IPiI-CFE«33

ENtICO FEIMI ATOMIC POWER PLANT

CURREiT EXPERIEiCE SERIES

COHPILMIOi OF CURREiT TECHilCM EXPERIEiCE IT

EiRICO FERMI ATOMIC POWER PLAiT MM 1319

R.E. Mueller

Assistait Project Eiiineer

Unitei States Atenic Enerif Commissien

Coitract i i . AT flM)-865

Prtject Airisineiit i o . 15 Af^ «-^5

C. E. Branfan

Fermi Project En|

APDA

VkmAAftoA ^ L E G A L N O T I C E

. 1 „,- TOntractor of t i t Commlsn •> or IW>»- ; „ , , io»traa-.r p.^i-ons

PiEPAiED BY

Atomic Power OeYeiopment Associates, Inc.

with the Cteperatien of

Power Reactor Dewelopment Company

mi

Tie Oetroit Eilson Csmpanf

^t"x^if'^fk^'^7m^d arrangement and is subject to the terms thereof.

ISSUEii Octoler 19eS

Sc-

• t

DISCLAIMER

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency Thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document.

T A B L E O F C O N T E N T S

Sec t ion P a g e

LIST OF ILLUSTRATIONS . . . . . . . . . . iv

LIST OF T A B L E S . v

P R E F A C E . 1

L C U R R E N T E X P E R I E N C E SUMMARY 3

II. O P E R A T I O N S . S

A. STATUS OF R E A C T O R SODIUM AND GAS S Y S T E M S . . . . . . 5 B . STEAM G E N E R A T O R P E R F O R M A N C E 5 C. GAS SYSTEMS P E R F O R M A N C E . . . 7 D. F U E L AND R E P A I R BUILDING SODIUM SYSTEM . . . . . 7 E . RADIOACTIVE WASTE DISPOSAL 'i

III. P H O T O G R A P H I C SURVEY O F HOLDDOWN MECHANISM U A. E Q U I P M E N T INSTALLATION 11 B . D I F F I C U L T I E S E N C O U N T E R E D 13 C. HOLDDOWN P H O T O G R A P H S 20

IV. STATUS O F P L A N T MODIFICATIONS UNDER CONSTRUCTION 23 A. F U E L T R A N S F E R F A C I L I T Y 23 B . AUXILIARY F U E L STORAGE F A C I L I T Y 23 C. M A L F U N C T I O N D E T E C T I O N A N A L Y Z E R . . . 25 D. PRIMARY SYSTEM COLD T R A P ROOM MODIFICATIONS . 27 E . D E L A Y E D N E U T R O N D E T E C T O R 29

V. P L A N T MAINTENANCE . 3 5 A. PRIMARY SHIELD TANK BOOT SEAL

R E P L A C E M E N T C O M P L E T E D 35 B . R E P A I R OF NO. 1 PRIMARY SODIUM P U M P 38 C. N E U T R O N D E T E C T O R CHANNEL M A L F U N C T I O N 38 D. R E P A I R O F DEW P O I N T H Y D R O M E T E R IN

STEAM CLEANING C H A M B E R 3^

VL S P E C I A L INVESTIGATIONS . . . . . . . . 41 A. USE O F FLOWGUARDS IN SUBASSEMBLIES

BEING STUDIED , , . . . . . . . . . 41 B . P O W E R RANGE SIGNAL A M P L I F I E R NOISE . 41 C. NOISY L O O P - 3 F L O W M E T E R . . . 41

iii

LIST OF ILLUSTRATIONS

Fig . No. Page

1 Holddown Inspection Tool P r i o r to Inser t ion in Reactor . . . . . . 12

2 BorescopeSj Camera , and Light in Access

Penet ra t ion No. 5 12

3 Defective Keyway Slots in Service Hose Collar . 15

4 Separation of Service Hose Joints Near Collar . . . . . . . . . . . . . . 15

5 Bowed Quartzl ine Lamp Bulbs 15

6 Blackened P y r e x Envelope for Lamps 15

7 Copper Tube Connection for Purge Gas Line at Top of Motor Compar tment 17

8 Copper Tube Extension Through Bottom of Motor Compartnaent . 17

9 Holddown Inspection Tool in Reactor During Light Test . . . . . . 18

10 View of Southeast Sector of Holddown Pla te . . . . . . . . . . . . . . . . . 21

11 View of Northwest Sector of Holddown Pla te 22

12 Insulating Underside of Decay Tank Shield Plug 24

13 Stepped Steel Liner in Loading P o r t 24

14 Heater Stack During Construction . . . . . . . . . . . . . . . . . . . . . . . . . 24

15 Heater Stack Assembled on Bottom of Storage Rotor . . . . . . . . . 24

16 Close-Up of Heater Stack Assembly Under Storage Rotor . . . . . 26

17 Storage Rotor in P lace Inside Decay Tank 26

18 Rotor Shaft Pene t ra t ion Through Inner Shield Plug 26

19 Inner Plug Cover P la te Being Lowered Over Rotor Shaft 26

iv

Fig . No.

LIST OF ILLUSTRATIONS (Continued)

Page

20 Location of Ne w Elec t romagnet ic Pump for P r i m a r y System Plugging Indicator 28

21 Location of F lowmete r for P r i m a r y Sodium Hydrogen Detector . 28

22 Moderator-Shie ld Assembly Box for Delayed

Neutron Detector 32

23 Moderator-Shie ld Assembly Box Pa r t i a l ly Fi l led 32

24 Cable Leads Out Top of Assembly Box 32

25 Cable Leads Through Penet ra t ion in Operating Floor . . . . . . . . 32

26 P r i m a r y Shield Tank Boot Seal Pa r t i a l ly Installed . 36

27 Mating Surfaces for Boot Seal Closure Splice 36

28 Clamping of Closure Splice after Gluing . 36

29 Stitching of Closure Splice 37

30 Completed Boot Seal Installation 37

31 Two Views of Spalled Bearing Races — Thrus t Bearing Assembly of the No. 1 Pump Shaft 40

LIST OF TABLES

Table No. Title Page

1 P r i m a r y System Cover Gas Activity 7

2 P r i m a r y System Cover Gas Analysis 8

V

PREFACE

PURPOSE

The purpose of this monthly r epor t is to make available to the fast r eac to r p rogram the cu r r en t experience being gained from the Enr ico F e r m i Atomic Power Plant ,

SCOPE

The scope of this r epo r t includes all phases of cu r ren t operat ions and maintenance experience concerning the nuclear portion and re la ted sys tems of the Enr ico Ferm.i Atomic Power Plant .

E a r l i e r Fe rmi experience in cer ta in selected a r ea s was recorded in a s e r i e s of technical r epo r t s completed by Atomic Power Development Assoc ia tes , Inc» , for the U. S, Atomic Energy Commission under AEC Con­t r a c t s No. AT ( l l - l ) - 8 6 5 , P ro jec t Agreement 15. This s e r i e s of r epor t s provides detailed information on the nuclear test ing, mach ine ry dome, s team gene ra to r s , pumps, f lowmeters , level de tec to r s , sodium sampling and de ­velopment of the p r i m a r y sodium sys tem.

I tems in the sections of this r epor t a r e selected on the bas is of thei r special significance during the month. Other i tems may be found in the monthly r epor t submitted to the Atomic Energy Comnaission by Power Reactor Development Company in compliance with the r equ i rement s of Provis iona l Operating License No. DPR-9 , as amended.

BACKGROUND

The F e r m i r eac to r achieved initial c r i t ica l i ty on August 23, 1963. An extensive s e r i e s of nuclear t e s t s was conducted at power levels below 1 Mwt, through 1965. A high power (200 Mwt) l icense Avas i ssued on Decem­ber 17, 1965, and operation in excess of 1 Mwt was initiated on December 29, 1965.

In January 1966, the power was ra i sed in a s e r i e s of steps to 20 Mwt. On April 1, 1966, power was f i r s t r a i sed to 67 Mwt and on July 8, 1966 operation at 100 M-wt was init iated. On October 5, 1966, fuel damage oc­cur red during an approach to power. Since that t ime the r eac to r has been shut down while the cause of damage is being eliminated and the reac to r r e ­s tored to the operating condition.

1

It i s assumed that those reading this r epor t have a genera l famil iar i ty with the plant. As an aid to the r e a d e r , a perspec t ive drawing of the plant was included at the back of A P D A - C F E - 1 . In addition, a topical index ap ­p e a r s at the end of APDA-CFE-28 .

Since this r epor t is intended to follow closely the cu r ren t proceedings at the F e r m i plant, it mus t neces sa r i l y be t rea ted as p re l imina ry informa­tion, subject to supersedence in the light of subsequent exper ience .

