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ORNL-4812 UC-80 - R e a c t o r Technology

MOLTEM-SALT REACTOR PROGUN

THE DEVELOPMENT STATUS OF MQLTEM-SALT BREEDER REACTORS

XiI. W. Rosenthal, Program D i r e c t o r P. N. Haubenreich, Associate Direc tor R. B. Briggs, Associa te Di rec tor

August: 1972

OAK RIDGE KATIQNAL LABOMTOKY Oak Ridge, Tennessee 37830

o p e r a t e d by U N I O N CARBIDE CORPORATION

f o r the E.S . ATOMIC mmeY COXMISSION

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ABSTRACT

Molten-salt reactor technology, under development since 1947,

A connected

The

has led t o a concept of a high-temperature, thermal-neutron breeder reactor that operates on the t h o ~ i u m - ~ ~ ~ U fuel cycle. processing plant that continuously removes protactinium and fission products from the fuel salt is a bas ic feature of the system. success of the Molten-Salt Reactor Experiment that was operated be- tween 1965 and 1969, the development of a new processing method that allowed simplification of the breeder design, and the potential breed- ing performance, economfcs, and safety of the concept, are cited i - n this report as arguments for the continued development of MSBR's. The report reviews the status of the technology, identifies further development needs f o r an MSBR, and gives the program staff's assess- ments of the uncertainties and the likelihood of success. Separate. chapters are devoted t o reactor physics, chemistry, graphite, reactor metals, reactor eomponents and systems, ce l l s and building, control and instrumentation, fuel processing, maintenance, design studies, and environmental effects and safety.

Keywords: review, molten salts, reactors, breeding, development, design, maintenance, safety, chemistry, processing, a l l o y s , graphite.

CONTENTS

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..... ,.. . . . &%*

Chapter Page

1. INTRODUCTION, S W R Y , A m CONCLUSIONS . * 0 . . a 0 D . * * h Backgroun$ . . . . . . . . . . . . . . . . . . . . . . . . . 2 Features of t he Single-Pluid Breeder Reactor . . . 4 The Processing Plan t FOP the Single-Fluid Breeder . a 6 Nuclear and Economic Performance of the Breeder . e . . 6 The Status of Development, the f i j o r Uncertainties, and the Alternatives . . - . . . . a e . . . a . e e 8

~eactor ~hysfcs ana F ~ ~ I cycles e a e e . a . a a 8 Fuel and Cookant Chemistry . a . . e . 8 Graphite .. e - . e e * . . * . . * . e * . . 9 Materials f o r Salt-Containing Vessels and Piping e . . 10 Reactor Components and Systems . . . . e e e 12 Cells , Bui ld ings , and Containment e e a a e a . a I e 14 Instrumentation and Controls . . e e . . . e . e . e I 4 Fuel Processing . . e e . e . e a . e . 15 Maintenance . . e . . . e . e e e . e 17 Design Studies and Capital Cost Estimates . . e e 1 7 Environmental Effects and Safety a e e . e . a e e e 18

Future Development Program e . e . . . - e a . a e 1 9 The Incentives for MSBR Development . . e e . a e 2 1

Fuel Utilization . e . e a . e a e e e e a e a . a 22 P o w e r C o s t e e . e e . e * a . e n 0 . e 0 0 . . e . 22 Safety * 0 . a a e . . a * * e e e s a e m * e . * 0 * 25

m e Likeiifaooa sf success . e e . . a . . . a 26 Fuel Utilization . . . . e e . a a e a . 27 Powerrcost * * . e e a . e 0 . s 0 0 . D 0 . . 0 D * 27 Safety s . . 0 a . s 0 . e . e 0 * 0 . . . e * e rn 28

Overall Conclusions . . . . . - e a e a . e . a a 38 References f o r Chapter li . . . e . . e e e . . . . e e 31

2. EVOLUTION AND DEVELOPPENT OF NOLTEN-SALT Origins . . a e . - C . O s . . s 0 . .

Rela t ion tu Other Fluid-Fuel Programs . Early MSBR Concepts . . . . e e e a

T h e M S R E . * . . * . . o . e * . . a

Description e . a . e a . . e e . Development and Construction e . e

Operation e . e 0 . . . 0 . . . m . . Results...... - .

