

WIPP:

GENERAL COMMENTS

FOR REMOTELY HANDLED (RH) TRU WASTE

86 C.l.

WIPP WASTE ACCEPTANCE CRITERIA FOR RH TRU WASTE

Source:

WIPP-DOE-069,

Rev. 2, D r a f t C, d a t e d August 1984.

Any combustible TRU waste s h a l l be packaged i n a

Combustibility:

noncombustible c o n t a i n e r .

Required i f more t h a n 1 w t % i s in form of p a r t i c l e s <10

Immobilization:

microns, o r i f more t h a n 15 w t % i s (200 microns in diameter. t i c u l a t e d e s i c c a n t s (e.g.,

Sludges:

Par-

P o r t l a n d cement) are exempted.

S h a l l be packaged s u c h t h a t i n t e r n a l c o r r o s i o n of t h e c o n t a i n e r

does n o t occur. Liquid Waste:

Free l i q u i d s are n o t allowed; minor amounts in c a n s o r

b o t t l e s are acceptable.

E x p l o s i v e s and Compressed Gases:

TKU waste s h a l l c o n t a i n no e x p l o s i v e s

o r compressed g a s e s , as d e f i n e d by 49 CFR 173, s u b p a r t s C and G.

Pyrophoric Material:

No more t h a n 1 w t % may be p y r o p h o r i c forms of

r a d i o n u c l i d e metals, and t h e s e s h a l l be g e n e r a l l y d i s p e r s e d i n t h e

waste.

Q r o p h o r i c materials o t h e r t h a n r a d i o n u c l i d e s s h a l l be ren-

d e r e d s a f e by mixing w i t h s t a b l e materials (e.g.,

R a d i o a c t i v e Mixed Waste:

No hazardous waste i s p e r m i t t e d u n l e s s i t i s

a l s o co-contaminated w i t h TRU waste. identified.

g l a s s o r concrete).

R e a c t i v e material s h a l l be

C o r r o s i v e materials must be n e u t r a l i z e d , rendered non-

c o r r o s i v e , o r packaged i n a manner t o e n s u r e c o n t a i n e r adequacy through t h e design l i f e t i m e

Container:

May be t h e RH c o n t a i n e r i t s e l f , o r i t may be t h e c o n t a i n e r

i n s i d e an overpack.

It must meet d e s i g n c o n d i t i o n s f o r "Type A"

packaging, 49 CFR 173.412(b),

s p e c i f i e d by DOT.

Container (and

l a b e l i n g ) s h a l l be c e r t i f i e d f o r a d e s i g n l i f e of a t l e a s t 20 y e a r s from d a t e of c e r t i f i c a t i o n .

Package S i z e and Handling:

Maximum s i z e 26" O.D.

(3.1 m) i n c l u d i n g t h e p i n t l e .

(0.66 m) and 121" long

Must have an a x i a l p i n t l e , of a

d e s i g n a c c e p t a b l e t o WIPP, and no o t h e r l i f t i n g d e v i c e s .

S h a l l n o t exceed 8000 l b s (3636 kg).

Waste Package Weight:

Not g r e a t e r t h a n 100 Rem/hr a t any p o i n t .

S u r f a c e Dose Rate:

Neutron

c o n t r i b u t i o n s g r e a t e r t h a n 75 mRem/hr s h a l l be r e p o r t e d i n t h e d a t a package.

S u r f a c e Contamination:

Smearable contamination no g r e a t e r t h a n 50 x 10-1

C u r i e s p e r 100 c m 2 f o r a l p h a and 4fi0 x

p e r 100 c m 2 f o r beta-

g amma.

Thermal Power:

Not g r e a t e r t h a n 300 w a t t s per package.

Nuclear C r i t i c a l i t y :

S h a l l n o t exceed lL.9 g / l i t e r of f i s s i o n a b l e i s o t o p e s

(averaged o v e r 5 l i t e r s w i t h a maximum 50% void s p a c e ) .

I f such

r e a s o n a b l e d i s t r i b u t i o n cannot be a s s u r e d , t h e n t h e c a n i s t e r i s l i m i t e d t o 240 g t o t a l ( i n Pu-239 f i s s i l e gram e q u i v a l e n t s ) .

The

c a n i s t e r may be loaded w i t h DOT 17C drums which w i l l p r o v i d e i n t e r n a l p a r t i t i o n i n g and i n c r e a s e ( s i c ) t h e l i m i t s t o 100 g f o r each 30 g a l drum

and 200 g f o r e a c h 55 g a l drum.

Pu-239 E q u i v a l e n t A c t i v i t y :

C i (Plutonium

Labeling:

Packages s h a l l c o n t a i n no more t h a n 1000 PE-

Equivalent c u r i e s ) .

Each package s h a l l be u n i q u e l y i d e n t i f i e d w i t h a permanently

a t t a c h e d number a t l e a s t 2" high.

Data Package:

C e r t i f i e d d a t a provided p r i o r t o shipment s h a l l i n c l u d e :

Package i d e n t i f i c a t i o n number; Dated c e r t i f i c a t i o n s t a t e m e n t t h a t waste c o n t e n t and packaging are i n accord w i t h t h e WIPP WAC, and t h e waste i s u n c l a s s i f i e d ;

Waste g e n e r a t i o n s i t e ; Date o f packaging; Maximum S u r f a c e Dose Rate; Weight; Container type ; P h y s i c a l d e s c r i p t i o n of waste form; Assay i n f o r m a t i o n , i n c l u d i n g PE-Ci and Pu-239 f i s s i l e gram e q u i v a l e n t contents ; Hazardous materials (non-radionuclide)

c o n t e n t : i d e n t i f i c a t i o n and

quantity; Measured o r c a l c u l a t e d thermal power;

Date of shipment; Carrier i d e n t i f i c a t i o n ; Other i n f o r m a t i o n c o n s i d e r e d s i g n i f i c a n t by t h e s h i p p e r .

(2.2.

WIPP CERTIFICATION COMPLIANCE REQUIREMENTS

Source:

"Draft A" of WIPP-DOE-158

d a t e d August 1984:

For u n c l a s s i f i e d , RH,

TRU waste, b o t h newly-generated and retrieved-from-storage;

a l l other

a p p l i c a b l e DOE o r d e r s must c o n t i n u e t o be m e t .

Container:

May be t h e RH c o n t a i n e r i t s e l f , o r i t may be t h e c o n t a i n e r

i n s i d e a n overpack.

It must meet d e s i g n c o n d i t i o n s f o r "Type A"

packaging, 49 CFR 173.412(b),

s p e c i f i e d by DOT.

The c o n t a i n e r (and

l a b e l i n g ) s h a l l be c e r t i f i e d f o r a d e s i g n l i f e of a t least 20 y e a r s from d a t e of c e r t i f i c a t i o n .

Package S i z e and Handling:

Maximum s i z e 26" O.D.

(3.1 m) i n c l u d i n g t h e p i n t l e .

(0.66 m) and 121" long

Must have an a x i a l p i n t l e , of a

d e s i g n a c c e p t a b l e t o WIPP, and no o t h e r l i f t i n g d e v i c e s .

Required if more t h a n 1 w t % i s i n form of p a r t i c l e s <10

Immobilization:

microns, o r i f more t h a n 15 w t % i s <200 microns i n diameter. t i c u l a t e d e s i c c a n t s (e.g.,

Par-

P o r t l a n d cement) are exempted.

Free l i q u i d s are n o t allowed; minor amounts i n c a n s o r

Liquid Waste:

b o t t l e s are a c c e p t a b l e .

Sludges:

S h a l l be packaged s u c h t h a t i n t e r n a l c o r r o s i o n of t h e c o n t a i n e r

does n o t occur.

Pyrophoric Material:

No more t h a n 1 w t % may be pyrophoric forms of

r a d i o n u c l i d e metals, and t h e s e s h a l l be g e n e r a l l y d i s p e r s e d i n t h e

waste.

Pyrophoric materials ' o t h e r t h a n r a d i o n u c l i d e s s h a l l be ren-

d e r e d s a f e by mixing w i t h s t a b l e materials (e.g.,

glass or

concrete).

Explosives and Compressed G a s :

Not g r e a t e r than trace q u a n t i t i e s of

e x p l o s i v e compounds o r no v e s s e l s c a p a b l e of being p r e s s u r i z e d g r e a t e r than 7 psig.

R a d i o a c t i v e Mixed Waste:

No hazardous waste i s p e r m i t t e d u n l e s s i t i s

a l s o co-contaminated with TRU waste. identified.

