UC-80, Reactor/67531/metadc... · Holographic Fringes Produced on a Tube Pressur- ized to 2000 psi. . 7.2 Area of Cladding of PNL 1-18 Examined in the Shielded Electron Microprobe

UC-80, Reactor Technology

FAST FLUX TEST F A C I L I T Y

QUARTERLY TECHNICAL REPORT

DECEMBER 1 9 6 9 , JANUARY, FEBRUARY 1 9 7 0

B. Wolfe Acting Project Manager

Compiled by C. P. Cabell

April, 1970

BATTELLE MEMORIAL INSTITUTE PACIFIC NORTHWEST LABORATORIES RICHLAND, WASHINGTON 99352

I P r i n t e d i n t h e U n i t e d S t a t e s of America A v a i l a b l e from

1 C l e a r i n g h o u s e f o r F e d e r a l S c i e n t i f i c and T e c h n i c a l I n f o r m a t i o n

I N a t i o n a l Bureau o f S t a n d a r d s , U.S. Department o f Commerce S p r i n g f i e l d , V i r g i n i a 22151

1 P r i c e : P r i n t e d Copy $ 3 . 0 0 ; M i c r o f i c h e $ 0 . 6 5

F A S T F L U X T E S T F A C I L I T Y

Q U A R T E R L Y T E C H N I C A L R E P O R T

D E C E M B E R 1 9 6 9 , J A N U A R Y , F E B R U A R Y 1 9 7 0

A B S T R A C T

T h i s r e p o r t was p r e p a r e d by B a t t e l l e - N o r t h w e s t u n d e r

C o n t r a c t No. AT(45- 1 ) - 1830 f o r t h e Atomic Energy Commission,

D i v i s i o n o f R e a c t o r Development and T e c h n o l o g y , t o summarize

t e c h n i c a l p r o g r e s s made i n t h e F a s t F l u x T e s t F a c i l i t y Program

d u r i n g December 1969 and J a n u a r y and F e b r u a r y 1970 .

BNWL-325

BNWL-501

BNWL- 541

BNWL-567

BNWL-660

BNWL- 880

BNWL-917

BNWL-941

BNWL- 1090

BNWL- 1174

BNWL- 1 2 75

P R I O R R E P O R T S I N T H I S S E R I E S

FFTF Summary T e c h n i c a l R e p o r t 1 - 1 - 6 6 t o 1 2 - 3 1 - 6 6

FFTF Q u a r t e r l y T e c h n i c a l R e p o r t 1 - 1 - 6 7 t o 3 - 3 1 - 6 7

FFTF Q u a r t e r l y T e c h n i c a l R e p o r t 4 - 1- 67 t o 6 - 3 0 - 6 7

FFTF P e r i o d i c T e c h n i c a l R e p o r t 7 - 1- 67 t o 1 2 - 3 1 - 6 7




FFTF P e r i o d i c T e c h n i c a l R e p o r t 1 0 - 1 - 6 8 t o 2 - 28- 69


FFTF Q u a r t e r l y T e c h n i c a l R e p o r t 6- 1 - 6 9 t o 8- 31-69

FFTF Q u a r t e r l y T e c h n i c a l R e p o r t 9 - 1 - 6 9 t o 1 1 - 3 0 - 6 9

iii

CONTENTS PAGE N O .

ABSTRACT . iii

PRIOR REPORTS IN THIS SERIES . iii

LIST OF FIGURES. i x

LIST OF TABLES . x i i

INTRODUCTION . xv

CHAPTER I . PROGRESS HIGHLIGHTS. . 1.1

CHAPTER 11. PLANT DESIGN . . 2 . 1

A . O v e r a l l P l a n t Design . . 2 . 1

3 . FFTF S i t e , S t r u c t u r e s , Containment and U t i l i t i e s . 2.3

1. E l e c t r i c a l I n s u l a t i o n f o r H e l i c a l and L i n e a r I n d u c t i o n E lec t romagne t Pumps . . 2 .3

CHAPTER 111. COMPONENTS . . 3 .1

A . R e a c t o r Components . . 3.1

1. Development o f Methods f o r A t t a c h i n g Wear Pads t o Flow Ducts . . 3 . 1

B . Heat T r a n s p o r t P r o c e s s Technology . . 3 . 7

1. Dump Heat Exchanger A n a l y s i s . . 3 .7

2 . S i m u l a t i o n o f Fue l Region f o r D i g i t a l and Hybr id P i p e Rupture Models . . 3.10

3. Hybr id S i m u l a t i o n o f t h e R e a c t o r and Heat T r a n s p o r t System . . 3.12

4. V e s s e l Thermal T r a n s i e n t s f o r Scram w i t h F u l l Flow; Comparison of Oxide and Carb ide Fue l . . 3.13

5 . Heat T r a n s p o r t System C o n t r o l S tudy . . 3.16

C . O t h e r Component Technology . . 3.19

1. R e a c t o r Deck Development Mockup. . 3.19

CHAPTER IV. INSTRUMENTATION AND CONTROLS . . 4.1

A . FFTF I n s t r u m e n t a t i o n and C o n t r o l s Systems . . 4.1

1. FFTF Neutron Flux Moni to r ing . . 4 . 1

B . I n s t r u m e n t a t i o n and C o n t r o l Development. . 4.11

1. A n a l y s i s o f S i n g l e Versus Double D i f f e r e n t i a t i o n o f Neutron D e t e c t o r S i g n a l s . . 4.11

PAGE N O . 2 . Low Level Neutron Flux I n s t r u m e n t a t i o n . 4.12

3. I n - R e a c t o r Coolant Tempera ture S e n s o r s . . 4.15

C . Other I n s t r u m e n t and C o n t r o l s Technology . . 4.19

1. Review o f Methods f o r Reac to r V e s s e l S u r v e i l l a n c e . 4.19

2 . P l a n t P r o t e c t i o n System R e l i a b i l i t y A n a l y s i s . . 4.20

3 . T r i a n g u l a t i o n f o r Fue l F a i l u r e L o c a t i o n . . 4 . 2 2

CHAPTER V . SODIUM TECHNOLOGY . . 5 . 1

CHAPTER VI. CORE DESIGN . . 6 . 1

A . Core Mechanics Technology . . 6 . 1

1. Core R a d i a l R e s t r a i n t Model. . 6 . 1

2 . S w e l l i n g and Creep E f f e c t s upon F a s t R e a c t o r Core S t r u c t u r a l Design . . 6.4

B . Core P r o c e s s Technology. . 6.6

1. Fue l Assembly Design and T e s t i n g . . 6.6

2 . H y d r a u l i c Model o f R e a c t o r V e s s e l O u t l e t Region . . 6 .8

C . I r r a d i a t i o n T e s t i n g Technology . . 6 .11

1. Closed Loop Tube Nozzle C l o s u r e Development. . 6 .11

2 . C losed Loop I n s u l a t i o n S t u d i e s . . 6.15

D . O t h e r Core Technology . . 6 .16

1. Examinat ions of T e s t Specimens . . 6.16

CHAPTER VI I . FUELS AND MATERIALS . . 7 . 1

A . F u e l s and M a t e r i a l s E v a l u a t i o n . . 7 . 1

1. B4C - S t a i n l e s s S t e e l C o m p a t i b i l i t y . . 7 . 1

2 . R e s i d u a l S t r e s s e s i n I r r a d i a t e d F u e l C ladd ing . . 7 . 2

3 . Weldment S t u d i e s Specimen S i z e . . 7.3

4 . Mechan ica l T e s t i n g o f Fuel P i n Cladding . . 7.3

5 . S t r e s s Rupture S t u d i e s - E f f e c t o f Aging o f Type 316 S t a i n l e s s S t e e l . . 7 . 1 2

6 . Damage A n a l y s i s . . 7.15

7 . Fue l Clad I n t e r f a c e . . 7 . 1 7

PAGE N O . B . M a t e r i a l s Technology . . 7 . 2 1

1. U n i a x i a l Creep . . 7 . 2 1

2 . Weldment S t u d i e s . . 7 . 2 1

3 . High S t r a i n Rate E f f e c t s . . 7.23

4 . Notched T e n s i l e E f f e c t s . . 7.24

5 . I n - R e a c t o r Creep Measurements . . 7.24

6 . R a d i a t i o n E f f e c t s on Absorbing M a t e r i a l s f o r C o n t r o l Rods . . 7.25

7 . Image Enhancement . . 7.26

CHAPTER V I I I . FUELS RECYCLE . . 8 . 1

A. F u e l Technology. . 8 . 1

1. Fue l Vendor P r e q u a l i f i c a t i o n . . 8 . 1

2 . U02 I n s u l a r P e l l e t F a b r i c a t i o n . . 8 . 1

3 . Off-Gas Versus D e n s i t y o f Mixed Oxide P e l l e t s . . 8 .2

4 . Pu02 S i n t e r a b i l i t y T e s t i n g . . 8 . 3

5 . Fue l F a b r i c a t i o n f o r T e s t P i n s f o r I r r a d i a t i o n i n EBR-I1 . . 8.4

B . Cladding Technology. . 8.4

1. LMFBR Fue l and C ladd ing I n f o r m a t i o n C e n t e r . . 8.4

2 . E v a l u a t i o n o f X-Ray F l u o r e s c e n c e Method f o r V e r i f i c a t i o n o f A l l o y Composi t ion . . 8.6

3. Eddy C u r r e n t Cladding T e s t e r . . 8 . 6

4 . Cladding Procurement and Development . . 8 .8

C . Fue l P i n Technology. . 8.10

1. Fue l P i n End Closure Welding Deve lopment . . 8.10

D . F u e l Subassembly Technology. . 8.12

1. C C T L Mark I T e s t Assembly C o m p r e s s i b i l i t y T e s t s . . 8.12

CHAPTERIX. PHYSICS . . 9 . 1

A . Core P h y s i c s . . 9 . 1

1. S t a b i l i t y A n a l y s i s of t h e F a s t T e s t R e a c t o r 9 . 1

2 . Notes on t h e Use o f t h e " Eng inee r ing Mockup" a s a Nuc lea r Design Tool . . 9 .2

PAGE NO. -- -- 3. Inverse Multiplication Monitoring

of Subcritical Reactivity Changes in FTR . . 9.4

4. Central Fuel and Peripheral Control Ring Reactivity Worths in the FTR-2 Critical . 9.10

B. Radiation and Shielding . . 9.13

1. Effect of Cobalt Content in Steel on Shield Requirements . . 9.13

2. Radiation Levels in Heat Transport Cell . . 9.14

3. Neutron Attenuation Characteristics of Stainless Steels . . 9.18

4. ZPPR/FTR-2 Shield Experiments. . 9.23

CHAPTER X. SAFETY . . 10.1 A. Safety Analyses . . 10.1

1. Sodium Fire Studies Involving Outer Containment . . 10.1

2. FFTF Containment Analysis - CACECO Code . . 10.1 3. Post DBA Containment Transients - SOHOT Code . 10.4 4. A New Computational System for Fast Reactor

Accident Investigation . . 10.8 5. On the Treatment of Spatial Feedback Effects

in Fast Reactor Accident Analyses. . 10.12 B. Other Safety Technology . . 10.15

1. Use of Delay Beds for Radioactive Gas Decay Storage . . 10.15

APPENDIX A Organization Codes for FFTF Periodic Technical Reports . A-1

APPENDIX B

FFTF BNWL Reports Issued - December 1, 1969 February 28, 1970 . . B-1

L I S T O F F I G U R E S PAGE NO.

Section Through Center of a Conventional Spot Weld with Nugget Between Aged Inconel 718 (0.060 in. thick) and Type 304 SS (0.143 in. thick). . 3.3

Enlargement of One Area in Fusion Nugget from Figure 3.1, Showing Typical Cracks . . 3.3

Section Through Center of a Solid-State Bond Spot Weld Between Aged Inconel 718 (0.060 in thick) and Type 304 SS (0.143 in. thick) . . 3.4

Photomicrograph of the Solid-State Spot Weld Shown in Figure 3.3 . . 3.4

Four-Axial, Six-Radial Node Model . . 3.8

Comparison of the TAP Reference Simulation with 4- and 8-Axial Node, 6-Radial Node Models . . 3.9

Reactor Model for Digital and Hybrid Pipe Rupture Simulations . . 3.11

Tube Outlet Transient Core Scram, Full Flow . . 3.14

Vessel Outlet Transient Core Scram, Full Flow . 3.15

Open Loop Frequency Responses for the Controlled Process in a Heat Transport Circuit . 3.17

Contours of Constant IP (Index of Performance) for Controller Number 2 Settings with (dashed contours) and Without (solid contours) Controller Number 3 Hoop Closed . . 3.18

Fabrication Progress of Reactor Deck Development Mockup . . 3.20

Percent of Ex-Vessel Monitor Signal due to 25, 50 and P O 0 Stored Fuel Elements Versus Total Core Source Rate . . 4.2

Total Core Source Rate Versus Time Following Instantaneous Scrams to k = 0.9 and k = 0.99 . 4.4

Total Gamma Dose Rate (R/hr) Versus Time After Shutdown at 96.0 cm from the Core Centerline on the Core Midplane . 4.7

Neutron Flux Monitoring Low Level Coverage . . 4.8

Flux Monitoring and Control Power Coverage . . 4.9

Modified Gamma Test Facility . 4.14

Integral Bias Characteristics Taken with Current Sensitive Preamplifier . . 4.16

PAGE NO.

Exterior View of 1/3 Scale FFTF Reactor Vessel Outlet Region Model . . 6.10

Environmental Test Chamber . . 6.13

Interior Environmental Test Chamber . . 6.14

2.5 Reaction Zone on 316 Stainless Steel Exposed to B4C Powder for 1000 Hours at 600 OC . 7.1

Holographic Fringes Produced on a Tube Pressur- ized to 2000 psi. . 7.2

Area of Cladding of PNL 1-18 Examined in the Shielded Electron Microprobe. 7.5

Specimen Current, Cesium, and Plutonium Distribution in a Grain Boundary Intersection in PNL 1-18. . 7.6

Variation of Cesium Concentration with Distance from the Maximum Concentration Within the Three Grain Boundaries Shown in Figure 7.4 7.7

Microstructure of Ring Test Samples (Test Temperature = 900 OF) . . 7.10

Precipitate Delineation of Cladding Grain Boundaries in Upper Fueled Region of PNL 1-14 . 7.11

The Effect of Aging on the Biaxial Stress- Rupture Properties of AISI Type 316 Stainless Steel . 7.13

The Effect of Aging on the Ductility of Biaxi- ally Stressed AISI Type 316 Stainless Steel . . 7.14

Ruptured Capsules of Lot 'F' 304 (left) and Lot 'G' 316 Stainless Steel (right) Charged with 1 g of Anhydrous Rubidium Hydroxide and Aged 519 hr at 900 O F . 7.18

Transverse Section of Lot ' F ' Type 304 Stainless Steel Charged with Rubidium Hydroxide and Aged -

519 hr at 900 OF . 7.19

Transverse Section of Lot 'G' 316 Stainless Steel Charged with Rubidium Hydroxide and Aged 519 hr at 900 O F . 7.20

Process Diagram for PNL-9, 10, and 11 Fuel Pellets . . 8.5

Verification that Samples were not 316 SS Alloy Based on Molybdenum Content and Associated Ka Lines . . 8.7

PAGE NO. Histogram of SS Tubing Produced by a Conventional Tube Drawing Process . 8.8

Histogram of Tubing Produced by the Special Process . . 8.9

References FFTF Fuel Pin End Closure Weld Penetration . . 8.11

Phase Plane Plot of Feedback Functions . . 9.2

Engineering Mockup-FTR Overlay . . 9.5

Assembly 56B Quarter Core Areal Profile . . 9.8

FTR-2, ZPPR-1-70, Areal Profile . . 9.11

Relative " ~ e - 6 0 ~ o Gamma Intensity . 9.15

Shutdown Decay Curves for " ~ e and 6 0 ~ o . . 9.16

A Comparison of Calculated and Measured 1°g(n,a) Radial Reaction Rate Distribution in the ZPPR/FTR2 . . 9.25

A Comparison of Calculated and Measured Radial Gamma Dose Distribution in the ZPPR/FTR 2 . . 9.27

Containment System Schematic for SOHOT . . 10.6

Transient Response for a Large Sodium Bubble Passing Through a Fast Test Reactor Core . 10.10

Change in the Effective Doppler Coefficient During a Pipe Rupture Accident . . 10.14

L I S T OF T A B L E S PAGE NO.

Baseline Design Data. . 2.1

Wear Pad Thermal Cycling Tests on Tube 61 . . 3.6

Specific Characteristics of Two Selected Preamplifiers . . 4.15

Comparison of Pre- and Post-Irradiation Time Response . 4.18

Bending Distortion in FFTF Core Components . . 6.5

High Stress Rate Test Results on 304 Stainless Steel . . 7 . 2 3

Corrected 'OB Burnup Levels . . 7 . 2 5

Insulator Pellet Processes . . 8 . 2

Sinterability of Various Source Pu02 Powders. . 8.3

Results of FTR/FTR Engineering Mockup Comparative Calculations . 9.6

Calculated Reactivity Worths Deduced from Calculated Rates of Various Detectors . . 9.9

Experimental Results and Corresponding Diffusion Theory Values . . 9.12

Operating and Shutdown Times to Maximize Plant Efficiency as a Function of Valve Leakage . . 9.18

Weight Percent Composition of Type 316 and 304 Stainless Steels . 9.20

Model Configuration and Composition . . 9.20

Ratio of Reaction Rate to Reaction Rate in Type 316 SS Case . . 9.22

FFTF Containment Model for the CACECO Code . . 10.3

FAST FLUX TEST F A C I L I T Y

QUARTERLY TECHNICAL REPORT

DECEMBER 1 9 6 9 , J A N U A R Y , FEBRUARY 1 9 7 0

INTRODUCTION

B a t t e l l e - N o r t h w e s t , a s FFTF P r o j e c t Manager, i s d i s -

c h a r g i n g d u a l r e s p o n s i b i l i t i e s . One major r e s p o n s i b i l i t y i s

management of t h e end-p roduc t o r i e n t e d d e s i g n and c o n s t r u c t i o n

program t o e n s u r e conformance t o t e c h n i c a l r e q u i r e m e n t s and

t o e s t a b l i s h e d c o s t s and s c h e d u l e s . P r o g r e s s i n t h i s a r e a i s

r e p o r t e d monthly th rough t h e FFTF Monthly I n f o r m a l T e c h n i c a l

R e p o r t .

The second major r e s p o n s i b i l i t y d i s c h a r g e d by BNW i s

management o f t h e d i s c i p l i n e - o r i e n t e d t e c h n o l o g i c a l program

r e q u i r e d f o r e n s u r i n g t e c h n i c a l adequacy o f t h e FFTF d e s i g n .

P r o g r e s s i n t h i s h i g h l y t e c h n i c a l a r e a i s t h e s u b j e c t of t h i s

and o t h e r FFTF Q u a r t e r l y T e c h n i c a l R e p o r t s .

An o v e r a l l summary o f p r o g r e s s i s g i v e n i n Chap te r I .

P r o g r e s s i n d i s c i p l i n e - o r i e n t e d t e c h n o l o g i c a l work i s p r e -

s e n t e d i n Chap te r s I 1 th rough X . These c h a p t e r s g e n e r a l l y

c o r r e s p o n d t o t h e LMFBR Program P l a n Elements . S u b d i v i s i o n s

of t h e c h a p t e r s , however, a r e based upon s p e c i f i c FFTF compo-

n e n t s , s y s t e m s , f a c i l i t i e s , and programs.

Wi th in C h a p t e r s I 1 th rough X , r e p o r t s on s p e c i f i c t o p i c s

show i n t h e i r t i t l e s t h e code o f t h e r e s p o n s i b l e FFTF o r g a n i -

z a t i o n . These codes a r e l i s t e d i n Appendix A .

BNWL- 1328

The development of an a d e q u a t e , i d e a l i z e d d i g i t a l s imu-

l a t i o n o f t h e dump h e a t exchanger has been concluded w i t h t h e

a d o p t i o n of a c o u n t e r - c u r r e n t , c o n c e n t r i c - t u b e model u s i n g

4 - a x i a l and 6 - r a d i a l n o d e s .

I N S T R U M E N T A T I O N A N D CONTROL

Adequate low l e v e l FFTF n e u t r o n f l u x m o n i t o r i n g w i l l b e

p r o v i d e d by t h e combinat ion of a v a r i a b l e - p o s i t i o n , p u l s e -

t y p e , i n - v e s s e l n e u t r o n m o n i t o r and a f i x e d - p o s i t i o n , p u l s e -

t y p e , o u t - o f - v e s s e l n e u t r o n m o n i t o r . T h i s a r rangement w i l l

compensate f o r t h e e f f e c t on o u t - o f - v e s s e l m o n i t o r r e a d i n g s

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

v e s s e l .

I t i s now p lanned t o u se xenon g a s t a g g i n g i n t h e f i r s t

FTR c o r e t o l o c a t e f a i l e d f u e l . Gas d isengagement t e s t s a t

ANL have been r e d i r e c t e d t o e v a l u a t e t h e e n t r a i n m e n t aad s o l u -

b i l i t y of xenon i n sodium, and f u t u r e ANL t e s t s of FFTF

i n - v e s s e l f lowmeters w i l l e v a l u t e t h e e f f e c t o f bubb les on

t h e f lowmeter s i g n a l .

C O R E D E S I G N

The development of s o l i d - s t a t e d i f f u s i o n methods f o r

a t t a c h i n g I n c o n e l 7 1 8 ' ~ a d s t o s t a i n l e s s s t e e l d u c t s i s e s s e n -

t i a l l y comple te . D i s t o r t i o n problems have been n e a r l y e l i m i -

n a t e d th rough t h e combined u s e o f a r e d e s i g n e d i n t e r n a l c o l l e t

f i x t u r e and e l e c t r o n - b e a m s e a l we ld ing o f t h e pad edges .

Development of methods t o a t t a c h S t e l l i t e 6 8 wear pads t o

s t a i n l e s s s t e e 1 d u c t s was u n s u c c e s s f u l .

* C o m p i l e d b y C . P . C a b e l l ( 3 9 4 )

Remote we ld ing o f t h e c l o s e d l o o p n o z z l e p l u g t o t h e

r e a c t o r t o p f a c e s p o o l p i e c e w i l l b e r e q u i r e d each t ime a

c l o s e d l o o p t u b e i s r e p l a c e d i n t h e r e a c t o r . A new BNW remote

weld head b e i n g deve loped t o pe r fo rm t h i s f u n c t i o n h a s s u c c e s s -

f u l l y comple ted a s e r i e s of s i x remote s e a l welds o v e r mol t en

sodium i n s i d e an e n v i r o n m e n t a l t e s t chamber.

F a b r i c a t i o n of t h e CCTL Mark I1 2 1 7 p i n f u l l - s c a l e f u e l

assembly h a s been comple ted . Shipment t o Argonne N a t i o n a l

L a b o r a t o r y f o r l i f e - t e s t i n g i n t h e sodium t e s t l o o p w i l l t a k e

p l a c e i n e a r l y March. P r o t o t y p i c FTR e n v i r o n m e n t a l c o n d i t i o n s

o f 1100 t o 1150 OF a t 525 gpm w i l l b e p r o v i d e d i n a 9000-hr

t e s t t o s t u d y p i n bund le e r o s i o n , c o r r o s i o n , f r e t t i n g and v i b r a -

t i o n e f f e c t s and i n s t r u m e n t a t i o n package pe r fo rmance .

ORNL has p r o v i d e d c o n c e p t u a l d e s i g n f o r equipment t o b e

used i n remote d i s a s s e m b l y of i r r a d i a t e d f u e l s u b a s s e m b l i e s ,

s u b s e q u e n t n o n d e s t r u c t i v e examina t ion of p i n s , and r eassembly

of t h e f u e l e l e m e n t .

FUELS A N D M A T E R I A L S

C r e e p - r u p t u r e r e s u l t s on spec imens from Subassembly X018

show t h a t l a r g e r e d u c t i o n s (up t o a f a c t o r of 200) i n r u p t u r e

l i f e of Type 316 SS o c c u r a f t e r i r r a d i a t i o n t o a p p r o x i m a t e l y

3 x 10" n/cm2 ( t o t a l ) i n t h e t e m p e r a t u r e r a n g e 1000 t o 1100 OF.

These l o s s e s i n r u p t u r e l i f e imply t h a t t h e a l l o w a b l e s t r e s s e s

f o r h i g h l y i r r a d i a t e d components may be s i g n i f i c a n t l y lower t h a n f o r u n i r r a d i a t e d components. For example, t h e s t r e s s t o

a c h i e v e a r u p t u r e l i f e o f 1000 h r i n an u n i r r a d i a t e d m a t e r i a l

a t 1100 OF i s a b o u t 32,000 p s i , w h i l e t h e s t r e s s t o r e a c h a

s i m i l a r r u p t u r e l i f e a f t e r i r r a d i a t i o n t o 3 .5 x 10" n/cm 2

( t o t a l ) i s o n l y a b o u t 21,000 p s i .

F U E L S R E C Y C L E

T e s t s a r e i n p r o g r e s s t o e v a l u a t e f u e l p i n s produced by

c o n t r a c t o r s p a r t i c i p a t i n g i n t h e p r e q u a l i f i c a t i o n program.

E v a l u a t i o n of t h e i n i t i a l sh ipment of 59 p i n s i s n e a r l y

comple te .

An o r d e r from Atomics I n t e r n a t i o n a l f o r t e n s i l e d a t a i s

be ing f i l l e d by t h e LMFBR Fue l and Cladding I n f o r m a t i o n

C e n t e r ; 180 s t r e s s - v e r s u s - s t r a i n c u r v e s have been p r e p a r e d

from 90 e x p e r i m e n t s i n t h e f i l e and fo rwarded t o AI. The

f i l e f o r a u s t e n i t i c s t a i n l e s s s t e e l mechan ica l p r o p e r t i e s now

c o n t a i n s 2447 t e s t s , i n c l u d i n g 30 t e s t s added t h i s month.

P H Y S I C S

E x p e r i m e n t a t i o n i n t h e ZPR-9, FTR-3 assembly has resumed.

Neutron spec t rum measurements a t t h e c o r e c e n t e r a r e comple te .

Doppler expe r imen t s a r e s c h e d u l e d n e x t .

E x t e n s i v e p a r a m e t r i c s t u d i e s have p roved t h e F a s t T e s t

R e a c t o r (FTR) t o be v e r y s t a b l e . The n e g a t i v e Doppler e f f e c t

i s t h e dominant mechanism p r o v i d i n g t h e prompt shutdown

c o e f f i c i e n t .

Comparisons o f FTR-2 e x p e r i m e n t a l d a t a and c a l c u l a t e d

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

of t h e FTR r e f l e c t approx ima te ly 2 1 0 % u n c e r t a i n t y i n t h e c a l -

c u l a t e d v a l u e s o f p e r i p h e r a l c o n t r o l r o d s t r e n g t h s and a p p r o x i -

m a t e l y a 30% o v e r - c a l c u l a t i o n of t h e r e a c t i v i t y wor ths of

c e n t r a l l y l o c a t e d changes i n f i s s i l e p lu ton ium d e n s i t i e s

a r i s i n g from f u e l burnup o r changes i n t h e compos i t ions of

t e s t l o o p s .

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

of t h e FTR a r e t o b e v e r i f i e d i n an e n g i n e e r i n g mockup of

t h e FTR. T h i s mockup i s t o be c o n s t r u c t e d i n Argonne N a t i o n a l

L a b o r a t o r i e s ' ZPR-9 c r i t i c a l f a c i l i t y . Wi th in t h e l i m i t a t i o n s

o f t h e s q u a r e m a t r i x s t r u c t u r e of ZPR-9 and t h e p l a t e l e t

m a t e r i a l s i n v e n t o r y , t h e mockup w i l l be a s e x a c t a s p o s s i b l e .

D e t a i l e d e x p e r i m e n t a l p l a n n i n g i s p r e s e n t l y underway.

SAFETY

A c o n s i s t e n t b a s i s f o r e s t a b l i s h i n g t h e r e a c t i v i t y ramp

r a t e , e f f e c t i v e Doppler c o e f f i c i e n t , and a p p r o p r i a t e e q u a t i o n

o f s t a t e d u r i n g f a s t r e a c t o r e x c u r s i o n s h a s been d e f i n e d .

B a s i c a l l y , t h e method c o n s i s t s of a c o u p l i n g o f t h e m u l t i c h a n -

n e l n e u t r o n i c s - h e a t t r a n s f e r computer program, M E L T- 1 1 , w i t h

t h e two- d imens iona l d i sas sembly computer program, VENUS.

A more d e f i n i t i v e code (CACEO) f o r c a l c u l a t i o n o f t h e

i n i t i a l p h a s e o f con ta inmen t t r a n s i e n t s a f t e r a h y p o t h e t i c a l

c o r e d i s a s s e m b l y a c c i d e n t i s now o p e r a t i o n a l . T h i s code

i n c o r p o r a t e s t h e e f f e c t of gaseous l e a k a g e from h i g h t o low

p r e s s u r e a r e a s and t h u s p r o v i d e s more a c c u r a t e computa t ions

o f maximum p r e s s u r e b u i l d u p .

C H A P T E R 1 1 . P L A N T D E S I G N

A . O V E R A L L P L A N T D E S I G N

P r i n c i p a l FFTF concep t c h a r a c t e r i s t i c s and d a t a a r e under

r ev iew. No o f f i c i a l changes have been made d u r i n g t h e

r e p o r t i n g p e r i o d .

TABLE 2.1. B a s e l i n e Design Data

Genera l P l a n t Data

R e a c t o r Systems (31000)

Core arrangement

Des ign l i f e

T o t a l power, i n i t i a l

U n i t s Values

v e r t i c a l

y e a r s 2 0

MWt 400

R e a c t o r c o o l a n t sodium

R e a c t o r b u l k i n l e t t e m p e r a t u r e , i n i - t i a l OF 600 u l t i m a t e OF 750

R e a c t o r b u l k o u t l e t t e m p e r a t u r e i n i t i a l c o r e OF 8 5 0 d e s i g n maximum and u l t i m a t e OF 1050

Core t e m p e r a t u r e r i s e a v e r a g e i n i t i a l OF 300 u l t i m a t e OF 350 d e s i g n maximum OF 4 0 0

R e a c t o r cove r g a s argon

Core

Number of c o r e l a t t i c e p o s i t i o n s

D i r e c t i o n of c o o l a n t f l o w upward

D r i v e r Fue l

C ladd ing m a t e r i a l

Fue l geometry

R e a c t o r V e s s e l M a t e r i a l

Type 316 SS

hexagonal p i n c l u s t e r

Type 304 SS

Heat T r a n s p o r t System (32000)

Pr imary Loops

- Number

TABLE 2.1. (contd)

Genera l 1'1 silt Data

- Primary Loop M a t e r i a l

Primary Pumps

- Number

- Design f low r a t e

- Design pump head

- A v a i l a b l e n e t p o s i t i v e s u c t i o n head

- Design t empera tu re

- Speed c o n t r o l

I n t e rmed ia t e h e a t exchangers

- Number

- Type

- LMTD

I n i t i a l

- Capac i ty

I n i t i a l

i j l t i m a t e

I r r a d i a t i o n T e s t i n g System (33000)

T e s t F a c i l i t i e s

Closed loops

- T e s t s e c t i o n o u t l e t

t empera tu re

- T e s t s e c t i o n d iamete r

- M a t e r i a l ( i n - c o r e t ube )

Un i t s

gp* f e e t

f e e t

OF

Values

Type 304 SS

wound r o t o r motor w i t h l i q u i d r h e o s t a t

3

V e r t i c a l s h e l l and t u b e

OF 1400 (bypass flow pe rmi t t ed )

i n . 2 . 5 - 3 . 0

Type 316 SS

B . F F T F S I T E , STRUCTURES, C O N T A I N M E N T , A N D U T I L I T I E S

1. E l e c t r i c a l I n s u l a t i o n f o r H e l i c a l and L i n e a r I n d u c t i o n

E l e c t r o m a g n e t i c Pumps

R . G . Baumgartel ( 9 2 5 )

EM i n d u c t i o n - t y p e pumps have been s p e c i f i e d i n t h e FFTF

d e s i g n f o r c i r c u l a t i n g r a d i o a c t i v e sodium. C a l c u l a t i o n s

i n d i c a t e t h a t t h e s e pumps w i l l be exposed t o a gamma r a d i a t i o n

dose r a t e of l o 4 R/hr t o 10' R /h r . Survey o f t h e l i t e r a t u r e

and c o n v e r s a t i o n s w i t h EM pump d e s i g n e r s and i r r a d i a t i o n

s p e c i a l i s t s i n d i c a t e t h a t a g r o s s gamma dose of ~2 x 10 10,

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

p r o p e r t i e s o f t h e pump wind ings .