Recent M~lten-Salt Reactor Concepts a . Current Programs I . . . e . - . . e

USAEC PloHten-Salt Reactor Programs . Industrial Studies . . . . Foreign Programs . e e . s e * e e

References f o r Chapter 3 . . . . e . .

P u r p o s e . * . . - . e

REACTORS . . e . 3 3 r . . . * * . . * * 33 . . 0 * . . . . . 0 34 . . L O . . * . . . 3% e . . . * e . s . . 35 0 0 . . . . . . 0 0 35 . . . * . . . e 0 0 36 . . * . . . a , . . 36 . s o e . . . e o . 48 . s . . . s * . . * 41 m . . a . . . * . . 4 2 e . . * . . . * * . 45 * * . . . D * . . . 45 * e . . . . a . . * 46 0 . . * * 0 * 1 e . 46 m . * . e . . r a . 48

Chapter

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

Page

3. DESIGK CONCEPT OF THE SINGLE-FLUID MSBR 0 . omh, Reference Design * * 0 . m 0 . * 0

Objec t ives D I e s I . s 0 * e 0 e e 0

O r e Csnservatisn * 0 0 . . 0 . * 0 0 . P s w e r C o s t . a . e e e * D * e * e

S a f e t y and Environmental Cons idera t ions Technical F e a s i b i l i t y * D s a s D . e D

General e ~ ~ ~ ~ e p t s f t h e s i n g i e - n u i a weeder Features of the Referenee Design e I

Alternatives t o t h e Reference Design e . . a

Ebasco Variat ions f rom QRXL Design e e e

Low-Power-Density Core e e . e a

References f o r Chapter 3 a e e e e a e e e

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vi

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Chapter Page

5. (cont.)

Fission Product. Behavior . e a . . . . a e . e . e . a . 116 General.. . a s . . . e . - . a a 116 Major Groups and Y i e l d s . e e . e e e e . e e . . a 1 1 7

S a l t S a m p l e s . . - . . . * . . . e - . a E22 Deposition e . a . . I . e . e e . e . e . 1 2 2 G a s S a m p l e s . . ~ . . . ~ . . . . . . . f . O ~ . . ~ 125

Nob leMeta l s e . a . . a . = e e e e . . e . 125 Salt-Borne . . a e . e . a e a . . a . 1125 Niobium . * . - * . . e * . . a e * . . . e a . - - 1 2 9 Gas-Borne . e a . e . . . . . a a . a . = 129 Deposition on Graphite and Hastelloy N e . e . * . 138

Iodine O . . O ~ . . . . . D . . . O O . . L ~ . . . s . 133 EvaLrnation . a I a . a a e e . e e a . e . . . e 133 Futurework a . e . a a . . e . e . e e 135

Coolant Salts . . . e e e e e . . . . . 135 Basis f o r Choice of Composition . e e e . . a a - . 135 Present Status of FHuoroborate Chemistry a . a . a 137

Phase Behavior - . . I . a = a I . a a e e e I 137 Behavior w i t h Hydroxide Ion e . e a e . . e 139 Physical Properties . . . e . . a e e e 139 Compatibility w i t h Hastelloy N e e . a a . a . . 141 Interactions with Steam . . . . . - . . . e a 142 Interactions with Fuel S a l t e e . a e . a e . - a 1 4 2 Purification of Fluoroborate Mixtures . e e e e . . 144 Radiation and Stability e . . . - . . . . e 145

Evaluation and Summary of Needed Work e . . e . a 145 Analytical Chemistry e a . . a . a . e e . e a 146

Requirements . e . a . e . e . . a e . a 146 Experience . * . . e e a . e . . . . e e 1 4 7

Sampling * . . s D . * - D . . * a * . . f - s e s . * 148 Oxide r D . . P . . . . . . . . . l O . . r D . . . s 148 Uranium a e # . - . . . - . . * . * . . . e * . E49 u3-t . . s . . . . . . . . . . . . . . . . . s * s e a a49 Spectrophotometry of Radioactive Samples e a e . 1 4 3 GasAnalysis . . . . . . . . . . . . . . . . . . 152 Gama Spectrometry at the MSE!E e . e e e a e . e e 152 Bismuth . . e e * . * . a * . . * . - - * . e - e 152