Reactive material s h a l l be

C o r r o s i v e materials must be n e u t r a l i z e d , rendered non-

c o r r o s i v e , o r packaged i n a manner t o e n s u r e c o n t a i n e r adequacy through t h e d e s i g n l i f e t i m e .

Waste Package Weight: Nuclear C r i t i c a l i t y :

S h a l l n o t exceed 8000 l b s (3636 k g ) . F i s s i l e c o n t e n t no more t h a n 50 g / f t 3 , averaged

o v e r 5 f t 3 volume and 50% void space.

I f uniform d i s t r i b u t i o n can-

n o t b e a s s u r e d , t h e c o n t a i n e r i s l i m i t e d t o 240 g t o t a l ( i n Pu-239 f i s s i l e equivalents).

Pu-239 E q u i v a l e n t TRU A c t i v i t y :

S h a l l n o t exceed a v a l u e ( i n C u r i e s ) TBD.

The Pu-239 e q u i v a l e n t i s based on MPC v a l u e s , DOE Order 5480.18, Chapter X I .

S u r f a c e Dose Rate:

Not g r e a t e r t h a n 100 Rem/hr a t any p o i n t .

Neutron

l e v e l s s h a l l be l i m i t e d t o 75 mRem/hr a t t h e c o n t a i n e r s u r f a c e ( ! ) .

Smearable contamination no g r e a t e r t h a n 50 x

Surface Contamination:

C u r i e s p e r 100 c m 2 f o r a l p h a and 450 x

p e r 100 c m 2 f o r beta-

g amma.

Thermal Power: Combustibility:

Not g r e a t e r t h a n 300 w a t t s p e r package. Any combustible TKU waste s h a l l be packaged in a noncom-

bustible container.

Gas Generation:

All RH TRU w a s t e c a n i s t e r s s h a l l be v e n t e d , through a

Rocky F l a t s - t y p e

Color Coding:

carbon f i l t e r o r e q u i v a l e n t .

No c r i t e r i o n s p e c i f i e d .

Each package s h a l l be u n i q u e l y i d e n t i f i e d w i t h a permanently

Labeling:

a t t a c h e d number a t l e a s t 2" high.

The s h i p p e r s h a l l have o p e r a t i n g procedures

Documentation/Compliance:

w i t h methods f o r d e t e r m i n a t i o n of a l l r e q u i r e d d a t a .

The d a t a

package s h a l l be t r a n s m i t t e d t o WIPP p r i o r t o shipment, i n a format a c c e p t a b l e t o WIPP.

A c e r t i f i c a t e of compliance s h a l l be provided

by a d e s i g n a t e d i n d i v i d u a l from t h e c e r t i f y i n g f a c i l i t y and be maint a i n e d by t h e s h i p p e r .

C.3.

WIPP:

Source:

GENERAL COMMENTS

(Excerpted from WIPP-DOE-069)

91 The f a c i l i t y i s n o t y e t a u t h o r i z e d t o be permanent.

Therefore, r e t r i e v a l

must be allowed f o r up t o 20 y e a r s under p r e s e n t c r i t e r i a .

Some e x p e r i m e n t a l packages w i l l b e allowed.

Out of 170 acres, 10 acres

i s f o r e x p e r i m e n t a l purposes.

KH TRU h a s a s u r f a c e dose r a t e >200 mRem/hr, but may n o t be g r e a t e r t h a n 100 Rem/hr.

Pu-239 F i s s i l e G r a m E q u i v a l e n t i s based on Q f f , assuming an o p t i m a l l y moderated i n f i n i t e a r r a y .

i s c h a r a c t e r i z e d by:

Pu-239 E q u i v a l e n t A c t i v i t y ( e x p r e s s e d i n PE-Ci) k AM =

1 Ai/CFi

i= 1

where t h e r e are k i s o t o p e s , A i i s maximum a c t i v i t y of i s o t o p e i , CFi

i s t h e MPC c o r r e c t i o n f a c t o r f o r i s o t o p e i , o b t a i n e d by m u l t i p l y i n g t h e MPC i n 10 CFR 20, Appendix B, Table 1, column 1 f o r s o l u b l e

materials by 5 x 1 0 l 1 m l / C i ,

t o normalize r e l a t i v e t o Pu-239.

TRU Waste i s d e f i n e d as d e f e n s e waste contaminated w i t h c e r t a i n alphae m i t t i n g i s o t o p e s of atomic number g r e a t e r t h a n 92 and h a l f - l i v e s g r e a t e r t h a n 20 y r s , i n c o n c e n t r a t i o n s g r e a t e r t h a n 100 nCi/g.

Waste Container i s t h e d i s p o s a b l e containment i n t e n d e d f o r emplacement a t WIPP, i n c l u d i n g any i n t e g r a l l i n e r o r s h i e l d i n g .

Package i s t h e

c o n t a i n e r and c o n t e n t s .

Waste volume p e r c e n t i s t h e material volume, e x c l u d i n g t r a p p e d void

space, of t h a t form compared t o t h e t o t a l waste volume, b u t not compared t o t h e package volume.

Appendix D.

ANALYSIS OF MSRE CELL PENETRATIONS

Prepared by

D. Macdonald and A. C. Williamson

Martin Marietta Energy Systems, Xnc., Engineering August 21, 1985

D. 1 INTRODUCTION The o b j e c t i v e of t h i s s t u d y i s t o review and comment on one a s p e c t o f t h e i n t e g r i t y of t h e MSRE f a c i l i t y t o c o n t i n u e t o s a f e l y s t o r e t h e f u e l and f l u s h s a l t s p r e s e n t l y l o c a t e d i n t h e d r a i n t a n k c e l l of B u i l d i n g 7503.

cell w a l l s .

This s t u d y i s concerned w i t h p e n e t r a t i o n s through t h e

These p e n e t r a t i o n s were e v a l u a t e d i n t h e c o n t e x t of

o v e r l a p p i n g containment envelopes composed of v a r i o u s c e l l groupings. The more t h a n 100 p e n e t r a t i o n s i n t o t h e r e a c t o r , d r a i n t a n k , and f u e l p r o c e s s i n g c e l l s ( F i g . D.1)

a s s o c i a t e d w i t h e a c h proposed envelope are

d e s c r i b e d by l o c a t i o n , t y p e , c u r r e n t c o n d i t i o n , and p o t e n t i a l f o r f u t u r e use.

indicate cell

The i d e n t i f i c a t i o n numbers shown on Fig. D . l

p e n e t r a t i o n s and r e f e r t o i d e n t i f i c a t i o n numbers shown on f a c i l i t y drawings; t h e y are a l s o r e f e r e n c e d t o Table D.l

of t h i s study.

Possible

c l o s u r e o p t i o n s are proposed f o r t h o s e p e n e t r a t i o n s n o t needed f o r f a c i l i t y maintenance o r f o r f u t u r e f u e l t r a n s f e r .

These e v a l u a t i o n s of t h e

c o n d i t i o n of t h e p e n e t r a t i o n s are incomplete a t p r e s e n t and w a r r a n t f u r t h e r s t u d y t o e s t a b l i s h t h e requirements f o r any recommended c o u r s e o f a c t i o n w i t h r e g a r d t o long-range p l a n s f o r s a f e s t o r a g e of t h e f u e l and e v e n t u a l f i n a l decommissioning of t h e f a c i l i t y .

D.2

CONTAINMENT ENVELOPES

While t h e MSRE w a s i n o p e r a t i o n , t h e f u e l s a l t w a s c i r c u l a t e d i n t h e r e a c t o r , d r a i n t a n k , and f u e l p r o c e s s i n g c e l l s .

The f u e l and f l u s h

s a l t s have been s t o r e d i n t h r e e c r i t i c a l l y s a f e s t o r a g e t a n k s i n t h e d r a i n t a n k c e l l f o l l o w i n g f a c i l i t y shutdown i n 1969.

Since t h e t h r e e

c e l l s are i n t e r c o n n e c t e d t o v a r y i n g d e g r e e s , t h i s s t u d y was o r g a n i z e d i n t e r m s of t h r e e containment envelopes ( F i g . D.2).

Envelope 1 i s composed

o f t h e r e a c t o r , d r a i n t a n k , and f u e l p r o c e s s i n g c e l l s .

These c e l l s are

grouped t o g e t h e r because t h e y c o n t a i n e d most of t h e r a d i o a c t i v i t y w h i l e t h e MSRE w a s o p e r a t i n g .

Envelope 2 i s made up of t h e r e a c t o r and d r a i n

t a n k c e l l s , which are s t i l l connected v i a an open p e n e t r a t i o n ( t h e p e n e t r a t i o n t o t h e processing c e l l i s sealed).