F a b r i c a t o r s o f t h e h e l i c a l and l i n e a r i n d u c t i o n - t y p e

pumps u s e a h i g h t e m p e r a t u r e e l e c t r i c a l i n s u l a t i o n on t h e

motor windings t h a t c o n s i s t s o f g l a s s t h r e a d wrapped around

a copper w i r e and impregna ted w i t h a s i l i c o n e r e s i n b i n d e r .

The impregna ted , i n s u l a t e d w i r e i s wrapped around a m e t a l c o r e

t o form t h e s t a t o r c o i l o f t h e EM pumps. Dipped i n a s i l i c o n e

r e s i n , t h e s t a t o r c o i l i s baked a t a h i g h t e m p e r a t u r e t o

p o l y m e r i z e and h a r d e n t h e s i l i c o n e r e s i n . A f l e x i b l e ,

l a m i n a t e d - g l a s s m i c a - g l a s s t a p e i n s u l a t i o n i s used t o i n s u l a t e

t h e s t a t o r ground w i r e .

A s u r v e y o f t h e p u b l i s h e d l i t e r a t u r e r e v e a l e d t h a t KAPL

pe r fo rmed i r r a d i a t i o n t e s t i n g on t h e e l e c t r i c a l i n s u l a t i n g

m a t e r i a l s f o r t h e Submarine I n t e r m e d i a t e R e a c t o r Program.

C . Mannal, KAPL, r e p o r t e d i n Nuc leon ics June 1954 o f

i r r a d i a t i o n t e s t r e s u l t s on e l e c t r i c a l i n s u l a t i o n m a t e r i a l s

t h a t were t o be u s e d i n t h e SIR p r i m a r y - c o o l a n t pump. The

p a p e r s t a t e d t h a t " i r r a d i a t i o n s were conduc ted on f o u r k i n d s

* The 20-year accumulated r a d i a t i o n dose i n a 1 x 10' R / h r gamma r a d i a t i o n f i e l d .

o f samples : a f a c s i m i l e s t a t o r , vo l t age- b reakdown s a m p l e s ,

a b r a s i v e b a r s and r e s i n f i l m s . " Manna1 summarized t h e r e s u l t s

o f t h e s e t e s t s a s f o l l o w s : " Tes t s of v o l t a g e breakdown,

m e c h a n i c a l p r o p e r t i e s , and gas e v o l u t i o n o f i r r a d i a t e d samples

i n d i c a t e t h a t a s i l i c o n e - r e s i n impregna ted mica and g l a s s t a p e

i n s u l a t i o n w i l l be s a t i s f a c t o r y up t o l o l o R i f i t i s n o t i n

a s e a l e d c o n t a i n e r . "

G l a s s and most i n o r g a n i c m a t e r i a l s a r e q u i t e r e s i s t a n t t o

damage from gamma r a d i a t i o n . An accumula ted gamma dose o f

$ 2 x 10" r a d s i s n o t e x p e c t e d t o change t h e p h y s i c a l o r

chemica l p r o p e r t i e s o f t h e g l a s s i n s u l a t i o n e x c e p t t o d a r k e n

i t s c o l o r . The s i l i c o n e r e s i n b i n d e r , which i s an o r g a n i c

m a t e r i a l , w i l l po lymer ize and become q u i t e b r i t t l e and may

b r e a k o f f i n t o s m a l l p a r t i c l e s o r s a n d . S i n c e t h e main f u n c -

t i o n o f t h e s i l i c o n e r e s i n i s i n t h e assembly o f t h e motor

w i n d i n g s , v e r y l i t t l e change i s e x p e c t e d t o o c c u r i n t h e

e l e c t r i c a l per formance o f t h e EM pump a f t e r t h e gamma i r r a d i a -

t i o n t o t h e above accumula ted d o s e .

C H A P T E R 111. COMPONENTS

A. R E A C T O R COMPONENTS

1. Development of Methods for Attaching Year Fads to Flow

Ducts

W. F. Brown (AOO) and R. N. Johnson (962)

a. Summary

The development of wear pad attachment processes is

essentially complete for the wear pad design. (Design is a

4 in. wide band of Inconel 718, 0.050 in. thick, wrapped

around the duct.) The following conclusions summarize the

results of the program:

Resistance spot welding techniques were developed for

attaching I l ~ c ~ n e l 718 to stainless steel. The techniques

were not strictly welding, since no fusion occurred, but

were solid-state diffusion bonding. These techniques

allowed distortion-free, crack-free, high strength

anchoring of the wear pad to the surface of the duct.

Seal welding of the edges of the pad to the duct by TIG

welding caused relatively severe distortions in the first

attempts (up to 0.026 in. decrease in internal diameter).

Redesign of the internal collet fixture and the use of

electron-beam welding reduced this distortion to a

maximum change in the diameter of 0.006 in. with the

average change being much less.

a Since the duct and the wear pad materials have different

thermal expansion coefficients, thermal cycling tests

were conducted in an effort to determine the number of

cycles to foil the attachment or seal welds. Thermal

cycling under increasingly severe conditions for a total

of 72 cycles at temperatures from 400 O F to as high as

1400 O F and back to 400 OF was unsuccessful in breaking,

cracking, or disturbing in any detectable way any of the

s e a l we lds o r s p o t w e l d s . Maximum h e a t i n g and c o o l i n g

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

m o l t e n s a l t b a t h a t 1400 OF, s t a b i l i z i n g a t t e m p e r a t u r e ,

t h e n quench ing i n an a i r b l a s t f i x t u r e t o 400 OF, and

r e p e a t i n g . Some s l i g h t t u b e d i s t o r t i o n s ( a v e r a g e l e s s t h a n

0.005 i n . change i n d i a m e t e r ) accumula ted d u r i n g t h e

t h e r m a l c y c l i n g , b u t were judged a c c e p t a b l e , e s p e c i a l l y

c o n s i d e r i n g t h e s e v e r i t y of t h e c o n d i t i o n s and t h e f a c t

t h a t maximum wear pad t e m p e r a t u r e i n t h e r e a c t o r s h o u l d b e

l e s s t h a n 950 OF f o r t h e f i r s t c o r e .

Z f f o r t s t o a t t a c h S t e l l i t e 6B wear pads were u n s u c c e s s f u l .

b . R e s i s t a n c e Spo t Welding

F i g u r e s 3 . 1 and 3 .2 show s e c t i o n s t h r o u g h t h e c e n t e r o f a

c o n v e n t i o n a l s p o t weld w i t h f u s i o n nugge t between aged

I n c o n e l 718 and Type 304 SS. Al though t h e t e n s i l e - s h e a r

s t r e n g t h r a n g e s 5000 t o 6000 l b , g r o s s c r a c k i n g o c c u r r e d .

F i g u r e s 3 . 3 and 3 .4 show s e c t i o n s th rough t h e c e n t e r o f a s o l i d -

s t a t e bonded s p o t weld . T e n s i l e - s h e a r s t r e n g t h s f o r t h i s s i z e d

weld r a n g e s from 4000 t o 5000 l b . Cracks were n o t o b s e r v e d

i n t h e s e t y p e w e l d s .

c . Thermal Cyc l ing T e s t s

Thermal c y c l i n g o f t e s t assembly t u b e No. 61 , was c o n t i n -

ued t h i s q u a r t e r . The t u b e assembly has now been s u b j e c t e d t o

a t o t a l of 7 2 c y c l e s . The c o n d i t i o n s f o r t h e s e t e s t s i n c l u d i n g

l a s t q u a r t e r ' s t e s t s a r e shown i n T a b l e 3 . 1 . A f t e r t h e f o u r t h

t h e r m a l c y c l i n g t e s t , t h e I n c o n e l 718 wear pad was r educed from

0 .060 i n . t o 0.050 i n . t h i c k by g r i n d i n g .

I n o r d e r t o i n c r e a s e t h e h e a t i n g r a t e , t h e s a l t b a t h was

h e l d a t 1470 OF d u r i n g t h e s i x t h t e s t r u n . When t h e p a r t

t e m p e r a t u r e approached 1200 OF, t h e p a r t was removed manua l ly

and a i r quenched. The r a p i d h e a t b u i l d u p r a t e made it d i f f i c u l t

t o a c h i e v e a un i fo rm maximum t e m p e r a t u r e . The a v e r a g e r e c o r d e d

Neg 469-2536A 1OX

Etchant: HCL-H202 and 10% Oxalic Acid

FIGURE 3.1. Section Through Center of a Conventional Spot Weld with Nugget Between Aged Inconel 718 (0.060 in. thick) and Type 304 SS (0.143 in. thick). Gross cracking consistency occurs with these welds.

Neg 469-2536C 250X -


FIGURE 3.2. Enlargement of One Area in Fusion Nugget from Figure 3.1, Showing Typical Cracks.

Neg 469-2540A 1OX

FIGURF: 3.3. Section Through Center of a Solid-State Bond Spot Weld Between Aged Inconel 718 (0.060 in. thick) and Type 304 SS (0.143 in. thick). Cracking was not observed in these type welds.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -


FIGURE 3.4. Photomicrograph of the Solid-State Spot Weld Shown in Figure 3.3. The aged Inconel 718 is shown at top and Type 304 SS is shown at the bottom.

maximum temperatures reached for the wear pad thermocouple was

1268 O F and for the tube thermocouple was 1364 OF. The range

of the maximum temperatures recorded was 1130 to 1409 O F for

the wear pad thermocouple and 1256 to 1418 O F for the tube

thermocouple.

Visual and nondestructive tests were made on the welds

and wear pads after each thermal cycling test. Ultrasonic

inspection of the spot welds revealed no failures. Radio-

graphic inspection showed no indication of cracking in spot

welds or in the fusion welds. Liquid penetrant and visual

inspection revealed a small crack 1/32 in. long in the center of the seal weld at a corner between sides 3 and 4 toward the unnumbered end of the tube. Very faint liquid

penetrant indications were observed at four corners and in

several locations on flat 6 at the toe of the seal weld

adjacent to the stainless steel tube. Visual examination

I at 10X and 30X magnification revealed crack-like cavities.

I These crack-like cavities are caused by some of the tenacious

I scale formed during the thermal cycling tests in the salt

I bath furnace and which was not removed completely during the

I cleaning. After the final thermal cycling tests and before

I cleaning, these crack-like cavities were very pronounced and

I appeared around most of the circumference of the tube

I adjacent to the weld. Most of these crack-like cavities

I were removed during cleaning. Although some distortion did

I occur during the thermal cycling it was relatively small

I compared to that which occurred during the fusion welding

I of wear pads.

B . H E A T T R A N S P O R T P R O C E S S T E C H N O L O G Y

1. D u m ~ Heat Exchan~er Analvsis

R. N. Madsen (822)

The development of an adequate, idealized digital simula-

tion of the dump heat exchanger has been concluded with the

adoption of a counter-current, concentric-tube model using

4-axial and 6-radial nodes. This node arrangment is presented

in Figure 3.5. The determination that this is an adequate

representation follows an extensive study in which a refer-

ence simulation was developed and a study was conducted of

idealized simulations. These earlier developments have been

reported in previous quarterly reports.

The effect of additional axial nodes for the 6-radial

node model has been recently investigated. A comparison of

the TAP reference simulation with 4- and 8-axial node,

6-radial node models is presented in Figure 3.6. There is

insufficient variation in the results, particularly in the

prediction of the more critical sodium exit temperature, to

justify the additional complexity of the increased number of

nodes. Therefore the 4-node model was adopted for inclusion

in the heat transport simulation work.

For some transient investigations this model required an

inordinate amount of computer time. The controlling time

constant being the air node integrations, and this because

of the very small heat storage associated with the air, a

method of calculating air node temperatures by means of

"pseudo-algebraic" equations instead of the differential

equations was investigated. This method calculates the air

node temperatures assuming that the air heat storage is zero,

thus making this calculation algebraic. However, this arrange-

ment creates algebraic feedback loops which are not allowed

by the DYNASYAR code. To bypass this problem, a simple lag

rl

a

-4

2 6 I

a, C

O [I)

differential equation is used with a time constant of 0.1.

Hence the use of the term pseudo-algebraic. This method gives

results identical to the differential equation in only about

half the computer time.

This entire study is currently in preparation for issue as

a topical report BNWL-1319.

2. Simulation of Fuel Region for Digital and Hybrid Pipe

Rupture Models

C. D. Flowers (822)

The core zone for digital and hybrid pipe rupture reactor

models is simulated with separate fuel, clad and coolant

regions as shown in Figure 3.7 Fuel temperatures are calcu-

lated at four axial and three radial mesh points, while clad

and coolant temperatures are calculated at four axial mesh

points.

The axial mesh points are equally spaced between the

bottom and top of the active fuel region. The radial mesh

points in the fuel region, however, may be located in a variety

of positions. Two schemes for dividing the fuel region

radially have been investigated: (1) equal volume per unit

length radial regions, and (2) equal A-radius radial regions.

These models have also been compared with a much more complex

model of the core,using the MELT-I1 computer code.*

MELT-I1 is a coupled neutronics heat transfer code which

was designed primarily for investigating fast reactor core

behavior under major accident conditions. However, the code

can also be used to investigate less severe transients. For

this study the code simulated six rows of subassemblies. The

fourth row subassembly was simulated as the average core

subassembly. The average subassembly fuel pin is divided into

18 axial nodes, with 10 radial nodes (seven radial fuel nodes

* T o b e p u b l i s h e d

' p H 1

TpH1-T O U T L E T P L E N U M

FIGURE 3 - 7 0 Reactor Model f o r D i g i t a l and Hybrid Pipe Rupture Simulat ions

T ~ ~ 2 -

W ~ ~ l

U P P E R A X I A L R E F L E C T O R

f t a

a - a -

a - L O W E R A X I A L

R E F L E C T O R

t t-tJ

- a

F U E L

- w

a -

- - 1 w

-

a -

z a -I 0 0 U -.

-.

a w

n Q 1 U a -

w

ZE 3 H

! - - - O m 0 v,

I- Z a Z ' m a I- v,

rx o + U w A LL W rx

1 a - n a rx

+ Z a --I 0 o u

rx 0 t- U w 1 LL w rx

--I a t- W z v, v, a a

I t m

t- Z a -I o 0 U

v, v, a a I t m

plus the bond, clad and coolant nodes). This compares with four

axial mesh points and five radial fuel pin regions (three fuel

plus clad and coolant) in the simplified reactor model used in

the pipe rupture simulations. Both steady state and transient

conditions were studied in the model comparison analysis.

The results of the analysis indicated that the equal

A-radius fuel node geometry should be used in pipe rupture

simulation models for the following reasons:

It predicts a higher core average fuel temperature which

will provide higher coolant and clad temperatures following

the loss of coolant type of transient,

It better represents nodal average fuel temperatures based

on the fuel radial temperature profile,

It predicts higher transient hot channel core outlet and

clad temperatures which is conservative for safety analyses,

and

It provides good transient agreement with the more complex

MELT-I1 core model.

3. Hybrid Simulation of the Reactor and Heat Transport System

R. D. Benham and A. L. Gunby (822)

The new simulation programs have been written and checked

out: (1) BIAS, a program used to subtract steady-state or dc

values in order to expand the scale on a transient variable;

and (2) SIGEN, a routine which produces a predetermined step,

ranp, or sinusoid function for input anywhere in the simulation.

The overall hybrid simulation (designated HYSIM-2A) of

vessel and process systems (multiple loop) has been fully

checked out. The reactor core model consists of 3 axial fuel

nodes and 3 axial coolant nodes. System transients have been

performed to provide base information for the simulation, and

it is now being used to gather information on process control

design. HYSIM-2A now utilizes a shielded board with shielded

patch cords. Model differences from the previous version of

HYSIM-2A are:

Three axial nodes in the core,

Wound-rotor-motor driven pumps, with level correction,

Four axial nodes for both IHX's and DHX's.

4. Vessel Thermal Transients for Scram with Full Flow;

Comparison of Oxide and Carbide Fuel

A. L. Gunby (822)

In order to obtain a more realistic estimate for primary

'hot leg transients at ultimate conditions, the hybrid simula-

tion HYSIM-2A was used for both the current oxide core and a

hypothetical carbide core (based on parameters reported in

BNWL-914). A core scram with full flow was examined as a

function of outlet plenum mixing.

Results are shown in Figures 3.8 and 3.9. Tube outlet

temperature for a carbide core decreases significantly faster

than for an oxide core at the same conditions. This effect

is due to the relatively high conductivity of the carbide fuel,

resulting in a much lower fuel temperature. Because of the

lower fuel temperature, there is less stored heat available

in the carbide fuel following core shutdown.

Figure 3.9 shows the effect at the vessel outlet. For a 3 value of 700 ft mixing volume, the ratio of transient rates

for carbide at ultimate conditions of oxide at initial condi-

tions is 1.65. Since this extrapolation factor differs

significantly from a previously assumed value of 1.25, we

recommend the use of a hypothetical advanced core in simulation

of vessel transients for ultimate conditions, as contrasted

to the present 1.25 factor based on oxide fuel.

rl

Err

2

Err

BNWL- 1328

5. Heat Transport System Control Study

R. A. Harvey and S. A. Hunt (823)

The simplified dynamic simulation of the heat transport

system was compared with the more detailed hybrid simulation prepared by Gunby,* and was found to be suitable for high

speed use in control system studies. Time scales of up to

1000 times faster than real time were used to define system

dynamic characteristics and trends associated with controller

adjustments. A method of determining the adequacy of controller

adjustments and controller configurations was developed.

The heat transport system control configuration consisting

of the following controllers is presented here to demonstrate

the form of the results:

* Controller No. 1 - Controls the DHX sodium outlet tempera-

ture by manipulating the air flow.

Controller No. 2 - Controls the IHX primary sodium outlet

temperature by manipulating the set

point of Controller No. 1.

Controller No. 3 - Controls the reactor sodium outlet

temperature by manipulating the primary

loop sodium flow rate.

The process frequency responses for the three open loop systems

are shown in Figure 3.10. The frequency response for the

Controller No. 1 system did not include the air flow actuator

characteristics.

The control modes for the controllers were selected to be:

Controller No. 1 - Proportional plus derivative,

Controller No. 2 - Proportional plus integral,

a Controller No. 3 - Proportional plus integral.

An integral error-squared function was used as an index of

performance (IP); an example of its use is shown in Figure 3.11.

* S e e S e c t i o n III. B - 3

P R O P O R T I O N A L G A I N

FIGURE 3.11. Contours of Constant IP (Index of Performance: for Controller Number 2 Settinqs with (dashed contours) and Without (solid contours) Controller Number 3 Loop Closed. (The IP is the integral of the error squared for number 2 controller in response to a step increase in set point.)

The IP contours which enclose the optimum controller settines are shown for Controller No. 2 controller change when the

No. 3 controller loop is closed. Other things that chang

optimum controller settings were found to be air temperature,

sodium flow rates, power level, the settings of the other

controllers, the type of disturbance introduced into the system,

and the controller scheme used.

C. O T H E R C O M P O N E N T T E C H N O L O G Y

1. Reactor Deck Development Mockup

B. G. Smith (914), W. Trask, and W. S. Kelly (COO)

The objective of this nlockup is to aid the Reactor Plant

Designer in finalizing the conceptual design of the area above

the reactor vessel cover by providing information about spatial

relationships of components and related hardware, instrumenta-

tion, and piping.

Fabrication of a full scale three-dimensional mockup of

the central cover hardware and shielding was completed as

shown in Figure 3.12. This includes instrumentation, electri-

cal and cooling lines to the control rod drives and test loops.

Fabrication of a closed loop module and shielded pipe trench

is being completed for installation.

The simulated components and shielding for this mockup

were constructed of quarter-inch thick foamboard, cut and

formed to the desired shape and secured with contact cement.

All instrumentation, electrical, cooling lines, and piping

is commercial grade plastic pipe and fittings, supported by

steel angles.

Neg 700434-1

FIGURE 3.12. Fabrication Progress of Reactor Deck Development Mockup

C H A P T E R I V . I N S T R U M E N T A T I O N A N D C O N T R O L S

A . F F T F I N S T R U M E N T A T I O N A N D C O N T R O L S S Y S T E M S

1. FFTF Neutron Flux Monitoring

a. Effect of Stored Fuel on Ex-Vessel Monitor System

E. T. Boulette and C. A. Mansius (813)

Monitoring of the FTR core neutron flux level from shut-

down to full power (400 MW) is complicated by the presence of

in-vessel stored fuel. At very low power levels (<1 W) a

large fraction of the signal to the out-of-vessel monitor will

be due to neutron flux from the stored fuel, and accurate core

monitoring will be compromised. To circumvent this difficulty,

the current design includes in-vessel monitors in the vicinity

of the shield-reflector interface. Because of their proximity

to the core, these in-vessel monitors saturate at a low reactor

power level (10 to 100 W). The problem is to locate these

detectors to assure adequate monitoring over the power

range from shutdown to full power.

The monitoring capability of 2 3 5 ~ fission chambers is

highly dependent upon the gamma/neutron flux ratio at the

detector location. To determine the monitoring range of a

detector of this type, one must know the variation in the

gamma and neutron flux with changes in the power level. In

addition, the effect of stored fuel must be taken into account.

Figure 4.1 shows the effect of stored fuel on the

ex-vessel monitor signal as a function of the neutron source

rate in the core for 25, 50, and 100 fuel subassemblies in

storage, based on extrapolation of calculations made with

2DBS for concept V-A. In all cases, we assumed that a third

of the stored fuel elements were placed in each 120" sector

of the FTR. In all three cases (25, 50, and 100 stored fuel

assemblies) we assumed that the fuel density in the stored

fuel zones was the same. To check extrapolations involved

P E R C E N T O F E X - V E S S E L M O N I T O R S I G N A L D U E T O S T O R E D F U E L ,

FIGURE 4.1. Percent of Out-of-Vessel Monitor Signal due to 25, 50, and 100 Stored Fuel Elements Versus Total Core Source Rate.

i n t h e s e c a l c u l a t i o n s , a two-d imens iona l d i f f u s i o n t h e o r y

c a l c u l a t i o n was made w i t h 2DBS on concep t V - A i n which t h e

n e u t r o n s o u r c e r a t e was f i x e d a t 1.1 x 10' n / s e c ( c o r r e s p o n d i n g

t o a s u b c r i t i c a l sys t em w i t h k = 0 . 9 ) . C a l c u l a t i o n s were made

w i t h and w i t h o u t s t o r e d f u e l i n t h e sodium a n n u l u s . The

r e s u l t s i n d i c a t e d t h a t a t f u l l shutdown (k = 0 .9 ) a b o u t 80 t o

8 5 % of t h e s i g n a l a t t h e o u t - o f - v e s s e l m o n i t o r i s due t o s t o r e d

f u e l . T h i s c a l c u l a t i o n assunled a s t e a d y s t a t e c o n d i t i o n ; i . e . , t h e d e l a y e d n e u t r o n p r e c u r s o r s g e n e r a t e d a t f u l l power

have decayed t o t h e e x t e n t t h a t t h e f i x e d s o u r c e i n t h e c o r e

( spon taneous f i s s i o n and a , n r e a c t i o n s ) p r e d o m i n a t e s . The

e x t r a p o l a t i o n shown i n F i g u r e 4 . 1 i n d i c a t e s t h a t a b o u t 70% o f

t h e s i g n a l w i l l be due t o s t o r e d f u e l . The agreement between

t h e s e two numbers v a l i d a t e s t h e e x t r a p o l a t i o n t e c h n i q u e used

t o g e n e r a t e t h e c u r v e s i n F i g u r e 4 . 1 .

I n a d d i t i o n t o t h e s e d a t a , one must a l s o know t h e t ime

v a r i a t i o n o f t h e t o t a l c o r e s o u r c e r a t e f o l l o w i n g a l a r g e

p e r t u r b a t i o n ( e . g . , a scram t o a k of 0 . 9 ) . I n F i g u r e 4 .2

i s p l o t t e d t h e c o r e n e u t r o n s o u r c e r a t e v e r s u s t ime a f t e r

shutdown f o r i n s t a n t a n e o u s scrams t o k = 0 . 9 and k = 0 . 9 9 .

To g e n e r a t e t h e s e c u r v e s , t h e f o l l o w i n g as sumpt ions were made:

The scrams a r e i n s t a n t a n e o u s .

@ A t f u l l power, 90% of t h e f i s s i o n i s 2 3 9 ~ u f i s s i o n and

1 0 % i s 2 3 8 ~ f i s s i o n .

The n e u t r o n s o u r c e r a t e i n t h e c o r e a t any t ime f o l l o w i n g

shutdown i s s imply ( 1 - k ) - ' t i m e s t h e sum o f t h e f i x e d

s o u r c e i n t h e c o r e ( spon taneous f i s s i o n and ( a , n )

r e a c t i o n s w i t h oxygen) and t h e d e l a y e d n e u t r o n s o u r c e

r a t e .

The t o t a l d e l a y e d n e u t r o n s o u r c e r a t e , S D , decays a s t h e

sum of e x p o n e n t i a l s

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28

T I M E A F T E R S H U T D O L N , t , mi n

FIGURE 4.2. Total Core Source Rate Versus Time Following Instantaneous Scrams to k = 0.9 and k = 0.99

where

= 3.34 x 10 - 19 So n/sec (neutron source rate at 400 MW)

p 9 = i i -th delayed neutron fraction for 2 3 9 ~ u fission

238 - Pi

- 'th delayed neutron fraction for 2 3 8 ~ fission

A:39 = decay constant associated with the i -th delayed

neutron fraction for 2 3 9 ~ u fission

~f~~ = decay constant associated with the i -th delayed

neutron fraction for 2 3 8 ~ fission

t = time in seconds

Equation (1) does not account for secondary delayed neutrons

(i.e., delayed neutrons generated by delayed-neutron-induced

fission); however, this effect is believed to be negligible.

Figures 4.1 and 4.2 show at which time following a scram

the out-of-vessel monitors become unreliable. The out-of-

vessel monitors are considered unreliable when the percent of

the out-of-vessel monitor signal due to stored fuel is so great

as to mask-out changes in the signal from the core. Also,

Figure 4.2, shows the 2 3 5 ~ fission rate at the in-vessel

detector as a function of time following scram. At full -

power (core source strength = 3.34 x 1019 n/sec) the 235u - - fission rate at the detector location is 1.4 x 10 15

fissions/sec-g of 2 3 5 ~ . Since the 2 3 5 ~ fission rate at the

detector location is essentially proportional to the core

source strength, the 2 3 5 ~ fission rate may be obtained for

any time following scram from Figure 4.2.

In addition to these data, one must know the gamma

intensity at the detector location to assess the detector's

monitoring capability. The total gamma dose rate at the

in-vessel detector location is plotted in Figure 4.3 versus

time after shutdown. The major contributors to the total dose

rate are "~n(n,~) and 59~o(n,y) reactions. The fission

product decay gammas and the 23~a(n,y) gammas will yield dose

rates of the order of lo4 R/hr and 10' R/hr respectively, and

therefore will not contribute significantly to the total dose

rate for the first few hours following a scram. Note that a

buildup time of 5 yr has been assumed for the 59~o(n,y) reaction.

Thus, it is only at about 50% saturation.

Employing the data presented in Figures 4.1 to 4.3, one may

determine at which time following a scram the ex-vessel monitors

become unreliable. In addition, one can determine the required

operating characteristics for the in-vessel detectors to assure

continuous neutron monitoring. (See paragraph IV A 1 b)

b. Neutron Flux Monitor Range and Overlap Considerations

The individual neutron flux monitor ranges have been

reinvestigated. We have determined that it is possible to

provide an adequate flux monitoring system utilizing the follow-

ing monitors:

A variable-position, pulse-type, low-level, in-vessel

neutron monitor.

A fixed-position, pulse-type, low-level, out-of-vessel

neutron monitor.

A fixed-position, compensated, mean-current, logarithmic,

intermediate range monitor.

A fixed-position, uncompensated, mean-current, linear, high-level monitor.

The scaling calculations are summarized by Figures 4.4 and 4.5

in this report.

If the in-vessel low level channels are scaled as shown in

Figures 4.4 and 4.5, three decades can be covered before a

-

T O T A L -

\ 5 6 ~ ~ ( t l j 2 = 2 . 5 3 h r )

- - - -

-

-

-

- \ 6 0 ~ a ( t , / 2 = 5 . 2 Y E A R S ; B UI L D U P TI ME = 5 Y E A R S )

-

T I M E A F T E R S H U T D O W N , t , m i n

FIGURE 4.3. The Total Gamma Dose Rate (R/hr) Versus Time After Shutdown at 96.0 cm from the Core Centerline on the Core Midplane.

1 OOKW

1 OKW

X

lOOW

1 OW

1W

1 OOmW

TIME AFTER SHUTDOWN (MIN.)

FIGURE 4 . 4 . Neutron Flux Monitoring Low Level Coverage

1 OOW

1 OOmW

1 OOOMW

1 OOMW

1 OMW

1 OOKW

1 OOW

1W

1 OOmW

FIGURE 4.5. Flux Monitoring and Control Power Coverage

4 . 9

switchover to the out-of-vessel, low-level channels is required.

The out-of-vessel, low-level channels are scaled to provide an

adequate count rate on the low end and to provide proper over-

lap with the intermediate log channels on the upper end. The

intermediate channels overlap the high-level channels for three

decades. Figure 4.5 shows the complete power coverage.

The in-vessel channels are scaled such that the detector

count rate at 30$ shutdown is 50 cps. Calculations by Baird*

and Uotinen* showed that when using a detector with 1.8 g of

2 3 5 ~ , 250 cps can be achieved at 30$ shutdown. If the system

is adjusted for operation at 1 x lo6 R/hr (20% sensivity) , the resulting count rate is 50 cps. The power level covered by

these channels is 10 mW to approximately 100 W.

The out-of-vessel channels are scaled to give 50 cps at

the time the in-vessel channels are counting 10' cps (220 W). If the detector were located midcore:" the calculated count rate

3 at 20 W would be 7 x 10 cps, indicating that an excess of

neutrons would allow scaling the channel down to the SO cps

level by physical positioning of the detector. The power level

covered by these channels is 1 W to about 500 W.

The worst case environment at which the in-vessel detector

must operate is defined by analyzing the scram (k = 0.9) case.

The out-of-vessel detector may be used down to a power level

where 90% of the count rate is caused by core neutrons and

10% by stored fuel. This point is 17 min following a k = 0.9

scram with 50 stored fuel assemblies. Figure 4.4 shows that

the in-vessel detector is counting below full-scale at about

10 min after a scram. At this time the total gamma at the

in-vessel location would be 2.2 x lo6 R/hr. The in-vessel

detector would be used for the balance of the shutdown and

* Exper imen ta l P h y s i c s S e c t i o n .