Current Research and Development e . . . e . e . . . . . E52 Electrochemical Research . . . e . . - a . a . e 153 Spectrophotometric Research . . . . e . . . e 1 5 9 Transpiration and Gas Analysis . . e . . . . a 1 6 1 Pn-Efne Applications . . . . . . e . e . e . e . 163

P u t u r e W o r k . . . . . . . . . . . . . . . . . . . . . . . 165 Evaluation 166

Stable Salt-Soluble P l u o r ~ i d e s . a . . a - . a . e . 122

References for Chapter 5 s 0 0 . 0 0 . . D 0 . . s s . e . 1 6 7

Vii

22% 222 222 222 226 226

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Chapter Page

8. (cont . ) . . ,.... ,&

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Pump Experience e e . e . . e e . . . e . a e . Short-Shaft Bump . . . . . . . a . e a e a . Long-Shaft Pump . . . . e . . e . . e e

I n d u s t r i a l Experience and I n t e r e s t . . . . e e

S t a t u s of Pump Technology . . = e . e . . . e a e . . Sca l ing up Pump Capaci ty , . . e e . . . . e e

F a b r i c a t i o n . e . . a . . a a . . . . - Long-Shaft Pump . . . . a e . a a . I e . a

P o t e n t i a l Improvements . . a . . . . a . e

I n d u s t r i a l Involvement . . . . e . I . e a e

E f f e c t s of U n c e r t a i n t i e s . . . . a . e . . e

S a l t Pump Development Requirements a . e . e . a e . Evalua t ion . . O . . . . . O a . . O O . . e . O .

Coolant System e e . a a . . a . . e . . e . e . . D e s c r i p t i s n . . . . . . . . . . . . . . . . . . . . . . a

Experience wi th Coolant Sal ts . . . . . . a e a

S t a t u s s f F lus robora t e Coolant Technology . e . e a . U n c e r t a i n t i e s i n Use of F luorobora te a e e . e . a e

Fur the r Development Work . e . . e e a . a e . . a

D e s i . . . . . . . . . . . . . . . . . . . . . . . . .

Cover G a s Addit ion t o and Removal from

Corrosion Product Deposi t ion e . e . . . e . . e e . a

Mist Control . e e . a . . . a . . . . e e

C o o l a n t L e a h a a e a . . . . . . . e . . Evalua t ion a . . e . e a a . . e . . . e e .

Heat Exchangers a e . e . e . e . e a . . . e . . e . Requirements and Criteria f o r the Brimary Heat

Exchangers and S t e a m Generator . e e . . a e . . Current Concepts . . . . . e e . . . e . . Heat Trans fe r Experience . . e . . e e . . e . . S t a t u s of Heat Exchanger Technology e . . . . . . . a

U n c e r t a i n t i e s and Thei r S e n s i t i v i t y t o Nonachievement of Objec t ives . . . . e . . a . . . e .

Feedwater Temperature L i s t e . . - . . . a . e . . . a

Tube Sheet P r o t e c t i o n . . e . . . . a - . . a . Flow I n s t a b i l i t i e s i n t h e S t e a m Generator e . e a . Conf igura t ion . e . . e . . e e e . . . a . . Pressure Ful se from Rupture of a Steam Tube e . . . Cor re l a t ions and Phys ica l P r o p e r t i e s . . a . . . a . Thermal Trans i en t s . . . . . . . . . . . e a . e . S t e a m Wastage and Leak Detec t ion

( S t e ~ i ~ Generator) . . a . . . . a . . . . F i s s i o n Product Deposi t ion e . . . e . e e e e e

Materials Compat ib i l i ty e . . a . e . . . . e

F a b r i c a t i o n Techniques . e . . e e . e e .

t h e P u m p B o w l . . * 0 0 . m * 0 0 * * D . . . e . e

on-Line Analysis . . . 0 . . . . . a . e . s . s D D

Materials Experience * . . a 0 . . * e e . e . . * s . .