Also, t h e processing

c e l l i s more a c c e s s i b l e and more l i k e l y t o be u t i l i z e d i n t h e f u t u r e

REF.

DWG. X3E-12598-001

m-m /A-36 - E-36 A-24 - F-24 G-R 7

REACTOR

CELL

DRAIN 31-36

43-53

n-20

21-30

Fig.

D-l.

Identification

and location

cell

penetrations

the

MSRE.

REF. DWG. X3E-12598-001

ENVELOPE I

ENVELOPE 1

Fig. D-2.

Containment envelope options.

than i s t h e r e a c t o r c e l l .

Once t h e p r o c e s s i n g c e l l i s a c c e s s e d , t h e

p e n e t r a t i o n s a s s o c i a t e d w i t h Envelope 2 (between t h e f u e l p r o c e s s i n g and d r a i n t a n k c e l l s ) can be examined and s e a l e d .

F i n a l l y , Envelope 3 i s

t h e d r a i n t a n k c e l l i t s e l f , where t h e f u e l and f l u s h s a l t s are a c t u a l l y Once t h e r e a c t o r c e l l has been opened, t h e l a r g e p e n e t r a t i o n

stored.

between t h e d r a i n t a n k c e l l and t h e r e a c t o r c e l l can be s e a l e d .

D.3

DESCRIPTION OF PENETRATIONS During r e a c t o r o p e r a t i o n , t h e molten f u e l s a l t had t o be maintained

a t a t e m p e r a t u r e above 840'F

( t h e m e l t i n g p o i n t of t h e s a l t ) i n o r d e r t o

p r e v e n t a plug of s o l i d s a l t from forming.

This w a s achieved by

surrounding s a l t t r a n s f e r l i n e s with electrical h e a t e r s , i n s u l a t i o n , thermocouples, p r e s s u r e r e a d i n g i n s t r u m e n t s , and redundant instrumenThis complex a r r a y of e l e c t r i c a l and i n s t r u m e n t a t i o n l i n e s

tation.

n e c e s s i t a t e d numerous p e n e t r a t i o n s through t h e c e l l w a l l s .

In a d d i t i o n

t o t h e c e l l w a l l p e n e t r a t i o n s , t h e r e are two l a r g e c e l l - t o - c e l l

a 36-in.

nings: D.3),

opening between t h e r e a c t o r and d r a i n t a n k c e l l s (Fig.

and a 14-in.

( F i g . D.4).

ope-

opening between t h e d r a i n t a n k and r e p r o c e s s i n g c e l l s

These two openings c a r r y i n s u l a t e d , h e a t e d l i n e s f o r s a l t

t ransf er.

D.4

REACTOR CELL PENETRATIONS

T y p i c a l r e a c t o r c e l l p e n e t r a t i o n s ( s e e Figs. D.5 through D.9)

e l e c t r i c a l , thermocouple, water, off-gas,

are

and s a l t t r a n s f e r l i n e s .

o f t h e s e p e n e t r a t i o n s p a s s through t h e sand and w a t e r - f i l l e d

All

annulus.

I n a d d i t i o n , t h e r e a c t o r c e l l p e n e t r a t i o n s are provided w i t h some mechanism t o a l l o w movement r e l a t i v e t o t h e c e l l w a l l s .

The 12-ft r a d i u s

i n d i c a t e s t h e r e a c t o r containment c e l l w a l l , which was c o n s t r u c t e d of s t a i n l e s s s t e e l p l a t e r a n g i n g from 1-1/4 t o 4-in.

i n thickness.

The

15-ft r a d i u s i n d i c a t e s t h e r e a c t o r t a n k l i n e r , which was c o n s t r u c t e d of 3/8-in.-thick

s t a i n l e s s steel plate.

The l i n e s shown i n s i d e t h e l a r g e r

p e n e t r a t i o n s are p r e s e n t l y connected o r were used as s p a r e s and l e f t capped.

REF. DWG. X3E-12598-002

HFiATER 4 INSULATION

-_-----

- --- ---

_--__---_-__---_--_---

----I

- - - - lc -1 I

- -I -----_----_----

_.__I

c?” WALL

THK.

tank

cell.

SCH. 40 PIPE

..REA~T~~~AIN

Fig.

D-3.

Existing

interconnecting

TANK INTERCONNECT

penetration

between

reactor

cell

and

drain

REF.

DNG.

x?L-12598-003

u\i ;:

I---

between Fig.

D-4.

Existing

salt

transfer

line

penetration

drain

tank

cell

and fuel

processing

cell-

REF.

DNG. X3E-12598-EOOZ

$â&#x20AC;&#x2DC;SCH.44

DIA L~L,

Fig.

D-5.

Typical

existing

CELL SIDE

MIN. OFFSET

electrical,

thermocouple

PIPE

and instrumentation

pentrations

into

reactor

cell.

101

REF. DWG. X3E-12598-002

d' SCH.

SAMPLER AND SAMPLER OFFGAS LINES

Fig. D-6.

Existing sampler and sampler offgas l i n e penetrations into reactor c e l l .

REF.

DUG. X3E-12598-002

SEAL PLATE

Ctll

r----------_-0r---------- -_-_--_ Ir--.- -------_-_- ---_ : ---------- i _-_-I

SIDE

-___ _-__

---. ----___ ---.-_-----I III ---_----.-_

+ 15’R -I

\ WATER

Fig.

D-7.

Existing

LINES AND

water

8” SCH. 40 PlPE

OFFGAS LINER

and offgas

penetrations

into

reactor

cell.

(BOTH

END9

REF. DWG. X3E-12598-003

~~NSTRUMENTATION\

ELLCTRICAL

i-l NE5

COOLANT

AIR\. COVERGAS

L\NES

.8”R-

, ‘-$

-4 DRAWN TANK

Fig.

Y4’ THREADED COUPLINGS CELL

D-8.

Typical

existing

DRAIN

penetrations

into

drain

tank

cell.

PLATE

REF. DWG. X3E-12598-003

SCH.4-0 PIPE

----r L” 2 W-L /’I I i’ :

D P

a b Y

h---LT,?

, j

HELIUM\ Fig.

D-3.

Typical

water

WATER L IIVES

and helium

penetrations

into

drain

tank

cell.

40 PIPE

105 D.5

D R A I N TANK AND FUEL PROCESSING CELL PENETRATIONS

F i g u r e s D.8 and D.9 show t y p i c a l e l e c t r i c a l , cover g a s , c o o l a n t

a i r , helium, and water t r a n s f e r l i n e s .

All of t h e s e l i n e s , except f o r

t h o s e i n t e r c o n n e c t i n g t h e two c e l l s , pass through t h e c o n c r e t e c e l l w a l l i n t o access areas.

As i n t h e r e a c t o r c e l l , t h e l i n e s a r e e i t h e r con-

n e c t e d o r were used as s p a r e s and l e f t capped.

D.6

TABULATION OF PERTINENT INFORMATION

Much i n f o r m a t i o n about t h e c e l l p e n e t r a t i o n s h a s been c o l l e c t e d and t a b u l a t e d ( T a b l e D.l).

This t a b l e h a s been d i v i d e d i n t o t h r e e s e c t i o n s ,

one f o r e a c h of t h e main c e l l s ( r e a c t o r , d r a i n t a n k , and f u e l processing).

Table headings are:

( 1 ) p e n e t r a t i o n i d e n t i f i c a t i o n number,

( 2 ) type/usage, ( 3 ) present condition, ( 4 ) l o c a t i o n i n t h e c e l l , ( 5 ) access area, ( 6 ) s i z e of t h e major and i n t e r i o r p e n e t r a t i o n s , ( 7 ) d e t e r m i n a t i o n as t o whether t h e p e n e t r a t i o n i s needed now o r i n t h e f u t u r e ,

(8) c l o s u r e o p t i o n s , and ( 9 ) envelope involved.

The p r e s e n t c o n d i t i o n

o f t h e p e n e t r a t i o n s (connected, capped, o r empty) i s y e t t o be d e t e r mined; however, a d e t a i l e d o n - s i t e i n s p e c t i o n would p r o v i d e most of t h i s information.

Some of t h e p e n e t r a t i o n s used i n t h e f a c i l i t y , and t h e i r

need f o r maintenance o r f o r f u t u r e s a l t t r a n s f e r , were n o t r e a d i l y a v a i l a b l e a t t h e t i m e t h i s s t u d y w a s completed.