* * A p o s i t i o n i n t h e f l u x m o n i t o r i n g t h i m b l e a t t h e midcore p lane and 9 6 cm r a d i a l Z y from t h e c o r e c e n t e r l i n e .

through the refueling cycle. For startup, the in-vessel detec-

tor would be used up to a power level of 20 W when the out-of-

vessel detector would be counting 50 cps. The out-of-vessel channels would be used to about 10 kW when the intermediate

system would be used. The extreme case gamma at the out-of-

vessel location is 5 x lo3 R/hr due to 2 4 ~ a immediately

following a shutdown. If a compensated ion chamber is used,

this would mean that for a 10:l ne~l.tron-to-gamma signal, a

flux of 3.4 x lo5 nv would be required by the intermediate

channel for proper operation. The scaling is based on a

neutron flux of 10" nv ('OB equivalent) available at the

out-of-vessel location at full power. This results in more

than a decade overlap between the low-level and intermediate-

level (Figures 4.4 and 4.5) . B. I N S T R U M E N T A T I O N - A N D C O N T R O L D E V E L O P M E N T

1. Analysis of Single Versus Double Differentiation

of Neutron Detector Signals

C. N. Jackson, N. C. Hoitink, N. S. Porter, R. C. Weddle,

(MOO), and D. C. Thompson (931)

One of the questions consistently addressed to the

detection of neutrons with fission counters concerns the

relative advantages of double versus single differentiation

of the detector signal with charge-sensitive preamplifiers.

The experiment described below (designed to compare the effects

of using both methods in our detector studies) answers this

question. In this experiment we have shown that double

differentiation is clearly superior when a low level

neutron detector is exposed to gamma dose rates greater than

1 x lo4 R/hr. This experiment required the measurement of

integral bias curves at the PNL Gamma Facility using a single

counting channel for various gamma levels and for different

electronic differentiation conditions. Curves taken at each

gamma level (1 x lo4, 1 x lo6 and 2 x lo6 R/hr) showed the noise,

gamma and alpha results and the neutron measurements for

constant electronic gains and for constant counting rates at

the 10 V bias operating points. 4

At gamma levels of 1 x 10 , use of double differentiation did not provide significant improvements in neutron sensitivity.

At gamma levels of 1 x lo6 and 2 x lo6 R/hr double differentia-

tion produced gain factors of approximately 3 and 4, respec-

tively. These improvements were made both under conditions of

constant electronic gains and constant counting rate conditions.

These improvements shown by double differentiation result from

two basic principles. With the double differentiation the

narrower pulse pile-up becomes a problem. Furthermore, the

use of a second differentiation circuit produces a filtering

effect which reduces some of the lower frequency noise, hence

producing a cleaner signal.

2. Low Level Neutron Flux Instrumentation

C. N. Jackson, N. C. Hoitink, N. S. Porter, N. C. Weddle, (MOO), and D. C. Thompson (931)

a. Thermal "Noise" Induced in Cables and Connectors

Low-level signals from high voltage neutron detectors are

frequently obscured by "breakdown pulse noise" when coaxial

cables supplying high voltage to the detectors are heated.

Cable noise tests were made on a neutron detector wherein

~3 ft of two coaxial cables were heated to 370 to 390 O F

for 1200 hr. (One coaxial cable is used for high voltage

supply, while the other is used for signal). The two-cable

system exhibited no detectable amounts of thermal noise. A

single cable tested under similar conditions showed a severe

noise problem.

b. Multiple Input Preamplifier

Evaluation tests on the developmental model of a

commercial three-input preamplifier were completed. This unit

comprises three separate channels of amplification, pulse

shaping and discrimination prior to summation of the signals

in an output stage. It also features discriminator analysis

in each channel for rejection of gamma-caused pileup pulses.

The neutron count rate for three clustered detectors

increased approximately three times over that of a single unit

throughout a gamma background range from lo4 to 5 x lo5 R/hr.

In principle, the multi-input instrument worked well and will

probably find legitimate application where several detectors

can be used simultaneously (following calibration and discrim-

inator setting procedures) and where higher neutron sensi-

tivity per channel may be needed.

c. BNW Gamma Test Facility Modification

Modifications to the BNW Gamma Test Facility will be

complete by the end of March 1970. The fully modified facility will consist of an array of eight (4 in. OD x 0.065 in. wall)

304 SS thimbles fixed at a gamma flux level of about

1.5 x lo6 R/hr and one movable (2.0 x lo4 - 2.0 x lo6 R/hr)

4 in. OD stainless steel thimble (previously installed).

Figure 4.6 shows the modified assembly, where each thimble

incorporates a retaining cup for precise positioning of the

80-g Pu/Re neutron source. The three concentric (broken)

circles represent small, flat 6 0 ~ o elements added to increase

the source strength to 6.1 x 10' Ci. For the eight fixed tubes,

this configuration will place the heated detectors in a gamma

flux of about 1.5 x lo6 R/hr, and at a temperature of 100 O F

3 to 1100 O F and in a neutron flux of 3.5 x 10 nv as desired.

- Radi a1 ly Adjustable Typical Test Thircble and Test Thirble Neutron Source Illolder a t Fixed 13-in. Radial Position

FIGURE 4.6. Modified Gamma Test Facility

Although the modification of this gamma test facility is

not complete at this time, preliminary detector tests are

already under way.

Preamplifier Evaluation

Performance measurements of preamplifiers allowed selec-

tion of two types for planned routine use in the testing

program for low-level counting systems. Both a current-

sensitive unit and a charge-sensitive unit were found to

exhibit a rise time of about 3 0 nsec, thereby providing needed

response capability for use with the various fissiorl counters.

Table 4.1 provides specific characteristics of the two

selected preamplifiers.

TABLE 4.1. Specific Characteristics of Two Selected Preamplifiers

Conversation Rise Time, Model Gain nsec Noise

(charge-sensitive) 0 . 2 5 V/pC ~3 0 4 2 . 6 x L O equivalent ion pairs RMS with 3 0 0 0 pF input capacitance

(current-sensitive) 0 . 0 2 V/uA ~ 3 0 0 . 0 8 PA RMS maximum

The integral bias curve of Figure 4.7 illustrates the type of

neutron and alpha characteristics relative to system background

noise that can be obtained with the current-sensitive amplifier

selected.

3. In-Reactor Coolant Tem~erature Sensors

N. C. Hoitink, N. S. Porter, R. C. Weddle, (MOO),

and D. C. Thompson (931)

This task focuses on the developmental testing and evalu-

ating of thermocouples to provide reliable, commercially avail-

able sensors for measuring the coolant temperatures in the FTR

thermal and nuclear environment. Pre- and post-irradiation

e l e c t r i c a l c h a r a c t e r i z a t i o n s t u d i e s provide in format ion about

accuracy , r e l i a b i l i t y , response t ime , and o t h e r parameters of

cand ida t e s enso r s a f t e r exposure i n a f a s t f l u x r e a c t o r

( E B R- I I ) environment.

DISCRIMINATOR VOLTAGE

FIGURE 4.7. Integral Bias Characteristics Taken with Current Sensitive Preamplifier

Further comparisons were made of pre- and post-irradiation

performance of thermocouples irradiated in EBR-I1

Capsules BT-3 and BT-4.

The preliminary conclusion (described in the previcus

quarterly report) that irradiation did not produce a

significant change in time-constant values was verified.

Analysis of the pre- and post-irradiation time-response

recordings permitted redetermination of the 0.63% time

constant for each sensor. To ensure uniformity for acquisi-

tion of data, the pre-irradiation values were redetermined

by the same personnel and by the same methods involved in the

post-irradiation examinations. Since only insulated-junction

thermocouples will be purchased in the future (both for tests

and reactor installation), the time-response tests reported

here cover only such sensors.

Table 4.2 lists the pre- and post-irradiation time

constants for the insulated-junction units. In each case, the

listed values represent averages for three-time response

measurements. Individual time constants for each recording

were determined by a semi log plot of response versus time.

The values listed for the pre- and post-irradiation

measurements indicate close agreement in most cases. No

certain explanation exists at this time for the disagreement

noted for a few of the sensors. However, possible conditions

which could account for the discrepancies include limitations

on the accuracy of the time-constant measurement (as imposed by

a rather large amount of periodic noise on the pre-irradiarion

time response recordings) or variations in the stirring speed

of the salt bath. Measurement accuracies should be about

tO.10 sec for the pre-irradiation conditions.

1 . F a s t F lux T e s t F a c i l i t q Q u a r t e r l y T e c h n i c a l R e p o r t , S e p t e m b e r , O c t o b e r , November 2969, BNWL-1275. B a t t e l l e - N o r t h w e s t , R i c h l a n d , Wash ing ton , January 1970 .

a, [I)

C

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BNWL- 13.28

C . O T H E R I N S T R U M E N T A N D C O N T R O L S T E C H N O L O G Y

1. Review of Methods for Reactor Vessel Surveillance

K. 0. Creek (932)

Four techniques were evaluated for viewing the outer

surface of the reactor vessel under reference conditions.

Of these techniques (fiber optics, borescope, telescope-mirror,

and television), the television is considered the most practi-

cal. However, a surveillance space of 3 to 6 in. is needed to

accommodate a coolable camera head.

a. Fiber O~tics

Partial visual inspection of the vessel surface can be

made via a glass fiber optic bundle. This bundle is capable

of following a twisting access path into the guard vessel.

The glass readily withstands 500 OF. However, 30% of the

light striking the bundle is lost due to reflections at the

entrance and exit to the fibers, and light is lost at the

rate of about 10% per foot in the length of the bundle. A

3 ft long bundle will transmit about 50% of the incident light.

Fiber optics are normally used in lengths up to 6 ft with a

maximum feasible length of 25 to 30 ft.

The glass fibers are subject to browning in the radiation

field requiring frequent replacement of the unit. Additional

investigation of radiation tolerance is required.

b. Borescope

Borescopes are, in general, wide-angle, short-focus

optical systems for close-up viewing of surfaces, such as the

inside walls of piping, which cannot be inspected by line-of-

sight techniques. Borescopes, 1 3/4 to 2 in. in diameter and

50 ft long, are available commercially. They can withstand

the temperature and radiation. However, a nearly straight

line access path is required.

The borescope is too inflexible to follow the curvature

under the vessel. A borescope with a 10 ft section of fiber

optics attached to the end could be considered to view the

bottom of the vessel if access holes for the borescope were

obtained.

c. Telescoue-to-Mirror System

In this method an image of the surface of the vessel is

transmitted to a telescope by' a simple mirror attached to a

long, movable rod. Access holes in the reactor cover must be

provided for the telescope and rod.

This method is not recommended due to severe alignment and

vibration problems of the moving mirror and inability to view

under the vessel. If straight line access is obtained for the

mirror on a rod, then a borescope is a better choice.

d. Television

A radiation-tolerant T'V camera head 1 l/2 in. in diameter

is commercially available. Attached to a flexible, temperature

tolerant access cable and looking into a 4 5 O mirror, the unit

could follow a twisting path. It could also view underneath the

vessel. The camera head is temperature-limited to about 100 O F

because of the photoconductive layer on the vidicon faceplate;

therefore, a gas-cooling annulus surrounded by insulation must be added to the camera head diameter. In a study of the cooling

problem, Southwest Research Institute recommended at least a

3 in. diameter for the cooled camera.

2 . Plant Protection System Reliability Analysis

0 . B. Monteith (821)

The evaluation of the PPS to investigate false scrams has

been completed. Each instrumentation subsystem has been exam-

ined for the components and combinations of their failures which

would result in a false scram. Some simplifying assumptions

were employed:

The failure of a single channel to a fail-safe condition

will be annunciated and repair instituted.

The average repair time of a channel that has failed safe

is 1 hr.

The fail-safe failure rate of a channel is 50% of the

total channel failure rate.

a Component failures are independent.

Employing nominal component failure rates, the following

results were obtained for the various PPS instrumentation

subsys tems . Subsys tern False Scrams per hr

Power Level Neutron 0.7 x

Power Level Flux Rate-of-change 0.9 x

Bulk Outlet Temperature 0.05 x

Primary Loop IHX Outlet Temperature 0.2

Closed Loop Coolant Outlet Temperature 0.2 x loq7

Reactor Flux/Flow Ratio 3.0 x

Closed Loop Flux/Flow Ratio

Reactor Vessel Coolant Level

Electrical Power Supply

Seismoscope

Primary Loop Coolant Flow

Containment System

Open Loop Outlet Temperature

Closed Loop Surge Tank Level

Closed Loop IHX Outlet Temperature

To estimate the overall PPS false scram rate due to

instrumentation failures, we arbitrarily establish three heat

transport loops, two open loops, and six closed loops. Based

on these total subsystems the PPS false scram rate is - 6 3.1 x 10 per hr or about 0.03 per year.

T h i s f a l s e scram r a t e , which i s v e r y s m a l l c o n s i d e r i n g

p a s t r e a c t o r e x p e r i e n c e , i s t h e r e s u l t o f t h e e v a l u a t i o n o f

equipment f a i l u r e s o n l y . F a l s e scrams a r e a l s o e x p e c t e d from

t r a n s i e n t s and f l u c t u a t i o n s o f p l a n t p a r a m e t e r s a s w e l l a s from

human-induced c o n d i t i o n s , and t h e s e fo rmer k i n d s o f f a l s e scrams

w i l l c o n s t i t u t e t h e major p o r t i o n o f t h e t o t a l . No a t t e m p t h a s

been made t o e v a l u a t e t h e s e l a t t e r t y p e scrams i n t h e above

r e s u l t s b e c a u s e o f u n c e r t a i n t y of d a t a and a s u i t a b l e a n a l y t i c

t e c h n i q u e does n o t e x i s t .

Because t h e a n a l y t i c a l r e s u l t s above y i e l d such a v e r y low

f a l s e scram r a t e from equipment f a i l u r e s , we c o n c l u d e t h a t t h e

PPS i s w e l l d e s i g n e d i n t h i s r e g a r d and no f u r t h e r e v a l u a t i o n

of f a l s e scrams i s p lanned a t t h i s t i m e .

3 . T r i a n g u l a t i o n f o r Fue l F a i l u r e Loca t ion

J . J . Regimbal (823)

Flow p a t t e r n s i n t h e o u t l e t plenum of t h e H y d r a u l i c Core

Mockup (HCM) were t e s t e d by measur ing t h e t r a n s p o r t o f s m a l l

a i r b u b b l e s from v a r i o u s c o r e d u c t s t o m o n i t o r i n g p o s i t i o n s

on t h e 8 i n . o u t l e t p i p e s . The r e s u l t s f u r n i s h an a d e q u a t e

b a s i s f o r p l a n n i n g f u r t h e r t e s t s of t h e f e a s i b i l i t y o f l o c a t i n g

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

m o n i t o r i n g f o r b u b b l e s moving p a s t u l t r a s o n i c s e n s o r s on each

o u t l e t p i p e .

These t e s t s , and o t h e r s a s w e l l u s i n g d i f f e r e n t t a g g i n g

m a t e r i a l , show t h a t f l o w t o each o u t l e t i s g e n e r a l l y s e c t o r e d .

Measurements o f t h e a r r i v a l t i m e and a m p l i t u d e o f c a l i b r a t e d

g a s r e l e a s e s a l s o have d e m o n s t r a t e d t h e r e p e a t a b i l i t y of

t r a n s p o r t c h a r a c t e r i s t i c s from one c a s e t o a n o t h e r f o r a g i v e n

g a s r e l e a s e .

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

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

In Figure 4.8, times of earliest arrival are related simply to

shortest distance of travel (plan view) from a given duct to

the outlet position indicated. Such data, augmented with

amplitude information at each nozzle demonstrates the potential

feasibility of locating types of FTR failures which release

some 100 cm3 of fission gas in a short ($10 sec) burst.

/ -

A R E L A T I V E T O N O Z Z L E N o . 1

- R E L A T I V E T O N O Z Z L E N o . 2

-

-

/ O N E L A T T I C E U N I T , A P P R O X . / ----

I I I I I I I I I I I I I I I I

0 5 1 0 1 5

I N J E C T I O N D I S T A N C E F R O M N O Z Z L E , R E L A T I V E U N I T S

FIGURE 4.8. Air Bubble Transport Times

C H A P T E R V . S O D I U M T E C H N O L O G Y

Progress in the Sodium Technology Program for the FFTF is

summarized in the Quarterly Progress Report, Sodium Chemistry

Subdepartment, October-December 1969, BNWL-1200-2, Battelle-

Northwest, Richland, Washington, February, 1970.

RE.YTRA/NT LOADING ACROSS FLATS -- -. - R€STAA/NT L O W G ACROSS PO/NT;S

1 / 1 77zL:- 6 8 HYDRA L L / C CL AMD ASSbMBL Y

2 ,3) 4 : 5) I

> i-/

I , I 1 - I I - -~

: I / / ,;, ;, ...~ .*" -"rm"."cm ,,...m,..c.,...,. -^" U. S. ATOMIC ENERGY COMMISSION

MODEL S C M PLAN

i 3 U O G - F c 1'"''"' 4703.0/

XEFERZNCE DRAwINas S"C""* S W W S

NEXT USED ON SK-3-14762 1 - 1 -

C H A P T E R V I . C O R E D E S I G N

A. C O R E M E C H A N I C S T E C H N O L O G Y

1. Core Radia l R e s t r a i n t Model

G . R . Waymire (811) and L . R . Besel (913)

Although t h e core r a d i a l r e s t r a i n t problems a s s o c i a t e d

w i t h s i n g l e core duc t s a r e amenable t o a n a l y s i s u s ing p r e s e n t

a n a l y t i c a l t o o l s , t h e problems a s s o c i a t e d w i t h t h e a r r a y of

duc t s p r e s e n t a complexity which, whi le t h e o r e t i c a l l y p o s s i b l e

t o analyze, becomes complex i n implementat ion.

To circumvent t h i s a n a l y s i s problem, a s t r u c t u r a l l y

a c c u r a t e model o f t h e co re i s r e q u i r e d which can be used t o

s tudy t h e o v e r a l l s t r u c t u r a l core problems.

The p o s s i b i l i t y of u s ing a s c a l e model o r s e c t i o n model

o r a combination has been i n v e s t i g a t e d a s a more economical

s o l u t i o n t o t h e problem. These a l t e r n a t i v e s , however, r e s u l t

i n problems e i t h e r w i t h o b t a i n i n g a l l d e s i r e d paramete rs

s imu l t aneous ly , i n t h e ca se of a s c a l e model, o r w i th be ing

a b l e t o p r o p e r l y mock-up boundary c o n d i t i o n s i n t h e c a s e of

a segmental model. A f t e r reviewing t h e problems wi th Westing-

house , i t was j o i n t l y determined t h a t development e f f o r t of

t h e s i m u l a t e d core model (SCM) should c o n c e n t r a t e on a f u l l

s c a l e model.

The concep tua l de s ign f o r t h e SCM i s shown on SK-3-14762

and SK-3-14763. The model uses mechanical tub ing f o r simu-

l a t e d s t i f f n e s s w i t h hexagonal pads l o c a t e d a t t h e c o n t a c t

p l a n e s .

I n t h e o u t e r rows of t h e c o r e where extreme deformat ions

occu r , t h e t ub ing may r e q u i r e bending t o t h e c a l c u l a t e d duc t

deformat ions . I n t h e i n n e r rows, o f f s e t r e p l a c e a b l e pads

w:ll be used.

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swe l l i ng g r a d i e n t i f c reep i s n o t cons idered . However, i f

neutron- induced c reep i s cons idered , t h e u n r e s t r a i n e d duc t

i s p r e d i c t e d t o bow inward about 1 / 4 i n . This u n r e s t r a i n e d

d e f l e c t i o n i s a l s o very s e n s i t i v e t o t h e temperature g r a d i e n t

ac ros s t h e d u c t . This is because t h e neutron- induced c r eep

causes t h e thermal s t r e s s i n t h e duc t t o g r e a t l y reduce from

i t s i n i t i a l va lue a t beginning of l i f e . Under most cond i t i ons

i n FFTF, neutron- induced c reep i s p r e d i c t e d t o main ta in t h e

bending s t r e s s below i t s i n i t i a l thermal va lue even though

t h e s w e l l i n g g r a d i e n t i s a c t i v e t o i n c r e a s e t h i s bending

s t r e s s . A s a r e s u l t , when t h e thermal g r a d i e n t and t h e

r e s t r a i n t s a r e bo th removed t h e r e i s a tendency f o r a n e t

inward movement of t h e duc t top i n c o n t r a s t t o t h e outward

movement i f c reep i s neg l ec t ed . These c a l c u l a t e d u n r e s t r a i n e d

bending d i s t o r t i o n s a r e t a b u l a t e d i n Table 6.1.

TABLE 6.1. Bending Distortion in FFTF Core Components

Core Component

Fuel S/A Duct

Fuel S/A Duct

Fuel S/A Duct

Fuel S/A Duct

Fuel S/A Duct

Fuel S/A Duct

Sa fe ty Rod Thimble

Control Rod Thimble

Closed Loop

Closed Loop

Row No. -

Unres t r a ined Maximum D e f l e c t i o n During Refue l ing . i n .

0.0126 inward

0.0214 inward

0.0185 inward

0.0094 inward

0.1464 inward

0.3100 inward

0.0172 outward

0.1374 inward

0.0293 inward

0 . I467 inward

Note t h a t a d j a c e n t duc t s w i l l i n t e r a c t i n such a way t h a t

t h e s e components w i l l n o t a c t u a l l y expe r i ence t h e duc t

top d e f l e c t i o n c a l c u l a t e d i n Table 6 .1 Note a l s o t h a t t h e

s a f e t y rod th imble i n row fou r i s p r e d i c t e d t o bow outward

i n c o n t r a s t t o a l l o t h e r duc t s . I n t h e s a f e t y rod t h e h e a t i s

genera ted i n t h e poison p ins which a r e above t h e co re dur ing

o p e r a t i o n . I n a l l o t h e r components t h e h e a t i s gene ra t ed i n

t h e co re . This d i f f e r e n c e i n temperature d i s t r i b u t i o n causes

t h e d i f f e r e n c e i n bending d i s t o r t i o n which was c a l c u l a t e d .

We conclude t h a t neutron- induced c reep has a s i g n i f i c a n t

e f f e c t upon co re component bending d i s t o r t i o n . We a l s o con-

c lude t h a t t h e u n r e s t r a i n e d bending d i s t o r t i o n i s very s e n s i -

t i v e t o t h e temperature d i s t r i b u t i o n i n t h e co re component

dur ing o p e r a t i o n .

B . C O R E P R O C E S S T E C H N O L O G Y

1. Fuel Assemblv Design and Tes t i ng

E . G . S tevens (913)

a . CCTL Mark I 1

F a b r i c a t i o n of t h e CCTL Mark I 1 2 1 7 p i n f u l l - s c a l e f u e l

assembly has been completed. Shipment t o t h e t e s t loop a t

Argonne Nat iona l Laboratory where t h e f u e l assembly w i l l be

sodium l i f e t e s t e d w i l l t ake p l a c e i n e a r l y March. P r o t o t y p i c

FTR environmental cond i t i ons of 1100 t o 1 1 5 0 OF (maximum

s t e a d y - s t a t e temperature) a t 525 gal/min w i l l p rov ide p i n

bundle e r o s i o n , c o r r o s i o n , f r e t t i n g , and v i b r a t i o n e f f e c t s a s

w e l l a s i n s t r u m e n t a t i o n package performance d a t a f o r 9000 h r .

b. Fuel Assembly V ib ra t i on Tes t i ng

E . G . S tevens (913) and G . R . Sawte l l e , (COO)

A 1 9 - p i n , 0 .250- in . tube O D , 30 m i l w i r e wrap assembly

(B-1 t e s t ) i n s t rumen ta t i on has been r e f i n e d t o i n c r e a s e i t s

impedence-detect ing s e n s i t i v i t y t o measure low l e v e l p i n

v i b r a t i o n s (approximately 1 m i l ampl i tudes ) . A no-flow duc t

shake r t e s t was run i n February as a p r e lude t o wa te r f low

t e s t s .

Design of a 19-pin, 0 .230- in . OD, 56 m i l w i r e wrap assembly

(B-2 t e s t ) i s nea r ing completion. Three types of v i b r a t i o n

s enso r s a r e t o be used i n t h e ins t rumented p i n s : accelerom-

e t e r s , impedence d e t e c t o r s , and s t r a i n gages. F a b r i c a t i o n

completion i s scheduled f o r June.

c . Hvdraul ic Tes t i ng of FFTF Fuel Assemblies

J . Muraoka (913)

The o b j e c t i v e of t h i s program i s t o e v a l u a t e t h e p e r f o r -

mance of FTR d r i v e r f u e l subassemblies i n terms of p r e s s u r e

drop-flow behav io r , l o c a l f low d i s t r i b u t i o n and coo lan t mixing.

The program i s d iv ided i n t o t h r e e sub t a sks t o examine 7 , 37,

and 217-pin subassembl ies . The seven-pin-bundle t e s t s w i l l

p a r a l l e l t h e hea t ed seven-pin-bundle t e s t s . The r e s u l t s of

t h e s e two t e s t s p rov ide t h e i n p u t f o r an a n a l y t i c a l model.

The 37-pin wate r t e s t s w i l l be used t o ex tend a n a l y t i c a l

model t o p r e d i c t behavior i n a 217-pin subassembly. The f i n a l

217-pin t e s t w i l l p rov ide t h e exper imenta l v e r i f i c a t i o n of

t h e a n a l y t i c a l model t o p r e d i c t f u l l - s i z e subassembly behavior .

I n t h i s r e p o r t p e r i o d t h e fo l lowing accomplishments were

made p r e p a r a t o r y f o r t h e seven p i n t e s t s :

a A l l d e s ign was completed.

a Cons t ruc t i on of t h e 2 i n . ins t rumented f low loop was

completed.

a Qua l i t y Assurance documentation was completed on t h e

ins t rumented p i n s of t h e f i r s t seven p i n subassembly.

a Noise a n a l y s i s c a l i b r a t i o n t e s t assembly was compelted

and v e l o c i t y probe c a l i b r a t i o n s a r e about 30% complete.

d . Heat T r a n s f e r C h a r a c t e r i s t i c s of FFTF Fuel

Subassemblies

J . Muraoka (913)

The o b j e c t i v e of t h e program i s t o d e f i n e t h e thermal

h y d r a u l i c behavior of e l e c t r i c a l l y hea t ed seven-p in subassemblies

i n sodium t o suppor t t h e FFTF f u e l des ign . Two seven-p in

subassemblies have been examined. The f i r s t subassembly

t e s t examined a t i g h t , normal p i n bundle . The r e s u l t s were

r e p o r t e d i n t h e p rev ious FFTF q u a r t e r l y r e p o r t . I n t h i s

r e p o r t p e r i o d t h e second subassembly t e s t i n g was completed.

The second subassembly examined a t i g h t bundle i n an ove r s i zed

duc t t o examine t h e e f f e c t of manufacturing t o l e r a n c e accumu-

l a t i o n s . The s i g n i f i c a n t p r e l imina ry conc lus ions of t h i s

t e s t a r e :

Inc reas ing t h e bundle t o duc t c l ea rance i n c r e a s e d t h e

temperature d i f f e r e n c e ac ros s t h e o u t e r p i n row. I n c r e a s -

ing t h i s c l ea rance from 3.5 t o 15 m i l s ( r a d i a l c l e a r a n c e )

i n c r e a s e d t h e temperature d i f f e r e n c e by a s much a s 30 t o

40%.

a The h o t s p o t measured under a w i r e wrap i n t h e 30' p o s i t i o n

was n o t exces s ive . The d a t a i n d i c a t e d t h a t a w i r e wrap

f a c i n g an i n n e r subchannel i n c r e a s e s t h e l o c a l c l a d tem-

p e r a t u r e about 25 O F . The h e a t f l u x i s a nominal

500,000 ~ t u j h r - f t 2 i n t h e s e t e s t s .

The c l a d temperature v a r i a t i o n i n an o u t e r row p i n was

s i g n i f i c a n t l y l e s s than t h e maximum coo lan t t empera ture

v a r i a t i o n . These temperature v a r i a t i o n s i n d i c a t e a two-

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

around t h e p i n .

2 . Hydrau l ic Model of Reactor Vessel O u t l e t Region

H . Leigh (954) and D. L . B a l l a r d (COO)

Tes t s a r e be ing performed on a h y d r a u l i c model t o s t udy

gas en t ra inment and mixing cond i t i ons i n t h e o u t l e t r eg ion of

t h e FFTF r e a c t o r v e s s e l . Water i s being used a s t h e t e s t

media.

I . F a s t F l u x T e s t F a c i l i t y Q u a r t e r l y T e c h n i c a l R e p o r t , S e p t e m b e r , O c t o b e r , November 1969, BNWL-1275. ~ a t t e Z Z e - f l o r t h w e s t , R i c h l a n d , W a s h i n g t o n , January 1970.

The model i s a nominal 1 / 3 s i z e s i m u l a t i o n of t h e r e a c t o r

between t h e co re e x i t and t h e v e s s e l cover . F igure 6.1 shows

an e x t e r i o r view of t h e model. The model i s connected t o a

3600 gal/min c a p a c i t y loop w i t h f low c o n t r o l and measurement

c a p a b i l i t i e s on t h e i n l e t and each of t h e t h r e e o u t l e t s .

Each o u t l e t i s provided wi th a t r a n s p a r e n t p l a s t i c spool

p i e c e f o r obse rva t ion of t h e d i s cha rge s t ream.

A newly developed u l t r a s o n i c t r ansmis s ion technique , (1 1 was used t o q u a n t i t a t i v e l y measure gas en t ra inment on t h e s e

model t e s t s . The appara tus used i n t h i s technique measures

a t t e n u a t i o n changes of u l t r a s o n i c energy caused by gas

bubbles i n t h e u l t r a s o n i c beam ( t h e appara tus does n o t d e t e c t

d i s s o l v e d g a s ) . The u l t r a s o n i c t r a n s d u c e r was l o c a t e d on t h e

d i s cha rge p ipe w e l l downstream of t h e convergence of t h e

t h r e e d i s cha rge flows on t h e model. The system was c a l i b r a t e d

a t each f low r a t e and each model c o n f i g u r a t i o n t o r e s u l t i n

a system meter ou tpu t versus vo id volume f r a c t i o n . These

c a l i b r a t i o n d a t a t hen made i t p o s s i b l e t o o b t a i n a c c u r a t e

q u a n t i t a t i v e in format ion on void f r a c t i o n f o r each t e s t

c o n f i g u r a t i o n .

T e s t s t o d a t e , have shown t h a t a problem of gas e n t r a i n -

ment does e x i s t f o r some o u t l e t r eg ion c o n f i g u r a t i o n s . The

t e s t s have shown t h a t t h e model i s s u i t a b l e f o r e v a l u a t i o n of

t h i s problem, and r e s u l t s have i n d i c a t e d t h a t good d a t a can

be ob t a ined r ega rd ing vo id f r a c t i o n f o r each s p e c i f i c

c o n f i g u r a t i o n .

One of t h e des ign f e a t u r e s o f t h e FFTF i s t h e use of

" ins t rumen ta t i on suppor t p l a t e s " a c t u a t e d by " ins t rumen ta t i on

t r e e s . " These i tems were modeled w i th r e s p e c t t o melted

2 . Fas t Flux T e s t F a c i l i t y Q u a r t e r l y T e c h n i c a l Repor t , September , October , November 1969, BNWL-2275. Bat teZZe- Nor thwes t , R ich land , Washington, January 1970.

N e g 0 6 9 3 3 2 4 - 3 't

FIGURE 6 . 1 . E x t e r i o r V i e w of 1 /3 Scale FFTF R e a c t o r V e s s e l Out- l e t R e g i o n M o d e l

BNWL- 1328

s u r f a c e . The model t e s t s have shown t h a t t h e p o s i t i o n of t h e

ins t rument suppor t p l a t e s above t h e top of t h e d r i v e r f u e l

has a s i g n i f i c a n t i n f l u e n c e on t h e s u r f a c e tu rbu lence and t h e

r e s u l t a n t a i r ent ra inment i n t h e e f f l u e n t s t ream.