229 2 2 3 2 31 2 33. 2 31 232 2 32 233 233 233 2 3 3 2 34 2 34 2 35 236, 236 237 233 242 2 4 3

243 2 4 3 244 244 244 245 245

245 247 25Q 250 2 5 1

252 252 2 5 3 253 253 253 254 2 54

254 254 254 255

... .... i ...... I ._

ix

Chapter

8. (cant.)

255 255 255 256 257 257 257

259 260 268 261 262 262 262

26 3 263 264 2 64 264 265 265 265 265 266 267 268 268 268 269 269 269 270 230 231 271 2 7 3 233 2 7 3 273 2 34 2 74 276 276

282 284 286

282

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Chapter

8. (cont.)

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MSWGasSystems e . -

DeSCriptiOn . . 0 . . . . s . . . . . . 0 . . e e . 6

Analysis of Noble Gas Stripping . e e . a . e . O f f - G a s System Performance . . . * . . . . e

Development Studies . . . . a e e . . Effects of Unknowns and Uncertainties . . e e e . . . e e

Future Work e . * e . * . 0 e e 6 . . I . * * - . e . Overall Evaluation e a . . a . e . . . I .

Summary . . ~ . . O . . . . e . O . . O O . . . ~ * ~ . ~ ~

References f o r Chapter 8 . . . . e . . e e . e . . e a a . e

9. CELLS, BUILDINGS, AF3B CONTAINMENT . - e a . . . a . . e

Requirements e . a a a . . . e . a e . e e . . MSKE . . . . . s . . . . I . . . O e . . . . * ~ ~ . ~ *

MSBRBuilding. * . e * . * . a e . . e e e * .

M S B R C e P l s 0 . e . s . 0 . . * - 0 . e . e D D . * 0 0 .

De§CriptiQn a e . . . . e . e . . a . . . a a e e

Status and Uncertainties . . a a . e . . e e e e . . Evaluation . . e e . e . . e a . . e . . . .

10. PLANT CONTROL AND ENSTKUMENTATXON e e . . . e a e . Requirements and Current Concepts . . . . e . e e . . e

Systems f o r N o r m a l Operation e . . . e . . e e a

Emergency Systems . . e . . . - e . a . e - . . a e

Features Peculiar to XSBR e e e . . a . . e e . a

Experience with the MSRE: and Other Facilities a . * e . e

In§trUlTl@lltatiQn e . . . a e . e a e . . . . . e e

Control Analyses 0 . . I * * . * a . . 0 D . . s * * . . * D

Computer Models . 0 . 0 0 * . . e * I . . . D * e . e

Analysis of Steady-State Conditions . e . e . . e a . Analysis of Transient Behavior e . . . . . . Accident Analyses . . . . . . . . a . . . . e e . Reactivity Control . . e . a . . . a . . e . . . . . a

Instrumentation . . . t . . . D 0 . s e . e . . * m 0 . . High-Temperature Flux Sensors . a . . e a e . . *

Process Instrumentation 0 . . . . . 0 . . . s e a . a 6

Rod Drives . . . * . . e * . a * . . - - . . e e

Salt Throttling Valves . . . - a . . . e e e e . . a

Digital Computer Application f o r Control and

Chemical Plan t Instrumentation and Control . . e . Uncertainties and Alternatives . . e e e . e . . . . e

Evaluation . . . . . e e . . . . . . . . . . * . . . References f o r Chapter 16 . . . . . . . . e . . . e e

BataHandling * e . e . . * . . * 0 . e 6 0 * 0 . .