2

I. CURRENT EXPERIENCE SUMMARY

The r eac to r vesse l remained par t ia l ly drained of sodium during May while a photographic survey of the holddown mechan i sm was conducted. The m i r r o r and other equipment needed to photograph the holddown fingers were uti l ized in the r eac to r four t imes during the month to obtain the requi red p i c tu r e s . The quality of some of the p ic tu res taken was not as good as had been expected because of r e c u r r i n g difficulties encountered with poor l ight­ing; however, the p ic tu res were found to be sa t isfactory for ana lys i s . Very good p ic tures were obtained in the a r e a where subassembly melt ing occur red , which is the a r ea of pr incipal i n t e re s t . A p re l imina ry evaluation of the photographs shows no evidence of misal igned holddown fingers^

Feedwater p r e s s u r e drop t e s t s were conducted on the No. 1 and No. 2 s team genera to r s to de te rmine whether the poppet-type orif ices in the water tubes had re sea ted following the recent isolation t e s t s . The t e s t r e su l t s indi­cate that some of the poppets did not r e s e a t in the No. 1 unit . The unit will be opened next month to de te rmine the cause and extent of the problem. The No. 3 s team genera tor developed a leak at the s team manifold cover plate when it was filled with water and feedwater flow t e s t s on it were postponed until the cover plate bolts a r e re torqued.

Checkout of the new fuel t r an spo r t facility e rec ted in the r eac to r building was begun and is about 50% complete^ All of the dr ives were ene r ­gized and the controls t es ted . However, the j acksc rew used to r a i s e and lower the plug cask was damaged. This has delayed the final checkout some­what»

Erec t ion of the auxi l iary fuel s torage facility in the No, 2 equipment decay tank is about 75% complete . This month insulation was instal led on the unders ide of the shield plugs, and steel l i ne r s were instal led in the load­ing por t and shaft penetra t ions through the shield plugs. The s torage ro to r , hea te r stack, and thermocouples were also instal led inside the tank and the shield plugs placed in the i r final position^

Work has continued on instal lat ion of the malfunction detection analyzer (MDA) in the r eac to r control room. The cable r acks for the signal cables to the analyzer were e rec ted in the r e l ay room and pulling, rerout ing, and i n t e r ­connecting of the signal cables was begun. Construction of a t e m p o r a r y s imula tor for use in checking out the sys tem was also begun.

Erec t ion of a delayed neutron detector sys tem for the r eac to r at a location below the r e a c t o r building operating floor was completed except for

3

the final cable connections. The detector is positioned outside the secondary shield wall between the p r i m a r y sodium outlet pipe ve r t i ca l runs of loops 1 and 2.

Replacement of the boot seal for the p r i m a r y shield tank was com­pleted. The p r i m a r y shield tank a tmosphere was subsequently purged with dry nitrogen; by the end of the month the dew point of the shield tank a t m o s ­phere had been reduced from +35 F to -40 F . P r e l i m i n a r y leak test ing of the new seal , made at a p r e s s u r e of 8 inches WCG, showed no significant p r i m a r y shield tank leakage.

The ro tor for the No. 1 p r i m a r y sodium pump motor , -which las t month was sent out for machining of the slip r ings , was re turned and re in­stal led. F u r t h e r inspection of the No. 1 pump revealed that the bear ing r ace s of the pump shaft th rus t bear ing assembly have an i r r e g u l a r wear pa t tern and they a r e being polished for r e u s e .

4

II. OPERATIONS

A. STATUS OF REACTOR SODIUM AND GAS SYSTEMS

The p r i m a r y system remained par t ia l ly drained of sodium throughout the month to conduct the holddown photographic survey. During this t ime the t e m p e r a t u r e of the p r i m a r y sys tem w^as inaintained between 350 F and 380 F by the pipe and ves se l induction and r e s i s t ance h e a t e r s .

All th ree loops of the secondary sodium sys tem remained filled with sodium at appro xiniately 350 F . Feedwater p r e s s u r e drop t e s t s on the water sides of the No. 1 and No. 2 s team genera to r s were conducted; when water was added to the No. 3 unit, a leak developed at the s team manifold and the unit had to be vented before hydraulic t e s t s could be per formed.

No cold-trapping of the primary^ secondary, or fuel and r epa i r building t r ans fe r tank sodium sys tems was perforjned. No moveinent of subassembl ies was made during the month.

The below-floor a r ea of the containment building and the p r i m a r y cold t r ap room a tmosphere reniained purged with a i r throughout the month. This was neces sa ry to allo'w erect ion of the delayed neutron detector sys tem in the containment building and make modifications to the p r i m a r y sodium plugging indicator c i rcui t in the cold t r ap room. The p r i m a r y shield tank a tmosphere was purged with dry ni trogen following rep lacement of the p r i ­m a r y shield tank boot seal .

B. STEAM GENERATOR PERFORMANCE

Therma l shock t e s t s were performed on the No. 1 s team genera tor by isolating and venting las t month (see APDA-CFE-32 , Sec. II. C), and on the No. 2 and No. 3 units la te in 1968 (see APDA-CFE-26 , Sec, IIL C. 1 and APDA-CFE-28 , Sec. III. B. 1). Feedwater flow p r e s s u r e drop t e s t s were scheduled on the units this month to de te rmine whether all the poppet-type p r e s s u r e drop orif ices recent ly instal led in the water tubes (see APDA-CFE-32 , p 27) had re sea ted following the isolation t e s t s .

During the second week in May, the th ree s team gene ra to r s were filled with water using wate r obtained from the No. 4 hea te r , where plant condensate was heated under p r e s s u r e to 350 F . Circulat ion at a p r e s s u r e of 600 psig was establ ished by a plant boi ler feed pump through the s team genera tor and main s team bypass line back to the No, 4 hea te r .

5

The feedwater-flow - v e r s u s - p r e s s u r e - d r o p t e s t s were conducted on the No, 1 unit on May 14 and on the No, 2 unit on May 16, Water flows of 120, 000 to 210, 000 Ib /h r were used,* the l a t t e r flow being the nominal value for 200 Mwt operating conditions. The sys tem t empe ra tu r e was i so ­the rma l at 350 F and the wate r p r e s s u r e was 600 psig. The m e a s u r e d p r e s ­sure drop a c r o s s the No, 1 s team genera tor var ied from 5, 9 psi to 16, 16 psi at the two flow e x t r e m e s . These values a r e sma l l e r than the 6. 8 psi and 19, 8 psi p r e s s u r e drops m e a s u r e d at the same flow r a t e s for the No. 1 unit l as t month before the isolat ion t e s t s (see APDA-CFE-32 , Sec, II, C), On this b a s i s , i t i s believed that severa l of the poppet-type p r e s s u r e drop o r i ­fices in the water tubes were lifted during the isolat ion t e s t s and have r e ­mained in the up posit ion. P r e l i m i n a r y es t ima tes indicate that between five and ten orif ices out of a total of 1200 could be stuck in the up posit ion. It is thought that they might be hung up on the special t e s t thermocouples in­stalled in the water tubes of this unit. The water side of the No. 1 unit has been vented, purged, filled with ni trogen, and capped. Sodiuin will be drained from the unit p r io r to renaoval of the water inlet manifold cover to de te rmine the cause and extent of the reduced p r e s s u r e drop.

The m e a s u r e d p r e s s u r e drops a c r o s s the No. 2 steam genera tor at the two flow ex t r emes were 6. 1 psi and 19. 2 ps i , respec t ive ly . Although p r e s s u r e drop data a r e not available for this unit p r io r to the isolat ion t e s t s l as t year , the m e a s u r e d values a r e only about 4% sma l l e r than predicted; they a r e a lso in close agreement with the p r e s s u r e drops m e a s u r e d a c r o s s the No. 1 unit before i t s isolat ion t e s t s (see above). It has been concluded, the re fore , that all orif ices in this unit did r e s e a t following the isolation t e s t s . The water side of the unit has been vented, purged, filled with ni trogen, and capped.

A leak developed at the s team ananifold cover plate of the No, 3 s team genera tor when it was filled with water at 600 psig in prepara t ion for feed-water flow t e s t s . The water side of the unit subsequently was vented, purged, filled with ni trogen, and capped. An at tempt was made to seal the leak by re torquing the head bolts of the s team manifold cover plate , which was com­pleted by the end of the month. The unit will be refilled with water to de­t e rmine whether the s team leakage has been el iminated.

No cold-trapping was performed on any of the secondary sodium loops during May. The plugging t empe ra tu r e in the th ree loops fluctuated between

* Actually, flows as low as 10, 000 Ib /h r were used. However, re l iable p r e s s u r e drop data could not be obtained at flows l e s s than 60, 000 Ib /h r . Only the data for the 120, 000 to 210, 000 Ib /h r flows a r e given he re because they a r e the only data which can be di rect ly compared with the p re - i so la t ion tes t data given in APDA-CFE-32 .

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260 F and 280 F with only minor var ia t ions between loops; the bulk sodium t empera tu re was maintained at approximately 350 F throughout the month,

C. GAS SYSTEMS PERFORMANCE

Since the las t repor ted data (see APDA-CFE-32) , the following p r i ­m a r y system cover gas activity and gas analysis inforixiation have been obtained.