I R R A D I A T I O N T E S T I N G T E C H N O L O G Y

1. Closed Loop Tube Nozzle Closure Development

a . Scope and Objec t ives

C . A . Munro (914)

One of t h e major problems i n a s s u r i n g i n d i v i d u a l removal

and replacement of t e s t specimens i n t h e ope ra t i on of a t e s t

r e a c t o r such a s t h e FFTF i s t h e s e l e c t i o n of methods f o r

s e a l i n g r e a c t o r cover p e n e t r a t i o n s . The cover p e n e t r a t i o n s

r e q u i r e t h a t a primary r e f u e l i n g c l o s u r e i s made on each

c lo sed loop tube . This c l o s u r e , which i s made a t t h e top

p o r t i o n of t h e tube (nozz l e ) , i s d i f f i c u l t t o achieve because

of the requirement f o r a smal l space envelope and t h e high

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

The o b j e c t i v e of t h i s development program i s t o i n v e s t i -

g a t e both t h e mechanical s e a l i n g concept and t h e welding-

c u t t i n g concept f o r making t h i s connect ion.

b . Closed LOOD Nozzle Mechanical Closure S t u d i e s

R . Kolowith ( 9 1 4 ) and M . R . K r e i t e r (COO)

An e x t e n s i v e program of t e s t i n g a v a i l a b l e commercial

mechanical c l o s u r e s has been completed. None of t h e c l o s u r e s

t e s t e d met t h e requirement f o r maximum gas leakage of

a tm/sec under a l l t h e des igna t ed c o n d i t i o n s . Hence we

have concluded t h a t t he remotely operab le and compact c l o s u r e

r equ i r ed f o r t h i s a p p l i c a t i o n i s n o t w i t h i n t h e c u r r e n t s t a t e

of technology.

c . Closed LOOD Nozzle Weld Closure S t u d i e s

R . F . Gilmore (914) and L . J . Rousseau (COO)

A new remote weld head has s u c c e s s f u l l y completed a s e r i e s

of s i x remote s e a l welds over molten sodium i n s i d e t h e env i ron-

mental t e s t chamber. Figure 6.2 shows t h e e x t e r i o r o f t h e

chamber whi le F igure 6 .3 shows t h e i n t e r i o r of t h e chamber

w i th t h e remote weld head i n p o s i t i o n t o perform a nozz le

weld.

P r i o r t o weld t e s t i n g , t h e chamber was evacuated t o around

500 p and then back f i l l e d w i th helium gas . The r e c i r c u l a t i n g

gas p u r i f i c a t i o n system was used t o main ta in t h e oxygen con-

t e n t a t l e s s than 1% and mois tu re a t l e s s than 2 % . Molten

sodium was admi t ted i n t o t h e nozz le spoo l p i e c e and t h e weld

j o i n t a r e a was s t a b i l i z e d t o 4 7 5 O F f o r 2 h r . The sodium was

t hen d r a i n e d back i n t o t he r e s e r v o i r , and t h e remote weld was

made. Sodium was once aga in brought up i n t o t h e t e s t specimen

t o a l e v e l of 1 - 1 / 2 i n . below t h e weld a r e a and h e l d a t 450 t o

500 O F f o r 2-1/2 h r .

Three of t h e t e s t specimens were i n spec t ed r a d i o g r a p h i c a l l y ;

both X-ray and i r r a d i a t i o n sources were used. The X-ray r a d i o -

graphs showed t h e weld bead shape t o be uniform and of t h e

d e s i r e d shape. One of t h e specimens was p r e s s u r i z e d t o

250 p s i g and h e l d f o r 2-1/2 h r a t 530 O F t o v e r i f y s t r u c t u r a l

i n t e g r i t y . Mass spec t rometer helium l e a k d e t e c t i o n t e s t s

performed on a l l t h e specimens have shown leakage l e s s t han

a tm/sec through t h e s e a l weld. S t a t i s t i c a l d a t a i s be ing

ga the red t o f u r t h e r e v a l u a t e machine d u r a b i l i t y and weld j o i n t

c h a r a c t e r i s t i c s .

BNWL- 1 3 2 8 "

Neg 51298-3

FIGURE 6.3. Interior Environmental Test Chamber

2 . C losed Loop I n s u l a t i o n S t u d i e s

K. R . Wheeler , S. W . B inega r (AOO), and S. M. G i l l (962)

Thermal s t r e s s e s i n t h e w a l l s o f t h e c l o s e d l o o p t u b e s

e x t e n d i n g th rough t h e FTR c o r e w i l l be minimized by means o f

f e l t e d m e t a l i n s u l a t i o n . The purpose of t h i s s t u d y i s t o

d e t e r m i n e t h e combina t ion of i n s u l a t e d w a l l s t r u c t u r a l p a r a -

m e t e r s which g i v e a r e q u i r e d t h e r m a l c o n d u c t i v i t y of

a p p r o x i m a t e l y 2 B t u / h r / f t / O F . I n s u l a t e d w a l l s e c t i o n s w i l l

be e v a l u a t e d i n a i r and i n f lowing sodium o v e r a r a n g e of

t e m p e r a t u r e s up t o and i n c l u d i n g 1200 O F .

Commercial ly produced c y l i n d e r s f a b r i c a t e d by b r a z e

bonding a l a y e r o f f e l t e d m e t a l * i n s u l a t i o n t o t h e OD s u r f a c e

of a 304 SS t u b e were o r d e r e d i n J u l y 1969. These t e s t p i e c e s ,

t o be u l t i m a t e l y f a b r i c a t e d i n t o p r o t o t y p i c c l o s e d l o o p w a l l

s e c t i o n s , formed t h e b a s i s f o r e v a l u a t i n g : (1) t h e i n f l u e n c e

o f f e l t e d m e t a l d e n s i t y and bonding on t h e r m a l c o n d u c t i v i t y

and ( 2 ) any f a b r i c a t i o n problems a s s o c i a t e d w i t h t h e u s e of

t h i s m a t e r i a l f o r s m a l l d i a m e t e r c y l i n d e r s .

Forming methods employed by t h e f e l t e d m e t a l p r o d u c e r a r e

o n l y c a p a b l e of f a b r i c a t i n g 0.20 d e n s i t y o r l e s s m a t e r i a l i n t o

c y l i n d e r s r e l a t a b l e t o c l o s e d l o o p d e s i g n . T e n s i l e i n s t a b i l i t y d u r i n g room t e m p e r a t u r e bend ing i s obse rved f o r h i g h e r d e n s i t i e s .

A c y l i n d e r o f 0.20 d e n s i t y f e l t e d m e t a l b r a z e bonded t o an

i n n e r 304 SS s h e l l was s u c c e s s f u l l y f a b r i c a t e d i n December 1969.

The p r o t o t y p i c sandwich c o n s t r u c t i o n of t h e c l o s e d l o o p w a l l

was comple ted a t BNW w i t h a d d i t i o n o f t h e o u t e r s h e l l . Argon

g a s was s e a l e d i n t o t h e f e l t e d m e t a l i n t e r s t i c e s and t h e com-

p o s i t e c y l i n d r i c a l w a l l s e c t i o n was e v a l u a t e d f o r i t s t h e r m a l

conduc tance i n an a x i a l l y h e a t e d f u r n a c e p r o v i d i n g r a d i a l h e a t

f low.

* ChemicaZ m a k e u p as f o Z Z o w s : 0 . 3 % C , 2 . 0 % Mn, 1 . 0 % S i , 0 . 0 4 % P , 0 . 5 % Cu, 0 . 5 % Mo, 0 . 0 3 % S, 1 7 . 0 t o 1 9 % C r , a n d 7 t o 1 0 % N i .

6.15

Thermal conductance K ( B t u / h r / f t / " F ) can be c a l c u l a t e d

from E q u a t i o n (1)

qk = AT Kk (1)

The h e a t i n p u t qk and t h e r a d i a l t e m p e r a t u r e d r o p AT a c r o s s t h e

composi te w a l l a r e a l l r e a d i l y measurab le q u a n t i t i e s . Thermal

c o n d u c t i v i t y v a l u e s f o r t h e 0.20 d e n s i t y i n s u l a t i o n t e s t s e c -

t i o n o v e r a t e m p e r a t u r e range 900 t o 1400 O F v a r y from 0.312

t o 0.435 B t u / h r / f t / O F f o r 900 O F and 1400 O F , r e s p e c t i v e l y .

R e s u l t s i n d i c a t e t h a t a composi te w a l l must be c o n s t r u c t e d w i t h

g r e a t e r h e a t conductance t h a n t h i s f i r s t t e s t sample .

T e s t s p lanned f o r n e x t q u a r t e r i n c l u d e :

Use o f he l ium gas i n t h e i n t e r s t i c e s o f 0.20 d e n s i t y

f e l t e d m e t a l t o i n c r e a s e conductance and

E v a l u a t i o n o f t h e the rmal c o n d u c t i v i t y o f 0.60 d e n s i t y

f e l t e d m e t a l i n a f l a t sandwich c o n s t r u c t i o n . I f 0.60

d e n s i t y m a t e r i a l p roves t o be t h e optimum i n s u l a t i o n , a

s t u d y o f forming methods w i l l be u n d e r t a k e n .

O T H E R C O R E T E C H N O L O G Y

1. Examinat ions o f T e s t Specimens

C . L . Boyd (942)

a . Disassembly-Reassembly Equipment

Copies of t h e ORNL r e p o r t , which d e s c r i b e s t h e c o n c e p t

and development program f o r equipment needed t o r emote ly p o s i -

t i o n and examine FFTF c o r e components and f u l l l e n g t h t e s t

a s s e m b l i e s up t o 4 3 f e e t long were i s s u e d . The remote examina-

t i o n o p e r a t i o n s i n c l u d e removal o f t h e p i n bund le from t h e

f low d u c t , v i s u a l i n s p e c t i o n , pho tography , measurement o f

o v e r a l l d imensions and i n t e r p i n s p a c i n g , d i s a s s e m b l y o f t h e

2 . J . N . Ba i rd e t aZ. Conceptual S tudy o f DisassembZy Equip- ment f o r Examinat ion o f F F T F Core Components and T e s t A s s e m b l i e s , ORNL-TM-2759. Oak Ridge NationaZ Labora tory , Oak R i d g e , T e n n e s s e e , January 2970.

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

reassembly o f t e s t a s s e m b l i e s f o r f u r t h e r i r r a d i a t i o n .

A s c o n c e i v e d , t h e FFTF Disassembly-Reassembly Equipment

(DRE), shown i n drawing M-11325-EM-050 c o n s i s t s o f a p o s i t i o n -

i n g machine and t o o l i n g . The DRE w i l l be c a p a b l e o f b e i n g

remote ly i n s t a l l e d , o p e r a t e d , and m a i n t a i n e d i n a h o t c e l l

w i t h a d r y i n e r t a tmosphere (argon) where i t w i l l be s u b j e c t e d

t o h i g h gamma r a d i a t i o n , r e s i d u a l sodium and sodium v a p o r ,

and h i g h r a d i a n t h e a t . S u c t i o n- f l o w c o o l i n g o f an assembly

c o n t a i n i n g f u e l w i l l be p r o v i d e d d u r i n g d i s m a n t l i n g and exam-

i n a t i o n by means o f d e v i c e s b u i l t i n t o t h e p o s i t i o n i n g machine.

A c o o l i n g c a p a c i t y of up t o 20 kW w i l l be p r o v i d e d by a x i a l

f low of a rgon c o o l a n t t h r o u g h t h e assembly , and a c o o l i n g

c a p a c i t y o f up t o 10 kW w i l l be p r o v i d e d by t r a n s v e r s e f low

o f a rgon c o o l a n t th rough t h e f u e l bund le .

The c o n c e p t o f t h e p o s i t i o n i n g machine i s based on t h e

o p e r a t i n g p h i l o s o p h y of v e r t i c a l l y maneuvering t h e assembly

t o p r o v i d e optimum viewing and m a n i p u l a t i o n and upon

t h e need t o a x i a l l y wi thdraw t h e p i n bund le from t h e s e v e r e d

f low d u c t t o expose t h e bundle f o r examina t ion . The amount

o f v e r t i c a l maneuvering r e q u i r e d i s reduced by t h e u s e o f

t h r e e c e l l o p e r a t i n g l e v e l s , each o f which i s equipped w i t h a

v iewing window, a p a i r o f s e a l e d m a s t e r - s l a v e m a n i p u l a t o r s ,

and a work t a b l e . Emphasis h a s been p l a c e d on t h e u s e o f

mas t e r - s l a v e m a n i p u l a t o r s a s much as p o s s i b l e f o r f u n c t i o n a l

o p e r a t i o n s .

The t o o l i n g used f o r t h e d i s a s s e m b l y and examina t ion

o p e r a t i o n s w i l l b e p o r t a b l e i t ems t o be p o s i t i o n e d and used

on t h e work t a b l e s w i t h t h e m a n i p u l a t o r s . The i t e m s needed

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

s l i t t h e f low d u c t t h a t forms t h e j a c k e t o f t h e p i n b u n d l e ,

v a r i o u s t o o l s and c u t t e r s needed t o d i s a s s e m b l e and reassemble

BNWL- 1328

t h e p i n b u n d l e , and measur ing equipment , which i s n o t now

c o n s i d e r e d t o be p a r t o f t h e d i sassembly- reassembly equipment .

The s t r u c t u r a l f rame o f t h e p o s i t i o n i n g machine f o r 4 3 - f t

specimens i s approx imate ly 58 f t 6 i n . t a l l , and i t c o n s i s t s

o f a modular column and b a s e t h a t i s anchored t o t h e c e l l

f l o o r . The working p o r t i o n s o f t h e machine c o n s i s t o f t h r e e

s e p a r a t e s p e c i f i c - p u r p o s e s l i d e b o d i e s t h a t r i d e i n t r a c k s o r

ways on t h e f a c e o f t h e column and h o l d s p e c i a l i z e d subassem-

b l i e s t h a t per form v a r i o u s work o p e r a t i o n s , The upper s l i d e

i s equipped t o g r a s p t h e upper end f i t t i n g o f a c o r e o r t e s t

assembly t r a n s p o r t e d t o t h e machine by c r a n e , and t h e lower

s l i d e i s equipped t o g r a s p t h e lower end o f an assembly.

The lower s l i d e a l s o has a plenum f o r a x i a l c o o l i n g o f t h e

assembly and a p o w e r - r o t a t e d f a c e p l a t e t o t u r n t h e assembly

d u r i n g c u t t i n g and examina t ion o p e r a t i o n s . The midd le s l i d e

i s equ ipped w i t h c o o l i n g sh rouds f o r t r a n s v e r s e c o o l i n g o f

t h e exposed f u e l b u n d l e , and v a r i o u s clamps and f i x t u r e s can

a l s o be mounted on i t s f a c e . These s l i d e a s s e m b l i e s may be

moved up and down i n d e p e n d e n t l y o r any two o r a l l t h r e e o f

them may be moved i n u n i s o n . For d i s a s s e m b l y o p e r a t i o n s ,

t h e midd le s l i d e moves w i t h t h e p i n bund le and i s s l a v e d t o

t h e lower s l i d e f o r downward wi thdrawal o f bo t tom- suppor ted

b u n d l e s . Converse ly , t h e middle s l i d e i s s l a v e d t o t h e upper

s l i d e f o r upward wi thdrawal o f t o p - s u p p o r t e d b u n d l e s .

Recent changes i n c r i t e r i a f o r t h e s u b j e c t equipment

r e q u i r e s t h a t a d d i t i o n a l work be per formed t o augment t h e

c o n c e p t u a l s t u d y . This a d d i t i o n a l work may be g e n e r a l l y

d i v i d e d i n t o t h r e e p a r t s a s f o l l o w s :

Determining t h e e f f e c t s upon t h e d i sassembly- reassembly

equipment and f a c i l i t y r e l a t e d r e q u i r e m e n t s when t h e

l e n g t h s o f FFTF c o r e components and t e s t a s s e m b l i e s a r e

r educed t o 1 2 f e e t .

P r e p a r i n g new c o s t and s c h e d u l i n g d a t a f o r f u t u r e p o r t i o n s

o f t h i s p r o j e c t t o r e f l e c t new c r i t e r i a .

Documenting t h e r e s u l t s o f t h e s e a d d i t i o n a l s t u d i e s i n an

addendum t o t h e c o n c e p t u a l s t u d y r e p o r t . ( 1

b . Decay Heat Removal Development

D . R . Dickenson, T . C . Reihman, and R . A. H i l d n e r (COO)

The majo r g o a l o f t h i s t a s k i s t o e v a l u a t e t h e o p e r a t i n g

c o n d i t i o n s ( e . g . , f low r a t e s , f low s p l i t and p r e s s u r e d rop)

i n o r d e r t o a d e q u a t e l y c o n t r o l t h e f u e l c l a d t e m p e r a t u r e o f a

d i s c h a r g e d f u e l assembly d u r i n g f u e l examina t ion . The c r i t i c a l

problem demons t ra t ed i n t h e FY 1969 t e s t i n g was h o t zones due

t o l o c a l f low s t a g n a t i o n p o i n t s d u r i n g removal o f t h e d u c t

from t h e f u e l assembly . The problem was caused by i n t e r f e r e n c e

between t h e combined a x i a l p o s i t i v e d i s p l a c e m e n t and t r a n s v e r s e

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

To p r e v e n t t h e h o t s p o t s and t o a s s i s t i n t h e c o n t r o l o f

i n - c e l l c o n t a m i n a t i o n , t h e decay h e a t removal method was

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

a x i a l f low. M o d i f i c a t i o n s t o t h e t e s t f a c i l i t y t o s i m u l a t e

t h e new method have been comple ted .

I . See Re fe rence 1 , page 6 . 1 3 .

6.20

C H A P T E R V I I . F U E L S A N D M A T E R I A L S

A . F U E L S A N D M A T E R I A L S E V A L U A T I O N

1. B C - S t a i n l e s s S t e e l C o m p a t i b i l i t y -4 L . R . Bunne l l (AOO)

The c o m p a t i b i l i t y o f u n i r r a d i a t e d and i r r a d i a t e d B4C w i t h

Type 316 SS a t 550 and 600 O C f o r 1000 h r was r e c e n t l y

i n v e s t i g a t e d . The i r r a d i a t e d B C was o b t a i n e d by s c r a p i n g 4 h i g h burnup m a t e r i a l f rom t h e s u r f a c e s of 9 9 % TD p e l l e t s

i r r a d i a t e d i n a Hanford r e a c t o r . B4C powder of r o u g h l y t h e

same p a r t i c l e s i z e ( -325 mesh) was used a s a s t a n d a r d . Each

c a p s u l e used i n t h e t e s t c o n t a i n e d an e n c l o s e d dead w e i g h t t o

p r e s s u r i z e t h e s t a i n l e s s s t e e l - B4C i n t e r f a c e t o 100 p s i . No

r e a c t i o n o c c u r r e d i n each o f t h e samples t e s t e d a t 550 O C .

However, when b o t h samples were h e a t e d a t 600 O C , t h e y r e a c t e d

t o y i e l d a r e a c t i o n l a y e r abou t 2.5 p t h i c k , a s shown i n F i g u r e 7 .1 . There was no d i s c e r n a b l e d i f f e r e n c e between

r e a c t i o n s o f v i r g i n o r i r r a d i a t e d B 4 C .

Neg 470-36B 500X

FIGURE 7.1. 2 . 5 p R e a c t i o n Zone on 316 S t a i n l e s s S t e e l Exposed t o B4C Powder f o r 1000 Hours a t 600 O C .

2 . R e s i d u a l S t r e s s e s i n I r r a d i a t e d Fue l C ladd ing

J . F . B a t e s and R . L . F i s h (722)

Work i s p r o c e e d i n g t o d e t e r m i n e i f r e s i d u a l s t r e s s e s i n

u n f u e l e d spec imens can be d e t e c t e d by means o f o p t i c a l i n t e r -

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

have d e m o n s t r a t e d t h a t i n t e r f e r e n c e holograms can b e produced

th rough 1 2 i n . o f l e a d g l a s s . The t e c h n i q u e a p p e a r s t o b e

a d a p t a b l e t o h o t c e l l work. F i g u r e 7 . 2 shows a d e m o n s t r a t i o n

o f t h i s t e c h n i q u e . I n t h i s d e m o n s t r a t i o n , a hologram f o r an

u n f u e l e d s e c t i o n of c l a d d i n g was c o n s t r u c t e d . S u b s e q u e n t l y ,

t h e spec imen was s t r e s s e d t o 2000 p s i by i n t e r n a l g a s

p r e s s u r i z a t i o n , and a new hologram was made. The two

images were t h e n super imposed which r e s u l t e d i n t h e i n t e r f e r -

ence p a t t e r n s of F i g u r e 7 . 2 . The magnitude o f t h e s t r e s s e s

c a l c u l a t e d from t h e f r i n g e s a g r e e d w e l l w i t h c a l c u l a t i o n s based

on e l a s t i c t h e o r y .

FIGURE 7 . 2 . Ho lograph ic F r i n g e s Produced on a Tube P r e s s u r i z e d t o 2000 p s i

3 . Weldment S t u d i e s Specimen S i z e

A . L . Ward, A . J . L o v e l l , and L . D. Blackburn (AOO)

A t e n s i l e t e s t s t u d y was made t o d e t e r m i n e whe the r a

l a r g e r d i a m e t e r specimen would improve t h e r e p r o d u c i b i l i t y o f

t e s t r e s u l t s and a l s o b e more r e p r e s e n t a t i v e o f t h e b u l k weld

m a t e r i a l b e i n g s t u d i e d . R e s u l t s from t h e l a r g e r spec imens

( 0 . 2 5 0 - i n . gage d i a m e t e r , 1 . 1 2 5 - i n . gage l e n g t h ) t e s t e d i n t h e

r ange f rom 600 t o 900 OF.are i n g e n e r a l agreement w i t h r e s u l t s

from t h e m i n i a t u r e ( 0 . 1 2 5- i n . gage d i a m e t e r , 1 . 1 2 5 - i n . gage

l e n g t h ) specimen used i n t h e weldment i r r a d i a t i o n e x p e r i m e n t .

No c o n s i s t e n t improvement i n t h e magnitude of d a t a s c a t t e r was

obse rved upon comparison o f t h e two s e t s o f r e s u l t s . T h e r e f o r e ,

p r e s e n t p l a n s f o r f u t u r e i r r a d i a t i o n e x p e r i m e n t s i n v o l v i n g

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

spec imen.

4 . Mechanica l T e s t i n g o f Fue l P i n C ladd ing

R . L . F i s h ( 7 2 2 ) , L . A . Pember, J . W . Weber,

R . D . L e g g e t t ( 7 5 0 ) , and E . D . J e n s e n (AOO)

The purpose of t h i s program i s t o p r o v i d e a b a s i s f o r

e v a l u a t i n g t h e combined e f f e c t s of f u e l c l a d d i n g i n t e r a c t i o n ,

f l u e n c e and o p e r a t i n g t e m p e r a t u r e on t h e p o s t i r r a d i a t i o n b u r s t

and s t r e s s - r u p t u r e p r o p e r t i e s of f u e l p i n c l a d d i n g .

B u r s t p r o p e r t i e s o f f u e l e d c l a d d i n g s e c t i o n s from P N L - 1

s e r i e s f u e l p i n i r r a d i a t i o n s a t 900 OF have been g i v e n i n

p r e v i o u s q u a r t e r l y r e p o r t s . The most i m p o r t a n t f i n d i n g i n

t h e s e p r e v i o u s l y r e p o r t e d s t u d i e s was a v e r y low s t r e n g t h and

d u c t i l i t y r e g i o n above t h e r e a c t o r midp lane . The low s t r e n g t h

i s t h o u g h t t o b e due t o g r a i n boundary a t t a c k d u r i n g t e s t i n g

o f s e n s i t i z e d c l a d d i n g . The n a t u r e o f t h e c o r r o s i v e has n o t

been i d e n t i f i e d .

A d d i t i o n a l f u e l - c o n t a i n i n g c l a d d i n g specimens p r e p a r e d i n

a d r y , i n e r t a tmosphere , b u t s t o r e d f o r a b o u t 10 months i n h o t

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

have r e v e a l e d i n t e r g r a n u l a r c r a c k s d u r i n g l e a k t e s t i n g . These

spec imens were from t h e upper f u e l e d r e g i o n s o f PNL 1-16 and

1 - 1 8 p i n s .

The o r i g i n o f t h e s t r e s s e s n e c e s s a r y t o c a u s e t h i s c r a c k i n g

i s n o t known b u t t h e c r a c k o r i e n t a t i o n s u g g e s t s t h e p i n s may

have been b e n t . The i n t e r g r a n u l a r f a i l u r e i n PNL 1 - 1 6 and 1 - 1 8

o c c u r r e d a t ambient t e m p e r a t u r e s which d e m o n s t r a t e s t h e g r a i n

boundary weakness e f f e c t i s n o t c o n f i n e d t o e l e v a t e d

t e m p e r a t u r e s .

The e l e c t r o n microprobe h a s been used t o examine g r a i n

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

p e n e t r a t i o n by f i s s i o n p r o d u c t s . The c l a d d i n g of f u e l p i n

specimen PNL-1-18 which r e v e a l e d f i s s u r e s d u r i n g l e a k t e s t i n g

was examined f o r ces ium, i o d i n e , sodium, phosphorus , and

rub id ium. One s i d e o f t h i s s e c t i o n which r e v e a l e d t h e t y p i c a l

c l a d d i n g m i c r o s t r u c t u r e a t f i s s u r e s was examined f o r t h e above

e l e m e n t s . F i g u r e 7 . 3 shows t h e a r e a examined. X-ray images f o r

t h e above e l e m e n t s r e v e a l e d o n l y one a r e a of s u f f i c i e n t l y h i g h

c o n c e n t r a t i o n t o r e g i s t e r on t h e o s c i l l o s c o p e d i s p l a y . Cesium

w a s c o n c e n t r a t e d a t t h e i n t e r s e c t i o n o f two g r a i n b o u n d a r i e s

l o c a t e d 50 from t h e f u e l - c l a d d i n g boundary , a s shown i n

F i g u r e 7 . 4 . The a r e a o f h i g h cesium c o n c e n t r a t i o n a l s o showed

b a r e l y d e t e c t a b l e amounts of i o d i n e , b u t n o t enough f o r a n

X-ray image d i s p l a y . Cesium o c c u r s i n t h e g r a i n b o u n d a r i e s

e x t e n d i n g i n a l l t h r e e d i r e c t i o n s from t h e ces ium s p o t shown i n

F i g u r e 7 . 4 . T h i s i s shown i n F i g u r e 7.5 i n which t h e ces ium

c o u n t i n g r a t e ( c o r r e c t e d f o r background) i s p l o t t e d a g a i n s t

d i k t a n c e from t h e g r a i n boundary i n t e r s e c t i o n f o r e a c h g r a i n

boundary . P lu tonium was moni to red s i m u l t a n e o u s l y w i t h ces ium

and was n o t d e t e c t a b l e i n t h e c l a d d i n g i n any l o c a t i o n sampled ,

i n d i c a t i n g t h a t t h e cesium i s n o t p o l i s h i n g d e b r i s . The con-

c e n t r a t i o n o f ces ium would be v a l u a b l e i n f o r m a t i o n , b u t c a n n o t

. FIGURE 7 . 3 . Area of Cladding of PNL 1-18 Examined i n t h e Shielded E lec t ron Microprobe. Arrow I n d i c a t e s Grain Boundary 1n te r s . ec t ion Shown

e i n F igure 7 . 4

W FIGURE 7 . 4 . Specimen Cur r en t , Cesium, and Plutonium D i s t r i b u t i o n i n a Gra in Z

Boundary I n t e r s e c t i o n i n PNL 1-18. ( S c a t t e r e d d o t s on cesium and 5 plutonium d i s p l a y s a r e background. White a r e a s r e p r e s e n t t h e P

e lement d i s t r i b u t i o n s . Gra in bounda r i e s beyond t h e f i s s u r e r e g i o n w p3

a r e n o t r e s o l v a b l e . 80 x 80 mic rons ; 1000X.) OC,

0 0 5 10 1 5

DISTANCE, p

FIGURE 7.5. V a r i a t i o n of Cesium Concen t r a t i on w i t h D i s t ance from t h e Maximum Concen t r a t i on Within t h e Three Grain Boundaries Shown i n F i g u r e 7 .4 . P l o t numbers r e f e r t o numbers i n F igu re 7 .4 .

be d e t e r m i n e d w i t h o u t knowledge o f t h e d i s t r i b u t i o n o f ces ium

w i t h d e p t h . T h i s i s , t h e obse rved c o u n t i n g r a t e s c o u l d r e p r e -

s e n t 100% cesium i n a v e r y t h i n l a y e r o r a much lower c o n c e n t r a -

t i o n d i s t r i b u t e d i n t h e g r a i n boundary t o a g r e a t e r d e p t h .

D e t e c t a b l e amounts of cesium were a l s o obse rved i n two g r a i n

b o u n d a r i e s 25 and 50 from t h e i n s i d e of t h e c l a d d i n g .

A n a l y s i s f o r phosphorus and rub id ium w i t h i n g r a i n

b o u n d a r i e s was a t t e m p t e d and no d e t e c t a b l e amounts of e i t h e r

e l e m e n t c o u l d be found u s i n g b o t h a r e a X-ray d i s p l a y s and p o i n t

c o u n t i n g w i t h i n g r a i n b o u n d a r i e s .

Sodium from t h e c o o l a n t was a l s o s u s p e c t e d of h a v i n g caused

t h e c l a d d i n g f a i l u r e ; however , a r e a X-ray s c a n s showed no

d e t e c t a b l e sodium. P o i n t c o u n t i n g a c r o s s t h e c l a d d i n g i n 1 p

s t e p s showed one l o c a t i o n seeming ly c o n t a i n i n g sodium; however ,

r e t u r n i n g t o t h e s e a r e a s and making wavelength s c a n s on t h e

s u s p e c t e d a r e a s gave no i n d i c a t i o n o f sodium. I n v e s t i g a t i o n

i n t o t h e h i s t o r y o f t h i s p i n s i n c e removal from t h e r e a c t o r

r e v e a l e d t h a t i t had been washed w i t h w a t e r and a l s o w i t h

a l c o h o l . T h i s would remove sodium on t h e o u t s i d e and p r o b a b l y

t o some e x t e n t w i t h i n t h e s e p a r a t e d g r a i n s n e a r t h e o u t s i d e of

t h e p i n .

The c a u s e of t h e boundary weakness i s v e r y i m p o r t a n t t o

f a s t r e a c t o r t e c h n o l o g y . I f t h e weakness i s due t o s to rag ,e

env i ronment , t h e n p i n h a n d l i n g p r o c e d u r e s must be improved i n

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

i n f u e l p i n pe r fo rmance , t h e n t h e c l a d d i n g w i l l n o t b e c a p a b l e

of s u p p o r t i n g t h e l o a d s which a p p e a r s a f e from u n f u e l e d i r r a d i a -

t i o n e x p e r i m e n t s .

I n o r d e r t o c l a r i f y t h e mechanism i n v o l v e d w i t h t h e g r a i n

boundary weakness , a number o f d e f i n i t i v e e x p e r i m e n t s have been

conducted and a d d i t i o n a l e x p e r i m e n t s a r e p l a n n e d .