2 86 2 86 287 288 290 294 296 297 29 7 300

309 309 309 309 310 411 3 1 2 313

315 315 3 15 316 316 317 318 320 321 321 322 3 2 3 32 3 324 324 324 325 325

326 326 326 328 329

xi

Page

331 a 31

333 335 439 339 34 3 346 34 7 34 7 349 35 0 35 l 35 E 35 2 353 354 35 6 35 6 35 3 35 8 35 8 359 3.59 35 9

360 36 1 362

12 . rn1NTEP;rnCE a * P 0 . e e a

concept s a . 6 0 . * 0 0

Technologica l Background EISE P r e p a r a t i o n s 0 D . a

Extent of MSW Experience ConePusions f rom Pzsa " 0

Reference Des ign MSBR - * 0

Containment a 0 * * e e

A f t e r h e a t . 0 e 0 a . G r a p h i t e Replacement e a

S t a t u s , e a e e a = - Fur ther Work m 0 D . . e 0 0

E v a l u a t i o n . = . . References f o r Chapter 1 2 0

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13. DESIGN STUDIES Ab919 CAPITAL COST ESTIMATES - I n t r o d u c t i o n e e . a e . . . e . . Primary Systems Layout and S t r u c t u r a l Design

Background and S t a t u s . e . e e . a

S e n s i t i v i t y t o U n c e r t a i n t i e s a e e e

Future Work e e e e a . e . . e . Eva lua t ion . a e e . e . .

Design Methods - Cudes and Standards a . e

Background . = e e e e e

S t a t u s e a 0 0 a a 0 . m D 0 . r s

S e n s i t i v i t y t o U n c e r t a i n t i e s e . F u t u r s Work * . . . e e e . e e

Evalua t ion . e . + . e . a

C a p i t a l Costs . a . e e . a

Background and S t a t u s a . . S e n s i t i v i t y t o U n c e r t a i n t i e s a e . Eva lua t iun = . e e . e a e

Conclusions - . a . e e e e e

References f o r Chapter 2.3 a e e e e e a

. . 0 . . 0 . . 379 e 0 0 . 0 0 . . 379 . e . . . e . * 379 * . . . , D . . L 379 . . . e . e e . 380 . D e . . e e . 381 * . * * e . . * 381 0 0 e . a . m . 381 . . * * . . e 0 38% . . . . e * . . 38% . e * . . * * . 382 - . . D O . . * 383 a . . e . . . # 384 . * * . . * 0 . 384 . . . . e . . . 384 0 * . . 0 * . . 385 e * a o e . e o 386 . * 0 0 * . 0 e 386 * * . . D O . . 387

14 . ENVIRONPENTAL EFFECTS AND SAFETY e e . . e a a . a e 389 General Considera t ions a e . a a . . . * . e e e e - 389 C h a r a c t e r i s t i c s of Reference-Design MSBR . . e e . a . 390

Environmental E f f e c t s of Normal Operation e e . e - e e 390 Nuclear S a f e t y e e e a e e a e . e e 391 Radionuclide Decay Heat ing . a e e a a a a a . 395 I n t e r a c t i o n of Materials e . . e . a . e . 399

Coolant S a l t Hn te rac t ions . . e a . e a e a 400 Engineered S a f e t y Fea tu res . a . e e . a . e e 402 S i t i n g Cons idera t ions . . . . . . a e . 403

T r a n s p o r t a t i o n During C o n s t r u c t i ~ n . e e . e . a 404 T r a n s p o r t a t i o n During O p e r a t i o n . . . e a . - a . 404 E f f l u e n t s e . * . e . . e . . * . . * . 406 Radionuclide Inventory . . . . e . e . e . . e I . 406 Design-Basis Accident . e . . e e . . . a a . a e 406 Decommissioning . . . . . e . . e e . . . . . . 406 Summary . - . . . . . . . . . a e a . e a 408

Experience and Knowledge e . . . e . . . . . e . e e 408 Containment . . . e a . . a e . e a e . . . . 408 Ins t rumen ta t ion and Cont ro l . e . . . . e . e e 489 S a l t Handling . . e . . . e . . . e . . . . e e 409 Uranium Behavior . . . . e e . . + e e . e e . 409 Fission-Product Behavior . . . . . . e a . 418 K i n e t i c Behavior . . . e . . . e . . . . a . . e 411

F u r t h e r w o r k . a e . . . a . . . . . . e . . . - a . 4 l E E v a l u a t i o n . . . . . . . . * . . . . * * . . . * . . . - . . 415 References f o r Chapter 1 4 . e . e e e e . . . * - . 416

COrrQSiOn . . ~ O D . . O O . . . . . . . . . O . ~ ~ 399

X i i i