D.7

CLOSURE OPTIONS Numerous p e n e t r a t i o n s are c u r r e n t l y needed f o r f a c i l i t y s u r v e i l l a n c e

maintenance.

The s o l i d s a l t i s h e a t e d a n n u a l l y t o recombine f l u o r i n e ,

i n a d d i t i o n t o t h e p e r i o d i c measurements of t e m p e r a t u r e and p r e s s u r e . Besides t h e p e n e t r a t i o n s needed f o r s u r v e i l l a n c e and maintenance, t h e f a c i l i t y must m a i n t a i n t h e c a p a b i l i t y f o r t r a n s f e r r i n g t h e f u e l and f l u s h s a l t s o u t of t h e d r a i n t a n k c e l l i n t h e e v e n t t h i s may be r e q u i r e d i n the future.

S e v e r a l c l o s u r e o p t i o n s are a v a i l a b l e f o r t h o s e penetra-

t i o n s t h a t are n o t needed now o r i n t h e f u t u r e .

Penetrations with

i n t e r i o r l i n e s can be s e a l e d i n one of two ways ( F i g . D.10).

Each

i n t e r i o r p e n e t r a t i o n can be capped and l e f t i n place, o r t h e end sealp l a t e can be removed, t h e i n t e r i o r l i n e s c u t i n s i d e t h e l a r g e r penetrat i o n , and t h e s e a l - p l a t e r e p l a c e d w i t h a new, s o l i d p l a t e .

The o p t i o n

Table D-1.

MSRE reactor and drain tank cell penetration l i s t .

TYPE/IISAGE

I.D.

PRFSENT CONDITION

CELL LOCATION

ACCESS AREA

SIZE

South South South South South South South South South South South South South South South South South South

South Smith South South South South South

€SA ESA

3" 1n 6"

€SA

ESA ESA ESA ESA S w t h ESA S o u t h ESA S o u t h €SA S o u t h ESA S o u t h ESA S o u t h ESA S o u t h ESA S o u t h ESA S o u t h ESA Waste C e l l Waste C e l l W e s t of Bide. W e s t of Blde. F u e l Proc. C e l l Fuel Proc. C e l l F u e l Proc. C e l l F u r l Proc. C e l l F u e l Proc. C e l l F u e l Proc. C e l l F u e l Proc. Cell F u e l Proc. C e l l F u e l Proc. C e l l F u e l Proc. C e l l North ESA North ESA N o r t h ESA North ESA North ESA North ESA North ESA

NEEDED

CLOSIIRF. OPTIONS

EWE1 OPF

Drain Tank C e l l 1

S1EA'l FROM LWMES (1 )

FROM DOMES (1 ) WATW TO STFAM DOMES WATFB TO STEAM D I N E S WATER ( 1 ) WATER ( I ) SPARE ( 1 ) SPARE ( I ) HEI.IUM ( 1 ) HELIUM ( I ) HF.I.IIJM ( I ) HELIUM ( I )

3 4 5

6 7 R 9 10

11 12

13 14 15 16 17 18

19 20

Wall Wall Wall Wall Wall Wall Wall Wall Wall Wall Wall Wall Wall Wall Wall Wall Wall Wall West W a l l West W a l l North W a l l North W a l l North W a l l North W a l l North W a l l North W a l l North W a l l North W a l l North Wall North W a l l East W a l I Fast W a l l East W a l l

STFA'l

HELIUM ( 1 ) HEI.IIM ( 1 ) IIEI.II1M ( I HELIUM ( I )

SLYP DISCHARGE ( I ) SLYP DISCHARGE ( 1 ) A I R TO SUMP ( 1 ) AJR TO SllW ( 1 )

22 23 24 25 26 2i

2R 29 30

A-36 8-36 C-36 D-36 E-36 A-24 B-24 - .

INSTRLXFNTATION ( 2 9 ) TNSTRLYENTATION ( 3 6 ) THIZRYOCWPLF^S ( 3 6 ) Tl(ER*IOCMIPl.ES ( 3 6 ) ( 36 ) THER%WPl.ES ELECTRICAL (24) ELFCTRTCAI ( 2 4 ) -l.l..__.-_.

East East East East ...

. . . ~

Wall Wall Wall Wall ..

. ..,

.. .-

1" 1"

1 1 1

1/2" i n 1"

1" 1" 1" 1/2" i n 1" 1/2" i n 1" 1/2" i n I "

1 1 1 I I 1 1 1 1 1 I

1 I I 1

1 1

3/41' 3/4" 3/4" 3/4"

I I 1

1 I OR 2

I OR 2

1 OR 2

1 2 2 2

1 OR I OR 1 OR 1 OR 1 OR I OR 1 OR 1 OR 1 OR

1 1/2" 1- 1/ 2" 1 1/2" 1- 1/2" 1 1/2"

4" 1- 1/2" 1- I /2" 1-1 /2" 14" 3/4" 3/4" 3/41' 3/41' 3/4" 3/16" i n 3/4" 3/16" i n 3/6" .

1" 1" 1/2" i n 1/2" i n 1/2" i n 1/2" i n

1 1 1 1 1

n 6"

2 2 2 2 2 2 2 2 2

2 2

2 2 2 2 1 1

2 3

3 3

I I

. ...

I^__

. .

.-. ..

T a b l e D-1,

continued. -

c-24 D-24 E-24

F-24 G H I

J K L M N 0

P Q R

EI.ECTRICA1. EI.ECTRICAL EIEmRICAI. El .EC?'RICAI. SPARE ( I )

(24) (24) (24) (24)

SPARE ( 1)

COVER c f i ( 3 ) SPARE (1) SPARE ( I ) SPARE ( 1) CMPONENT COOIANT AIR ( 3 ) C(MPONENT COOLANT AIR ( 3 ) C(MP0NEW COOLAm AIR ( 1) DP CELL (4) LFAK DETECTOR ( 1 2 ) LFAK DETEClYHl ( 12)

Reactor C e l l I I1 I11 IV V VI VI1 VI11 IX X

XI XI1 XI11 XIV

xv XVI

XVII XVIII

XIX

xx XXI

XXII XXlII

xx 1v XXV

REACTOR LEN( DFTECTORS ( 6 0 ) ELFXTRICAL ( 44 ) ELFCTRICAI. (44) 'IHERMOCOIE'LES (60) INSTRLMENTATION ( 6 0 ) SAMPLER OFFGAS SAWIXR FUEL PLMP AUX. PIPING ( 8 ) NEUTRON INSTRIIMENT TUBE FUEL P W P LIQ. LEVEL. ( 6 ) FUEL P1.W AUX. PIPING ( I t ) COMPONENT COOLANT AIR ( 1 ) COOLANT SALT TO HX ( 1) W.41ER LINES ( 2 ) SPARE ( 2 ) WAT.R LTNES ( 2 ) WATER LThTS ( 2 ) WATER LINES ( 2 ) COOL. SALT TU RADIATOR ( I ) OFFGAS ( 3 ) OFFGAS ( 2 ) CELL EXHAUST DIKT ( 1 ) THEXMKDUE'1.E (38) IMAIN TANK CEI.1. INTERCON. SUMP

North ESA

East W a l l East W a l l East W a l l East W a l l East Wall East W a l l East W a l l East W a l l East Wall East W a l l East W a l l Esst W a l l East W a l l East W a l l East W a l l East W a l l

Ft-in.,

836 874

836 834 836 847 847

836-9 834-5 844-6 836-9 829-10 840-10 839-9 839-9 839-9 839-9 839-9 837 839-9 839-9 824-10 836 825-2 Bottom

N o r t h !?SA N o r t h ESA N o r t h ESA North ESA

North North North North North

ESA ESA

ESA North ESA N o r t h ESA North ESA N o r t h ESA S o u t h ESA South ESA

3/16'' i n 3/4" 3/16" i n 3/4" 3/16" i n 3/4" 3/16" i n 7/4" 6" 6" 6'' ( 3 1 / 2 " ) 6" 6" 6" 6" ( 3 3 / 4 " ) 6" ( 7 7/4") 6" (ONE 1 1/2") 6" ( 4 1/2") 6" ( 1 2 1/4") 6" (12 1/4")

3 7 3 3

No No NO NO No

I OR 2 1 OR 2 1 OR 2 I OR 2

1 1

I 1 1 1

I 1

I OR 2

1 1 1 1 1

OR 2

OR 2 OR 2

1 I 1 1

OR 2 OR 2

1 OR 2 1 OR 2

I I

2 OR 3

2 O R 7

2 OR 7

2 o R 3 2 OR 3

Degrees 15 30

S o u t h E5A S o u t h ESA

South E S A South ESA

24" ( 6 0 1 / 4 " ) 24" ( 6 1";38 3 / 4 " ) 24" ( 6 1";38 3 / 4 " ) 24" ( 7 3 / 4 " ; 2 8 1/2";25