I n i t i a l r e s u l t s were ob t a ined from a r i n g t e s t on a

specimen c u t from a b i a x i a l t e s t sample which f a i l e d p r e -

mature ly by g r a i n boundary f r a c t u r e i n a b i a x i a l t e s t . I n t h e

r i n g t e s t a 1 / 4 - i n . long s e c t i o n of c l add ing i s p u l l e d i n a

t e n s i l e machine i n such a way a s t o c r e a t e t a n g e n t i a l s t r e s s

i n t h e c l add ing w a l l . Fuel and f i s s i o n p roduc t s a r e removed

p r i o r t o t e s t i n g a t 900 O F . The meta l lography on t h e s e r i n g

t e s t r u p t u r e s i s shown i n F igure 7 . 6 . The good d u c t i l i t y and

s t r e n g t h e x h i b i t e d by t h i s c l add ing w i t h t h e f u e l and f i s s i o n

p roduc t s removed c o n t r a s t s g r e a t l y w i th t h e ve ry low d u c t i l i t y

(<1 .0% A D I D ) , i n t e r g r a n u l a r f a i l u r e s observed a t t h e same t e s t

t empera tu re i n f u e l e d c l add ing from t h e same r e g i o n of t h e

f u e l p i n . This i n d i c a t e s t h a t t h e premature f a i l u r e s a r e due

t o a c o r r o s i v e a t t a c k from w i t h i n t h e f u e l p i n and a r e n o t a

r e s u l t of e x t e r n a l a t t a c k o r i n h e r e n t c l add ing g r a i n boundary

weakness. Two b u r s t t e s t s (one f u e l e d and one w i t h f u e l

removed) a r e planned t o v e r i f y t h e e f f e c t s observed i n t h e s e

r i n g t e s t s . Carbon e x t r a c t i o n r e p l i c a s a r e a l s o be ing ob t a ined

from t h e r i n g t e s t samples f o r f u r t h e r c h a r a c t e r i z a t i o n o f

t h e i r m i c r o s t r u c t u r e .

a . I r r a d i a t i o n Conditons: @t - 3.7 x n/crn2 ( E > 0 . 1 M ~ V )

b. I r r a d i a t i o n Condi t ions: $t - 2.8 x n/cm2 (E > 0 . 1 MeV)

Tave - 9 4 0 OF

F I G U R E 7 .6 . Mic ros t ruc tu re of Ring T e s t Samples (Tes t temperature = 9 0 0 O F . )

F u e l p i n s PNL 1 - 9 , 1 - 1 2 , 1 - 1 3 and 1- 14 were he l ium l e a k -

t e s t e d f o r p o s s i b l e f i s s u r e s . These p i n s have n o t been

p u n c t u r e d n o r o t h e r w i s e i n t e n t i o n a l l y compromised. T h i s d i d

n o t r e v e a l any f i s s u r e s o r l e a k s . The o u t s i d e s u r f a c e o f t h e

c l a d d i n g on t h e s e same f u e l p i n s was r e p l i c a t e d w i t h c e l l u l o s e

n i t r a t e p l a s t i c . T h i s r e p l i c a t i o n d i d n o t r e v e a l any i n t e r -

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

s i g n i f i c a n t c h a r a c t e r i s t i c r e v e a l e d by t h e r e p l i c a s was a

pronounced d e l i n e a t i o n o f t h e g r a i n b o u n d a r i e s i n t h e upper

f u e l e d r e g i o n of PNL 1- 14 ( F i g u r e 7 . 7 ) . T h i s i s b e l i e v e d t o be heavy c a r b i d e p r e c i p i t a t i o n and i s n o t unexpec ted i n v iew

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

i r r a d i a t i o n .

FIGURE 7.7. P r e c i p i t a t e D e l i n e a t i o n o f C ladd ing G r a i n ~ o u n d a r i e s i n Upper F u e l e d Region of PNL 1- 14

5 . S t r e s s R u ~ t u r e S t u d i e s - E f f e c t of Aeine

o f Type 316 S t a i n l e s s S t e e l

R . W . Barker (722)

The o b j e c t i v e o f t h i s program i s t o de te rmine t h e e f f e c t s

of f a s t r e a c t o r i r r a d i a t i o n on t h e b i a x i a l s t r e s s - t o - r u p t u r e

p r o p e r t i e s of c and ida t e f a s t r e a c t o r c l add ing m a t e r i a l s .

Emphasis i s c u r r e n t l y be ing p l aced on t e s t i n g thermal c o n t r o l

specimen r e l a t e d t o EBR-I1 Subassembly X-022.

The specimens a r e made from 0 .208- in . d i a m e t e r ,

0 . 008- in . w a l l , AISI Type 316 SS t ub ing i n a s - r e c e i v e d c o n d i -

t i o n , i . e . , a sma l l degree of c o l d work r e t a i n e d from t h e

f a b r i c a t i o n p r o c e s s e s .

Specimens were aged a t 800 O F f o r 3045 h r i n sodium

(02-15 ppm; C-29 ppm). Res idua l sodium was removed by

d i s s o l v i n g and r i n s i n g w i t h wa t e r and d ry ing w i th e t h y l

a l c o h o l . B i a x i a l s t r e s s - r u p t u r e t e s t s were subsequen t l y p e r -

formed a t 1000 and 1200 O F by p r e s s u r i z i n g t h e t u b u l a r s p e c i -

mens w i t h a h i g h p r e s s u r e gas and ho ld ing t h e p r e s s u r e con-

s t a n t u n t i l r u p t u r e occur red (F igure 7 .8 ) . The d a t a show an

i n c r e a s e d r u p t u r e s t r e s s f o r t h e aged m a t e r i a l over t h a t of

t h e a s - r e c e i v e d m a t e r i a l . The s t r e n g t h i n c r e a s e a t 1000 OF i s

n o t r e a d i l y appa ren t a t r u p t u r e t imes l e s s than 100 h r , w h i l e

r u p t u r e t imes g r e a t e r than 100 h r t h e s t r e n g t h i n c r e a s e i s

about 1 0 % . A t 1200 OF, t h e d i f f e r e n c e between r u p t u r e

s t r e n g t h s i n c r e a s e s w i t h i n c r e a s i n g r u p t u r e t ime t o abou t 20%

a t 1000 h r r u p t u r e t ime . An a d d i t i o n a l t e s t a t 20,000 p s i

and 1 2 0 0 OF i s u n f a i l e d a t 2500 h r , which shows t h a t s t r e n g t h

i n c r e a s e p e r s i s t s t o l onge r r u p t u r e t imes . D u c t i l i t y of t h e

aged m a t e r i a l (F igure 7 .9) i s a l s o a f f e c t e d . A t 1 0 0 0 O F , t h e

d u c t i l i t y appears t o have been s l i g h t l y enhanced f o r r u p t u r e

t imes l e s s t han 50 h r b u t degraded f o r g r e a t e r t imes t o r u p t u r e .

Also , t h e l o s s of d u c t i l i t y becomes g r e a t e r w i t h i n c r e a s i n g

r u p t u r e t ime .

8 52 '=: 4 -

[..o: x !sb - ssjtl ls ~ O O H wnwl xvw

U a)" a) a m +I h* W E 0 LI m

D u c t i l i t y o f a s - r e c e i v e d m a t e r i a l was lower a t 1200 OF

t h a n a t t h e o t h e r t e s t t e m p e r a t u r e s , 100 and 1400 OF. However,

t h e a g i n g t r e a t m e n t markedly enhanced t h e 1200 OF d u c t i l i t y .

D u c t i l i t y i n c r e a s e s r ange from abou t 50% a t 10 h r t o 100% a t

600 h r .

6 . Damage A n a l y s i s

J . L . S t r a a l s u n d ( 7 2 2 ) , H . R . B rage r (7AO), and

J . F. Ba tes (722)

The o b j e c t i v e s of t h i s e f f o r t a r e t o e s t a b l i s h t h e

i r r a d i a t i o n - i n d u c e d s w e l l i n g c h a r a c t e r i s t i c s o f FFTF a l l o y s ,

t o r e l a t e f a s t - r e a c t o r - i n d u c e d s u b s t r u c t u r a l changes i n mic ro-

s t r u c t u r e t o c o r r e s p o n d i n g changes i n mechan ica l p r o p e r t i e s ,

and t o d e v e l o p means f o r d a t a e x t r a p o l a t i o n and i n t e r p o l a t i o n ,

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

E q u a t i o n s a r e p r e s e n t l y b e i n g deve loped e m p i r i c a l l y t o

d e s c r i b e t h e e f f e c t s o f n e u t r o n exposure and i r r a d i a t i o n

t e m p e r a t u r e on v o i d s i z e and c o n c e n t r a t i o n i n 304 and 316 SS.

The purpose of t h i s work i s t o deve lop a s e t o f t h r e e s e l f -

c o n s i s t e n t e q u a t i o n s d e s c r i b i n g t h e v o i d d i a m e t e r , v o i d con-

c e n t r a t i o n and v o i d volume ( s w e l l i n g ) o v e r a s wide a r ange

of e x p e r i m e n t a l c o n d i t i o n s a s p o s s i b l e . A c o n s i s t e n t s e t

o f e q u a t i o n s a c c o u n t i n g f o r t h e obse rved t r e n d s w i l l p r o v i d e

more c o n f i d e n c e i n e x t r a p o l a t i o n s t o t h e h i g h e r e x p o s u r e s

e x p e c t e d i n t h e FTR.

a . Void C o n c e n t r a t i o n s Equa t ions

Bes t f i t s o b t a i n e d t o d a t e f o r t h e v o i d c o n c e n t r a t i o n

d a t a developed a t BNW a r e :

BNWL - 132 8

where

@ t = n/cm2 (E > 0 . 1 MeV)

T = t empe ra tu r e , OK.

These e q u a t i o n s a r e based on t r a n s m i s s i o n e l ec t ron- mic ro scopy

of 1 7 specimens t h a t had been i r r a d i a t e d over t h e t empera tu re

range between 370 and 6 2 0 O C and t o f l u e n c e s between 2 0 .5 x 10'' and 5 .9 x l o z 2 n/cm .

The l i m i t e d amount of d a t a p r e s e n t l y a v a i l a b l e and t h e

u n c e r t a i n t y a s s o c i a t e d w i t h t h e i r r a d i a t i o n c o n d i t i o n s make i t

d i f f i c u l t t o de te rmine which e q u a t i o n p rov ide s t h e b e t t e r f i t

w i t h t h e d a t a .

b . Void S i z e Equat ions

S e v e r a l e q u a t i o n s were developed which p rov ide good

f i t s t o t h e vo id s i z e d a t a . Two examples a r e :

While d i f f e r e n t i n form, t h e s e equa t i ons p r e d i c t s i m i l a r

v a l u e s over t h e range of c o n d i t i o n s f o r which we have d a t a .

Equat ion (3) f i t s over t h e whole range of c o n d i t i o n s b e t t e r

t han Equa t ion (4) which was inc luded t o emphasize t h e i n s e n -

s i t i v i t y of vo id s i z e t o f l u e n c e . The e s t i m a t e d s t a n d a r d

d e v i a t i o n o f t h e f l u e n c e exponent i n Equat ion (4) i s 0 .042,

i . e . , h a l f a s l a r g e a s t h e exponent i t s e l f . Th i s i n d i c a t e s

t h a t t h e f l u e n c e dependency of t h e vo id s i z e d a t a i s a lmos t

s t a t i s t i c a l l y i n s i g n i f i c a n t .

7 . Fue l Clad I n t e r f a c e - R . W . Barker (722)

F u r t h e r work was conducted toward i d e n t i f y i n g c o r r o s i v e

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

o x i d e f u e l p i n s . ( I ) Capsu les c o n t a i n i n g p o t e n t i a l c o r r o s i v e

a g e n t s were c o n s t r u c t e d and t h e r m a l a g i n g begun. (2

T h i s expe r imen t was removed from t h e f u r n a c e a f t e r 519 h r

f o r an i n t e r m e d i a t e e x a m i n a t i o n . Most c a p s u l e s were found t o

be i n good c o n d i t i o n and were r e t u r n e d f o r f u r t h e r a g i n g . How-

e v e r , Lot I1Fl1 Type 304 and Lot l l G " Type 316 c a p s u l e s c o n t a i n i n g

anhydrous rubid ium hydrox ide had f a i l e d . The c o n d i t i o n o f t h e

c a p s u l e s i s shown i n F i g u r e 7 .10 .

O p t i c a l e x a m i n a t i o n showed an e x t e n s i v e ne twork o f i n t e r -

g r a n u l a r a t t a c k a s shown i n F i g u r e s 7 .11 and 7 .12 . Note t h a t

whole g r a i n s have been d i s l o d g e d . The s i m i l a r i t y between

mic rographs o f rub id ium hydrox ide a t t a c k and t h a t obse rved i n

BNW mixed o x i d e f u e l p i n s i s s t r i k i n g .

C a l c u l a t i o n s i n d i c a t e t h a t t h e i n t e r g r a n u l a r a t t a c k p r o - *

g r e s s e d under a s t r e s s of o n l y abou t 200 p s i , t h e r m a l s t r e s s e s

e x c e p t e d . Note t h a t t h e i n t e r g r a n u l a r a t t a c k o c c u r r e d n e a r t h e

e x t e r i o r s u r f a c e , a p p a r e n t l y a f t e r f a i l u r e . T h i s o b s e r v a t i o n

i s i m p o r t a n t because t h i s t y p e of a t t a c k may p r o g r e s s i n t h e

absence o f s i g n i f i c a n t s t r e s s e s .

1. FFTF Q u a r t e r l y T e c h n i c a l R e p o r t J u n e , J u l y , A u g u s t , 1969, BNWL-1174, B a t t e l l e - N o r t h w e s t , R i c h l a n d , W a s h i n g t o n , ( S e c t i o n V I I - A ) .

7

2 . Q u a r t e r l y T e c h n i c a l R e p o r t O c t o b e r , f louember, December, 1969, BNWL-1275, B a t t e l l e - N o r t h w e s t , R i c h l a n d , W a s h i n g t o n , ( S e c t i o n V I I - A ) .

BNWL - 1 3 2 8

-4 a ha\ a , - 4 !-I m 3 4 u aa aa, a, 34Jrn

4 p:m4 m M I - 0 M d

N I- I w

w P: - D C3

m H a, Fr z

h n m o * [I)

k a a, 3 3 p: [I)

B . M A T E R I A L S T E C H N O L O G Y *

1. U n i a x i a l C r e e ~

A . J . L o v e l l and L . D . Blackburn (AGO)

The o b j e c t i v e s of t h i s program a r e t o e v a l u a t e t h e e f f e c t s

of f a s t n e u t r o n i r r a d i a t i o n and envi ronment on t h e p r e - and

p o s t i r r a d i a t i o n u n i a x i a l c r e e p - r u p t u r e p r o p e r t i e s of FTR v e s s e l

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

m a t e r i a l s l i m i t s t o a s s u r e t h e i r s a f e and r e l i a b l e pe r fo rmance .

C r e e p - r u p t u r e r e s u l t s on specimens from Subassembly X018

show t h a t l a r g e r e d u c t i o n s i n r u p t u r e l i f e o f Type 316 SS

o c c u r a f t e r i r r a d i a t i o n t o a p p r o x i m a t e l y 3 x l o z 2 n/cmZ ( t o t a l )

i n t h e t e m p e r a t u r e r a n g e 1000 t o 1100 OF. These l o s s e s i n

r u p t u r e l i f e mean t h a t t h e a l l o w a b l e s t r e s s e s f o r h i g h l y

i r r a d i a t e d components may b e s i g n i f i c a n t l y lower t h a n f o r

u n i r r a d i a t e d components. For example, t h e s t r e s s t o a c h i e v e a

r u p t u r e l i f e o f 1000 h r i n u n i r r a d i a t e d m a t e r i a l a t 1100 OF i s

abou t 32,000 p s i , w h i l e t h e s t r e s s t o r e a c h a s i m i l a r r u p t u r e

l i f e a f t e r i r r a d i a t i o n t o 3 .5 x 10" n/cm2 ( t o t a l ) i s o n l y

abou t 21,000 p s i .

2 . Weldment S t u d i e s

A . L . j:Vard, A . J . L o v e l l , and L . D . Blackburn (AOO)

The o b j e c t i v e o f t h i s program i s t o p r o v i d e mechan ica l

p r o p e r t y and m e t a l l u r g i c a l s t a b i l i t y d a t a f o r FTR v e s s e l and

c o r e s t r u c t u r a l weldment m a t e r i a l s i n o r d e r t o d e f i n e a d e q u a t e

per formance under a n t i c i p a t e d FTR s e r v i c e c o n d i t i o n s .

T e n s i l e t e s t i n g of t h e f i r s t FTR v e s s e l weldment i r r a d i a -

t i o n e x p e r i m e n t has been comple ted . R e s u l t s have been r e p o r t e d

f o r a l l - w e l d spec imens from t h e TIG, M I G , submerged-a rc , and

s t i c k - e l e c t r o d e p r o c e s s e s . These r e s u l t s have shown t h a t t h e

t e n s i l e p r o p e r t i e s a r e e s s e n t i a l l y u n a f f e c t e d by i r r a d i a t i o n

t o ~1 x 10'' n/cm2 ( t o t a l ) a t 700 and 800 OF, w h i l e s u b s t a n t i a l

* R e p o r t e d by J . C. T o b i n ( 9 6 0 )

s t r e n g t h e n i n g and d u c t i l i t y l o s s a r e obse rved f o l l o w i n g i r r a d i a -

t i o n t o 3 .8 and 4.4 x l o 2 ' n/cm2 ( t o t a l ) a t 800 OF, e x c e p t i n

t h e c a s e of t h e s t i c k - e l e c t r o d e weld where d u c t i l i t y i s

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

w e l d - d e p o s i t e d m a t e r i a l s show s m a l l e r i r r a d i a t i o n - i n d u c e d y i e l d

s t r e n g t h i n c r e a s e s and s m a l l e r d u c t i l i t y l o s s e s t h a n t h e b a s e -

m e t a l ; however , t h e p r e i r r a d i a t i o n y i e l d v a l u e s were h i g h e r

and t h e d u c t i l i t i e s lower i n t h e weld m a t e r i a l .

I f a t o t a l e l o n g a t i o n c r i t e r i o n of 10% i s a p p l i e d t o FTR

v e s s e l m a t e r i a l s , i t a p p e a r s t h a t t h e weldments i n t h i s s t u d y

c o u l d b e employed s a f e l y , p r o v i d e d t h e maximum f l u e n c e 3 1 3

(4 .4 x l o L L n/cmL, t o t a l ) i s n o t exceeded. T h i s v a l u e may

w e l l c o n s t i t u t e t h e f l u e n c e l i m i t ( a t 800 OF) t o which t h e

TIG and M I G weld p r o c e s s e s a r e u s e f u l , s i n c e t h e s e weldments

showed p o s t i r r a d i a t i o n t o t a l e l o n g a t i o n v a l u e s n e a r 1 0 % .

A s t u d y has b e e n conducted t o d e t e r m i n e whe the r a l a r g e r

d i a m e t e r spec imen would improve t h e r e p r o d u c i b i l i t y o f t e s t

r e s u l t s and a l s o be more r e p r e s e n t a t i v e of t h e b u l k weld

m a t e r i a l b e i n g s t u d i e d . Specimens w i t h d i a m e t e r s of 0 . 2 5 0 - i n .

(compared t o 0 . 1 2 5 - i n . f o r t h e m i n i a t u r e specimen u s e d i n t h e

w e l d m e n t - i r r a d i a t i o n e x p e r i m e n t ) were f a b r i c a t e d from b a s e

m e t a l (Type 304) and weld m e t a l from t h e f o u r weld p r o c e s s e s .

T e n s i l e t e s t s were conducted i n t h e r ange from 600 t o 900 OF.

No w e l l d e f i n e d improvement i n b e h a v i o r was o b s e r v e d ; t h e

magni tude o f t h e s c a t t e r band i s e s s e n t i a l l y t h e same a s t h a t

shown by t h e m i n i a t u r e spec imens . T h e r e f o r e , p l a n s f o r f u t u r e

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

spec imen.

Some p r e l i m i n a r y r e s u l t s from c r e e p - r u p t u r e t e s t s of

s o l u t i o n - t r e a t e d b a s e m e t a l and weld m e t a l specimens from

X067 i r r a d i a t e d t o a p p r o x i m a t e l y 8 x l o z 1 n/cm2 ( t o t a l ) a t

1100 OF a r e now a v a i l a b l e . The s o l u t i o n - t r e a t e d b a s e m e t a l

and TIG we ld spec imens show s u b s t a n t i a l l o s s e s i n r u p t u r e

l i f e , w h i l e t h e s u b - a r c weld m e t a l shows l i t t l e change . Th i s

v a r i a t i o n i n r e s p o n s e t o i r r a d i a t i o n i s b e i n g i n v e s t i g a t e d .

3. High S t r a i n Rate E f f e c t s

J . M . S t e i c h e n (AOO)

The o b j e c t i v e o f t h e h i g h s t r a i n r a t e s t u d i e s i s t o

e v a l u a t e t h e e f f e c t s of h i g h s t r a i n r a t e s on t h e mechan ica l

p r o p e r t i e s of LMFBR m a t e r i a l s which a r e e x p e c t e d t o be used i n

t h e FTR v e s s e l and c o r e components. The r e s u l t s o f t h i s p r o -

gram w i l l p r o v i d e i n f o r m a t i o n on t h e b e h a v i o r of t h e v e s s e l

d u r i n g impact from w i t h i n and on t h e b e h a v i o r o f c o r e components

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

High s t r a i n r a t e t e s t i n g on 304 SS was completed d u r i n g

t h e p a s t q u a r t e r a t f o u r of t h e f i v e s t r a i n r a t e s o f i n t e r e s t . - 1 The comple ted t e s t r a t e s a r e 0 .10 , 1 . 0 , and 10.0 s e c .

T e s t i n g a t t h e f i f t h r a t e , 100.0 s e c - l , w i l l be i n i t i a t e d i n

t h e n e a r f u t u r e s i n c e t h e e l e c t r o - h y d r a u l i c t e s t sys tem which

i s t o be used f o r t h i s work r e c e n t l y a r r i v e d on s i t e .

- 1 The 0 .01 s e c r a t e d a t a i s p r e s e n t e d i n Table 7 . 1 . The

r e s u l t s o b t a i n e d a t s t r a i n r a t e s o f 0 . 1 , 1 . 0 , and 10 .0 s e c - 1

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

q u a r t e r l y r e p o r t . The i n f o r m a t i o n which h a s been o b t a i n e d a t

t h e f o u r s t r a i n r a t e s i s p r e s e n t l y b e i n g p r e p a r e d f o r a r e p o r t

which i s t o be completed i n t h e n e x t q u a r t e r .

TABLE 7 . 1 . High S t r a i n R a t e T e s t R e s u l t s on 304 S t a i n l e s s S t e e l

Elon a t i o n , % S t r a i n - l T e s t S t r e n g t h , x l o 3 p s i ( 1 f n . gage) Reduc t ion of

R a t e , Sec Temp., O F U l t i m a t e Y i e l d T o t a l Uniform A r e a , %

4 . Notched T e n s i l e E f f e c t s

J . M . S t e i c h e n (AOO)

The o b j e c t i v e o f t h e n o t c h e d t e n s i l e s t u d i e s w i l l b e t o

e v a l u a t e t h e e f f e c t s of a s h a r p n o t c h on t h e mechan ica l s t r e n g t h

of weldments t y p i c a l o f t h o s e found i n t h e FTR v e s s e l and com-

p o n e n t s . An e s s e n t i a l p o r t i o n of t h i s work w i l l i n c l u d e

e v a l u a t i o n o f t h e e f f e c t of f a s t n e u t r o n i r r a d i a t i o n on t h e

n o t c h s t r e n g t h of t h e s e weldments .

5 . I n - R e a c t o r Creep - Measurements - E . R . G i l b e r t (AOO)

E q u a t i o n s were deve loped f o r i r r a d i a . t i o n - i n d u c e d . c r e e p i n

s c l u . t i o n t r e a t e d and 20% cold.-worked Type 316 SS. The e q u a t i o n s

were b a s e d on: ( 1 ) H e s k e t h l s f o r n i u l a t i o n o f i r r a d i a t i c n - i n d u c e d

t r a n s i e n t and s t e a d y - s t a t e c r e e p , ( 2 ) a v a i l a b l e i n - r e a c t o r c r e e p

d a t a on aus t e n i t i c s t a i n l e s s s t e e l s , and(3 ) R u s s c h e r ' s damage

f u n c t i o n t o a c c o u n t f o r n-eut ron s p e c t r a l d i f f e r e n c e s i n t h e

v a r i o u s e x p e r i m e n t s . E f f e c t i v e s t r a i n and e f f e c t i v e s t r e s s were

used t o a c c o u n t f c r t h e c l i f f e r e n t s t a t e s of s t r a i n and s t r e s s

employed i n t h e e x p e r i m e n t s .

The f o l l o w i n g e q u a t i o n s were deve loped :

f o r s c l u t i o n t r e a t e d Type 316 SS, and

f o r 20% cold-worked Type 316 SS where i s e f f e c t i v e s t r a i n , - a i s e f f e c t i v e s t r e s s i n p s i , a = exp (1.405 - 0.0027 T ) where

T i s t e m p e r a t u r e i n d e g r e e s K e l v i n , @ i s t o t a l n e u t r c n f l u x i n 2

n/cm - s e c , and t i s t ime i n s e c c n d . ~ . For u n i a x i a l t e n s i o n - - - - & / a = C / O o and f o r p u r e s h e a r C / O = y / 3 ~ .

BNWL- 1328

6 . R a d i a t i o n E f f e c t s on Absorbing M a t e r i a l s f o r C o n t r o l Rods*

A. L . P i t n e r (AOO)

10 C o r r e c t e d B burnup l e v e l s , de te rmined by mass s p e c t r o -

m e t r i c a n a l y s i s , have been a p p l i e d t o boron c a r b i d e g a s

r e l e a s e d a t a t h a t were o b t a i n e d from t h e r m a l r e a c t o r i r r a d i a -

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

Table 7 . 2 . These a c t u a l burnup v a l u e s a r e h i g h e r t h a n t h o s e

which were c a l c u l a t e d from r e a c t o r o p e r a t i o n s d a t a , s o t h e

r e p o r t e d gas r e l e a s e f r a c t i o n s a r e c o r r e s p o n d i n g l y lower .

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

(1) The amount o f g a s r e l e a s e d i n c r e a s e s w i t h i n c r e a s i n g

i r r a d i a t i o n t e m p e r a t u r e . (2) Gas r e l e a s e i n t h e powders

a p p e a r s t o be independen t o f packing d e n s i t y b u t i n t h e

p e l l e t s , r e l e a s e v a r i e s i n v e r s e l y w i t h sample d e n s i t y .

TABLE 7 . 2 . C o r r e c t e d 'OB B u r n u p L e v e l s

Sample Form Temperature 'OB Burnup Gas R e l e a s e

1- 1 60% TD Powder 550 O F 4.68% 15 .6% 1 - 6 60% TD Powder 700 O F 4 . 2 4 % 28.3%

1- 7 80% TD Powder 600 O F 4.30% 1 4 . 9 % 1- 8 80% TD Powder 605 O F 4 .35% 1- 2 80% TD Powder Leaker 3.67% 1- 9 80% TD Powder 715 O F 4 .38% 25.6%

1-10 65% TD P e l l e t 865 O F 4 .44% 54.1% 1- 3 65% TD P e l l e t Leaker 3.76%

1- 4 90% TD P e l l e t 725 O F 3 .84% 27.7% 1-11 90% TD P e l l e t 860% 4.61% 1 - 1 2 90% TD P e l l e t 1120 O F 4 .64% 27.8%

1 - 1 3 99% TD P e l l e t 865 O F 4 .67% 11 .6% 1-14 99% TD P e l l e t 870 O F 4 .69% 1- 5 99% TD P e l l e t 1035 O F 3 .91% 20.9% 1- 15 99% TD P e l l e t 1130 O F 4 . 7 1 %

* R e p o r t e d by D. E . Mahagin ( 7 2 4 )

7.25

The g a s r e l e a s e measured f o r t h e 65% TD p e l l e t

(Sample 1 - 1 0 ) i s u n e x p e c t e d l y h i g h , b u t c o u l d n o t b e checked

because t h e c a p s u l e c o n t a i n i n g t h e o t h e r 65% TD p e l l e t l e a k e d

w a t e r . Two more s u b a s s e m b l i e s c o n t a i n i n g s i m i l a r samples a t

h i g h e r burnups have r e c e n t l y been d i s c h a r g e d and w i l l p r o v i d e

a d d i t i o n a l i n f o r m a t i o n on t h e b e h a v i o r of boron c a r b i d e a t

e l e v a t e d t e m p e r a t u r e s . One subassembly , o p e r a t e d a t tempera-

t u r e s of 500-750 OF, i s e s t i m a t e d t o have 'OB burnups of

~ 7 % , and t h e o t h e r , o p e r a t e d a t 550-1200 OF, i s e x p e c t e d

t o have r e a c h e d burnup l e v e l s o f > l o % .

7 . Image Enhancement

B . R . Hayward (723)

The p u r p o s e of t h i s t e c h n i q u e i s t o i n c r e a s e t h e d a t a

o u t p u t from o r d i n a r y p h o t o g r a p h i c n e g a t i v e s . k t o p i c a l r e p o r t

on image enhancement r e s u l t s r e l a t e d t o t h e FFTF Fue l Develop-

ment Program i s i n t h e f i n a l s t a g e s of c o m p l e t i o n . T h i s r e p o r t

d e s c r i b e s t h r e e image enhancement p r o c e s s e s t h a t show promise

( a ) p h o t o g r a p h i c (b) o p t i c a l and ( c ) computer . E x c e l l e n t

examples a r e i n c l u d e d t h a t show t h e c a p a b i l i t i e s of t h e p r o c e s s e s ,

however a l l o f t h e examples a r e n o t r e l a t e d t o m a t e r i a l s

t e c h n o l o g y . S i n c e image enhancement has been p r i m a r i l y a s p a c e

t echno logy program t h e r e has been l i m i t e d examples i n t h e n u c l e a r

m a t e r i a l s a r e a . Through t h e e f f o r t s of B a t t e l l e - N o r t h w e s t image

enhancement i s now b e i n g s u c c e s s f u l l y used by EBR-I1 on n e u t r o n

r a d i o g r a p h s o f i r r a d i a t e d f u e l p i n s . I t i s b e i n g u s e d t o d e t e c t

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

r e g i s t e r d i m e n s i o n a l changes a s s m a l l a s 0.0005 i n c h e s .

A d d i t i o n a l work i s i n p r o g r e s s a t BNW t o e v a l u a t e t h e

c a p a b i l i t i e s of t h e o p t i c a l p r o c e s s . The r e s u l t s a r e p r e l i m i n a r y

b u t a p p e a r v e r y e n c o u r a g i n g .

C H A P T E R V I I I . F U E L S R E C Y C L E

F U E L TECHNOLOGY

1. Fuel Vendor P r e q u a l i f i c a t i o n

H . T . B l a i r and J . E . Sammis (731)

Three c o n t r a c t o r s , Babcock and Wilcox, NUMEC, and United

Nuclear, a r e engaged i n a f u e l vendor p r e q u a l i f i c a t i o n program

which i s d i r e c t e d toward produc t ion of sma l l l o t s of f u e l

p e l l e t s and f u e l p i n s . During t h e r e p o r t i n g p e r i o d t h e work

i n s t r u c t i o n s f o r i n s p e c t i o n of f u e l p e l l e t s and p i n s a t BNW

were completed and approved. These i n s t r u c t i o n s r e q u i r e t h a t

ana lyses be randomized i n a manner t o e l i m i n a t e any sou rce

b i a s .

A shipment of 50 p r e q u a l i f i c a t i o n f u e l p i n s was r ece ived

from one vendor and i n s p e c t i o n work has begun. Nondestruc-

t i v e t e s t i n g equipment i n t h e demonstra t ion f a c i l i t y was

used t o l e a k check a l l 59 p i n s . A s t a t i s t i c a l sample of 15

p i n s was gamma scanned and checked wi th an a i r gage f o r o u t -

s i d e p r o f i l e . The f i f t e e n sample p i n s were then opened f o r

i n t e r n a l component i n s p e c t i o n and sampling f o r chemical ana ly -

s e s . A l l 30 end cap welds from t h e sample p i n s were submi t ted

f o r me ta l l og raph ic examination.