TABLE 1 PRIMARY SYSTEM COVER GAS ACTIVITY

Location

Reactor Cover Gas Reactor Cover Gas Reactor Cover Gas Reactor Cover Gas P r i m a r y Shield Tank P r i m a r y Shield Tank P r i m a r y Shield Tank P r i m a r y Shield Tank

Sample Date

5-8-69 5-14-69 5-21-69 5-29-69 5-8-69 5-19-69 5-21-69 5-29-69

G r o s s B e t a Ac t iv i t y , IdCi/cm-^

1.36 X 10"^ 7 . 4 5 X 10"'^ 2 . 1 1 X 10"^ 1.49 X 10"^ 2 , 6 6 X 10"^ 6. 30 X 10"^ 2 . 9 9 X 10"^ 3 ,49 X 10"^

D. FUEL AND REPAIR BUILDING SODIUM SYSTEM

No fuel-handling or s team-c leaning operat ions were per formed in the fuel and r epa i r building during the month of May. No cold-trapping of the t r ans fe r tank sodium sys tem was conducted. The sodium plugging t e m ­pe ra tu r e was 265 F at the beginning of the month and slowly rose to 272 F by the end of the month. The bulk sodium t empera tu re in the sys tem was maintained at approximately 450 F throughout the month,

E. RADIOACTIVE WASTE DISPOSAL

During May, 9, 203 gallons of liquid waste was discharged through the mete r ing pump to the north lagoon. The maximum specific activity m e a s u r e d in the liquid waste tanks in the fuel and r epa i r building was ap­proximate ly 5. 25 X 10" [JiCi/cm . The total activity discharged to the lagoon was approximately 16. 2 m i l l i c u r i e s . All effluent r e l eased after dilution with the circulat ing pump discharge was below maximum pe rmiss ib l e concentrat ion (MPC). Approximately 1 x lO" cubic feet of gaseous effluent was discharged through the plant waste gas stack during May. The concen­t ra t ion of activity was ve ry smal l and well below MPC after dilution in the stack blower and in the a tmosphere .

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TABLE 2 - PRIMARY SYSTEM COVER GAS ANALYSIS

Item

Oxygen Carbon Monoxide Carbon Dioxide Hydrogen Helium Methane Nitrous Oxide Nitrogen Argon Dew Point Shield Graphite

Tempera tu re

* Sample taken May 7, 1969

** Sample taken May 28, 1969. The p r i m a r y shield tank had been purged continuously for 14 days with dry nitrogen at this t ime (see Sec. V, A)

+ Technical Specifications state 1000 ppm maximum during r eac to r operation and during shutdown whenever p r i m a r y sys tem t e m p e r a t u r e s exceed 400 F

++ The recommended maximum for r eac to r operat ion is 10 ppm

+++ Technical Specifications state l e s s than -35 F except during maintenance, when values as l a rge as +80 F a r e allowed if p r i m a r y sys tem t e m p e r a t u r e s a r e l ess than 400 F

Reactor Cover Gas (Argon), ppm by volume

F i r s t Measurement ' '

Below 25 Below 10

30 Below 4+ Below 4 Below 10

350

Second Measurement >',< ; | <

P r i m a r y Shield Tank Atmosphere (Nitrogen), ppm by volume

During Boot Seal Repair'"

Below 25 15.8%+ Below 10 Below 10

25 345+ Below 4++ Below 2. 5 Below 4 Below 4 Below 10 Below 10

Not Measured

During Shield Tank Purge''"''

40 + Below 10

25 + 15

Below 4 Below 10

650 Remainder — Remainder — Not Measured

Not Measured +35 F+++

0.05% -40 F+++

315 F 308 F 315 F 308 F

Data a r e available from an environmental radiat ion survey made during the four-week period from F e b r u a r y 20 through March 20, 1969» A total of 81 environmental samples was collected and analyzed during this period and a summary of the activity levels found is as follows:

• The g ros s alpha and g ross beta activity levels of a i rborne dust samples obtained from the r e a c t o r si te a r e a and from a r e a s away from the r eac to r (to indicate the vicinity background) were found to be the same in both locations — approximately 3 x 10" |J.Ci/cm for the alpha activi ty in both cases and 14 x lO"-'-* ij,Ci/cm-* for the beta activity, thus indicating no a i rborne activity levels above background on the plant s i te . The activity levels a lso were e s sen ­t ial ly identical to those obtained in s imi la r m e a s u r e m e n t s made in 1967.

• Measurements of precipi ta t ion samples taken from the r eac to r site a r e a and from locations away from the r e a c t o r site also indi­cated no activity levels above background on s i te , the g ross alpha and g ross beta activity levels in both locations being approximately 0, 2 m C i / m i l e and 3. 5 m C i / m i l e , respec t ive ly . These values a lso correspond to the 1967 va lues .

• The specific activity of water samples taken from lakes and c reeks near the plant site and from the drinking water supply of neighbor­ing ci t ies showed no significant change in g ros s beta activity from s imi la r m e a s u r e m e n t s made in 1967, the activity levels in all cases being approximately 4 x 10"" jjCi/ml.

9

IIL PHOTOGRAPHIC SURVEY OF HOLDDOWN MECHANISM

The holddown inspection tool (see APDA-CFE-30 , Sec, III) and other equipment needed to photograph the f ingers of the holddown mechan i sm were used in the r eac to r four t imes in May as par t of the p rogram to obtain the requ i red s e r i e s of p ic tures for use in determining alignment of the holddo^wn f ingers . Photographs were taken at each of the t h r e e azimuth posit ions of the r eac to r vesse l rotating shield plug which were determined in the mock-up t e s t s (see APDA-CFE-30 , Sec, III. C) to be requ i red to view all four quadrants of the holddown finger a r r a y . A fifth inser t ion of the inspection tool into the r eac to r lat t ice was made without plug rotat ion or photography to per form an environmental t es t of the integrated lighting sys tem used. By the end of the month, the survey of the holddown finger a r r a y had been completed.

Because of r ecu r r i ng difficulties, pr incipal ly with the integrated lighting sys tem, the quality of some of the p ic tures obtained was not as good as had been expected. Ho^wever, they were found to be sa t is factory for ana lys i s . Very good photographs were obtained in the a r e a where subassem­bly melt ing had occur red , the pr incipal a r ea of i n t e re s t . P r e l i m i n a r y evalua­tion of the photographs shows no evidence of misal igned f ingers .

A, EQUIPMENT INSTALLATION

The holddown mechanism inspection tool was instal led in the r eac to r on May 7 in outer radia l blanket la t t ice position N07-P00. It was inse r ted from above the r eac to r , through a plast ic bag, in the No, 3 access pene t ra ­tion in the rotat ing shield plug, as shown in F igure 1. The Mark II borescope with c a m e r a at tachment, the Sunscope, and one ar t iculated viewing light were instal led in the adjacent No, 5 access penetrat ion as shewn in F igure 2 (see also APDA-CFE-9 , p 19; APDA-CFE-16 , p 5; and APDA-CFE-18 , p 21). The Sunscope and ar t icula ted viewing light were used to view the inspection tool during i t s inser t ion in the r eac to r and subsequently to view the layout of the flexible umbil ical cord (service hose) during plug rotat ion. Photographs were taken through the Mark II borescope , which focused on the spher ica l m i r r o r set on top of the inspection tool. Varying exposure t imes were used, depending on the lighting conditions. An automatic exposure calcula tor was attached to the c a m e r a to aid in determining the exposure t i m e s .

The equipment a r r angemen t remained essent ia l ly unchanged from that descr ibed above during subsequent inser t ions and photographic surveys on May 9, May 22, and May 29, except for minor var ia t ions made in the equipment locations in the plug access penetra t ions to gain g rea t e r ve rsa t i l i ty

11

105569

105669

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1^-' If

C«-* '

iriiiit Inspection Tool in Plastic tog

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FIG. 1 HiLDDOWi liSPECTIOi TOOL PilOB 1 liSERTIOi i i REACTOR

FIG. 2 BiRESCOPES. CAMERA. l i D LIGHT I i ACCESS

PEiETBITIOi iO . 5

12

in viewing and lighting. F o r the thi rd and fourth inse r t ions , the Mark III borescope (see APDA-CFE-9 , p 19) containing a new modified objective lens was substituted for the Mark II borescope to take advantage of i ts t h r e e - t i m e s - l a r g e r light gathering capabili ty. An additional ar t icula ted light, together with the Mark II borescope , also w a s instal led in the r e ­maining rotat ing plug access penetrat ion for the fourth survey. This was done to provide be t t e r lighting and m o r e versa t i l i ty for viewing the inspec­tion tool during i ts inser t ion in the r eac to r and subsequent se rv ice hose layout in the core cavity. It was found that although inser t ion of the inspec­tion tool -was aided by the added equipment, the bes t quality photographs of the holddown fingers were obtained when the two ar t icula ted l ights were not used. The ar t icula ted lights resu l ted in undes i rable shadows on the f ingers due to light blockage from the upper safety rod guide tubes , which extend below the holddown pla te . Thei r use also resu l ted in photographs of ve ry high cont ras t and ha r sh highlights which made accura te analysis m o r e diffi­cult than for photographs taken in the soft diffused light of the integrated lighting sys tem,

B. DIFFICULTIES ENCOUNTERED

A number of equipment difficulties were encountered during the at­tempts to photograph the holddown f ingers . Four separa te inser t ions of the inspection tool were requi red to complete the survey because of the need to remove the tool for repeated r e p a i r s and modificat ions. Each t ime the in­spection tool was removed, it was n e c e s s a r y to also remove , d ismant le , and clean accumulated sodium vapor deposits off each of the borescopes , in addition to cleaning the inspection tool m i r r o r .