South E A High Bay High Bay S e r v i c e Tunnel High Bay S p e c i a l Fq. Rm. Special Q. Rm. Special Q. Rm. Coolant C e l l Coolant C e l l Coolant C e l l Coolant Cell Coolant C e l l Coolant C e l l Coolant C e l l Coolant C e l l Coolant C e l l CDT m n n e l W e s t Tunnel Drain Tank C e l l

24" ( 6 0 ) / a " ) 4" ( 2 1/2") 6" 18" ( 3 1 / 2 " ; 4 3 / 4 " ; 1 I " ) 76" ( 1 0 ION CHAMBER GUIDES) 4" ( 6 1/4") 18" ( 2 1";11 1/21') 6" 24" 8" ( 2 1") 8" ( 2 2 " ) 8" ( 2 2") 8" ( 2 2 " ) 8" ( 2 2") 24" 6" ( 3 1") 6" (lVJ 1 1/4") 30" 24" ( 3 8 3/8") 36"

75 110 115 125 145 155 160 165 170 185 200 205 210 220 220 225 270 245 325 330 Center

3/8")NO NO NO

1 1

NO NO

I I

NO NO NO NO NO NO NO NO

NO NO NO

? 7

l o R 2 l o R 2 I o R 2 1oR2

I o R 2 7

IOR2 LOR2 2 2 O R T

I I I I I

I 1 I I 1 I I

Table D - 1 ,

continued.

F IJEL PRKESS TNG CELL 31 32 33 34 35 36 37

DRAIN STEAM LINE STEAV .im DISCHARGE STEAV LINE SEAY 1 . m

38 79 40 41

42 43 44 45 46 47 48

49 1JI .TRASONTC PROBE 50 I NSTRLYENTATI ON 5 1 I NSTRLMENTATI ON

52 57 1 NSERZMFS.ITATION 54 SALT ADDITION LINE

WALL WALL WALL WALL NORlH WALL NORTH WALL EAST WALL EAST WALL EAST WALL FAST WALL EAST WALL

NORTH NORTH NORTH NORTH

EASr WALL WEST WALL W E S T WALL WESTWALL WEST WALL WEST WALL WEST WALL WE3T WALL WEST WALL WEST WALL WEST WALL WEST WALL

ROOF I _ -

DFLON. CELL

DECON. CE1.L DECON. CELL DRAIN TANK CELL DECON. CELL DECON. CELL SPARE CELL SPARE CELL SPARE CELL SPARE CJXL SPARE CELL SPARE CELL HIGH BAY ABSOR. CUBE. ABSOR. CUBE. ABSOR. CUBE.

3/4" 314"

OR 2

OR 2 OR 2

I I

OR 2 OR 2 OR 2

1 1

1 1 1 1 1 1 1 1 I 1 1 1 1 1 I 1 I 1

No NO

6" 6"

YES

YES YES

YES

INS'IR. CUBE. INSIR. CUBE.

6" 2"

YES

ARSOR. CUBE. INSlR. CUBE. HIGH RAY ._

6" 6"

YES

1 1/2"

YES

YES YES

-- - -

I _

_. - ._ -.

OR 2

I OR 2

7/4" 6" 12" 12" 12" 3" 3" 8"

I I 2 I I

3/4"

4" 4"

I OR 2 1 OR 2 1 OR 2 1 OR 2

I 1

OR 2 OR 2

1 1 1 1 1 1 1

OR 2 OR 2 OR 2 OR 2 OR 2 OR 2 OR 2 OR 2 OR 2

I I

1 . . _ _ I -

ORNL-DWG

Needed Unneeded

lines

line

85-1194

(connectep

(cap te

Old

seal

plate

/ ---- . . .- -.. _ ’ .T, .?. v, .: : 7 .‘i .n :’ / / / / / / /

/ /

I /

CLOSURE OPTION NOTE:

Closure Fig.

option D-10.

CLOSURE OPTION 2 3 is a threaded Closure

options

plug. for

multiple

penetration

assemblies.

110

chosen depends on t h e use of t h e i n t e r i o r l i n e s .

i f any of t h e i n t e r i o r

l i n e s are needed, t h e n t h e s e a l i n g of i n d i v i d u a l l i n e s would a l l o w t h e needed l i n e s t o remain connected.

If none of t h e i n t e r i o r p e n e t r a t i o n s

i s r e q u i r e d , t h e method of r e p l a c i n g t h e s e a l - p l a t e w i t h a new, s o l i d p l a t e would e l i m i n a t e exposed l i n e s . with a threaded, pressure-tight

Electrical l i n e s can be s e a l e d

plug, s u c h as t h o s e used f o r s e a l i n g

spare electrical l i n e s i n the o r i g i n a l construction.

D.7

SUMMARY

The i n f o r m a t i o n developed i n t h e c o u r s e of t h i s i n v e s t i g a t i o n i n t o t h e c o n d i t i o n of t h e c e l l w a l l p e n e t r a t i o n s of t h e MSRE f a c i l i t y was of

a p r e l i m i n a r y n a t u r e , and more work i s needed.

Completion of t h e tabu-

l a t e d d a t a should be undertaken w i t h a p a r t i c u l a r a t t e n t i o n t o f u r t h e r on-site inspection t o v e r i f y conditions.

The p r e p a r a t i o n s r e q u i r e d f o r

c l o s u r e of most p e n e t r a t i o n s i s s t r a i g h t f o r w a r d s i n c e most of t h e

e l e c t r i c a l and g a s l i n e s are r e a d i l y a c c e s s i b l e and s e a l i n g can be achieved i n t h e same manner t h a t s p a r e l i n e s are capped.

c i a l p r e p a r a t i o n s w i l l be r e q u i r e d i n two cases:

However, spe-

(1) any p e n e t r a t i o n

t h a t w i l l , when c u t , have d i r e c t c o n t a c t w i t h c e l l atmosphere w i l l have t o be i d e n t i f i e d , and ( 2 ) t h e s a m p l e r and sampler off-gas l i n e s w i l l r e q u i r e c o n s i d e r a b l e e f f o r t t o remove t h e l e a d s h i e l d i n g above t h e p e n e t r a t i o n s i n o r d e r t o o b t a i n access.

Most of t h e p e n e t r a t i o n s i n t h e

f a c i l i t y a r e a s s o c i a t e d w i t h t h e r e a c t o r and d r a i n t a n k c e l l s .

Other

t h a n t h o s e p e n e t r a t i o n s r e q u i r e d f o r monitoring t h e f u e l s t o r a g e cond i t i o n s , f i n a l s e a l i n g of t h e w a l l p e n e t r a t i o n s t h a t e x i s t i n t h e d r a i n t a n k c e l l would a c h i e v e t h e m a x i m u m s e c u r i t y f o r in-place f o r an extended p e r i o d .

f u e l storage

The major e f f o r t , of c o u r s e , would be f o r t h e

c l e a n u p t o g a i n access t o t h e r e a c t o r and f u e l p r o c e s s i n g c e l l s so t h a t f i n a l i s o l a t i o n of t h e d r a i n t a n k c e l l could be achieved.

111

Appendix E.

BUILDING 7503 DRAINAGE SYSTEMS

Prepared by

F. J. P e r e t z

Martin Marietta Energy Systems, Inc.,

August 1985

Engineering

112

BUILDING 7503 DRAINAGE SYSTEMS

Thi

appendix

resent

a review o f t h e e x i s t i n g l i t e r t u r e and design data

f o r t h e B u i l d i n g 7503 drainage systems.

F u r t h e r work t o f i e l d check t h e

c o n d i t i o n o f t h e drainage systems would be u s e f u l , as would s t u d i e s t o d e f i n e t h e f l o w p a t t e r n s and volumes o f groundwater a t t h e s i t e .

Overall Description B u i l d i n g 7503 i s served p r i m a r i l y by f o u r drainage systems.

(1) A s p e c i a l

r a d i o a c t i v e l i q u i d waste system c o l l e c t s water from process and c e l l f l o o r d r a i n s i n a l i q u i d waste tank l o c a t e d i n t h e l i q u i d waste c e l l .

Waste i s

n e u t r a l i z e d i n t h i s tank i f necessary, and then i s pumped t o t h e LLW pumping s t a t i o n a t t h e northwest corner o f t h e s i t e .