2 . UO, I n s u l a t o r P e l l e t F a b r i c a t i o n - W . E . Warden (733)

Dimensional requirements f o r uranium d iox ide p e l l e t s f o r

p i n s f o r subassemblies PNL-9, 10 , and 11 a r e a d iameter of

0.194 + 0.0015 i n . and a l e n g t h o f 0.4 + 0.1 i n . The uranium

d iox ide i s s p e c i f i e d a s n a t u r a l enrichment.

Two p roces se s which produced accep tab l e i n s u l a t o r p e l l e t s

were (1) 2 w t % Carbowax added i n a s l u r r y of 20,000 p s i p r e s lug

and 30,000 p s i f i n a l p r e s s , and ( 2 ) 20,000 p s i g p re s lug of

a s - r e c e i v e d powder, d ry a d d i t i o n of 0 .3 w t % S t e r o t e x , and

30,000 p s i f i n a l p r e s s (Table 8 .1 ) .

TABLE 8.1. I n s u l a t o r P e l l e t P roces se s

Diameter Va r i ab l e Hourg lass ing , i n . Length, i n .

P re s lug +

0 .3 w t % S t e r o t e x 0 . 0 0 4

Pres l ug +

2 w t % Carbowax 0 . 0 0 5

The t a p e r and hou rg l a s s ing of t h e p e l l e t s remained approx i -

mately c o n s t a n t over t h e range of v a r i a b l e s examined. There-

f o r e , p e l l e t s produced by e i t h e r of t h e two accep tab l e p roces se s

w i l l r e q u i r e g r ind ing .

3. Off-Gas Versus Densi ty of Mixed Oxide P e l l e t s

M . J . Barr (731)

Analys i s of d a t a from e a r l i e r experiments and from t h e

r e c e n t l y completed f r a c t i o n a l f a c t o r i a l experiment showed t h a t

o f f - g a s q u a n t i t y and t h e percen tage of t h e o r e t i c a l d e n s i t y

a r e i n v e r s e l y r e l a t e d . The model equa t ion determined from

computer a n a l y s i s of l i m i t e d d a t a w i t h i n t h e 75 t o 89% range

of t h e o r e t i c a l d e n s i t y i s :

where

3 Y = o f f - g a s i n cm /g

Bo = a c o n s t a n t depending on b inde r type ( 0 - i n t e r c e p t )

B1 = a c o n s t a n t depending on b i n d e r type ( s lope)

X = p e r c e n t t h e o r e t i c a l d e n s i t y

E = conf idence band r e l a t e d t o b i n d e r type and f a c t o r

d e s i r e d .

An example of va lues ob t a ined f o r t h e c o n s t a n t s a r e a s

fo l lows : Constant Value

E (95% l e v e l ) % O . 74

However, a d d i t i o n a l d a t a from o t h e r development experiments

i n d i c a t e t h a t t h e o f f - g a s - d e n s i t y r e l a t i o n s h i p i s n o t l i n e a r ,

and va lues from s i n t e r e d p e l l e t s i n t h e 90 t o 95% t h e o r e t i c a l

d e n s i t y range do n o t f i t t h e curve . I n a d d i t i o n , v a r i a t i o n s

i n b inde r a d d i t i o n technique and i n d e n s i t y c o n t r o l methods

(such a s h igh p r e s s u r e p r e s l u g o r p r e s i n t e r i n g ) a r e a l s o

expected t o a f f e c t t h e equa t ion . Add i t i ona l d a t a a r e be ing

assembled i n an e f f o r t t o develop a more g e n e r a l equa t ion .

4 . Pu02 S i n t e r a b i l i t y Tes t i ng

M . J . Barr (731)

Table 8.2 shows t h e r e l a t i v e s i n t e r a b i l i t y of Pu02 from

t h e t h r e e sources c u r r e n t l y be ing cons idered f o r f a s t r e a c t o r

f u e l . Of t h e t h r e e source powders, c a l c i n e d o x a l a t e Pu02 was

t h e most d i f f i c u l t t o p r e s s as a s i n g l e oxide . P re s s ing d i f -

f i c u l t y was evidenced by p e l l e t d iameter v a r i a t i o n , p e l l e t

e j e c t i o n p r e s s u r e , and t h e i nc rea sed dwel l t ime r e q u i r e d .

TABLE 8.2. Sinterability of Various Source Pu02 Powders

S i n t e r e d Density A Diam PuO Source 2- % TD (11.46 g/cml) Densi ty Range Max-Min, i n .

Recalc ined Oxala te Lot #28-3-7 92.30 91.0 - 94.3 0.005

Burned Metal Lot #26-9-5

Calcined N i t r a t e 4 0 0 O C 92.38 91.7 - 92.8 0.0045 650 O C 91.73 90.7 - 93.0 0.003 800 O C 91.54 90.5 - 92.1 0.0035

1000 O C 91.17 90.4 - 91.8 0.003

5 . Fuel F a b r i c a t i o n f o r Tes t Pins f o r I r r a d i a t i o n i n EBR-I1

W. E . Warden (733)

Fuel f a b r i c a t i o n f o r EBR-I1 Subassembly PNL-9 i s i n

p r o g r e s s . This f u e l c o n s i s t s of 30% enr iched 2 3 5 ~ i n t h e

EBR-I1 t e s t composit ion of 7 5 % U02-25% P u 0 2 Four ki lograms

of b lended mixed oxide powder were p rocessed t o f u e l p e l l e t

p r e s s i n g accord ing t o the flow c h a r t (Figure 8.1) which was

e s t a b l i s h e d a f t e r a n a l y s i s of t e s t d a t a from 3 kg of 65%

e n r i c h e d 2 3 5 ~ and 1 kg of 30% enr iched 2 3 5 ~ f u e l . P r e s s i n g

and s i n t e r i n g of approximately 100 t e s t p e l l e t s r e s u l t e d i n

l e s s d e n s i f i c a t i o n than a n t i c i p a t e d .

B . C L A D D I N G T E C H N O L O G Y

1. LMFBR Fuel and Cladding Informat ion Center

J . R . Shober and B. R . Hayward (723)

The LMFBR Fuel and Cladding Informat ion Cente r , a d a t a

s t o r a g e , r e t r i e v a l and a n a l y s i s sys tem, was des igned t o con-

t a i n d a t a f o r a l l LMFBR type f u e l p i n s and s e l e c t LMFBR core

m a t e r i a l s . I t p r e s e n t l y c o n s i s t s of f i v e major s e c t i o n s :

a c l add ing f a b r i c a t i o n f i l e , a f u e l f a b r i c a t i o n f i l e , an

i r r a d i a t i o n h i s t o r y f i l e , a p o s t i r r a d i a t i o n examinat ion f i l e ,

and an exper imenta l p i n f i l e . Two major and two minor s e c -

t i o n s w i l l be added l a t e r . These w i l l i n c lude a f u e l p i n

f a b r i c a t i o n f i l e , a f u e l p i n subassembly f a b r i c a t i o n f i l e , a

documentation f i l e , and a s p e c i f i c a t i o n s f i l e .

Cladding f a b r i c a t i o n d a t a a r e being s t o r e d i n t h e sys tem

as t h e d a t a becomes a v a i l a b l e t o t h e c e n t e r . Cladding d a t a

a r e being s u p p l i e d t o Ba t te l l e -Nor thwes t i n t h r e e c a t e g o r i e s :

Cladding purchased a f t e r January 1969.

Cladding now i n t e s t t h a t was purchased be fo re January 1969.

Cladding purchased be fo re January 1969 and used i n t e s t s

completed i n t h e i n t e r i m .

S C R E E N I N G

( B L E N D I N G )

C R O S S B L E N D I N G

+ / D R Y I N G P.ND \

G R A N U L A T I O N 1 \

* P R E S L U G

I P R E S S I N G

FIGURE 8.1. Process Diagram for PNL-9, 10, and 11 Fuel Pellets

An i n t e r i m f u e l p i n f i l e was completed and r e a d i e d t o

r e c e i v e d a t a . Data a r e being compiled from publ i shed sou rces

and t r a n s f e r r e d t o d a t a i n p u t forms. T h i r t y a d d i t i o n a l t e s t s

were added t o t h e a u s t e n i t i c s t a i n l e s s s t e e l mechanical

p r o p e r t i e s f i l e b r ing ing i t s t o t a l t o 2 4 4 7 . The c r eep

p r o p e r t i e s d a t a f i l e now con ta in s d a t a from 2 4 7 t e s t s , 148

of which were added t h i s p a s t month. An o r d e r f o r t e n s i l e

d a t a from Atomics I n t e r n a t i o n a l was p a r t i a l l y f i l l e d . A

t o t a l of 180 s t r e s s versus s t r a i n curves was prepared from

90 experiments and forwarded t o them.

2 . Eva lua t ion of X-Ray Fluorescence Method f o r V e r i f i c a t i o n

of Al loy Composition

The X-ray f l uo re scence technique was used t o v e r i f y t h e

c l a s s i f i c a t i o n of s t a i n l e s s s t e e l samples a s e i t h e r 304 o r

316. Known a l l o y samples were used a s c o n t r o l s . Comparison

c h a r a c t e r i s t i c molybdenum Ka peaks were used a s t h e determin-

ing f a c t o r . Although t h e a n a l y s i s i s q u a l i t a t i v e , e f f o r t s

a r e be ing made t o add a q u a n t i t a t i v e a s p e c t through more

s t r i n g e n t c a l i b r a t i o n a g a i n s t known s t a n d a r d s . This method

of cu r so ry m a t e r i a l a n a l y s i s w i l l never r ep l ace t h e more

thorough, r e l i a b l e a n a l y t i c a l methods ; however i t adds

ano the r t o o l t o t h e QA f u n c t i o n where r a p i d s c r een ing i s

r e q u i r e d . Figure 8.2 shows how comparisons were made.

3. Eddv Cur ren t Cladding T e s t e r

H. G . Powers (740)

Proof o f p r i n c i p l e was achieved f o r an eddy c u r r e n t c l a d -

ding t e s t e r pancake c o i l technique w i t h s e q u e n t i a l sampling

of t h e c o i l s i g n a l s . Nine p a i r s of pancake c o i l s were used.

The s e q u e n t i a l sampling c i r c u i t r y (count ing , decoding and

analog g a t i n g c i r c u i t s ) was des igned and breadboarded. The

e n t i r e system was a c t i v a t e d . The system func t ioned accord ing

t o t h e d e s i r e d p r i n c i p l e . Future e f f o r t s w i l l be made t o reduce

t h e t r a n s i e n t s caused by t h e swi tch ing c i r c u i t s and t o develop

a s u i t a b l e readout dev ice . 8.6

Known 316 SS Alloy Note Mo K a Line (2-3% Mo)

Known 304 SS Alloy Note absence of Mo K a Line

L-37 Sample L-38 Sample

FIGURE 8 . 2 . V e r i f i c a t i o n That Samples Were Not 316 SS Alloy Based on Molybdenum Content and Assoc ia ted K a L ines

4. Cladding Procurement and Development

J . C . Tverberg , R . J . Lobs inger , and R . C . Aungst (721)

Histograms p r epa red from t h e eddy c u r r e n t d a t a o b t a i n e d

on l o t s o f t ub ing produced commercial ly by two d i f f e r e n t

p r o c e s s e s show t h e b e n e f i t of s p e c i a l hand l i ng du r ing t h e

f a b r i c a t i o n of t ub ing . F igure 8 .3 i s a h i s togram of t u b i n g

produced by a conven t i ona l tube drawing p roce s s wh i l e F ig -

u r e 8.4 i l l u s t r a t e s a h i s togram produced by a p roce s s employing

thorough c l e a n i n g between every f a b r i c a t i o n p a s s and u se o f

f r e s h drawing l u b r i c a n t s f o r each o p e r a t i o n .

D I S T R I B U T I O N O F E D D Y - C U R R E N T I N D I C A T I O N S - >0.001 i n .

6 i

M E A N 3 . 6 7 - E......... ......... ......... .......... .......... ......... .......... ......... .......... ......... .......... ......... .......... ......... .......... ......... .......... ......... .......... ......... - f....:::....... .......... .......... ....................................... .................-7 ......... ....................................... .......... ....................................... ................... ........................................ ................... ........................................ ................... ........................................ ......... C ......... .................... ....................

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

0 1 2 3 4 5 6 7 8 9 9t

N U M B E R O F I N D I C A T I O N S P E R T U B E

P R O C E S S : 20 m i n B R I G H T E T C H , 2 B A R D R A W S O N G R O U N D M A N D R E L , F I N A L P L U G D R A W

N O R M A L I Z E D I N T E G R A T E D A R E A : 33

R A T I N G : 6

FIGURE 8 . 3 . Histogram of SS Tubing Produced by a Conventional Tube Drawing Process

BNWL- 1 3 2 8

N U M B E R OF INDICATIONS PER TUBE

-

LOT: 9034901

M E A N = 1.46

NORMALIZED INTEGRATED AREA: 13.2

FIGURE 8 .4 . Histogram o f Tubing Produced by t h e S p e c i a l P r o c e s s

................. ................. ......... ................... ................................. ....................... .................... ................................. ....................... ................... ................................. ...................... ................... ................................. ...................... ................... ................... .............. ...................... ................... ................................. ...................... ................... ................... ........... .................... e........... .................. ................... ................... .................. .................. ................... ...................... ............... .................. ................... ...................... ............... ................... .................. .................. :................-...-.....a. .................. .................. ............................. .................. ................... .............. ............................. ................... ..................................... .................. ...................

....

........ ........ :.:.:.:.

...................................... ................... ................... .............. ............... .....-.-.: ~.... . . . . . . .... ................ ................... .................... , ................... ..................... , .................. .................... .................. ....................

C . F U E L P I N TECHNOLOGY

1. Fuel P in End Closure Welding Development

R . M . Crawford (733)

P a r t of a s t udy t o determine t h e e f f e c t of end cap machin-

i n g t o l e r a n c e s on t h e f i n i s h e d weld was completed. Three end

cap v a r i a t i o n s were examined a s fo l l ows :

The e f f e c t of vary ing t h e weld l i p t h i cknes s between

0 . 0 1 0 and 0.020 i n . ( see Figure 8 .5 , dimension A).

The e f f e c t of vary ing t h e weld l i p d iamete r between

0.208 and 0.228 i n . ( see Figure 8 .5 , dimension B ) .

The e f f e c t o f vary ing t h e c l e a r a n c e between end cap and

tube from 0.0005 t o 0.003 i n .

A l l of t h e samples i n each group ( a t o t a l of 104 welds) were

welded, measured, and radiographed i n s i x p o s i t i o n s . A l l of

t h e samples met e s t a b l i s h e d FTR p i n weld c r i t e r i a by r a d i o -

g r a p h i c examinat ion. The f i n i s h e d diameters ranged from

0.230 i n . ( t h e same a s t h e tube OD) t o 0.234 i n . Two weld

samples from each dimensional v a r i a t i o n (42 welds) were

examined m e t a l l o g r a p h i c a l l y t o determine t h e e f f e c t of t h e

machining t o l e r a n c e s on t h e p e n e t r a t i o n and t h r o a t t h i c k n e s s .

A l l of t h e welding parameters were h e l d c o n s t a n t du r ing

t h e t e s t i n o r d e r t o g e t only t h e e f f e c t of t h e dimensional

change on t h e f i n i s h e d weld. A l l of t h e samples examined

m e t a l l o g r a p h i c a l l y were accep tab l e welds and had a t l e a s t one

wa l l t h i cknes s a t any p o i n t and no i n d i c a t i o n of c r a c k s ,

p o r o s i t y , o r o t h e r i r r e g u l a r i t i e s . Meta l lographic examina-

t i o n r evea l ed t h a t t h e p e n e t r a t i o n i s a f f e c t e d by d iamete r and

th i cknes s of t h e weld l i p . A s t h e weld l i p d iameter i n c r e a s e s

from 0.208 t o 0.228 i n . t h e weld p e n e t r a t i o n i n c r e a s e s from

0.046 t o 0.060 i n . and t h e width of t h e weld decreases from

0.080 t o 0.050 i n .

FIGURE 8.5. Refe rence FFTF F u e l P i n End C l o s u r e Weld P e n e t r a t i o n

The weld c o n f i g u r a t i o n v a r i e s from 0.033 i n . p e n e t r a t i o n

by 0.063 i n . wide when t h e weld l i p i s 0.010 i n . t h i c k t o

0.060 i n . p e n e t r a t i o n by 0.056 i n . wide when t h e weld l i p

i s 0.020 i n . t h i c k .

D. F U E L S U B A S S E M B L Y T E C H N O L O G Y

1. CCTL Mark I T e s t -4ssembly C o m p r e s s i b i l i t y T e s t s

D . E . B lahn ik and R . B . Baker (732)

The o b j e c t i v e o f t h e compress ion t e s t s was t o d e t e r m i n e

t h e s p r i n g i n e s s t h a t e x i s t s w i t h i n a Mark I assembly bund le

when compressed s y m m e t r i c a l l y from a maximum d u c t s i z e t o

beyond t h e o r e t i c a l t i g h t n e s s . The l o a d on t h e s i m u l a t e d

d u c t w a l l was t o be de te rmined a s a f u n c t i o n o f a c r o s s - t h e -

f l a t s d imens ions .

The CCTL Mark I f u e l assembly was s u b j e c t e d t o compress ion

t e s t s i n which a l l s i x s i d e s o f t h e bund le were advanced

inward i n e q u a l inc rement s ( m a i n t a i n i n g a r e g u l a r hexagona l

geometry) o v e r a f o u r f o o t span o f t h e bund le . The bund le

was compressed w h i l e i n t h e v e r t i c a l p o s i t i o n t o minimize t h e

e f f e c t of g r a v i t y . One s i d e o f t h e t e s t a p p a r a t u s had a two

f o o t l o a d measurement s e c t i o n s o t h a t d u r i n g bund le compres-

s i o n o r decompress ion t h e s i d e l o a d c o u l d be measured a s a

f u n c t i o n o f hexagona l s i z e .

The r e s u l t s fo l lowed a p a t t e r n t h a t was e x p e c t e d b a s e d

upon p r e v i o u s d a t a . There i s a r e l a t i v e l y f l a t s l o p e up t o

t h e p o i n t where t h e o r e t i c a l t i g h t n e s s o f t h e bund le o c c u r s .

Bundle S p r i n g i n e s s - When a t i g h t b u n d l e , s u c h a s Mark I , i s i n t h e v e r t i c a l p o s i t i o n , t h e f u e l p i n s cannot bow towards t h e c e n t e r . T h e r e f o r e , most o f t h e o u t e r p i n s a r e f o r c e d outward by a combina t ion o f t h e i r own n a t u r a l bow and t h e f o r c e s t r a n s m i t t e d by t h e naturaZ bow o f i n t e r n a l p i n s . When a b u n d l e i s compressed t o t h e o r e t i c a l t i g h t - n e s s a l l o f t h e n a t u r a l s p r i n g i n e s s i s d i s p e r s e d . I f a b u n d l e i s compressed beyond t h e o r e t i c a l t i g h t n e s s , t h e f u e l p i n s a c t a s a combina t ion o f l e a f and t o r s i o n s p r i n g s .

2 . Bundle T h e o r e t i c a l T i g h t n e s s - T h e o r e t i c a l p o i n t a t which a l l f u e l p i n s and w i r e s are compressed t i g h t l y t o g e t h e r w i t h o u t any d e f o r m a t i o n o f t h e bund le components . There i s no outward d i s p l a c e m e n t due t o naturaZ bow o f t h e f u e l p i n s and n o gaps be tween w i r e s and f u e l p i n s .

Then, i n a narrow band i n t h e t h e o r e t i c a l t i g h t n e s s r a n g e ,

t h e r e i s a t r a n s i t i o n i n t o h i g h e r s p r i n g c o n s t a n t s which

p r o b a b l y e x t e n d w e l l beyond 250 l b / f t / s i d e o f t h e bund le .

The t e s t a p p a r a t u s used was des igned f o r a 250 l b / f t / s i d e

l o a d l i m i t , s o t h e compress ion t e s t r u n s were s t o p p e d a t

t h a t p o i n t .

CHAPTER I X . PHYSICS

A . C O R E PHYSICS

1. S t a b i l i t y Analys is of t h e Fas t Tes t Reactor

James R. Sheff (831)

The s t a b i l i t y a n a l y s i s of t h e Fas t Tes t Reactor (FTR)

m e r i t s d i s c u s s i o n because f e a t u r e s of t h e r e a c t o r d i f f e r e n t i a t e

i t from o t h e r f a s t r e a c t o r s . The most s i g n i f i c a n t d i f f e r e n c e s

a r e t h e l a r g e s i z e , 1033 l i t e r s , and h igh power l e v e l , 400MWt.

The Doppler e f f e c t r e p l a c e s t h e expansion e f f e c t s a s t h e

dominant mechanism prov id ing t h e prompt shutdown c o e f f i c i e n t .

The nega t ive Doppler c o e f f i c i e n t i s -3 .2 x pe r " C .

A s t anda rd lumped feedback pa th model invo lv ing a l i n e a r -

i z e d s e t of ma t r ix equa t ions d e s c r i b i n g t h e neu t ron i c s and

feedback mechanisms i s used f o r t h e a n a l y s i s . The approach

i s nove l , however, i n t h e d e s c r i p t i o n of t h e r e a c t o r v i a more

than a s i n g l e node s o t h a t such e f f e c t s a s t h e s p a t i a l depen-

den t sodiuin void c o e f f i c i e n t could be adequa te ly t r e a t e d .

The sodium void c o e f f i c i e n t i s p o s i t i v e a t t h e co re c e n t e r bu t

becomes nega t ive i n t h e o u t e r reg ions of t h e co re .

The r e s u l t i n g feedback f u n c t i o n f o r t h e FTR r e f e r e n c e

c o r e , t h e s o l i d l i n e i n F igure 9 . 1 , i s s een t o be s t a b l e s i n c e

m u l t i p l i c a t i o n by t h e zero power t r a n s f e r f u n c t i o n causes only

a r a t h e r smal l ang le c lockwise r o t a t i o n i n t h e t h i r d quadran t .

The measurable range from w = 0.006 t o w = 50 i s shown by t h e

ba r s a c r o s s t h e curve.

Extensive pa rame t r i c s t u d i e s have proved t h e system very

s t a b l e . The Doppler c o e f f i c i e n t was reduced by g r e a t e r t han

t e n f o l d i n a l l c a se s showing any tendency toward i n s t a b i l i t y .

The only two ca se s d i scovered which were a b s o l u t e l y u n s t a b l e

a r e shown i n F igure 9.1. Along wi th t h e ze ro Doppler

c o e f f i c i e n t s , i t was necessary t o e i t h e r l e t t h e f u e l

FIGURE 9.1. Phase P l ane P l o t o f Feedback Func t ions . w = 0 . 0 0 6 and 60 r ad / s ec a r e i n d i c a t e d by t h e da shes

- a c r o s s t h e c u r v e s .

=- 0.1

- --- <-- -h

h

0.01 5 - >-

E

7- \,\ I ,--.

\ \ \ \ -

Z Y

z U /' i

t I I \ + 0.001 I

\ 1 , I L

I , , , I 1 1 1 1 I . . a , 1 , 1 l , 1 1

0.01 0.001 0.01 0.1

I I 1 .o

- - - --- FTR, NO DOP., 140 FUEL EXPANSION

-1 .o - - FTR, NO DOP., POSITIVE TUBE EXP.

--- EBR-I1 (EXPER.)

A

expans ion c o e f f i c i e n t go t o z e r o o r i n t r o d u c e a p o s i t i v e

expans ion c o e f f i c i e n t f o r t h e f u e l assembly t u b e s .

C o n d i t i o n a l i n s t a b i l i t y has a l s o been found i n a few c a s e s

n e a r t h o s e p roduc ing a b s o l u t e i n s t a b i l i t y . Power l e v e l s o f

100 t i m e s f u l l power would be r e q u i r e d t o produce i n s t a b i l i t y .

An a n a l y t i c f i t t o t h e EBR-I1 e x p e r i m e n t a l f eedback

f u n c t i o n d a t a i s a l s o shown f o r compar ison . One n o t e s

t h a t t h e b e h a v i o r i s q u i t e s i m i l a r t o t h e z e r o Doppler

c o e f f i c i e n t c u r v e s . T h i s s i m i l a r i t y might b e expec ted s i n c e

EBR-I1 h a s a v e r y s m a l l Doppler c o e f f i c i e n t .

I n c o n c l u s i o n , t h e s t a b i l i t y a n a l y s i s of t h e FTR d i f f e r s

from o t h e r f a s t r e a c t o r s p r i m a r i l y because o f e f f e c t s produced

by i t s l a r g e r s i z e . I n a d d i t i o n , t h e sys t ems s t u d i e d a r e

s t a b l e a t l e a s t t o t h e e x t e n t t h a t t h e model i s a c c u r a t e .

Not i n c l u d e d a t t h i s t ime a r e e f f e c t s of t h e sys t em e x t e r n a l

t o t h e r e a c t o r .

2 . Notes on t h e Use of t h e " Eng inee r ing Mockup" a s a

Nuc lea r Design Tool

R . A . B e n n e t t , S . L . Engstrom, J . V . Nelson , (833)

and P. L . Hofmann (800)

The u s e o f e n g i n e e r i n g mockup, c r i t i c a l expe r imen t s

c o n s t i t u t e s an i m p o r t a n t e lement i n t h e n u c l e a r d e s i g n of

compl i ca ted and n o v e l r e a c t o r s . The g o a l o f t h e mockup

exper imen t i s t o v e r i f y t h e d e s i g n v a l u e s of t h e n e u t r o n i c s

c h a r a c t e r i s t i c s of t h e r e a c t o r .to b e b u i l t . The e x t e n t t o

which t h e p h y s i c a l c h a r a c t e r i s t i c s o f t h e r e a c t o r can be r

a c c u r a t e l y mocked-up i n t h e c r i t i c a l assembly d e t e r m i n e s i t s

v a l u e a s a d e s i g n t o o l . I f o n l y a c o a r s e mockup can be

a c h i e v e d , t h e r e q u i r e d amount o f e x t r a p o l a t i o n and i n t e r -

p o l a t i o n i n c r e a s e s , and t h e u t i l i t y of t h e mockup exper iment

i s g r e a t l y d i m i n i s h e d .

1 . Reac tor DeveZopment Program Progress R e p o r t , A N L- 7 3 9 , October 1 9 6 7 .

In order to assure a useful engineering mockup configura-

tion, detailed experimental planning, including extensive pre-

calculation, is necessary. This calculational activity is

presently underway in order to plan the engineering mockup

experiments for the FTR.

The facilities available for the FTR engineering mockup

experiments are the ANL ZPR assemblies, specifically ZPR-9.

The matrix structures of these facilities are essentially square

and fixed. The platelet inventories of materials are limited

and only a discrete spectrum of compositions are possible.

Figure 9.2 illustrates one possible ZPR arrangement to simulate

the hexagonal FTR geometry, if only whole matzrial drawers can

be used. Each zone in the square lattice mockup, although

slightly different in volume from its FTR counterpart, has the

same mass of materials.

Two-dimensional (x,y), and hexagonal coordinate calculations

were carried out for different reactor conditions. The resulting

multiplication constants are compared in Table 9.1. A comparison of different control rod worths is also shown.

For the configuration shown, the multiplication constants

are consistently higher for the mockup by a few thousandths.

Control strengths in the engineering mockup are consistently

underestimated by 5 to 10%. These calculational trends will

be used in the planning of the engineering mockup experiments

in order to increase their accuracy and consequent utility.

Inverse Multiplication Monitoring of Subcritical Reactivity

Changes in FTR %.

S. L. Engstrom, R. A. Bennett, and V. 0 . Uotinen (833)

It is presently planned that reactivity changes during

refueling of FTR and those occurring during initial steps in

the approaches to critical will be monitored with a portion of

the Low Level Flux Monitoring System. Inverse multiplication

TABLE 9.1. Results of FTR/FTR Engineering Mockup Comparative Calculations

Multiplication Constants

keff

Engineering Configuration Description FTR Mockup

1. Reactor shutdown - all rods in 0.8858 0.8971

2. All safety rods out 0.9538 0.9606

3. All safety and in-core rods out 1.0087 1.0124

4. All safety rods out, asymmetric in-core control rod in 0.9893 0.9939

5. All safety, control, and peripheral control rods out 1.0445 1.0465

Worth(%Ak/k) Calculation Reactivity Engineering

Numbers FTR Mo ckup

All safety rods (3) 1 and 2 8.05 7.37

All in-core control rods (4) 2 and 3 5.70 5.20

One in-core control rod 3 and 4 1.94 1.84

All peripheral control rods (15) 3 and 5 3.40 3.21

Total control strength 1 and 5 17.15 15.91

Total in-core control strength 1 and 3 13.75 12.57

t e c h n i q u e s a r e t o be u s e d . One can v e r y r e a s o n a b l y e x p e c t t h a t

changes i n f u e l l o a d i n g s of d r i v e r s o r t e s t l o o p s and c o n t r o l

mot ions n e a r any of t h e e l emen t s of t h e m o n i t o r i n g sys tem w i l l

s e r i o u s l y p e r t u r b t h e i r r e s p o n s e s and u l t i m a t e l y produce r e s u l t s

t h a t must b e c o r r e c t e d .

T h i s problem has been i n v e s t i g a t e d e x p e r i m e n t a l l y i n ZPR-I11

Assembly 56B by Argonne N a t i o n a l L a b o r a t o r y a s a p a r t o f t h e

B a t t e l l e - N o r t h w e s t FTR C r i t i c a l Exper iments Program. C o n t r o l

r o d s were i n s e r t e d a t t h e boundary o f t h e c o r e o f t h e assembly

and t h e i n v e r s e m u l t i p l i c a t i o n r a t e was moni to red w i t h s e n s o r s

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

o u t s i d e t h e ZPR-I11 m a t r i x a p p r o x i m a t e l y 100 cm from t h e c o r e

c e n t e r l i n e and a p p r o x i m a t e l y 60 cm from t h e n e a r e s t c o n t r o l zone.

The a r e a l p r o f i l e and c o u n t e r p o s i t i o n s a r e shown i n F i g u r e 9 . 3 .

Values o f t h e r e a c t i v i t y w o r t h s of r o d s d i f f e r e d by a s much a s

1 2 % f o r t h e v a r i o u s s e n s o r s .

I n an a t t e m p t t o i d e n t i f y which c o u n t e r was " b e s t" a s e r i e s

o f s u b c r i t i c a l c a l c u l a t i o n s were per formed w i t h a two d i m e n s i o n a l

I d i f f u s i o n t h e o r y model of t h e v a r i o u s e x p e r i m e n t a l c o n f i g u r a t i o n s .

The d i s t r i b u t e d e x t e r n a l s o u r c e o f n e u t r o n s due t o a - n r e a c t i o n

p i n Z 4 0 ~ ~ was r e p r e s e n t e d t o y i e l d a b s o l u t e f l u x l e v e l s . The

a c t u a l c a l c u l a t e d changes i n t h e s u b c r i t i c a l m u l t i p l i c a t i o n

c o n s t a n t s were compared w i t h v a l u e s i n f e r r e d from changes i n

2 3 5 ~ and 'OB r e a c t i o n r a t e s t h r o u g h o u t t h e c o r e . The r e s u l t s

a r e p r e s e n t e d i n T a b l e 9 . 2 f o r t h e s p e c i f i c e x p e r i m e n t a l s e n s o r . l o c a t i o n s and a r e shown g r a p h i c a l l y i n F i g u r e 9 . 3 f o r a l l

p o s s i b l e s e n s o r l o c a t i o n s . The t a b u l a t e d v a l u e s show t h a t a

s e n s o r s l o c a t e d a t t h e c o r e c e n t e r a r e " b e s t" . The c a l c u l a t e d

l i n e s o f " equa l o v e r - e s t i m a t i o n , " shown i n F i g u r e 9 . 3 , i l l u s t r a t e

t h a t any o t h e r p o s i t i o n i s worse .

1 . ANL R e a c t o r Deve lopment Program P r o g r e s s R e p o r t , A N L- 7 5 7 7 , Apr i l- May 1 9 6 9 .