The mos t ser ious difficulty encountered was repeated fai lure of the four 1500-watt Quartzl ine lamps located on the m i r r o r post . In th ree of the four surveys , the argon purge flow (3 cfm) to the in tegra l light c lus te r , in­tended to remove sodium vapor from the vicinity of the l ights , was los t before any photographs could be taken. This resu l ted in sodium deposition on the l ights , p rog re s s ive loss of light intensi ty during subsequent photog­raphy, and eventual overheating and fai lure of the l ights . In the other survey, contamination of the lamp purge gas caused deposition of foreign deposits on the l amps , which also resu l ted in the fading of the i l lumination intensity during the photography.

The lack of adequate lighting caused difficulties in focusing the c a m e r a on the m i r r o r and resul ted in long exposure t imes (of the o rder of severa l minutes in many cases) during the pic ture taking. This , in turn , resul ted in p ic tu res of l e s s than maximum resolut ion with p ic ture fuzziness caused by smal l movements of the borescope during the exposure , Borescope flutter could not be eliminated ent i re ly even though a rigid support cinch for the borescope was instal led at the top of the rotat ing plug.

13

A brief chronological summary of the difficulties encountered during the holddovsm finger photographic surveys in May is given below:

1. F i r s t Survey

Following the f i r s t inser t ion of the holddown inspection tool on May 7, difficulty was experienced in disengaging the bail located at the top of the tool r equ i red to lay down the se rv ice hose in the co re cavity. The locking keys located on e i ther side of the bai l , for use in holding the tool steady when it is lo-wered into the r eac to r , could not be disengaged from the keyway slots in the se rv ice hose col lar connection to the bail (see F igure 3). Disengagement was eventually made , but resu l ted in disconnection of the silicone rubber argon purge line at the point where it en te rs the housing compar tment for the m i r r o r dr ive motor . During subsequent rotation of the r eac to r vesse l shield plug to lay out the se rv ice hose, the hose contorted and the flex joints separa ted near the connection to the bail (see F igure 4). During the subsequent photography, as a r e su l t of the loss of purge gas , v i e w n g and photography became p rogres s ive ly m o r e difficult because of the diminishing i l lumination resul t ing from lamp blackening. Using an on-off mode of lamp operat ion, the total useful life of the lamps was about twenty minu tes , with about twenty additional minutes of ex t remely dim light. Most photographs had to be taken with one-minute exposure t i m e s ; in some cases exposure t imes as long as 1-1/2 minutes were used . The major portion of the lamp lifetime was requi red for orientat ion and focusing adjustments of the borescope .

Following removal of the inspection tool from the r eac to r , the separa ted portion of the se rv ice hose was r epa i red by s i lver soldering. The keyway slots for the bail pivots were filled with weld m a t e r i a l so that the pivot lugs were free to pivot at all posit ions and the argon purge line was reconnected. The four Quartzl ine lamp bulbs which had blackened and bowed from overheating were replaced, together with the P y r e x envelope around thein, which also was blackened and dis tor ted (see F igu re s 5 and 6),

2. Second Survey

In the second survey, made on May 9, init ial exposure t imes twice as long as those used in the f i r s t survey (two minutes v e r s u s one minute) were found to be requ i red . Also, the light intensi ty from the lamps on the post began to fade noticeably after only eight minutes of total lamp usage . By the t ime the lamp usage totaled thir ty-f ive minu tes , exposure t imes of four minutes were required^

When the inspection tool was removed from the r eac to r for examina tion, the argon purge line to the lamp c lus te r was found to be intact; however, the lamps and P y r e x envelope were again blackened and dis tor ted with a maximum t empera tu re of at l eas t 3, 000 F indicated by the softening of the

14

Keyway Slots

105769 FIG. 3 DEFECTIfE KEYWAY SLOTS

I i SERYICE HOSE COLLAM

Separated Joints

105869 FIG. 4 SEPMATIOi OF

SERWICE HOSE JOIiTS iEAR COLLM

105969 FIG. B BOWED ttUARTZLIlE LAMP

BULBS

106069 FIG. 6 BLACKEiED PYBEX EiWELOPE

FOi LAMPS

15

quar tz l a m p s . The spher ica l M i r r o r also contained a stain that could not be removed, and a rep lacement m i r r o r had to be ins ta l led. Investigation revealed that the probable cause of the lamp blackening was offgassing of low-volati le (less than 500 F) lubr icants used in the m i r r o r motor located in the motor compar tment d i rec t ly above the light c lus te r . In the original tool design, the silicone rubber argon purge line was connected to a copper tube entering the top of the motor compar tment . The purge gas spilled f i rs t into the motor compar tment , after which it was d i rec ted out of the mo to r compar tment through smal l holes located in the bottom of the compar tment to the light chamber below. Any offgassing of organic m a t e r i a l in the motor compart inent would therefore be c a r r i e d into the light chamber and collect (hot-trap) on the light bulbs .

On this assumption, a design modification was made to the tool in which the copper tube purge line connection at the top of the motor com­par tment was extended completely through and out the bottom of the motor compar tment . All remaining holes between the motor and light compar t ­men t s were blocked except the one used by the new purge tube, thus allow­ing the purge gas to be c a r r i e d d i rec t ly to the light chamber . These modi ­fications a r e shown in F igu re s 7 and 8. Purge flow to the motor compar t ­ment could be el iminated, since it served no useful purpose . High- tempera­tu r e operat ion of the m i r r o r dr ive motor had been previously demonst ra ted .

3. Light Test in Reactor

Following the purge line modifications and replacement of the damaged l ights , blackened P y r e x envelope, and stained m i r r o r , the inspec­tion tool was re turned to the r eac to r on May 20 for environmental test ing of the l ights to check out the modif icat ions. F igu re 9 is a photograph taken of the inspection tool through the Sunscope during the lighting tes t in the r eac to r in which the lights were operated on a six-minute-off, s ix-minute-on cycle continuously for th ree hours , accumulating a total lamp usage of 90 minu te s . Light intensity m e a s u r e m e n t s were made using the c a m e r a and i ts exposure calcula tor . The m e a s u r e m e n t s showed that the lamps operated for approximately one hour before any noticeable change in light output oc­c u r r e d . The calculated exposure t imes var ied from 3 to 5 seconds at the beginning of the t e s t to 8 to 10 seconds near the end of the t e s t . These t imes compared favorably with the 15 to 30 second maximum allowable exposure t imes for high resolut ion found to be requ i red in the mock-up t e s t s of the inspection tool (see APDA-CFE-30 , Sec. III. C). No deposits were found on the outer surface of the lamps or Py rex envelope when the tool was r e ­moved from the r eac to r at the conclusion of the t es t , verifying the adequacy of the design modifications made in the argon purge sys tem.

16

106169

FIG. 7 COPPER TUBE COiiECTIOi FOR PURGE GAS LliE IT TOP OF MOTOR COMPARTMEIT

f: 106269 ;

FIG. i COPPER TUBE EXTEiSiOi THROUGH BOTTOM OF MOTOR COMPIRTWEiT

17

106369

FIG. 9 HOlDDOWi liSPECTIOi TOOL I i REACTOR DURING LIGHT TEST

18

4. Third Survey

Shortly after the th i rd inse r t ion of the tool on May 22, an e l ec ­t r i ca l short developed in the wiring to the rotat ing m i r r o r mo to r winding which controlled clockwise rotat ion of the m i r r o r . Attempts at clockwise rotat ion resu l ted in a success ion of blown fuses; consequently, all subse­quent p ic ture taking was r e s t r i c t e d to counterclockwise m i r r o r rotat ion, which also el iminated control of the t i l t of the m i r r o r .

The initial p ic tu res were taken with exposure t imes ranging from 80 to 120 seconds, which were substantial ly longer than es t imated in the lighting tes t . Within a shor t t ime , the lighting began to fade even m o r e rapidly, and the survey was soon forced to a halt due to a lack of sufficient lighting.

When the inspection tool was removed from the r e a c t o r , i t was found that the purge hose was again severed near the top of the bai l . The lamps were blackened but not bulged or warped. They were replaced with new l amps . The P y r e x envelope was clean and in good condition and did not r equ i re rep lacement . A new rubber hose was instal led to replace the broken hose and the new hose re rou ted on the bai l in an attenapt to min imize the possibi l i ty that loose sections of hose could snag in the top of the bail during tool inser t ion and subsequent se rv ice hose layout.

No cause for the pa r t i a l fai lure of the m i r r o r dr ive motor was found. Disassembly of the mo to r revealed no defects . In bench t e s t s the motor operated norinal ly in both d i rec t ions ; however, as a p recaut ionary m e a s u r e before the moto r was re ins ta l led on the inspection tool post , the e lec t r i ca l leads were wrapped with glass tape and fastened secure ly to the bai l .

5, Four th Survey

When the inspect ion tool was inse r ted in the r eac to r for the fourth survey on May 28, the init ial effort to rota te the m i r r o r after se rv ice hose layout resu l ted in an e lec t r i ca l shor t in the wir ing of the mo to r dr ive nea r the top of the rotat ing shield plug. F u s e s were blown in the moto r control box. Following r epa i r of the short , visual observat ions miade through the Sunscope and Mark II borescope revealed that the argon purge hose was again broken off. As previously , the lighting available for p ic ture taking began to fade rapidly as the photography p r o g r e s s e d . Within two hour s , the exposure t ime p e r p ic ture had r i s en from 68 seconds to 4 minutes , causing te rminat ion of the survey.

The inspection tool was once m o r e removed from the r eac to r , and r e p a i r work is now in p r o g r e s s to rep lace the damaged argon supply hose with a new hose and to locate the hose on an a l te red route over the ba i l .