Waste i s then pumped over t o

t h e Bethel V a l l e y f a c i l i t i e s f o r c o n c e n t r a t i o n and disposal.

( 2 ) Non-

r a d i o a c t i ve d r a i nage , in c l u d i ng groundwater c o l 1ected by t h e b u i 1d i n g f r e n c h d r a i n system and water e n t e r i n g f l o o r d r a i n s o u t s i d e o f t h e c e l l s , i s c o l l e c t e d i n t h e b u i l d i n g sump.

Water i s then pumped o u t o f t h e sump and

discharged from a c a t c h b a s i n southwest o f t h e b u i l d i n g o u t t o a drainage area l e a d i n g t o Melton H i l l Branch.

( 3 ) Storm water i s c o l l e c t e d i n a

s e r i e s o f r o o f drains, and i s p i p e d t o another c a t c h b a s i n west o f t h e building.

This water i s a l s o discharged t o a drainage area.

(4) Sanitary

wastewater i s c o l l e c t e d and drained t o a s e p t i c tank and d r a i n f i e l d a l s o l o c a t e d west o f t h e b u i l d i n g .

F i g . E-1 shows a schematic o f t h e storm and

n o n r a d i o a c t i v e b u i d i n g water rainage systems, i n c l u d i n g t h e l o c a t i o n s o f t h e c a t c h basins and discharge p o i n t s .

Drawing D-A-AA-40888-C

( i n pocket i n s i d e

back c o v e r ) shows t h e f l o w diagram f o r t h e b u i l d i n g r a d i o a c t i v e and nonr a d i o a c t i v e c o l l e c t i o n p i p i n g systems.

F u r t h e r d e t a i l s on a l l o f t h e

113 'Jnclassif ied ORNL DWG a-9109

Fig. E-1.

Schematic diagram o f B u i l d i n g 7503 d r a i n a g e p l a n .

114

b u i l d i n g drainage systems a r e given i n OKNL-TM-728,

P a r t 1, and i n

ORNL/CF-77/391.

R a d i o a c t i v e L i q u i d Waste C o l l e c t i o n The c e n t r a l p o i n t f o r r a d i o a c t i v e l i q u i d waste c o l l e c t i o n i s a 11,000 g a l . tank l o c a t e d i n t h e 1 i q u i d waste c e l l i n t h e n o r t h ha1 f o f t h e b u i l d ing.

The major sources o f waste f o r which t h i s c o l l e c t i o n system was

designed are t h e f l o o r sumps i n each c e l l , decontamination s o l u t i o n s from t h e decontamination tank (which was never

n s t a l l e d ) , and drainage from

''hot" sinks.

n t h e b u i l d i n g sump room can a l s o

Radioactive water c o l l e c t e d

be s e n t t o t h e l i q u i d waste tank. system a r e l i s t e d i n Table E-1.

The major l i n e s o f t h e r a d i o a c t i v e waste Each c e l l i s p r o v i d e d w i t h a sump t o

c o l l e c t any water which m i g h t e n t e r t h e c e l l .

Steam j e t s a r e used t o move

water from t h e sump t o t h e waste tank i n a l l c e l l s except t h e d r a i n tank c e l l and t h e r e a c t o r c e l l .

Those two c e l l s use a i r j e t s t o a v o i d

i n t r o d u c i n g steam i n t o c e l l s c o n t a i n i n g f u e l s a l t s .

One o t h e r exception i s

t h e sump added t o t h e c o o l a n t d r a i n tank c e l l , which i s j e t t e d t o a sewer i n t h e west tunnel of t h e south e l e c t r i c s e r v i c e area.

Under normal condi-

t i o n s , no water i s p r e s e n t i n t h e sumps, i n d i c a t i n g t h a t t h e c e l l s do indeed remain dry.

Bui 1d i na Water Col 1e c t i on and D i sDersal The c e n t r a l p o i n t o f t h e nonradioactve b u i l d i n g water c o l l e c t i o n system i s t h e pump room and b u i l d i n g sump ( F i g . E-21, l o c a t e d underneath t h e s p e c i a l equipment room i n t h e southeast p a r t o f t h e b u i l d i n g .

Access t o t h e pump

room i s gained through a l a d d e r tunnel beginning on t h e main f l o o r ( e l e v a t i o n 852 f t ) .

Two sump pumps and one " p i t pump" a r e i n t h e pump room,

115

Table E-1. Line No.

Radioactive l i q u i d waste l i n e s

Description

Lines e n t e r i n g l i q u i d waste storage tank:

333 343 314 316 318 320 322 326 339 340 308 301 948

Reactor c e l l sump ( a i r j e t ) D r a i n tank c e l l sump ( a i r j e t ) Caustic scrubber tank steam j e t L i q u i d waste c e l l sump (steam j e t ) Equipment storage c e l l sump (steam j e t ) Spare c e l l sump (steam j e t ) Fuel processing c e l l sump (steam j e t ) P i t pump discharge Caustic a d d i t i o n Hot s i n k s Process water a d d i t i o n ( s i phon break 1 Waste pump discharge ( r e c i r c . & m i x i n g ) Waste tank vent t o blower

S t a i n l ess Stainless Steel Stainless S t a i n l ess S t a i n l ess S t a i n l ess S t a i n l ess S t a i n l ess S t a i n l ess S t a i n l ess S t a i n l ess S t a i n l ess

314" 314" 314" 314" 314" 314" 314" 2It 2 2 314" 2If 6I'

Stainless S t a i n l ess

2-112It 2- 112"

S t a i n l ess S t a i n l ess S t a i n l ess Stainless

2 2It 2

Lines e n t e r i n g waste pump:

300 303

L i q u i d waste storage tank discharge Decontamination tank discharge

Other 1 ines :

305 302 306 303

Waste pump t o c e n t r a l pumping s t a t i o n Waste pump t o sand f i l t e r Sand f i l t e r t o decontamination tank Decontamination c e l l sump t o waste pump

117

as seen i n t h e flowsheet D-AA-A-40888-C.

The sump and pump room were

c o n s t r u c t e d as p a r t o f t h e b u i l d i n g m o d i f i c a t i o n s f o r i n s t a l l a t i o n o f t h e A i r c r a f t Reactor Test (ART) i n t h e l a t e 1.950's, and was m o d i f i e d o n l y s l i g h t l y f o r t h e MSRE.

Thus, most o f t h e design i n f o r m a t i o n i s found w i t h

t h e design package f o r t h e ART.

Drawing D-KP-19040-F shows many o f t h e

c o n s t r u c t i o n d e t a i l s o f t h e b u i l d i n g drainage system.

The b u i l d i n g sump c o l l e c t s water from n o n r a d i o a c t i v e f l o o r d r a i n s throughout t h e f a c i l i t y , as l i s t e d i n Table E-2. drains.

Standard designs were used f o r these

The sump a l s o r e c i e v e s groundwater from a f r e n c h d r a i n system which

serves t h e deeper c e l l s and support areas i n t h e south end o f t h e b u i l d i n g , and t h e charcoal bed south o f t h e b u i l d i n g .

Again, t h i s f r e n c h d r a i n

system was l a r g e l y c o n s t r u c t e d as p a r t o f t h e ART m o d i f i c a t i o n s .

Figs. E-3,

E-4 and E-5 show cross s e c t i o n s of t h e b u i l d i n g foundations, w i t h t h e approximate e l e v a t i o n s o f t h e f r e n c h d r a i n s i n d i c a t e d .

Similar french

d r a i n s may e x i s t i n t h e o r i g i n a l n o r t h s e c t i o n o f t h e b u i l d i n g , b u t s p e c i f i c design i n f o m a t i o n was n o t found.

The two sump pumps i n t h e pump room were

r e c e n t l y instrumented t o determine what f r a c t i o n o f t i m e they operate. P r e l i m i n a r y i n d i c a t i o n s a r e t h a t t h e pump w i t h t h e deeper f l o a t operates about one hour a day, d i s c h a r g i n g 2000 g a l l o n s i n an hour.

The o t h e r pump,

which would o n l y operate should t h e f i r s t pump n o t be a b l e t o keep up w i t h t h e i n f l o w , has n o t operated d u r i n g t h i s p e r i o d o f observation.

A t one t i m e

d u r i n g t h e i n t e r i m p e r i o d between ART and MSRE c o n s t r u c t i o n , t h e sump pump f a i l e d and was o u t o f o p e r a t i o n f o r some time.

During t h i s time, t h e lower

l e v e l s o f t h e b u i l d i n g were f l o o d e d w i t h several f e e t o f water.