2.771 8.313 13.855 19.397 24.939 30.481 36.023 41.565 47.107 52.649 58.191 63.733 69.275 74.817 80.359 85.901

X- D I S T A N C E , crn

FIGURE 9.3. Assembly 56B Quarter Core Areal Profile. Lines show the % over-estimation of the worth of four large B4C rods.

'u [I) 0 rd

a 4 ~ C U a rd

a, [I) h

e 0 w r-. rl r. o v Dl a Ln d ~t - 1 s m cn 0 0 0

rl 0 0 rl d d a

a, U C C,

'4-4 E : k 5

0 'ud k rd

Oa, a > Nc, 0 6 - 4 c U a , m a , 507

u a -4 a, a, a, ~ a , a c, k a

0 C a , C U U4J U k id ha, O d 5 C 0 c, '4-4

7U a d

I 0 Grd zc, U U

d cd tJ n

6 3: Q, H

E - .7lz a0 ktJ cnd a, k +I

Comparisons of calculated values with the "best" experi-

mental results show an additional 5% disagreement or c/e

ratios of approximately 1.05 for both small and large rods.

4. Central Fuel and Peri~heral Control R i n ~ Reactivity

Worths in the FTR-2 Critical

R. A. Bennett, and J. V. Nelson ( 8 3 3 )

Experimental measurements have been made of reactivity

worths of segments of a peripheral control ring of B4C-steel-Na

and large fuel assembly-size plutonium samples from the core of

a full scale simulation of the FTR. These experiments were

performed by Argonne National Laboratory personnel in ZPPR

Assembly-1, the FTR-2 critical in the FFTF Critical Experiments

Program.

An areal profile of FTR-2 is shown in Figure 9.4 which

illustrates the arrangement of the core, central depleted zone,

peripheral control ring, and reflector. Additional detailed

descriptions of the experimental arrangements have been

reported. Reactivity measurements were made in alternating

steps in which fissile plutonium was removed from the core and

replaced by fertile uranium. These reactivity decreases were

approximately compensated for by the removal of segments of the

control ring, which in turn was replaced by reflector composi-

tion. The sequence of the experiments is indicated by the

numerical scheme shown in Figure 9.4, e.g., fissile material

was replaced first in Zone 1 and control material was replaced . second in Zone 2. The experimental results and corresponding

diffusion theory values were presented in Table 9 . 3 . v

Comparisons of the experimental data and calculated values

indicate that the neutronics design requirements of the FTR

1 . A N L R e a c t o r Deve lopment . -.. Program P r o g r e s s R e p o r t , A N L- 7 6 3 2 , O c t o b e r 1969 .

FIGURE 9.4. FTR-2, ZPPR-1-70, Areal Profile

[I]

3 0 m o n 0 - - 0 - = 3 = r m a, " .- 3 t n , 3 b 0 3 N 0 m U m = 3 3 5

4 LO' 3 0 3 0 0 N 0 0 W 3 C , = - =

, L O . . " d d d d d d d d & ; d ; = ; . ; ; ; ;

X U Y m c o m - O N U 0 r i 3 - 3 3 - 4 3

W : z Q 0 r f 3 o m ~ r ? ~ i o m s r ~ m r o . . . . . . . . . . . . . . . m a, " CL

3 0 3 3 0 0 i 0 3 ~ 3 + 3 ~ 3 + , , , , i , , , , ,

should reflect approximately '10% uncertainty (cf Co1.13) in

the calculated values of peripheral control rod strengths; and

approximately a 30% over-calculation (cf Col. 10) of the

reactivity worths of centrally located changes in fissile pluto-

nium densities arising from changes in the compositions of test

loops or fuel burnup. These analyses also indicate that the

discrepancy between calculated and measured multiplication

constants, (KE - KC) (cf Col. 7) increases linearly with the

mass of the plutonium test sample. One may infer from this

dependence that the troublesome fractional over-calculation of

reactivity worths of plutonium samples is approximately constant

for sample sizes from zero to 32 kg, the limit of these

experiments.

B . R A D I A T I O N AND SHIELDING

1. Effect of Cobalt Content in Steel on Shield Requirements C. A. Mansius (813)

It is anticipated that a number of radioactive components

from the Fast Test Reactor will require replacement at some

time during the lifetime of the facility. Replacement of large

components such as the core support structure will probably

require fabrication of a shielded container. The purpose of

this study was to determine the effect of the cobalt content

of the stainless steel used in the fabrication of the core

support structure on the shielding requirements during the

removal process.

Only long-lived radioisotopes will influence the shield

requirements, since replacement of the core support structure

would require an extended shutdown period. At the location of

the support structure, the neutron spectrum is relatively degraded

in energy and (n,y) reactions are dominant. Based on half life,

decay energy, and production rate, 6 0 ~ o and 5 9 ~ e will be the

predominant radioisotopes emitted by the support structure

The half life of 6 0 ~ o is 5.2 years and it emits both a 1.17 and

1.33 MeV photon per decay. The half life of 5 9 ~ e is 45 days

and it emits a 1.10 MeV photon in 56% of the decays and a

1.29 MeV photon in 44% of the decays. Because of the compara-

ble photon energies from the two isotopes, the relative gamma

intensity will be essentially independent of the shield

thickness.

The relative radiation intensity from 6 0 ~ o and " ~ e

depends on the cobalt content of the steel together with the

operating and decay history. Figure 9.5 gives the relative

intensity of the two isotopes as a function of operating time

and cobalt content. It is assumed the reactor operates at

400 MW for 75 days and is then shutdown for 25 days. For

this assumed cycle, 5 9 ~ e attains 87% of its saturated value

whereas 6 0 ~ o would reach a maximum of about 60% of its

saturated value (continuous cyclic operation). Figure 9.6

presents the decay curves for the two isotopes.

Calculations indicate that about 5 to 6 in. of lead

will be required to reduce the radi.ation intensity from the

core support structure to a level of about 25 mrem/hr at the

surface of the cask, based on the maximum relative 5 9 ~ e

activity shown in Figure 9.5. About 0.4 in. of lead is

required to effect a factor of 2 change in the radiation

intensity for either the cobalt or iron radiations. The data

in the two figures can be used together with this basic shield

information to estimate the required shield thickness as a

function of operating time, cobalt content, and shutdown time.

In most cases of interest it is found that shielding require-

ments will depend directly on the cobalt content of the steel.

2. Radiation Levels in Heat Transport Cell

W. L. Bunch, C. A. Mansius and D. R. Marr (813)

Access into the FFTF heat transport system (HTS) cells is

desirable to permit inspection and maintenance. Estimates were

D A Y S S I N C E S T A R T U P

FIGURE 9 .5 . Relat ive 59Fe - 6 0 ~ o Gamma I n t e n s i t y

made of anticipated radiation levels within the HTS cells as a

function of various operating conditions to provide information

for the conceptual design. The basic conditions considered are:

(1) entry into the cell following shutdown of the reactor, and

(2) reducing the reactor power and valving off the single HTS

cell of interest to permit decay of 2 4 ~ a , with entry into the

cell following shutdown of the reactor.

After 12 days delay time following shutdown of the reactor

to permit decay of 2 4 ~ a , it is estimated the average radiation

level in the cell will be about 30 mrem/hr because of the long-

lived (2.58 yr half life) 2 2 ~ a in the system. The radiation

level could be significantly higher as a result of corrosion

and fission products in the system. However, it will take

significant operating time for transport of corrosion products

to the cells, and fission product contamination will depend on

the fuel failure history that is experienced.

By operating the reactor at reduced power while one HTS

cell is valved off, it would be possible to reduce or eliminate

the 12 day wait to permit 2 4 ~ a decay. Table 9.4 indicates the

operating-shutdown intervals that would be employed as a function

of valve leakage to maximize plant efficiency. It is assumed

there would be no incentive to continue to operate at reduced

power once the radiation level due to 2 4 ~ a had achieved the

equilibrium value for the specific leakage rate.

To estimate the radiation level in the HTS cell as a

function of valve leakage, it was assumed the point of interest f within the cell was equidistant from all of the sodium within

the cell. The activity of the sodium at any point in the system

was related to valve leakage or flow rate based on time since

leaving the high pressure inlet plenum. The most important

single factor becomes the decay time in transit from the inlet

plenum to the HTS cell. It is obvious that within the cell

significant radiation gradients will exist at low flow

(leakage) rates. Methods are available to include the

exponential variation in source strength from straight pipe

sections; however, it was not deemed necessary to include such

refinement in this study. Detailed calculations can be made

for specific component arrangements and specific points of

interest.

TABLE 9.4. Operating and Shutdown Times to Maximize Plant Efficiency as a Function of Valve ~eakage*

Days 2 4 ~ a 2 4 ~ a Valve Leakage at 2/3 Intensity, Days Intensity, % gpm gph Power R/hr Down R/hr

* Assumes 7 5 , 0 0 0 g a l l o n s i n one HTS c e l l , 1 5 , 0 0 0 g p m f u l l f low r a t e

3. Neutron Attenuation Characteristics of Stainless Steels

D. R. Marr (813)

Summary

The decision to replace Type 304 SS with Type 316 SS in

the duct material as well as in the cladding indicated a need

to examine the relevancy of the existing neutron shielding

calculations which are based on the use of Type 304 SS. This

study provided the following results:

Type 316 SS is a slightly more effective shielding

material than Type 304 SS. Largest differences (up to a

factor of 2) are seen in the lower energy reactions.

Previously reported results based on the use of Type 304 SS

are thus conservative.

The higher shielding effectiveness of Type 316 SS is due to

molybdenum, which is present only in small percentage

amounts, and which has a much higher absorption cross-

section than any of the other components of stainless steel.

The shielding characteristics of stainless steel are not

sensitive to the chromium-nickel content within the ranges

established for Type 316 SS and Type 304 SS.

Most of the difference in neutron attenuation between

Type 316 SS and Type 304 SS is effected in transmission

through the reflector and about half way into the shield.

Discussion

The compositions of Type 316 SS and Type 304 SS are shown

in Table 9.5 together with the composition assumed in this study.

Type 316 SS differs from Type 304 SS in higher nickel content

offset by a corresponding decrease in the chromium content and

by the inclusion of about 2.5% molybdenum, which replaces some

of the iron. Type 316 SS also has a slightly higher density.

For the purpose of this comparison, a one-dimensional

spherical geometry model based on the radial configuration of

concept V-A was selected. This configuration is shown in

Table 9.6. The core barrel dimension was arbitrarily thickened

to 1 ft to study the attenuation in pure stainless steel.

1 . J . G . Y e v i c k . - F a s t R e a c t o r T e c h n o l o g y : P l a n t Des ign . M.I.T. P r e s s , Cambridge, M a s s a c h u s e t t s . p . 4 8 3 .

TABLE 9.5. Weight Percent composition of Type 316 and Type 304 Stainless Steels

T y p e 3 0 4 S S ( 7 . 9 0 g / c m 3 )

Y e v i c k T h i s S t u d y

T y p e 3 1 6 S S ( 7 . 9 8 g / c m 5 )

Y e v i c k T h i s S t u d y

6 1 . 9 2 - 6 8 . 9 2 6 6 . 4 2

< 0 . 0 8 0 . 0

1 6 . 0 0 - 1 8 . 0 0 1 7 . 0 0

1 0 . 0 0 - 1 4 . 0 0 1 2 . 0 0

< 2 . 0 0 1 . 5 0

< 1 . 0 0 0 . 5 0

C 0 . 2 0 0 . 0 8

2 . 0 0 - 3 . 0 0 2 . 5 0

TABLE 9.6. Model Configuration and Composition

O u t s i d e Mater ia l C o m p o s i t i o n ( V o l % ) Z o n e R a d i u s Na SS F u e l V o i d N i

C o r e I 3 8 . 6 c m 3 8 . 8 9 2 9 . 4 0 2 5 . 9 1 3 . 5 3 2 . 2 7

C o r e I1 6 0 . 2 3 8 . 8 9 2 8 . 0 6 2 6 . 2 6 3 . 5 8 3 . 1 2

R e f l e c t o r I 7 2 . 1 4 3 5 . 0 0 3 7 . 2 0 - - - - - - - - - 2 7 . 8 0

R e f l e c t o r I 1 9 6 . 0 3 3 . 0 0 3 3 . 7 0 - - - - - - - - - 3 2 . 3 0

S h i e l d 1 4 4 . 8 3 4 . 0 0 6 6 . 0 0 - - - - - - - - - - - - - -

C o r e B a r r e l 1 7 9 . 3 - - - - - 1 0 0 . 0 0 - - - - - - - - - - - - - -

T w e l v e i n t e g r a l q u a n t i t i e s o f p o s s i b l e s h i e l d i n g i n t e r e s t

w e r e c a l c u l a t e d u s i n g t h e c o n v e r g e d f l u x e s f r o m t h e d i s c r e t e

o r d i n a t e s t r a n s p o r t c o d e ANISN. An S 8 c a l c u l a t i o n w a s m a d e

w i t h ANISN u s i n g t h e HOMSET c r o s s s e c t i o n s o n e a c h o f t h e f o u r

f o l l o w i n g ca ses :

Case I ( 3 0 4 ) - A l l s t a i n l e s s u s e d i n t h i s case w a s

T y p e 3 0 4 S S as d e s c r i b e d a b o v e .

Case I1 (316) - A l l s t a i n l e s s used i n t h i s c a s e was

Type 316 SS a s d e s c r i b e d above .

Case I11 (316A) - A l l s t a i n l e s s used was m o d i f i e d

Type 316 SS having a m o d i f i e d chromium

and n i c k e l c o n t e n t (10% N i , 1 9 % C r ) .

Case I V (316B) - A l l s t a i n l e s s used was Type 316 SS,

b u t w i t h o u t t h e molybdenum.

The r e s u l t s of t h i s s t u d y a r e shown i n T a b l e 9 . 7 where , t a k i n g

Type 316 SS a s a b a s e c a s e , t h e e f f e c t of r e p l a c i n g i t w i t h each

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

S e v e r a l i t e m s s h o u l d be n o t e d :

e There i s l i t t l e e f f e c t i n t h e c o r e .

The 316A c a s e shows t h e r e i s l i t t l e e f f e c t due t o changing

t h e chromium-nickel r a t i o o v e r t h e r a n g e t h a t can be

e x p e c t e d t o encompass v a r i a t i o n s w i t h i n each t y p e s t e e l o r

between t h e two s t e e l s .

e Having exc luded an a p p r e c i a b l e e f f e c t due t o t h e change i n

chromium-nickel r a t i o , c a s e 316B (316 w i t h no Mo) shows

t h a t t h e p r imary d i f f e r e n c e due t o r ep lacemen t of

Type 3 0 4 SS by Type 316 SS i s due t o t h e molybdenum

c o n t e n t of t h e Type 316 SS. A c l o s e check of t h e HOMSET

a b s o r p t i o n c r o s s s e c t i o n s f o r molybdenum shows v a l u e s which

a r e s l i g h t l y h i g h w i t h r e s p e c t t o t h e l a t e s t e x p e r i m e n t a l

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

t h i s s t u d y .

R e a c t i o n s w i t h a s i g n i f i c a n t h i g h energy c o n t r i b u t i o n such

a s 2 3 8 ~ ( n , f ) o r b i o l o g i c a l d o s e do n o t show a l a r g e e f f e c t

due t o Type 316 SS r e p l a c e m e n t . 59 For t h o s e q u a n t i t i e s such a s Co ( n , y ) , which have an

e l e v a t e d low energy r e s p o n s e , t h e r e i s a p o i n t approx ima te ly

midway i n t h e s h i e l d where subsequen t a t t e n u a t i o n i s

r e l a t i v e l y independen t of t h e s t e e l u s e d .

n

d

rH

nn

cd

n

nn

e

WW

U

>>

>

6-

. ...d

...

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66

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acsr>da,ora, -

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mm

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a

4 . ZPPR/FTR-2 S h i e l d Exper iments

E . T . B o u l e t t e (813)

Exper iments i n s u p p o r t of t h e d e s i g n o f t h e F a s t T e s t

Reac to r (FTR) s h i e l d s were conducted a t Argonne N a t i o n a l

Labora to ry i n t h e Zero Power P lu tonium R e a c t o r (ZPPR). The

e x p e r i m e n t a l a r r angement approximated t h e b a s i c f e a t u r e s of

t h e FTR: a 1 0 0 0 - l i t e r , two-zone c o r e su r rounded by a 1 f t t h i c k

n i c k e l r e f l e c t o r and a s t a i n l e s s s t e e l - s o d i u m s h i e l d . Al though

t h e FTR s h i e l d i s su r rounded by an a n n u l a r sodium zone i n which

f u e l and o t h e r r e a c t o r components may b e s t o r e d , t h e ZPPR

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

P r o v i s i o n s were t h e r e f o r e made t o i n c l u d e a s t o r e d f u e l zone i n

t h e e x p e r i m e n t a l s h i e l d . Neutron and gamma d i s t r i b u t i o n s were

measured t h r o u g h o u t t h e c o r e , r e f l e c t o r , and s h i e l d , w i t h and

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

Neutron D i s t r i b u t i o n

The n e u t r o n d i s t r i b u t i o n was o b t a i n e d by measur ing t h e

r e a c t i o n r a t e t r a v e r s e s of 2 3 9 ~ u and 2 3 8 ~ w i t h f i s s i o n c o u n t e r s .

and o f 'OB w i t h a BF3 c o u n t e r . I n a d d i t i o n , Na and Mn f o i l s

were d i s p e r s e d t h r o u g h o u t t h e sys tem and i r r a d i a t e d . These f o i l s

were s e l e c t e d n o t o n l y because o f t h e i r d i f f e r e n t r e s p o n s e

f u n c t i o n s , b u t a l s o because of t h e impact t h e s e r e a c t i o n r a t e s

have on t h e FTR d e s i g n .

The two-d imens iona l d i f f u s i o n t h e o r y code Z D B S ' ~ ) , and t h e

8 o n e - d i m e n s i o n a l d i s c r e t e o r d i n a t e s code ANISN C 2 3 were used t o

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

1 . D . R. Marr. A U s e r ' s Manual f o r 2DBS, A D i f f u s i o n Theory S h i e l d i n g Code, BNWL-2291. B u t t e Z l e - N o r t h w e s t , R i c h l a n d , W a s h i n g t o n . February 1970.

2 . W . W . EngZe. A U s e r ' s Manual f o r ANISN, A One-Dimensionaz D i s c r e t e O r d i n a t e T r a n s p o r t Code w i t h A n i s o t r o p i c S c a t t e r i n g , K-1693. Union Carb ide Corp . , Oak R i d g e , T e n n e s s e e . 1967 .

experimental results. The nuclear data used was extracted from

the HOMSET(~) 31-group transport-corrected cross section set.

The measured and calculated 'OB reaction rate distribution with

no stored fuel in the shield are compared in Figure 9.7.

Similar agreement was found for the other reaction rate

distributions.

Gamma Distribution

The gamma distribution was measured by irradiating

lithium fluoride thermoluminescent dosimeters (TLD1s), which

were dispersed radially and axially throughout the core,

reflector and shield. Dosimeters were irradiated to a

suitable integrated exposure, one set with and one set without

stored fuel in the shield. Light output of each TLD was

measured subsequently and compared to calibrated standards.

The discrete ordinates transport theory codes ANISN and

DOT(^) were employed to calculate the gamma distribution for comparison to the experimental results. A ten-group gamma transport cross section set was generated employing the

code. The energy range of the calculation extended

from 10 MeV down to 0.015 MeV with equal (one MeV) group

widths except for the last group. The volume distributed

1 . D . R . Marr and M . G . Zimmerman. FTR S h i e l d Design Cross S e c t i o n s - - A P a r t i a l E v a l u a t i o n , BNWL-1197. B a t t e l l e - N o r t h w e s t , R i c h l a n d , Washington . 1969.

2 . F . R . Mynat t . Unpubl i shed Data. Union Carbide Corp . , Oak R idge , T e n n e s s e e . [ U s e r ' s Manual f o r D O T , A Two- Dimensional D i s c r e t e O r d i n a t e T r a n s p o r t Code w i t h A n i s o t r o p i c S c a t t e r i n g . ( t o be p u b l i s h e d ) . ]

3 . J . R . Knight and F . R . Mynat t . Unpubl i shed Data. Union Carbide C o r p o r a t i o n , Oak R idge , T e n n e s s e e . [ M U G - A Program f o r Genera t ing Mul t ig roup Photon Cross S e c t i o n s , ( t o be p u b l i s h e d ) ]

R A D I U S , cm FIGURE 9.7. A Comparison of Calculated and Measured (n,ci)

Radial Reaction Rate Distribution in the ZPPR/FTR 2

gamma source was calculated from the neutron flux solution

and included prompt fission gammas, fission product gammas,

and neutron capture gammas. A 2 3 5 ~ prompt fission gamma r 1 \

spectrum"' was employed in the calculation; however, evidence

suggests this spectrum to be a realistic approximation for

2 3 9 ~ u fission also. The fission product gamma spectrum was

generated using the computer code ISOSHLD based on a (3) fission product inventory obtained from the code RIBD .

The neutron capture gamma ray spectra were extracted from

data on thermal neutron capture reported in the literature.

A comparison of the calculated and measured radial gamma

dose distribution is shown in Figure 9.8, based on a S8-P3

ANISN cylindrical calculation with no stored fuel present.

The calculated ten-group gamma fluxes were converted to

roentgens ( 4 ) and normalized to the integrated experimental

exposure. Similar agreement was found at the other elevations.

Overall, the agreement between the calculated and experi-

mental results is believed adequate to permit use of these

techniques and nuclear data compilations in the preliminary

design of the FTR shields. Basis of the relatively consistent

difference between the experimental and calculated gamma

results is being sought.

1 . R . W . P e e l e , W. ZobeZ, and F . C . M a i e n s c h e i n . " S p e c t r u m o f Prompt Gamma Rays from Thermal F i s s i o n o f 2 3 5 ~ , " T r a n s . A m . NucZ. S o c . , voZ . 12 , p . 384. 1969.

2 . C . A . Mans iu s . A R e v i s e d Photon P r o b a b i l i t y L i b r a r y f o r Use w i t h ISOSHLD-111, BNWL-236, Supp lemen t 2 . B a t t e Z Z e - N o r t h w e s t , R i c h l a n d , Wash ing ton , A p r i l 1969.

3 . R . 0 . Gurnprecht. MathematicaZ B a s i s o f Computer Code RIBD, DUN-41 36 . DougZas U n i t e d N u c l e a r , I n c . , R i c h l a n d , W a s h i n g t o n , 1968 .

4 . R e a c t o r P h g s i c s C o n s t a n t s , ANL-5800. Argonne N a t i o n a l L a b o r a t o r y , Argonne , I Z Z i n o i s , J u l y 1963. Second E d i t i o n .

-

0

W

0

n I-

-J

u

=x W

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&

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3

3

I

v,

u

v,

4

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4

ZE v

-

T

A I ,Y -

0

I- 0

W

LL

W

0

0

U

1 n

=x

u

=I-u

I-

WZ

Z

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0

W~

N 1

-

\

I

C H A P T E R X . S A F E T Y

A . S A F E T Y A N A L Y S E S

1. Sodium Fire Studies Involving Outer Containment

P. R. Shire (821)

A series of sodium fire studies have been updated for an

outer containment vessel 135 ft in diameter with a volume of 3 1.3 million ft . In each case the outer containment vessel

was conservatively assumed to be completely closed with no

leakage; the initial condition was air at atmospheric pressure

and ambient temperature at 80 O F .

The following accident conditions were investigated:

Closed loop tube rupture in reactor top head box open 2 (33 ft ) to outer containment vessel.

2 Same as above, except 1000 ft vent opening represents

head box cover completely removed. 2 * Sodium pipe rupture in heat transient cell open (100 ft )

to outer containment vessel.

Fuel handling machine spray release, adiabatic conditions.

A second accident condition was found to represent the most

severe problems. Data from the study will be employed in

preparation of the Plant Safety Analysis Report (PSAR).

2. FFTF Containment Analysis - CACECO Code

R. D. Peak (821)

The digital computer code, CACECO, has been prepared and

used in the safety analysis of the FFTF containment design.

z This code predicts the transient temperatures and pressures in

the reactor cavity, reactor head box, HTS cells, and contain-

ment building following any accident that breaches the primary

sodium system. The CACECO code (cavity-cells-containment - - -

transient code) is an expanded version of the CONRAD code

described in BNWL-1174. The new code has the capability of

computing containment transients in four containment volumes

connected by vent or leakage paths. The code also has restart

capability so that long time transients can be computed in stages.

The CACECO code maintains accurate material and energy

inventories of the nitrogen-oxygen-sodium vapor-fission product

atmosphere and of the sodium pool in each containment volume

and thereby determines the total pressure in the volume, the

pool temperature, and the mixed atmosphere temperature. The

code provides for bulk boiling of the sodium pool as well as

for bulk condensation of the sodium vapor from the atmosphere,

each depending upon the effects of heat sources and sinks in

the volume, the sodium vapor-oxygen chemical reaction, and

atmospheric leakage flows between volumes.

The leakage analysis in the code uses a predictor-corrector

technique. In this analysis, the pressure differentials between

the several containment volumes and the differential between

the building volume and outside cause nitrogen, oxygen (when

present), sodium vapor (when present), and fission product

(when present) flows between the volumes and to the outside

which tend to reduce the pressure differentials. This analysis

is based upon the turbulent flow equation and accounts for

atmospheric inventory changes due to flows of material and

energy. The areas for leakage between the reactor cavity and 2 HTS cells, the six pipeways with 34.4 ft total opening in the

present design, and between the cavity and head box (an assumed 2 10 ft opening) allow huge flows at very small pressure differ-

C

entials. For example, the leakage between the cavity and cells

with only 0.01 psi differential would be about 1250 lb/min when

the cavity inventory is only 2140 lb. Any pressure differential

is rapidly dissipated by such flaws.

The CACECO code i s b e i n g a p p l i e d t o t h e s a f e t y a n a l y s i s

of t h e FFTF con ta inmen t d e s i g n . For t h e s e c a s e s , t h e FFTF

con ta inmen t d e s i g n was modeled w i t h f o u r volumes and 39 h e a t

s t r u c t u r e s a s summarized below. *

TABLE 10.1. FFTF Containment Model for the CACECO Code

Reac to r C a v i t y : volume 31,200 f t 3

number of h e a t s t r u c t u r e s 15

s u r f a c e a r e a o f i n s u l a t e d s t r u c t u r e s 7 ,030 f t 2

HTS C e l l s :

s u r f a c e a r e a o f s t e e l s t r u c t u r e s

volume

number o f h e a t s t r u c t u r e s

s u r f a c e a r e a of i n s u l a t e d s t r u c t u r e s

s u r f a c e a r e a of s t e e l s t r u c t u r e s

R e a c t o r Head volume 10 ,200 f t 3

Box : number of h e a t s t r u c t u r e s 7


Containment volume 1 ,118 ,000 f t 3

B u i l d i n g : number of h e a t s t r u c t u r e s 4


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

Al though most of t h e h e a t s t r u c t u r e s a c t a s h e a t s i n k s f o r

t h e s e n s i b l e h e a t , r e a c t o r a c c i d e n t e n e r g y , sodium-oxygen

chemica l r e a c t i o n h e a t , and decay h e a t e n e r g i e s , t h e s t e e l

s t r u c t u r e s , t h e l i n e r s i n t h e c a v i t y , c e l l s , and head box and

o t h e r exposed s t e e l , a r e t h e i n i t i a l s i n k s b e c a u s e of t h e i r

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

a r e t h e n e x t e f f e c t i v e s i n k s and t h e i n s u l a t e d s t r u c t u r e s a r e

the last effective sinks. In all recent cases, the atmosphere-

to-structure heat transfer has been based upon a temperature-

dependent heat transfer coefficient based on natural convection

of nitrogen. Also, this coefficient is enhanced by local

condensation when sodium vapor is present in the atmosphere.

Data from these studies are being employed in preparation

of the PSAR.

3. Post DBA Containment Transients - SOHOT Code

G. L. Fox (821)

A digital computer code, SOHOT, has been prepared for compu-

tation of long term pressure and temperature transients following

a hypothetical core meltdown. This core differs from the

previously described CACECO code in that it does not model the

rapidly occurring events immediately following a DBA, and also

differs in the level of detail in the heat transfer structure.

The SOHOT code models the type of hypothetical accident

where fuel is assumed to melt through the bottom of the reactor

vessel and guard vessel and release both sodium and molten fuel

to the floor of the reactor vault. The fuel produces fission

decay heat from solid and gaseous products which will heat the

sodium and the cavity until sodium boiling occurs. The sodium

vapor transfers the decay heat from the reactor cavity to the

connecting equipment cells and raises the temperature and

consequently its pressure. The pressure buildup is relieved

by gas leakage from the reactor cavity and equipment cells to

the containment sphere. The containnent sphere gas is heated

by the sodium-oxygen reaction and fission gas products which

raises its pressure. The code estimates temperature and

pressure in the various subdivisions of the containment system.

The mathematical modeling is described below:

a . F i s s i o n P r o d u c t Decay Heat

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

of power v e r s u s t i m e . A s p e c i f i e d f r a c t i o n of t h i s power

(20% f o r p r e s e n t work) i s assumed t o be a gaseous f r a c t i o n

which d i f f u s e s t h r o u g h o u t t h e r e a c t o r c a v i t y and equipment

c e l l s . The r emain ing s o l i d f r a c t i o n i s assumed t o s t a y i n

t h e r e a c t o r c a v i t y where i t h e a t s up t h e w a l l s and sodium.

b . Containment Geometry

The p h y s i c a l l a y o u t f o r t h e sys t em which i s be ing modeled

i s shown i n F i g u r e 1 0 . 1 . There i s f r e e p a s s a g e of g a s between

t h e r e a c t o r c a v i t y and t h e equipment c e l l s . The l e a k a g e r a t e s ,

L 2 and L3 a r e s p e c i f i e d a s p e r c e n t f low r a t e of g a s from t h e

c e l l unde r a c c i d e n t c o n d i t i o n s . The o t h e r p o i n t s l i s t e d on

F i g u r e 1 0 . 1 , s t a r t i n g w i t h t h e l e t t e r T , r e p r e s e n t t e m p e r a t u r e

p o i n t s . For t h e p r e s e n t s t u d i e s , t h e c o n c r e t e w a l l was c o n s i d -

e r e d 5 f t t h i c k i n a l l l o c a t i o n s .

c . Heat T r a n s p o r t E q u a t i o n s

T h i s model now r e q u i r e s a l i s t o f a s s u m p t i o n s . The

n o t a t i o n w i l l be s i m p l i f i e d by i d e n t i f y i n g t h e r e a c t o r c a v i t y

a s c e l l 1, equipment c e l l s a s c e l l 2 , and con ta inmen t s p h e r e

a s c e l l 3 .

The sodium v a p o r c o n t e n t i n c e l l s 1 and 2 i s de te rmined

by e q u i l i b r i u m c o n d i t i o n s a t t h e c e l l g a s t e m p e r a t u r e .

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

(1) I n i t i a l p h a s e where sodium i s b e i n g h e a t e d t o b o i l i n g

p o i n t .

(2) B o i l p h a s e where b o i l i n g o c c u r s .

(3) Dry phase where no sodium remains i n t h e r e a c t o r

c a v i t y . Sodium b o i l i n g o c c u r s when a l l n i t r o g e n h a s been t r a n s -

p o r t e d from c e l l 1 t o c e l l 2 .

C O N T A I N M E N T S P H E R E

H E A T S I N K

F I G U P ? 10.1. Containment System Schematic for SOHOT

Pressure in cell 1 and cell 2 are equalized by open

ductwork.

Since the pressure is equal in cells 1 and 2, the equation of

state which governs the system is

P1A + PSI = P2A + PS2 (1 Let 1 designate the particular cell being considered:

P1A = Cell 1 - partial pressure of nitrogen

PS1 = Cell 1 - partial pressure of sodium.