19

Considerat ion was given to replacing the sil icone rubber hose , which is ve ry flexible but has l i t t le s t rength, with a h igh- t empera tu re substi tute; but none could be found. All of the e l ec t r i ca l wiring for the lights and for the m i r r o r dr ive motor is also being replaced; the four Quartzl ine lamps "wil] be changed. Finally, the lighting sys tem is being converted frona a grounded system to an isolated sys tem to min imize the possibi l i ty that the l ights can short in the event the lighting c i rcui t becomes grounded.

C. HOLDDOWN PHOTOGRAPHS

During May, photographs were taken of all four quadrants of the hold-down finger plate^ The individual a r e a s covered in each of the four surveys were (I) the northwest and southwest quadrants ; (Z) southeast quadrant (the location -where mel ted and bent subassembl ies were found); (3) nor theast and southeast quadrants ; and (4) the southeast quadrant (see APDA-CFE-28 , F igure 10). Typical photographs of the southeast quadrant and the northwest quadrant a r e shown in Figi i res 10 and 11. Although the quality of some of the p ic tures was not as good as that of o the rs , mos t appear to have adequate c lar i ty and resolut ion to allow analysis for evidence of holddown finger d i s ­tort ion and misa l ignment . In only a few cases i s it believed the p ic tures cannot be accura te ly analyzed because of da rkness or fuzziness . P i c tu r e s of port ions of the nor theas t and southeast quadrants nea r the core edge a r e in this category. Also, no p ic tures of the holddown fingers were obtained near the core edge in the southwest quadrant . However, v e r y good photo­graphs were obtained in the a r ea of the southeast sec tor where subassembly melt ing and dis tor t ion had occur red . This is the a r ea of pr incipal in te res t ; the other a r e a s a r e of l e s s e r i n t e r e s t because the re is no evidence that ab­normal forces on subassembl ies occur red outside the southeast sec tor during the October 5, 1966 incident.

P r e l i m i n a r y analysis of the photographs to date shows no evidence of misa l ignment of the holddoAwn f ingers . Detailed analyses a r e now being made to verify this fact and also to verify that the p ic tures of l e s s e r quality (clarity) have adequate resolut ion for accura te graphical ana lys is . Following these analyses and r e p a i r of the inspection tool, it is planned that the tool will be r e in se r t ed in the r eac to r to rephotograph any a r e a s where definitive analysis of the p resen t photographs is doubtful, and to photograph that portion of the southwest sec tor m i s s e d in the e a r l i e r survey.

20

106469 FIG. 10 ¥IEW OF SOUTiEAST SECTOi OF HOLiiOWi PLATE

21

106569

^»f

. f >

«*f!

#

• 4

FIG. 11 ¥IEW OF iORTHWEST SECTOR OF HOLiDOWi PLATE

22

IV. STATUS OF PLANT MODIFICATIONS UNDER CONSTRUCTION

A. FUEL TRANSFER FACILITY

Last month erec t ion of the new fuel t r a n s p o r t facility in the r eac to r building was coixipleted (see APDA-CFE-32 , Sec. IV. A); this month checkout of the facility was approximately 50% complete with all d r ives being energized and the controls tes ted . Painting of the facility i s also near ly complete . However, the j acksc rew used to r a i s e and lower the plug cask on the br idge and t ro l ley s t ruc tu re was damaged. The j acksc rew is mounted on the br idge and t ro l ley s t ruc tu re and extends downward from the s t ruc tu re into the top of the plug cask. A drive moto r mounted on top of the plug cask is used to tu rn the sc rew to r a i s e and lower the cask. The damage occur red when in o rde r to ca l ibra te the facility the in ter locks were defeated^ The plug cask was accidental ly lowered too far , hitting the floor and bending the j acksc rew. A new jacksc rew has been o rde red . Final alignment and checkout of the t r anspo r t equipment will be delayed somewhat until the j acksc rew is replaced . The exit por t floor valve mus t also be instal led.

B. AUXILIARY FUEL STORAGE FACILITY

P r o g r e s s l as t month on converting equipment decay tank No. 2 in the r e a c t o r building to an auxi l iary fuel s torage facili ty (see APDA-CFE-30 , F igure 19) consisted of insulating the bottom and sides of the tank and in­stalling the false floor and dr ip pan inside the tank (see APDA-CFE-32 , Sec, IV. B). This month the unders ides of the shield plugs were insulated, s tee l l iner tubes were ins ta l led in the plug acces s por t s and ro to r shaft pene­t ra t ion , the fuel s torage ro to r was instal led in the tank together with the hea te r stack and thermocouple l eads , and the shield plugs were re turned and set in the i r final position in the tank. The auxi l iary fuel s torage facility is now about 75% complete .

F igure 12 shows the insulation being instal led on the unders ide of the decay tank inner shield plug. The inner and outer shield plugs were both removed from the tank and set on support b racke t s on the r eac to r building operating floor adjacent to the decay tank for this purpose . The 4-inch-thick blocks of Johns-Manvil le F ibe r f r ax insulation were held in place by b racke t s welded to the bottom of the shield plugs, and the insulation was covered with a 5-mil th ickness of corrugated aluminum protect ive lagging. F igure 13 is a photograph of a stepped steel l iner tube grouted in place in one of the two fuel loading access por t penetra t ions through the tank shield plugs, A s imi l a r l iner was instal led in the second access por t and in the ve r t i ca l penetra t ion for the shaft of the fuel s torage ro to r . Solid carbon steel shield plugs will be located in the acces s por t s "when they a r e not being used for

23

106669 106769 FIG. 12 liSULATIiG UiDERSIDE OF FIG. 13 STEPPED STEEL LliER l i

DECAY TAiK SHIELD PLUG LOIDliB PORT

106869 106969

FIG. 14 HEATER STACK DURIiG FIG. 15 HEATER STACK COiSTRiCTIOi ASSEMBLED Oi

BOTTOM OF STORAGE ROTiR

24

fuel loadings A bushing is located in the bottom of the l iner for the ro to r shaft penetra t ion to facil i tate center ing the ro to r shaft in the penetra t ion.

F igu re 14 is a photograph taken during the construct ion of the hea te r stack for the auxi l iary fuel s torage facility^ The hea te r stack will mainta in the argon a tmosphere of the s torage facility at approximately 360 F . The hea te r stacks which was l a te r centered and mounted on the unders ide of the s torage ro to r , consis ts of 15 Chromalox e lec t r i ca l r e s i s t ance hea t e r s located in the lower end of a 2- foot -square , 8-foot-long stack assemblv. The h e a t e r s will be operated at 110 volts or one-half of the i r ra ted voltage (220 volts) for inc reased re l iabi l i ty and at this dera ted c o n d i t i o n w i l l p r o v i d e a max imum capabili ty of 15 kw. Since this is considerably m o r e heat than n e c e s s a r y to mainta in the s torage a r e a t empe ra tu r e des i red , only about half of the c i rcu i t s will be energized at one tinae during facility use» When instal led, the stack extends to within 8 inches of the bottoixi of the sodium drip pan located on top of the false floor^ This allows argon to enter the bottom of the stack and pass over the h e a t e r s . Circulat ion of the heated argon will be by natura l convection up the stack and out openings located at the top.

F igu re s 15 and 16 show the hea te r stack mounted beneath the s torage ro to r p r i o r to instal lat ion of the s torage ro tor in the decay tank. The e l ec ­t r i ca l hea te r wire l eads , thermocouples l eads , and a gas sampling line were all brought up from the fuel s torage a r ea through the center of the hollow ro tor shaft. They will be connected to a t e rmina l junction box located at the top of the shaft. Lead shot will then be poured down the shaft around the leads to provide shielding against radiat ion s t reaming up the shaft.

F igure 17 is a photograph of the s torage ro tor with attached hea te r stack instal led on the t e m p o r a r y support b racke t s located inside the decay tank. The instal lat ion of sodium leak de tec tors on the dr ip pan and t h e r m o ­couples in var ious a r e a s inside the tank had a l ready been completed^ F i gu re s 18 and 19 show the facility following the r e inse r t ion of the insulated shield plugs in the tank. The remaining work on the facility involves completion of the e lec t r i ca l , thermocouple , purge , and sample gas line connections at the junction box and argon station instal lat ion of the hand-opera ted worm gear dr ive and indexing equipment at the top of the ro tor shaft above the shield plug, and conduct of mechanica l t e s t s of the facility.

C. MALFUNCTION DETECTION ANALYZER

During May, work continued on the instal lat ion of the MDA (see APDA-C F E - 3 1 , Sec. IV. C), The cable r acks for the many signal cables to the com­puter a r e p resen t ly being instal led in the re lay room di rec t ly below the com­pute r . After completion of the cable rack instal lat ion and cutting of the pene­t ra t ions in the control room floor for the thermocouple and other signal cable l eads , work will begin on pulling and install ing the cable feeds to the computer .

25

Thermocouple and Heater Leads Entering Hollow Rotor Shaft

107069 107169

FIG. I I CLOSE-UP OF HEMER STICK FIG. 1? STOBME iOTiB l i PLACE ASSEMBLY UiDER liSIBE i E C M T A i l STOiAGE ROTOR

\

m #

%

^

r.

s =

*k

»

«*.