This

experience i n d i c a t e s t h a t continued o p e r a t i o n o f t h e pumps i s necessary f o r t h e assured s a f e storage of t h e s a l t s i n t h e

MSRE f a c i l i t y .

118

Table E-2. Line No.

Standard b u i l d i n g drainage l i n e s .

Description

Material

Size

Cast i r o n Cast i r o n Steel Cast i r o n Cast i r o n Cast i r o n Cast i r o n Cast i r o n Steel Cast i r o n Steel

3 3 3 3 3 3 3 4It 3 2 3II

Cast i r o n Cast i r o n

4 4

Cast i r o n Cast i r o n

4 4

Cast i r o n Stain1 ess

3 2II

Steel Steel

3 2

Steel Steel

8'I 4

Steel Cast i r o n Steel

3 3 3

S t a i n l ess Concrete

2It 10"

D r a i n 1 i n e s e n t e r i n g sump:

352 353 354 364 355 356 357 358 359 365 325

Radiator a i r d u c t f l o o r d r a i n Radiator stack f l o o r d r a i n Coolant d r a i n c e l l f l o o r d r a i n Coolant d r a i n c e l l ( v i a 354) Blower house f l o o r d r a i n Blower house ramp d r a i n ( v i a 355) West tunnel f l o o r d r a i n ( v i a 355) Service room f l o o r d r a i n Service tunnel d r a i n Vent house v a l v e p i t d r a i n 55 gal drum d r a i n , p i t pump s u c t i o n

French d r a i n l i n e s e n t e r i n g sump:

361 363 362 360

Reactor c e l l f r e n c h d r a i n s Southeast f r e n c h d r a i n s ( v i a 361) Southwest b u i l d i n g and charcoal bed c e l l f r e n c h d r a i n s ( v i a 361) Sevice tunnel f r e n c h d r a i n s

D r a i n 1 i n e s e n t e r i n g 55 g a l . m o n i t o r i n g drum:

350 351

V e n t i l a t i o n stack d r a i n l i n e F i l t e r p i t d r a i n 1i n e s

Lines e n t e r i n g outdoor c a t c h basin:

327 337 331 330

Sump pump "A" discharge Sump pump "B" discharge ( v i a 327) Charcoal bed c e l l o v e r f l o w ( v i a 327) Reactor c e l l annulus overflovr P i t pump discharge ( v i a 331)

L i n e s e n t e r i n g p i t pump:

325 328 329

55 g a l . m o n i t o r i n g drum discharge Charcoal bed c e l l drainage Reactor c e l l annulus drainage

Other 1 ines :

326

P i t pump discharge t o l i q u i d waste storage tank Catch b a s i n t o f i e l d

119 ORNL-DWG 85-1195

21'- 0"

DRAIN T A N K

CELL

I '

F i g . E-3.

S e c t i o n of d r a i n t a n k cell f o u n d a t i o n s h o w i n g f r e n c h d r a i n , looking north.

excerpted

D-KS-1904CIA8,

---

--_----_ I

_..--

from

-_. _’ /... I

I ’

---

I!-

.-_

.___

‘XL

, .:.

Fig.

E-4.

Section

reactor

cell

foundations

i, ._

showing

,1.

french

‘,,,I.

drain,

,I; . : c‘ : ,_ ;;,. ,, ,: y.: a:\‘.‘. ‘, ,., ‘.,_ A : >: ,..q, , ‘.

looking

north.

(ART configuration)

excerpted from

D-KS-19040A8, R4

Fig. E-5.

SUMP Section o f south b u i l d i n g foundations showing sump and french d r a i n s , l o o k i n g n o r t h . (ART c o n f i g u r a t i o n )

122

Several l i n e s e n t e r i n g t h e pump room f l o w i n t o a 55 g a l . drum r a t h e r than e n t e r i n g t h e sump d i r e c t l y .

The drum i s used t o c o l l e c t drainage from areas

which m i g h t have contained small l e v e l s o f a c t i v i t y , and a l l o w s f o r m o n i t o r i n g p r i o r t o release.

The " p i t pump" c o u l d be used t o send drainage

c o l l e t e d i n t h e drum t o t h e r a d i o a c t i v e l i q u i d waste tank i n t h e event t h a t a c t i v i t y i s detected.

Water from t h e sump i s pumped up t o a c a t c h b a s i n southwest o f t h e b u i l d i n g , and f l o w s o u t i n t o a f i e l d through a 12 i n . concrete l i n e . F i g . E-1,

As shown i n

t h e 3 i n . pump discharge l i n e branches i n t o an 8 i n . c e l l annulus

d r a i n l i n e b e f o r e c i r c l i n g around t h e charcoal absorber p i t en r o u t e t o t h e c a t c h basin.

The r e a c t o r c e l l annulus can be emptied by pumping t o t h e

c a t c h b a s i n v i a l i n e 331 u s i n g t h e p i t pump.

T h i s o p e r a t i o n would remove a

major r e s e r v i o r o f water adjacent t o t h e c e l l i n which t h e s a l t s a r e now stored.

Caution i n disposal o f t h i s water would be d i c t a t e d by t h e

presence o f chromate r u s t i n h i b i t o r s , as w e l l as t h e p o s s i b i l i t y o f induced radioactivity

Storm Water Dispersal C o l l e c t i o n o f storm water i s accomplished w i t h a standard r o o f d r a i n p i p i n g system.

Water flows by g r a v i t y t o a c a t c h basin, separate from t h e one

s e r v i n g t h e b u i l d i n g sump, from which i t f l o w s o u t another 12 i n . concrete l i n e (Fig. E-1).

S i t e grading and d i t c h e s are used t o c a r r y storm water

from around t h e p e r i i n i t e r o f t h e b u i l d i n g .

123

S a n i t a r y Sewage C o l l e c t i o n and Disposal A standard s a n i t a r y sewage c o l l e c t i o n system was i n s t a l l e d i n t h e b u i l d i n g . Sewage flows by g r a v i t y t o a s e p t i c tank l o c a t e d west o f t h e b u i l d i n g . water l e a v i n g t h e s e p t i c tank then flows i n t o a d r a i n f i e l d west o f t h e s e p t i c t an k.

The

1 25

Appendix F.

GEOLOGIC INVESTIGATIONS RELATIVE TO MOLTEN SALT REACTOR DECOMMISSIONING

Dr.

D. W.

Byerly, Department of Geology

U n i v e r s i t y of Tennessee, Knoxville, Tennessee

December 1984

126

Geologic I n v e s t i g a t i o n s R e l a t i v e t o Molten S a l t Reactor Decommissioning D r . D. W. Byerly, Department of Geology U n i v e r s i t y of Tennessee, Knoxville, Tennessee

The Molten S a l t Reactor Experiment (MSRE) f a c i l i t y i s l o c a t e d i n t h e Melton V a l l e y area of t h e Oak Ridge N a t i o n a l Laboratory (ORNL).

The

v a l l e y i s bordered by Haw Ridge ( e l e v a t i o n 317 m) on t h e northwest and Copper Ridge ( e l e v a t i o n 400 m) on t h e s o u t h e a s t .

B u i l d i n g s housing t h e

r e a c t o r and o t h e r f a c i l i t i e s r e l a t e d t o t h e r e a c t o r are s i t u a t e d on t h e northwest s i d e of t h e v a l l e y n e a r t h e base of Haw Ridge.

Topographically,

t h e v a l l e y i s n o t f l a t , b u t i n s t e a d c o n s i s t s of r e l a t i v e l y s t e e p - s i d e d , irregularly-shaped,

275 m.

low h i l l s w i t h s u m m i t e l e v a t i o n s a v e r a g i n g about

R e l i e f i n t h e v a l l e y r a n g e s up t o 43 m.

The b u i l d i n g s a r e a t a ground e l e v a t i o n of about 259 m w i t h i n a s l i g h t

s w a l e ( p a r t i a l l y r e s u l t i n g from c o n s t r u c t i o n b a c k - f i l l )

n e a r t h e head of a

draw which i s t r i b u t a r y t o Melton Branch t h a t flows s o u t h w e s t e r l y through t h e main v a l l e y .

All d r a i n a g e from Melton V a l l e y u l t i m a t e l y e n t e r s t h e

C l i n c h River below Melton Hill Dam southwest of t h e c o n f l u e n c e of Melton Branch a t White Oak Creek. The g e o l o g i c a l c o n d i t i o n s of p o r t i o n s of Melton V a l l e y have been

i n t e r p r e t e d as f a v o r a b l e f o r s t o r a g e / d i s p o s a l of low-level r a d i o a c t i v e

wastes.