This expression may be differentiated with respect to time

and, using the gas law, provides an equation of state which

relates temperature and pressure changes within the cells.

The equation of state coupled with an energy balance and

gas leakage equations for the cells provides sufficient

equations to solve for temperature and pressure history for all

three cells.

The sodium transported from cell 1 to 2 during the

"Initial" phase is coupled to the mass of nitrogen transport.

This is represented by:

where M1 = Nitrogen mass in cell 1

MS = S o d i u ~ vapor transport from cell 1 to cell 2

R1 = Gas constant for nitrogen

RS = Gas constant for sodium.

i During the "Boil" phase, the quantity of sodium transported results from an energy balance since there is no further

nitrogen transport.

The quantity of heat lost from cell 1 by sodium transport

is represented by: dMS (HlSG - HlSL)

where HlSG = Enthalpy of sodium vapor at cell 1 temperature

HlSL = Enthalpy of liquid sodium at cell 1 temperature.

The quantity of heat gained by cell 2 by sodium transport

is represented by: dMS (HlSG - HZSL) ;if-

where H2SL = enthalpy of liquid sodium at cell 2 temperature.

d. Heat Transport to Walls

The heat is removed from the cells by quickly accessible

and slowly accessible heat sinks in addition to conduction to

the cell liner and into the concrete wall. The concrete wall

is modeled by six nodal elements of constant thermal properties

to produce the transient temperature distribution.

Data from these studies are being employed in preparation

of the PSAR.

4. A New Computational System for Fast Reactor Accident

Investigation

Alan E. Waltar (831)

Major fast reactor excursion calculations are characteris-

tically laden with numerous parametric studies due to uncertain-

ties in the state of the reactor during the extreme conditions u

hypothesized. An improvement over earlier methods k 2 ) has

been developed which permits elimination of a substantial degree

of arbitrariness in the range of parametrics by providing a

consistent basis for establishing the reactivity ramp rate,

effective Doppler coefficient, and appropriate equation of state

during the disassembly process.

1. D. E. Simpson, J. W. Hagan, A. E. Waltar, R. A. Harris, A. Padilla, and G. L. Fox. Preliminary Analysis of Postulated Maximum Accidents for the FFTF, BNWL-760. Battelle-Northwest, Richland, Washington, November 1968.

2. D. R. Mac Farlane, N. A. McNeaZ, T. J. Heames, W. T. Sha, and C. K. Youngdahl. "Reactivity Transients Leading to Disassembly in Oxide-Fueled Fast Reactors", Trans. Am. Nucl. Soc., uol. 12, p. 342. 1969.

Basically, the method consists of a coupling of the multi-

channel neutronics-heat transfer computer program, MELT-I1 (1)

with the two-dimensional disassembly computer program VENUS. ( 2 )

The MELT-I1 phase includes feedback effects due to Doppler

broadening, sodium voiding, and fuel relocation whereas the

VENUS phase includes Doppler broadening and the reactivity

feedback due to core disassembly. The accident sequence is

followed in MELT-I1 until fuel temperatures are elevated to

the point where sizeable disassembly pressures are attained.

At this time the fine structure temperature information is

volume averaged over the R-Z spatial mesh structure used in VENUS, and this input, along with the power distribution and

all reactivity feedback components, is used directly as the

starting point for the disassembly phase in VENUS. In

addition, the core is scanned for liquid sodium content to

determine the effective Doppler coefficient and to establish

whether a sodium-in or a sodium-out equation of state should

be employed at each particular VENUS mesh point.

An example of the type of problem which can be treated

by this coupled system is the highly asymmetric situation

arising by passing a large sodium bubble through the core.

The particular example presented is based on a bubble

162 liters in volume passing through an FTR-like core

(radius 1.60 cm, height %90 cm). Reactivity, power response,

and energy yield resulting from upward movement of the bubble

through the lower reflector and into the core are illustrated

in Figure 10.2. Disassembly conditions are established when

I . A l a n E . W a l t a r , Andrew P a d i l l a , J r . , and R i chard J . S h i e l d s . [ M E L T- 1 1 , A Two-Dimensional N e u t r o n i c s - H e a t T r a n s f e r Code f o r F a s t R e a c t o r S a f e t y A n a l y s i s , B a t t e l l e - N o r t h w e s t , R i c h l a n d , W a s h i n g t o n . f t o be p u b l i s h e d ) ]

2 . W . T . Sha and T . H . Hughes. U n p u b l i s h e d Data. Argonne N a t i o n a l L a b o r a t o r y , [VENUS - Two-Dimensional N e u t r o n i c - Hydrodynamic F a s t R e a c t o r Power E x c u r s i o n Computer Program. ( t o be p u b l i s h e d ) ]

- S O D I U M B U B B L E F E E D B A C K

- -

- -

-

- - - - - - -.-- - -

MELT- I I + - PHASE

-

/ TOTALENERGY A

GENERATED

TIME SCALE - I POWER

I

TIME FROM START OF ACCIDENT, MSEC

FIGURE 10.2. Transient Response for a Large Sodium Bubble Passing Through a Fast Reactor Core.

t h e c e n t e r o f t h e bubble r e a c h e s a p p r o x i m a t e l y t h e lower t h i r d

of t h e r e a c t o r . The ramp r a t e i s n e a r l y 80 $ / s e c and t h e

e f f e c t i v e Doppler c o e f f i c i e n t has dropped from an i n i t i a l

v a l u e of - 0 . 0 0 5 t o a p p r o x i m a t e l y -0 .0038 . The amount of

energy c o n t a i n e d i n t h e mol t en f u e l a t t h e end of t h e n u c l e a r

e x c u r s i o n i s c a l c u l a t e d t o b e 1120 MW-sec.

T i g h t c o u p l i n g between t h e p r e d i s a s s e m b l y and d i s a s s e m b l y

phase i s e s s e n t i a l t o p r o v i d e a r e a l i s t i c a p p r a i s a l i n energy

r e l e a s e , p a r t i c u l a r l y f o r an a c c i d e n t of t h i s t y p e because

of t h e c o r e inhomogenei ty ( v a r i a t i o n of sodium c o n t e n t )

i n v o l v e d . For example, i f a n a l y s i s of t h e above a c c i d e n t i s

a t t e m p t e d u s i n g o n l y a d i s a s s e m b l y c o d e , p a r a m e t r i c s i n c l u d i n g

a r a n g e of ramp r a t e s from 50 t o 100 $ / s e c , Doppler c o e f f i -

c i e n t s from - 0 . 0 0 3 t o - 0 . 0 0 5 , and e q u a t i o n s o f s t a t e v a r y i n g

from e s s e n t i a l l y f u l l sod ium- in t o f u l l sodium-out a r e

n e c e s s i t a t e d t o bound t h e problem. Such c a l c u l a t i o n s have been

per formed and t h e energy c o n t a i n e d i n mol t en f u e l r a n g e s from

181 t o 2407 MW-sec.

Acknowledgement

The a u t h o r i s i n d e b t e d t o D r . Wi l l iam T . Sha , Argonne

N a t i o n a l L a b o r a t o r y , f o r h i s keen i n t e r e s t and c o l l a b o r a t i o n

i n t h i s s t u d y .

5 . On t h e Trea tment of S p a t i a l Feedback E f f e c t s i n F a s t

R e a c t o r Acc iden t Analyses

Alan E . Wal t a r and Winston W . L i t t l e , J r . (831)

Numerous p a p e r s 2 , 3 ) have r e c e n t l y appea red which p o i n t

o u t t h e need f o r u s i n g a s p a c e - t i m e k i n e t i c s package when

a n a l y z i n g f a s t r e a c t o r t r a n s i e n t s . Although t h e d e s i r a b i l i t y

of such t e c h n i q u e s c a n n o t be a rgued i n an a b s o l u t e s e n s e , t h e y

i n t r o d u c e some v e r y p r a c t i c a l l i m i t a t i o n s i n te rms of b o t h

programming and computa t ion t i m e , p a r t i c u l a r l y f o r two o r t h r e e

d i m e n s i o n a l c o m p u t a t i o n s . The purpose of t h i s work i s t o

emphasize t h a t t h e d i s c r e p a n c y between lumped p a r a m e t e r and s p a c e

dependent models i s f r e q u e n t l y caused by d i f f e r e n c e s i n t h e

i m p o r t a n t f eedback t e r m s , and t h a t t h e s e d i f f e r e n c e s can be

g r e a t l y r educed by u s i n g a lumped n u c l e a r model coup led w i t h a

s p a c e dependen t f eedback model .

An example of an a t t e m p t t o accoun t f o r s p a t i a l f eedback

e f f e c t s and y e t r e t a i n t h e s i m p l i c i t y and speed a s s o c i a t e d w i t h

p o i n t k i n e t i c s i s t h e t r e a t m e n t of Doppler f eedback i n t h e

MELT- I1 code. dk ( 4 ) Assuming Tm r emains c o n s t a n t o v e r t h e t emper -

a t u r e r a n g e o f i n t e r e s t f o r an o x i d e f u e l e d c o r e , Doppler f e e d -

back i s computed a c c o r d i n g t o t h e f o l l o w i n g e x p r e s s i o n :

1 . G . K e s s l e r . "Space- Dependen t Dynamic B e h a v i o r o f F a s t R e a c t o r s Us ing t h e T i m e - D i s c o n t i n u o u s S y n t h e s i s Method," T r a n s . Am NucZ. S o c . , v o l . 1 1 , p . 569. 1968 .

2 . James F . J a c k s o n and W i l l i a m E . K a s t e n b e r a . "Space- Time Dgnamic S t u d i e s i n Large LMFBRrs w i t h ~eeudback ," T r a n s . A m . N u c l . S o c . , voZ i2, p . 705 . 1969 .

3 . D . A . Mene ley and K . 0 . O t t . " S p e c t r a l E f f e c t s i n L i q u i d - Me ta l F a s t B r e e d e r R e a c t o r T r a n s i e n t s , " T r a n s . A m . NucZ. S o c . , v o l . 12 , p . 706 . 1 9 6 9 .

4. A l a n E . W a l t a r , Andrew PadiZZa, J r . , and R i c h a r d J . S h i e l d s . [MELT-11, A Two-Dimensional N e u t r o n i c s - H e a t T r a n s f e r Code o r F a s t R e a c t o r S a f e t y A n a l y s i s , B a t t e Z l e - N o r t h w e s t ,

i i c h l a n d , W a s h i n g t o n . ( t o be p u b l i s h e d ) ]

TOTAL FUEL VOLUME

TOTAL FUEL VOLUME

where KD = original whole core Doppler coefficient I

W(i, j) = local Doppler weighting factor

V(i,j) = local nodal fuel volume

T(i,j) = local nodal fuel temperature

To(i,j) = original local nodal fuel temperature

Tl(i,j) = local nodal fuel temperature at the time local voiding occurs

F = effective normalized change in the Doppler coefficient for spectrum hardening due to sodium voiding

A = feedback value evaluated at T = T1.

Figure 10.3 illustrates the change in the effective

Doppler coefficient (Deff), calculated by dividing the change

in the Doppler feedback of Equation 1 by the natural logarithm

of the core average fuel temperature change over the same

time interval. The particular example is a guillotine break

in one inlet pipe of an FTR-like core (radius ~ 6 0 cm,

height ~ 9 0 cm). The overall drop in Deff up to the time of

initial coolant voiding results from the skewed fuel tempera-

ture buildup towards the top, lower worth region of the core.

Channel 1 (central subassembly) is assumed to begin voiding

at the core due to cladding failure and fission gas release.

Initial reactivity effects are negative, and the attendant

drop in power accentuates the relative temperature peaking at

0 . 5 1 .O 1.5

T I M E FROM START O F ACCIDENT, SECONDS

- START OF CHANNELS 4 & 5 VOIDING

- CHANNEL 3 VOIDING CHANNEL 2 VOIDING

- CHANNEL 1 VOIDING

- SPECTRUM EFFECT ON DOPPLER COEFFICIENT

EFFECTIVE DOPPLER COEFFICIENT

-

-

-

-

-

- NEGATIVE DOPPLER FEEDBACK ./. 1 . / - /

/ * /

.<- I I

FIGURE 10.3. Change in the Effective Doppler Coefficient During a Pipe Rupture Accident

I l l I I I I 1 1 1

t h e c o r e p e r i p h e r y . A s t h e v o i d moves downward i n t o t h e c o r e ,

however, t h e r e a c t i v i t y e f f e c t s a r e p o s i t i v e and t h e power

s u r g e peaks t e m p e r a t u r e s toward t h e c e n t r a l r e g i o n s . Hence,

D e f f i n c r e a s e s . T h i s phenomenon c o n t i n u e s a l t h o u g h t h e

e f f e c t s of spec t rum h a r d e n i n g r e s u l t i n g from c o o l a n t v o i d i n g

( t h e dashed l i n e ) become dominant and D e f f ha s dropped from

-0 .005 t o a p p r o x i m a t e l y -0 .0035 a t t h e t i m e t h e c o r e n e a r s a

d i s a s s e m b l y c o n d i t i o n . For t h i s t y p e o f a c c i d e n t , Doppler

f eedback i s shown t o b e f a i r l y s m a l l u n t i l t h e l a t t e r s t a g e s

of t h e a c c i d e n t . Even s o , however , t h e i n c l u s i o n o f a s p a t i a l

Doppler f eedback a c c o r d i n g t o Equa t ion 1 r e s u l t s i n a s u b s t a n -

t i a l l y h i g h e r power and i n t e g r a t e d ene rgy (%IS%) r e l a t i v e t o

t h e lumped model which u s e s a Doppler f eedback based on t h e

c o r e a v e r a g e t e m p e r a t u r e .

B. O T H E R S A F E T Y T E C H N O L O G Y

1. Use of Delay Beds f o r R a d i o a c t i v e Gas Decay S t o r a g e

C . J . Foley (925)

Contaminated g a s e s must be s t o r e d u n t i l r a d i o a c t i v e decay

p r o c e s s e s p e r m i t r e l e a s e a t l e v e l s a l lowed by F e d e r a l r e g u l a -

t i o n s . A d e l a y bed u t i l i z i n g a s o r b e n t m a t e r i a l i s b e i n g

c o n s i d e r e d f o r FFTF. A d e l a y bed i s a volume of s o r b e n t

m a t e r i a l such a s c h a r c o a l packed i n t o a c o n t a i n e r such a s

p i p i n g . Contaminated a rgon g a s p a s s e s i n t o t h e bed where

xenon and k r y p t o n a r e s o r b e d more s t r o n g l y t h a n t h e a rgon

c a r r i e r ; t h i s , i n e f f e c t , d e l a y s t h e p a s s a g e of t h e xenons

and k r y p t o n s w h i l e t h e a rgon p a s s e s t h r o u g h r e l a t i v e l y q u i c k l y .

Such a d e l a y bed would be p r e f e r a b l e t o t a n k s f o r

s e v e r a l r e a s o n s . The d e l a y bed e n v i s i o n e d would o p e r a t e a t

ambient p r e s s u r e and t e m p e r a t u r e and r e q u i r e o n l y modest f lows

of c o o l i n g w a t e r and no g a s compressor . A bed t h a t w i l l d e l a y

p a s s a g e of n o b l e g a s e s f o r 87 days has been p r e l i m i n a r i l y s i z e d .

The bed e n v e l o p e i s a p p r o x i m a t e l y 7 f t i n d i a m e t e r by 10 f t l ong

and h a s a p r e s s u r e d r o p of a p p r o x i m a t e l y 2 . 5 i n . of w a t e r t h r o u g h

t h e s o r b e n t f o r a g a s f low o f 0 .6 scfm. I n c o n t r a s t , p r e s s u r -

i z e d t a n k s t o pe r fo rm t h e same f u n c t i o n would c o n s i s t o f t h r e e

p r e s s u r e v e s s e l s each 1 0 f t i n d i a m e t e r by a b o u t 20 f t l o n g .

These v e s s e l s would s t o r e t h e con tamina ted c o v e r g a s a t a b o u t

10 atm p r e s s u r e . We b e l i e v e d e l a y beds o f f e r s i g n i f i c a n t

a d v a n t a g e s o v e r p r e s s u r e t a n k s because t h e s p a c e r e q u i r e m e n t s

f o r t h e d e l a y bed a r e l e s s t h a n t h e p r e s s u r e v e s s e l s and b e c a u s e

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

s i g n i f i c a n t p r e s s u r e b u i l d u p . Thus l e a k a g e of r a d i o a c t i v e g a s e s

from a d e l a y bed i s v e r y u n l i k e l y .

A P P E N D I X A

O R G A N I Z A T I O N C O D E S F O R F F T F P E R I O D I C T E C H N I C A L R E P O R T S

( E f f e c t i v e 1 - 1 - 1 9 7 0 )

Code

A00

COO

KO0

MOO

NO0

T C D

390

391

392

393

394

395

400

410

420

600

A u t h o r ' s O r g a n i z a t i o n

BNW Chemis t ry 6, M e t a l l u r g y D i v i s i o n

BNW P h y s i c s 6, E n g i n e e r i n g D i v i s i o n

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Procurement - R . J . Gandy

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FFTF F u e l s Dept . - E . A . Evans , W . E . Roake,

T . W . Evans

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Cladding Development - T . T . Claudson

Cladding Dev. 6 Procurement - J . C . Tverberg

Cladding E v a l u a t i o n - J . J . Holmes

F u e l C, Cladd ing I n f o . C e n t e r

F u e l Element Dev. - C . A . Burgess

P r o c e s s Dev. 6 Demonst ra t ion - R . E . B a r d s l e y

Subassembly Dev. - J . W . Thornton

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P. L . Hofmann, D . E . Simpson

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P l a n t E n g i n e e r i n g - D . P. S c h i v e l y

R a d i a t i o n 6 S h i e l d A n a l y s i s - W . L . Bunch

S a f e t y 8 Systems A n a l y s i s - R . E . P e t e r s o n

S a f e t y A n a l y s i s - D . D . S tepnewski

Systems A n a l y s i s - H . G . Johnson

C o n t r o l A n a l y s i s - R . A . Harvey

Rad. 6 Envi ron . S a f e t y

S a f e t y Tech. 6 P r a c t i c e s

Nuc lea r 8, P r o c e s s Tech. - R . E . Heineman

N u c l e a r A n a l y s i s - W . W . L i t t l e

Core A n a l y s i s - P . D. Cohn

Exper . P h y s i c s - R . A . B e n n e t t

O p e r a t i o n s - D . C . Boyd

P r o c e s s A n a l y s i s

FFTF E n g i n e e r i n g Department - D . L . C o n d o t t a ,

F. C . Gronemeyer, W . B . McDonald

R e a c t o r Design - S . 0. Arneson

S p e c i a l i s t s

R e a c t o r Components - R . C . Walker

Core E n g i n e e r i n g - J . F. Wett

Equipment E n g i n e e r i n g - C . A . Munro

F l u i d Systems - J . M. Batch

S p e c i a l i s t s

Sodium Technology - W . R . Wykoff

Heat Removal System - T . W . Wi the r s

T e s t Sys terns - P . F. Shaw

A u x i l i a r y Systems - R . V . Du l in

I n s t r u m e n t a t i o n E, C o n t r o l - C . D . Swanson

Tech. S t a f f

Reac to r I n s t r u m e n t a t i o n - R . R . Cone

P l a n t I n s t r u m e n t a t i o n - J . W . M i t c h e l l

F a c i l i t i e s 4 S i t e - E . M . J o h n s t o n

S t r u c t u r e s 6 U t i l i t i e s - F. H . Shade1

Fue l Examinat ion - C . L . Boyd

E l e c t r i c a l Systems - G . H . S t r o n g

Engr . C o o r d i n a t i o n E, P l a n n i n g - J . R . C a r r e l 1

Tech. S t a f f

Design P r o c e d u r e s E, C o n t r o l -

H . D . L e n k e r s d o r f e r

P r o j e c t Schedu l ing - D . R . Doman

Development 6 T e s t C o o r d i n a t i o n - K . G . Toyoda

M e t a l s , M a t e r i a l s E, Codes - J . C . T o b i n '

T e c h n i c a l S t a f f

F a b r i c a t i o n Development

M a t e r i a l s A p p l i c a t i o n

S u r v e i l l a n c e Program

E n g i n e e r i n g Q . A . 6 S t a n d a r d s - J . A . P e r r y

A P P E N D I X B

F F T F BNWL R E P O R T S I S S U E D - DECEMBER 1 , 1 9 6 9 - F E B R U A R Y 28, 1 9 7 0

BNWL Number Authors T i t l e

791 R . A . Harvey, S . S . H i n t z e H . C . M a r t i n , M . A . McLaughlin and 0 . B . M o n t e i t h

J . V . Nelson and S . L . DeMeyer

W . Babcock

Systems E f f e c t i v e n e s s Goals f o r t h e F a s t F lux T e s t F a c i l i t y

Group C o n s t a n t s f o r A n a l y s i s o f FFTF C r i t i c a l Exper iments

S t a t e of Technology- - Pumps, E x p e r i e n c e w i t h High Tempera ture Sodium Pumps i n N u c l e a r R e a c t o r S e r v i c e and T h e i r A p p l i - c a t i o n t o FFTF

W . R . Young A n a l y s i s o f FTR Phase B R . A. B e n n e t t C r i t i c a l Exper iments -

P a r t I , ZPR I 1 1 Assembl ies 52a, b , c , d , e

G . L . Fox A s p r i n , A Computer Code

M . T . Jakub and Core Radia.1 C o n s t r a i n t W . H . S u t h e r l a n d T h e ~ r y and A p p l i c a t i o n s

t o t h e FTR

F. E . Bard, J r . A F o r t r a n I V Computer Program t o Determine t h e P l a s t i c - E l a s t i c Creep and Thermal Deformat ions i n Thick-Wal led C y l i n d e r s

C . E . Leach Tap Loop: A S t a b l e C . L . K e l l e y J r . Thermal Analyzer Code f o r

Thermal A n a l y s i s of C losed H y d r a u l i c Systems

L . F. Lus t J u s t i f i c a t i o n f o r I n e r t - Atmosphere S h i e l d e d Sampling and A n a l y t i c a l F a c i l i t i e s f o r t h e FFTF

* Compiled b y L . R . S t e v e n s ( T C C I

BNWL- 132 8

BNWL Number Authors

1218 R . N . Madsen and S. H . C h r i s t e n s e n

1235 A . F. L i l l i e

1236 M . T . Jakub e t a l .

1241 K . R . Merckx and G . L . Fox

1247 R . E . Dahl and R . D . Bourquin

1291 D . R . Marr

T i t l e

Dynamic S i m u l a t i o n o f t h e FFTF Hea t ing and V e n t i l a - t i o n System

Thermal Aspec t s o f t h e FFTF R e a c t o r R e f u e l i n g System

Sugges ted I n t e r i m S t r u c t u r a l Design C r i t e r i a f o r t h e FTR Pr imary P i p i n g System

S i n t e r - A Program f o r C a l c u - l a t i n g R a d i a l Tempera ture D i s t r i b u t i o n s i n Oxide F u e l P i n s Undergoing S i n t e r i n g

Bippy, A Computer Code f o r t h e C o r r e l a t i o n o f F u e l E l e - ment Burnup and Cladd ing Damage

A U s e r ' s Manual f o r 2DBS A D i f f u s i o n Theory S h i e l d i n g Code

D I S T R I B U T I O N

No. of Copies

O F F S I T E

1 AEC Chicago Patent Group

G. H. Lee

32 AEC Division of Reactor Development and Technology

Director RDT Asst Dir for Nuclear Safety Analysis and Evaluation Br, RDT:NS Environmental and Sanitary Engrg Er, RDT:NS Research and Development Br, RDT:NS (2) Asst Dir for Plant Engrg, RDT Facilities Br, RDT:PE Components Br, RDT:PE Instrumentation and Control Br, RDT:PE Liquid Metal Systems Br, RDT:PE Asst Dir for Program Analysis, RDT Asst Dir for Project Mgmt, RDT Liquid Metals Projects Br, RDT:PM FFTF Project Manager, RDT:PM (3) Asst Dir for Reactor Engrg, RDT Control Mechanisms Br, RDT:RE Core Design Br, RDT:RE ( 2 ) Fuel Engineering Br, RDT:RE Fuel Handling Br, RDT:RE Reactor Vessels Br, RDT:RE Asst Dir for Reactor Tech, RDT Coolant Chemistry Br, RDT:RT Fuel Recycle Br, RDT:RT Fuels and Materials Br, RDT:RT Reactor Physics Br, RDT:RT Special Technology Br, RDT:RT Asst Dir for Engrg Standards, RDT Asst Dir for Nuclear Safety, RDT

t 215 AEC Division of Technical Information Extension 1 AEC Idaho Operations Office

C. W. Bills, Director

1 AEC San Francisco Operations Office

Director, Reactor Division

4 AEC Site Representatives

Argonne National Laboratory Atomics International General Electric Co., Sunnyvale Westinghouse Electric Corporation

No. o f Copies

4 Argonne N a t i o n a l L a b o r a t o r y

LMFBR Program O f f i c e ( 2 ) R . A . J a r o s s N . J . Swanson

Argonne N a t i o n a l L a b o r a t o r y Idaho F a l l s , Idaho

F . W . T h a l g o t t

Atomic Power Development A s s o c i a t e s

Document L i b r a r i a n

Atomics I n t e r n a t i o n a l FFTF Program O f f i c e

Babcock and Wilcox Co.

S . H . E s l e e c k G . B . Gar ton

B a t t e l l e - N o r t h w e s t R e p r e s e n t a t i v e

R . M . Fleishmann (ZPPR)

B e c h t e l C o r ~ o r a t i o n

J . J . Teachnor

Combustion E n g i n e e r i n g , I n c . (AEC)

W . P . S t a k e r , P r o j e c t Manager

Combus t i o n E n g i n e e r i n g 911 West Main S t . Cha t t anooga , Tennessee 37401 Mrs. N e l l H o l d e r , L i b r a r i a n

Genera l E l e c t r i c Co. Advanced P r o d u c t s O p e r a t i o n

Kar l Cohen ( 4 )

Nuc lea r Systems Programs

D. H . Ahmann

Genera l E l e c t r i c Co. , P l e a s a n t o n (AEC) Nuc leon ics L a b o r a t o r y

D r . H . W . A l t e r , Mgr.

Gulf Genera l Atomic I n c o r p o r a t e d (AEC)

D . Coburn

Idaho Nuc lea r C o r p o r a t i o n

J . A . Buckham

No. o f Copies

3 L i q u i d Meta l E n g i n e e r i n g C e n t e r

R . W . Dickenson

1 L i q u i d Meta l I n f o r m a t i o n C e n t e r

A . E . M i l l e r

Los Alamos S c i e n t i f i c L a b o r a t o r y

R . D . Baker D . B . H a l l

NASA Lewis Research Cen te r

R . A . H i ldebrand

Nuc lea r M a t e r i a l s and Equipment C o r p o r a t i o n (AEC)

C . S . Ca ldwe l l

Oak Ridge N a t i o n a l L a b o r a t o r y

H . G . Duggan W . 0 . Harms

Southwest Resea rch I n s t i t u t e

A . J . P i c k e t t

S t a n f o r d U n i v e r s i t y Nuc lea r D i v i s i o n D i v i s i o n o f Mech. Engrg.

R . She r

U n i t e d Nuc lea r C o r p o r a t i o n Resea rch and E n g i n e e r i n g C e n t e r L i b r a r y

West inghouse E l e c t r i c Corp. Atomic Power D i v i s i o n Advanced R e a c t o r Systems

E . C . Bishop D . C . Spencer (10)

O N S I T E - H A N F O R D

1 AEC Chicago P a t e n t Group

R . K . Sharp (R ich land)

2 AEC R ich land O p e r a t i o n s O f f i c e FFTF Program

J . M. S h i v l e y

No. o f Copies

4 A t l a n t i c R i c h f i e l d Hanford Company

L . M . R icha rds L . B . C h r i s t o p h e r H . P. Shaw R . E . Tomlinson

3 B a t t e l l e Memorial I n s t i t u t e

1 B e c h t e l C o r ~ o r a t i o n

M . 0 . Rothwel l

C o m ~ u t e r S c i e n c e s C o r ~ o r a t i o n

G . L . O t t e r b e i n C . D . Thimsen

Douglas U n i t e d Nuc lea r C o r p o r a t i o n

R . S . B e l l C . D . H a r r i n g t o n C . W . Kuhlman 0 . C . Schroede r

Hanford E n g i n e e r i n g S e r v i c e s , V i t r o , I n c .

J . M . Frame G . K l i g f i e l d

ITT/FSS

J . M . Hef fne r W . M . Hunt T . P. Leddy M . F . Rice C . W . Weeks

RDT A s s t . D i r . f o r P a c i f i c Northwest L a b o r a t o r y

West inghouse E l e c t r i c C o r ~ .

J. D . Herb

159 B a t t e l l e - N o r t h w e s t

F. W . Albaugh W . G . A l b e r t G . J . A l k i r e S . 0 . Arneson J . M . Ba tch J . L . Ba tes A . L . Bement, S r . R . A . B e n n e t t T. K . B i e r l e i n L. D . Blackburn C . L . Boyd

Boyd Brown Bunch Burgess C a b e l l ( 2 ) Cadwell C a l l e n C a n t r e l l C a r r e l 1 Cawley Chase

B a t t e l l e - N o r t h w e s t ( c o n t d )

T . D . C h i k a l l a G . A . L a s t T . T . Claudson D . C . L e h f e l d t J . C . Cochran F. J . L e i t z P. D . Cohn H . D . L e n k e r s d o r f e r D . L . Condot ta C . W . Lindenmeier R . R . Cone H . E . L i t t l e J . H . Cox W . W . L i t t l e G . M . Dalen C . E . Love J . M . Davidson D . Marinos F . G . Dawson R . P. M a r s h a l l D . R . de Halas W . B . McDonald V . A . DeLiso J . S . McMahon G . E . D r i v e r M . H . Meuser K . Drumhel le r J . W . M i t c h e l l R . V . D u l i n R . A . Moen J . F . Erben C . A . Munro E . A . Evans C . R . Nash T . W . Evans R . E . N i g h t i n g a l e L . M . F inch D . J . Oakley J . C . Fox D . P. OIKeefe R . J . Gandy L . T . Pederson E . E . G a r r e t t J . A . P e r r y S. M . G i l l R . E . P e t e r s o n E . D . G r a z z i n i H . G . Powers J . W . Hagen 0. W . P r i e b e J . P . Hale H . L . P r i n g l e W . L . Hampson J . C . R icha rdson J . E . Hanson W . D . Richmond K . M . Harmon W . E . Roake R . A . Harvey D . P. S c h i v e l y B . R . Hayward J . M . Seehuus E . N . Heck F. H . Shade1 R . E . Heineman D . W . Shannon J . W . Helm P. F . Shaw R . J . Hennig F. R . Shober G . M . Hesson D . E . Simpson P. L . Hosmann C . R . F . Smith J . J . Holmes J . E . Spanner J . E . I r v i n R. J . S q u i r e s M . T . Jakub D. D . S tepnewski B . M . Johnson G . H . S t r o n g H . G . Johnson C . D . Swanson R . N . Johnson J . W . Thornton E . M . J o h n s t o n J . C . Tobin L . A . J o n e s K . G . Toyoda J . N . Judy J . C . Tve rbe rg F . J . Kempf G . L . Tingey D . D . Knowles M . A . Vogel D . D . Lanning R . C . Walker

Battelle-Northwest (contd)

D. M. Walley F. W. Woodfield E . T. Weber D. C. Worlton J. H. Westsik J. M. Yatabe J. F. Wett H. H. Yoshikawa R. G. Wheeler W. R. Young L. A . Whinery FFTF File (10) R. D. Widrig FFTF TPO J. F. Williams Technical Information (5) T. W. Withers Technical Publications (3) N. G. Wittenbrock Legal, 703 Bldg. B. Wolfe Legal, ROB, 221A M. R. Wood

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