0*

'1 i

107269 107369

FIG. 18 ROTOR SHAFT PEiETBATIOi FIG. 19 l i i ER PLUG COWER PiME THROUGH l i i E R SHIELD PLUG BEIiG LOWERED OYER

ROTOR SHIFT

26

In p repara t ion for rerout ing the thermocouple cables to the junction boxes^ two c r i t e r i a thermocouples were re rou ted so that they can be r ead in the r eac to r control room during the rewir ing . The equipment enclosure for the t e m p o r a r y s imulator to be used in checking the operat ion of the malfunction detection analyzer has a r r i ved and is being insta l led.

D. PRIMARY SYSTEM COLD^TRAP ROOM MODIFICATIONS

Las t month a t e m p o r a r y lead shadow shield was e rec ted pa r t way around the p r i m a r y cold t r ap in the p r i m a r y sodium, se rv ice building cold-t r a p room to allow personnel a c c e s s for planned modifications to the sodium puri ty monitoring system (see APDA-CFE-32 , Sec. IV. D). This month the piping in the p r i m a r y co ld- t rap room was p repa red for the n e c e s s a r y cutting, re rout ing , and new equipment instal la t ion.

The p r i m a r y sodium serv ice sys tem modifications a r e being made to improve the accuracy , repeatabi l i ty , and sampling capabili ty of the p resen t p r i m a r y sodium plugging indicator sys tem and to allow the addition of a de­velopmental sodium hydrogen detector which labora tory t e s t s show has the potential capabili ty of continuously monitor ing sodium hydrogen content during r eac to r operat ion.

The modifications to the plugging indicator c i rcui t consis t essent ia l ly of changing the p resen t sys tem to a constant p r e s s u r e sys tem •which is no longer in para l le l with the p r i m a r y cold-trap. This should el iminate the per turbing effect which co ld- t rap operat ion previously was thought to have on operat ion of the plugging indicator . The sys tem is also being changed so that the smal l flow requi red through the plugging indicator can be controlled by an automatical ly operated e lec t romagnet ic pump added u p s t r e a m from the p resen t plugging indicator and i ts f lowmeter, r a the r than by the manual ly-operated throt t le valve used in the p resen t sys tem. The throt t le valve proved to be sensi t ive and difficult to adjust at the smal l flows requi red .

F igu re 20 shows the ba red piping ups t r eam from the p resen t plugging indicator and flowmeter at the location where the new elect romagnet ic pump will be added. To change the sys tem so that it is independent of co ld- t rap operat ion, the outlet piping from the plugging indicator will be re routed so that both it and the plugging indicator inlet l ine a r e connected close to each other , with no intervening components, on the main sodium serv ice line feed from the r eac to r building, thus forming a loop independent from the co ld - t r ap . P r i o r to bar ing the pipes for cutting, the serv ice l ines to the p r i m a r y co ld- t rap room were heated and blown c lear of sodium (back to the No. 1 IHX), the valves were closed to isola te the systena, and the line h e a t e r s were de-energ ized to freeze any sodium remaining in the piping. The line h e a t e r s , insulation, and lagging were then removed from, the section to be cut, and f reeze boxes were put around each section of pipe in prepara t ion for cutting.

27

107469

FIG. 20 LOCATIOi OF iEW ELECTROIiAGiETIC PUMP FOR PRIMARY SYSTEM PLUGGIiG liDICATOi

107569

FIG. 21 LOCATIOi OF FLOWMETER FOR PRIMABY SYSTEM HYiBOGEi DETECTOR

28

The hydrogen detector is scheduled to be added l a te r in the inlet of the bepass loop (in paral le l with the cold t rap) used for the sodium sample coil . The p resen t modifications consis t of install ing the magnet ic l iowmeter for the hydrogen detector in the inlet line ups t r eam from the proposed hydrogen detector location. F igure 21 shows the inlet line bared for the flowmeter instal lat ion.

P r i o r to install ing the e lec t romagnet ic pump in the modified plugging indicator loop, the pump was tes ted to de te rmine the maxiiiium safe voltage which could be applied to the pump with no sodium in the pump tube, without causing excess ive overheating of the tube. The pump is designed for a maximum t e m p e r a t u r e of 450 F . It was found that 95 volts produced a m a x ­imum 290 F t empe ra tu r e r i s e above the nominal 150 F ambient t empe ra tu r e after two hours of operat ion. This is considerably m o r e voltage than needed to produce s tar t ing flow in the plugging indicator . It was concluded, there fore , that by l imiting the applied voltage to 95 volts or l e s s , t he re will be suffi­cient power to produce flow, plus adequate protect ion against burnout during empty tube conditions. Instal lat ion of the new elect romagnet ic pump and flowmeter and rerout ing of the piping in the cold t r ap room will begin next month.

E. DELAYED NEUTRON DETECTOR

1. Background

A delayed neutron detector sys tem (DND) is being added to the plant for possible connection l a te r to the new malfunction detection sys tem (see A P D A - C F E - 3 1 , Sec. IV, C). The m o d e r a t o r - s h i e l d port ion of the sys tem was instal led this month below the r eac to r building operating floor on a plat ­form set on the equipment compar tment floor. The purpose of the DND is to detect e i ther fuel pin cladding failure or melt ing by means of the delayed neutrons given off by the halogen fission products r e l ea sed to the sodium coolant. Although the detection sensit ivi ty of the DND is not expected to be as grea t as that of the cover gas fission product moni tor p resen t ly instal led at the plant, i ts r esponse t ime should be much fas te r . It also can be used in conjunction with the cover gas f ission product detector during the forthcoming fuel test ing p rog ram to facil i tate identification of a noble f ission gas r e l e a s e from tes t pin fa i lure , as opposed to fai lure resul t ing in fuel mel t ing.

2. Design of the Delayed Neutron Detector

The DND system consis ts of four Reuter-Stokes boron-10 lined proport ional de tec tors mounted inside a combination mode ra to r - sh i e ld a s s e m ­bly box located below the r eac to r building operating floor on the equipment compar tment floor. The box is positioned between the ve r t i ca l runs of the 30-inch p r i m a r y sodium outlet l ines of loops 1 and 2, just outside the secondary shield wall , at a point where the l ines r i s e from the equipment compar tment

29

floor after passing underneath the secondary shield wall to enter the in te r ­media te heat exchanger tanks of each loop.

The ve r t i ca l pipe runs a r e only approximately 6 feet apar t at this location. Two de tec tors will be located adjacent to each of the 30-inch p r i m a r y sodium pipes , although only one of the two de tec tors will be used to moni tor each pipe and provide a signal to the e lect ronic counting sys tem at any given t ime . The spare de tec tor is being provided at each pipe because the a r ea where the de tec tors a r e located will be inaccesible once i r r ad ia ted fuel is s tored below floor in the auxi l iary fuel s torage facility, or when r eac to r operat ion is r e sumed . Two of the th ree p r i m a r y loops a r e being moni tored to a s s u r e that at l eas t one counting channel will be available at all t imes during per iods of anticipated two-loop operat ion. Also, the monitoring of two loops provides redundancy during th ree - loop operation, and during two-loop opera ­tion on loops 1 and 2. The de tec to rs have an upper t empe ra tu r e l imi t of 400 F; no forced cooling will be requ i red for them, since the below-floor a tmosphere t empe ra tu r e in this a r ea is not expected to exceed 130 F during 200 Mwt operat ion.

The de tec tors a r e mounted para l le l to the sodium pipe in the inode-r a to r - sh i e ld assembly box, which in turn s i ts on a heavy steel platform ra i sed th ree feet above the lower equipment compar tment floor between loops 1 and 2. The box has the shape of a rec tangle 70 inches long, 39 inches high, and 33 inches wide. The space around the de tec tors in the box is filled with lead, graphi te , and sheets of Bora l shielding m a t e r i a l . The Boral and lead a r e used to absorb and f i l ter out the high-level neutron and g a m m a - r a y background radiat ion in the a rea , which would otherwise adverse ly affect the operation of the de t ec to r s . The background radiat ion consis ts of low-energy neutron leak­age from the secondary shield wall and high-energy gamma radiat ion from radioact ive sodium in nearby pipes and components . The graphite is used to mode ra t e the low-level , h igh-energy delayed neutrons resul t ing from the de­cay of the B r - 8 7 and 1-137 fission product isotopes in the sodium, and thereby i nc r ea se the detector efficiency by improving sensi t ivi ty. B r -87 and 1-137 a r e the only two fission product halogen isotopes of impor tance in the six delayed neutron groups r e l eased to the coolant upon fuel fa i lure , since all o thers have half- l ives which a r e short compared to the es t imated 70 second sodium t r a n s ­por t t ime from the core to the detector location.

The geomet r ica l a r r angmen t of the shielding and moderat ing m a t e r i a l inside the detector a s sembly box is r a the r complex; in general , the a r r angemen t is as follows:

At the two ends of the assembly , adjacent to and facing the p r i m a r y sodium pipes , the space in the box between the pipe and de tec tors is filled f rom the outside inward with a 1/4-inch thickness of Bora l , four inches of

* Natura l boron carbide in an altuninum m a t r i x clad with aluminum.