The f a c i l i t i e s i n Melton V a l l e y used f o r h o s t i n g t h e ORNL-

g e n e r a t e d low-level r a d i o a c t i v e wastes i n c l u d e :

b u r i a l grounds, waste

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

Bedrock forming t h e f o u n d a t i o n f o r t h e MSRE c o n s i s t s of t h e lower p o r t i o n of a "package" of r o c k s r e f e r r e d t o as t h e Conasauga Group. Rocks of t h i s group g r a d e c o m p o s i t i o n a l l y downward i n t o t h e Rome Format i o n u n d e r l y i n g Haw Ridge and upward i n t o t h e Knox Group which forms Copper Ridge.

Variegated s h a l e s , commonly c a l c a r e o u s , comprise most of

t h e lower Conasauga; however, i n t e r c a l a t i o n s of s i l t y t o pure l i m e s t o n e may be p r e s e n t a s l e n s e s .

The upper p o r t i o n of t h e Conasauga, on t h e

s o u t h e a s t e r n s i d e of t h e v a l l e y where g r a d a t i o n w i t h t h e Knox Group o c c u r s , g e n e r a l l y c o n t a i n s more limestone.

1 27 The knobby topography i n Melton V a l l e y i s t y p i c a l of weathered and eroded s h a l e .

The knobs o r h i l l s are a l i g n e d i n rows p a r a l l e l i n g t h e

r e g i o n a l s t r u c t u r e , forming above t h e s h a l y bedrock, whereas t h e i n t e r v e n i n g low areas are o r d i n a r i l y u n d e r l a i n by t h e c a r b o n a t e rocks. above t h e bedrock i s v a r i a b l e i n t h i c k n e s s .

Regolith

Generally, it i s t h i c k e s t

( u p t o 9 m) on h i l l crests and t h i n n e s t ( l e s s t h a n 1.5 m) i n t h e f l a t , low-lying areas.

The t o t a l t h i c k n e s s of t h e Conasauga Group i s about

600 m. The trace of t h e Copper Creek f a u l t , a major t h r u s t f a u l t i n t h e Ridge and V a l l e y province of t h e s o u t h e r n Appalachian orogen, s t r i k e s NESW a l o n g t h e northwest s l o p e of Haw Ridge.

The f a u l t d i p s s o u t h e a s t

p r o j e c t i n g below Melton V a l l e y and Copper Ridge a t c o n s i d e r a b l e depth. Sedimentary s t r a t a of t h e Conasauga Group forming Melton Valley a l s o s t r i k e n o r t h e a s t and d i p t o t h e s o u t h e a s t , forming t h e hanging w a l l of t h e Copper Creek f a u l t .

The f a u l t and r e l a t e d deformation of t h e rocks

i n t h e v a l l e y r e s u l t e d from t e c t o n i s m t h a t o c c u r r e d over 200 m i l l i o n y e a r s ago.

Subsequent deformation of t h e s e r o c k s i s n o t e v i d e n t .

Considering t h e p r e s e n t t e c t o n i c s e t t i n g of North America and t h e f a c t t h a t t h e f a u l t a s w e l l as s t r u c t u r a l elements have n o t been a c t i v e ,

a t l e a s t d u r i n g t h e most r e c e n t 70 t o 80 m i l l i o n y e a r s , t h e area can be c o n s i d e r e d t o have a low seismic r i s k ( s e i s m i c r i s k zone 2, Modified

Mercalli i n t e n s i t y less t h a n V o r VI).

The n e a r e s t s i g n i f i c a n t e a r t h q u a k e

e p i c e n t e r s h i s t o r i c a l l y a r e C h a r l e s t o n , South C a r o l i n a , and New Madrid,

Missouri; however, b o t h are c o n s i d e r e d t o o d i s t a n t t o have o r have had s e r i o u s d e t r i m e n t a l impacts on t h i s area. J o i n t s o r f r a c t u r e s w i t h i n t h e Conasauga t h a t are a s s o c i a t e d w i t h p a s t t e c t o n i s m have n o t a p p r e c i a b l y a f f e c t e d t h e s t r e n g t h of t h e bedrock, but have r e s u l t e d i n a secondary e f f e c t i v e p o r o s i t y which i n f l u e n c e s t h e geohydrology of t h e v a l l e y .

In Melton V a l l e y , t h e zone of ground water s a t u r a t i o n g e n e r a l l y o c c u r s a t g r e a t e r d e p t h s beneath s u m m i t s t h a n i n t h e low-lying bottoms. I n low areas s u c h as a d j a c e n t t o p e r e n n i a l streams l i k e Melton Branch o r t o ephemeral streams i n t h e g u l l i e s d i s s e c t i n g t h e low h i l l s i n Melton

128 V a l l e y , t h e water t a b l e may be found w i t h i n 1.5 m below t h e l a n d s u r f a c e .

On h i l l t o p s , t h e d e p t h t o t h e water t a b l e may exceed 6 m.

The g e n e r a l

p a t t e r n of ground water movement i s l a t e r a l l y a l o n g bedding s t r i k e (NE-SW),

but j o i n t i n g o f t e n modifies t h i s pattern.

An a v e r a g e r a t e of

ground water movement w i t h i n t h e s h a l e s of t h e Conasauga h a s been d e t e r mined t o be 15 cm/day. Ground water behavior a t t h e s i t e i s a key f a c t o r which must be a d d r e s s e d p r i o r t o d e c i d i n g t h e d i s p o s i t i o n of t h e r a d i o a c t i v e materials c o n t a i n e d i n t h e MSKE f a c i l i t i e s .

A h y d r o l o g i c monitoring program should

be developed t o e s t a b l i s h b a s e l i n e q u a l i t a t i v e and q u a n t i t a t i v e water data.

Water i s a n important f a c t o r f o r a t l e a s t two r e a s o n s .

One, i t can

p o t e n t i a l l y d e t e r i o r a t e t h e waste c o n t a i n e r s , e s p e c i a l l y i f t h e geochemi s t r y of t h e water i s r e a c t i v e , and two, water i s t h e most l i k e l y v e h i c l e f o r t r a n s m i t t i n g t h e r a d i o a c t i v i t y t o t h e b i o s p h e r e should containment

fail. Although t h e MSKE f a c i l i t y i s a p p a r e n t l y sound s t r u c t u r a l l y , i t must b e k e p t i n mind t h a t t h e f a c i l i t y w a s n o t designed f o r long-term entombment of r a d i o a c t i v e wastes.

M u l t i l e v e l s of b a r r i e r s , i n c l u d i n g engineered

a s w e l l as t h e n a t u r a l g e o l o g i c s e t t i n g , a r e n e c e s s a r y f o r s a f e , long-term

s t o r a g e / d i s p o s a l of r a d i o a c t i v e wastes.

Therefore, s e v e r a l geological

a s p e c t s of t h e f a c i l i t y s i t e need more assessment of a s i t e - s p e c i f i c n a t u r e before on-site storage/disposal is considered a f e a s i b l e a l t e r n a tive.

To be a c c e p t a b l e , t h e s i t e should be c a p a b l e of s a f e l y c o n t a i n i n g

t h e wastes w i t h o u t i n s t i t u t i o n a l c o n t r o l s (i.e., i n f i l t r a t e d water, e t c . ) .

sump pumping of

Among t h e g e o l o g i c a s p e c t s t h a t should be

i n c l u d e d i n f u r t h e r e v a l u a t i o n of t h e s i t e i n c l u d e : C h a r a c t e r i z a t i o n of a l l e a r t h materials on the s i t e (anthropogeneous

m a t e r i a l , bedrock, e t c . ) 0

Site design-

s l o p e s , placement of f i l l s o i l s , u n d e r d r a i n s , founda-

t i o n s , etc. 0

S i t e hydrology

- water

i n v e n t o r y i n c l u d i n g q u a n t i t y and q u a l i t y ,

ground water flow n e t s , p i e z o m e t r i c l e v e l s , e t c . S i t e - s p e c i f i c i n v e s t i g a t i o n of t h e above should be c o n s i d e r e d as t h e v e r y minimum of any program p l a n f o r t h e e v a l u a t i o n of t h e s i t e f o r o n - s i t e entombment of t h e MSRE r a d i o a c t i v e materials.

129

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F. J. P e r e t z L. P. Pugh T. He ROW J. H. Swanks R. E. Thoma W. W. Thompson J. R. Trabalka V. C. A. Vaughen R. G. Wymer C e n t r a l Research L i b r a r y Document Reference S e c t i o n Laboratory Kecords RC Laboratory Records ORNL P a t e n t S e c t i o n

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