30

lead, and six inches of graphi te . The remaining two sides of the a s sembly and i ts top and bottom contain a 3 /4- inch thickness of Bora l , six inches of graphi te , four inches of lead, and finally th ree inches of graphite surrounding the de t ec to r s . Rectangular openings 13 inches by 1-1/4 inch by 1-1/4 inch a r e provided in the graphite at each end of the a s sembly for the de t ec to r s . The two de tec tors at each end a r e placed s ide -by-s ide facing the pipe with the two-inch space between the de tec to rs being filled with graphi te . The space in the middle of the box between the two sets of de tec tors is a lso filled with graphi te .

With this a r r angemen t of shielding and modera t ing m a t e r i a l , the background radiat ion enter ing the two s ides , top, and bottom of the box is effectively shielded to negligible levels at the location of the de t ec to r s . In addition, the design a s s u r e s that the major port ion of the background radiat ion enter ing the two ends of the box is a lso removed before it r eaches the de tec ­t o r s , but it allows the major port ion of the h igh-energy delayed neutron r a d i ­ation enter ing the ends to f i l ter through and be modera ted at the detector loca ­t i o n , thus resul t ing in an optimized s ignal - to-noise ratio.'"'

The de tec tors a r e mounted so that the i r weight is supported on the graphite at the bottom of the rec tangular detector spaces located in the graphite cubes at each end of the a s sembly box. Each detector has a 1/2-inch-d iamete r t r i ax ia l cable in tegra l ly at tached to i t . The four cables a r e routed upward through the graphite and lead shielding m a t e r i a l and a r e brought out of the box together at a cent ra l ly located fitting in the top of the box. The cables a r e then routed up through the r eac to r building operat ing floor by m e a n s of an existing 24-inch floor penetra t ion located on the north side of the contain­ment building. Rigid support for the cables to keep cable vibrat ion a t m in ­imum i s provided from the point where they emerge from the top of the mod­e r a to r - sh i e ld assembly box to the bottom, of the operat ing floor. This support i s provided by a special s t ruc tu re attached to existing beams in the below-floor a r e a , the cables being clamped at r egu la r in te rva ls along the support s t ruc tu re .

3. Erec t ion of Delayed Neutron Detector

Assembly of the DND below the operating floor was essent ia l ly com­plete by the end of May. The construct ion sequences is summar ized in F igu re s 22 through 25. F igure 22 shows the empty m o d e r a t o r - s h i e l d assembly box mounted on i t s s teel support platform outside the secondary shield wall between the ve r t i ca l pipe runs of p r i m a r y loops 1 and 2. F igure 23 is a photo­graph of the box approximately half filled with graphi te , lead, and Boral

* The background resul t ing from the fissioning of u ran ium impur i t i e s in the sodium coolant and from the u ran ium contamination on the surface of the fuel pins i s negligible.

31

Secondary Shield Wall

\

Loop 2

Holes in Graphite for Detectors

J

107669 107769

FIG. 22 MOiEBMOB-SHIELD ASSEMBLY FIG. 23 MODERATOR-SHIELD ASSEHBif BOX FOR DELAYED iEUTBOi BOX PARTIALLY FILLED

DETECTOR

107869

FIG. 24 CABLE LEAiS OUT TOP

OF ASSEMBLY BOX

107969

FIG. 25 CABLE LEADS THROUGH PENETiATIOi l i OPERATING FLOOR

32

shielding and modera t ing m a t e r i a l . The total weight of the assembly when completely filled was approximately six tons; al l six tons of m a t e r i a l had to be hand -ca r r i ed below-floor through a 24- inch-d iameter manhole in the operat ing floor. F igure 24 shows the completed a s sembly box with the cables for the four de tec tors emerging from the top. F igure 25 is a photo­graph of the detector cables at their penetration through the reac tor build­ing operating floor. The remaining work on the DND involves connecting the detector leads to the p reampl i f i e r s , which will be located adjacent to the floor penetrat ion, and making the connections to the readout equipment. The floor penetrat ion will be filled with lead shot to prevent radiation leak­age during r eac to r operat ion.

33

V, PLANT MAINTENANCE

A. PRIMARY SHIELD TANK BOOT SEAL REPLACEMENT COMPLETED

Instal lat ion of the new p r i m a r y shield tank boot sea l , which was begun l a s t month (see APDA-CFE-32 , Section IV. E) , was completed on May 16. F igure 26 is a photograph taken during the instal lat ion showing the new upper clamp r ing and new boot seal par t ia l ly in p lace . After clamping m o s t of the boot seal in place in this manne r , a 10-foot-long section was left exposed on the r e a c t o r ve s se l mach ine ry deck to allow the final c losure splice to be m a d e . The ends of the boot seal were cut so that about 2 inches of m a t e r i a l from each end could be overlapped at the top and bottom, as shown in F igure 27. The mating surfaces of the boot ends were then cleaned with dye penet rant c leaner and coated with Silast ic adhesive. After the p r e sc r ibed drying t ime , the mat ing surfaces were bonded together and clamped for a 24-hour cu re , as shown in F igure 28. Following removal of the c lamps , the cent ra l body of the seal was hand-sewn with two ve r t i ca l rows of nylon s t i tches , and the upper and lower overlapping sect ions were sewn with four horizontal rows of s t i tches , as shown in F igure 29. The ent i re joint was then coated on both sides with sil icone rubber cement; after the cement had cured the remaining 10-foot section of boot seal was insta l led in the seal annulus and clamped in place to complete the instal lat ion, as shown in F igure 30.

Following completion of the boot seal instal lat ion the ni trogen p r e s s u r e control sys tems for the p r i m a r y shield tank, which had been converted to a flow-through sys tem for the pas t yea r , were re tu rned to s e rv i ce . A dry ni t rogen purge flow of 5 cfm was then establ ished through the lower sweep header in o rde r to purge the shield tank of the a i r a tmosphere introduced during the boot seal rep lacement p r o g r a m . The ni trogen flow was l a te r inc reased to 20 cfm and maintained at that level until the gas pur i ty and dew point levels of the p r i m a r y shield tank a tmosphere had reached acceptable va lues . By the end of May, the dew point of the shield tank a tmosphere had been reduced from +35 F to -40 F , and the gas pur i ty levels given in Table 2 had been attained.

On May 27, p r e l i m i n a r y leak r a t e t e s t was conducted on the shield tank to check for g ross leakage and de te rmine the general integri ty of the new boot sea l . The t e s t was conducted over an 8-hour period with a p r e s s u r e of 8 inches WCG in the lower p r i m a r y shield tank. The m e a s u r e d leak r a t e was 18 scfh, which indicated that no significant leakage was occur r ing . Purging of the shield tank a tmosphere will be continued until the dew point is lowered to -45 F . Following th i s , the annual 2-psig leak ra t e t e s t will be conducted to make a final check on the integri ty of the new deck r ing boot s ea l s .

35

\ 108069

FIG. 2S PRIMARY SHIELD TAiK BOOT SEAL PARTIALLY liSTALLED

^^ i/ 108169

FIG. 27 MATIiG SURFACES FOR BOOT SEAL CLOSURE SPLICE

^

108269

FIG. 2S CLAMPIiG OF CLOSURE SPLICE AFTEi GLUIiG

36

108369

I0B469

FIG. 29 STITCHI iGf lF CLBSiiE SPLICE

J k

FIG. 30 COMPLETED BOOT SEAL liSTALLATIOi

37

B. REPAIR OF NO. 1 PRIMARY SODIUM PUMP

The ro tor for the No. 1 p r i m a r y sodium pump moto r , which "was siiipped off site las t month (see APDA-CFE-32 , Section V. C) for machining of slip r ings found grooved from a r c - o v e r , was re turned and re ins ta l led in the motor housing. In the mean t ime , the th rus t bear ing assembly for the pump shaft 'was d i sassembled for inspect ion. Inspection revealed an i r r e g u l a r wear pat tern in the bear ing r a c e s (see F igure 31). The spalled bear ing r a c e s will be polished for r e u s e . The seal faces in the No. 1 pump a r e also being replaced to c o r r e c t the oil leakage difficulty found las t month, which was thought to be the cause of the a r c - o v e r and subsequent slip r ing damage. The r eason for the high torque observed severa l months ago on the No. 1 pump (see A P D A - C F E - 3 1 , Section III. C) is sti l l under investigation. Although no cause for it has been found yet, it is known that the No. 1 pump, which is of a slightly different design than the other two p r i m a r y pumps , has always had higher torque than the other pumps .

C. NEUTRON DETECTOR CHANNEL MALFUNCTION

On May 13, during the daily logging of neutron detector signals taken -with the reac tor shut down, the shutdown count ra te on the low-sensi t ivi ty source range channel 2 detector (a vVestinghouse U-235 fission counter) was observed to have increased by approximately a factor of six above the count r a t e logged the previous day. No change occur red in the count r a t e on low-sensit ivi ty source range channel 1 detec tor , also a Westinghouse U-235 fission counter , located in the same neutron detector tube at the same position as source range channel 2. The count ra te on source ra te channel 2 was moni tored for severa l additional days , during which t ime i t remained at the high level of May 13.

P r e l i m i n a r y inspection of the channel indicated that a change in gain has occur red somewhere between the detector , located inside neutron detector tube No. 3 in the p r i m a r y graphite shield, and the d i sc r imina to r , located in the r e l ay room beneath the main r eac to r control room. This reduced the source of the t rouble to e i ther the preampl i f ier located in the neutron detector box set on the r e a c t o r building operating floor above the detector tube or to the pulse amplif ier located in the r e l ay room.

To de termine whether the preampl i f ie r or pulse amplif ier was the source of the unexplained gain, the supplementary high-sensi t iv i ty source range channel 2 detector circuit"" was energized and count ra te ra t ios between the

* The high-sensi t iv i ty source range channel 2 detector is located in neutron detector tube No. 4, which is adjacent to neutron detector tube No. 3. The high-sensi t iv i ty detector is a lso a Westinghouse fission counter , but it is canned inside z i rconium hydride to inc rease i ts sensit ivity so that it can be used in extending the life of the ant imony-beryl l ium neutron source used for r eac to r

38

low-sensi t iv i ty and high-sensi t iv i ty channel 2 de tec tors were compared . The count r a t e ra t io of the two channels was f i r s t obtained at the output of each preampl i f ie r . The rat io the re was the same as that obtained in previous m e a s u r e m e n t s made over the past severa l y e a r s , indicating that the gain shift was not in the preampl i f ie r of low-sensi t iv i ty source range channel 2 (excluding the unlikely possibi l i ty that both preampl i f ie r s had changed in an identical manner ) . This reduced the location of the gain shift to the pulse amplif ier of source range channel 2, This conclusion was confirmed by connecting an osci l loscope and a Hamner amplif ier at the output of the pulse amplif ier for channel 2 and running comparat ive d i sc r imina to r curves on both the low-and high-sensi t iv i ty channels . When these data were compared with e a r l i e r data, it was evident that the gain shift had occur red in the pulse amplif ier , since the fixed d i sc r imina to r for channel 2 was bypassed when the d i sc r imina to r curves were obtained.

The gain setting of the pulse amplif ier was subsequently adjusted to bring channel 2 into cal ibrat ion ^ t h previously establ ished data , i . e. , the gain was adjusted so that the shutdown count r a t e on channel 2 re turned to i ts normal value. The daily log of shutdown count ra te on source range channel 2 will be reviewed per iodical ly in the future for any fur ther sign of change.

D. REPAIR OF DEW POINT HYDROMETER IN STEAM CLEANING CHAMBER

The de w point hydrometer l o r the s team cleaning equipment in the fuel and repa i r building was checked and var ious minor r e p a i r s made . The cooling water supply to the hydromete r was also changed from general se rv ice -water to deminera l ized -water to min imize the plugging of the f i l ter which has occur red in the pas t . Initial checkout of the device indicates that i t i s operating sat isfactor i ly and that accura te dew point m e a s u r e m e n t s a r e being obtained. Fu ture p roces s cycles during fuel handling will es tabl ish the re l iabi l i ty of the ins t rument .

* s t a r t - up . The high-sensi t ivi ty source range channel 2 detector has its own preampl i f ie r , but a m i x e r c i rcu i t allows the same pulse amplifier and d i sc r imina to r to be used for it as a r e used for the low-sensi t iv i ty source range channel 2 detector , i . e. , the low-sensi t iv i ty detector count r a t e can e i ther be obtained separa te ly or the low-sensi t iv i ty plus h igh-sensi t iv i ty detector r e ­sponses can be obtained together .

39

\

\'.

108569 w

y AL

N >

A 108669

FIG. 31 TWO¥iEWS OF SPALLED BEARiiG RACES l i THHUST

BEARiiG ASSEMBLY OF iO.1 PUMP SHAFT

40

VI. SPECIAL INVESTIGATIONS

A. USE OF FLOWGUARDS IN SUBASSEMBLIES BEING STUDIED

Considerat ion is being given to the possibi l i ty of instal l ing flowguards in the core and inner radia l blanket subassembl ies of the new fuel loading. The flowguards would consis t of extensions of the subassembly nozzles which •would project below the lower core support plate when the subassembl ies a r e in posit ion in the r e a c t o r .

The purpose of the flowguards would be to prevent coolant blockage to subassembl ies from foreign objects , such as occur red in the October 5, 1966, incident. Various models of flowguards have been designed, built, and a r e presen t ly being tes ted; no decision has yet been made of the type to be used if flois'guards a r e adopted. However, until the studies a re completed, the instal lat ion of flow orif ices in the nozzles of the new inner rad ia l blanket subassembl ies begun las t month (see APDA-CFE-32 , Section VII. A), is being delayed because the type of orifice used may depend upon the flo^wgrard design adopted. A dimensional survey of the inner nozzle d i ame te r s of the new core and inner radia l blanket subassembl ies has a lso been completed for use in the flo-wguard design s tudies .

B. POWER RANGE SIGNAL AMPLIFIER NOISE

Tes t s were made on the dn/d t ( ra te of change of power) power range signal ampli f iers in the r eac to r control sys tem to de te rmine the i r sensi t ivi ty to power line voltage fluctuations. In sepera te t e s t s , step changes of 2 volts a-c were made in the power feeds to the four power range amplif ier modules in the dn/dt c i rcui t . The t e s t r e su l t s showed that deflections as l a rge as 1/4 volt occur red at the output of the ampl i f ie rs , corresponding to power changes as l a rge as 1/2 Mwt per minute . Some of the amplif iers were found to be m o r e sensi t ive to power line fluctuations than o the r s .

A voltage regulat ing t r a n s f o r m e r has therefore been o rde red for use in supplying power to all four ampl i f i e r s . It is expected that this modification will e l iminate future random fluctuations in the dn/dt m e t e r s during approach to power.

C. NOISY LOOP-3 FLOWMETER

A review was made of the operat ional h i s tory of the noisy f lowmeter in the 14-inch inlet sodium line of loop 3 (see A P D A - C F E - 1 , p20, and APDA-CFE-26 , p20). Noise levels as high as i_ 14% at 1/2 cps have been observed over a number of yea r s in this f lowmeter . The noise apparent ly s t a r t s or stops when a significant change in flow i s made . A review of all flow changes made , dating back to 1963, shows that in general the noise level has inc reased

41

in two distinct steps (1) in July 1965 a definite inc rease in noise level occur ­red and (2) in January 1966 another definite step inc rease occur red .

The loop-3 flowmeter was noted to be par t i cu la r ly noisy during the per iod August 3 to 5, 1966, at which t ime a 3-day, 100-Mwt, power-demon­s t ra t ion run was conducted. This is also the t ime when it is believed at leas t one of the loose zirconium segments was lodged beneath the lower core support plate . Subsequent data show that the m e t e r was still noisy after the f i r s t loose z i rconium segment -was removed from the r eac to r las t yea r . It is not known -whether the noise still p e r s i s t s now that the second loose segment has been removed, since sodium has been ci rculated only at pony motor flow on loop 3 since removal of the second segment and a check cannot be made at low flow.

Various theor ies have been postulated to account for the noisy flo-wmeter on loop 3, but the cause is sti l l not understood. It does not appear to be due to approach conditions (the pipe configuration do-wnstream from the flo-wmeter), since it has been observed -when the loop -was shut do-wn and r e v e r s e flo-w due to loop 1 and loop 2 existed in loop 3, Adjustment of the amplifier set-ings for the flo-wmeter do not el iminate the noise . It has been theor ized that the noise could be the r e su l t of pipe v ibra t ions .

42

DISTRIBUTION LIST

USAEC - Chicago Opera t ions Office

D i r e c t o r , Cont rac t s Division (2) G. H. Lee

USAEC - Washington D i r ec to r , RDT A.sst. Di r . , P r o g r a m Management , RDT Ass t . Dir . , Reactor Engineer ing , RDT Ass t . Di r . , Reac tor Technology, RDT Ass t . Dir . , Plant Engineer ing, RDT Ass t . D i r . . Nuclear Safety, RDT Pro jec t Manager , LMEC. RDT Projec t Manager , F F T F , RDT P r o g r a m Manager , LMBFR, RDT Liquid Metal P ro jec t s Branch , RDT Chem. & Chem. Separat ions Branch, RDT Reactor Phys ics Branch, ' RDT P""uels and Mate r i a l s Branch , RDT Applications and Fac i l i t i e s Branch , RDT Components Branch , RDT (2) Iiist rvuTientation and Control Branch, RDT .Sv.stems Engineering Branch, RDT Core Design Branch , RDT Fuel Handling Branch , RDT Special Technology Branch, RDT Reac tor Vesse l s Branch, RDT

USAEC-RDT Site Represen ta t ives Site Represen ta t ive , APDA Senior Site Represen ta t ive , ANL Sensor Site Represen ta t ive , AI Acting Senior Site Represen ta t ive , IdOO Site Represen ta t ive , CE Site Represen ta t ive , GA Site Represen ta t ive , GE Site Represen ta t ive , ORNL Site Represen ta t ive , PNL Site Represen ta t ive , SR Site Represen ta t ive , UNC

USAEC-DTIE R. L. Shannon (3)

USAEC-Ne-w York Operat ions Office J . D i s s l e r

USAEC-San F r a n c i s c o Operat ions Office J . Holliday

D i r e c t o r , LMFBR P r o g r a m Office, ANL A. A m o r o s i

D i r ec to r , LMEC, AI R. W. Dickinson

Aeroje t - Genera l Corpora t ion H. Dero-w

Argonne National Labora to ry R. Bane L. W. F r o m m S. Greenbe rg L. J . Koch S. Lawrosk i M. Novick F . Smith

Atomics In ternat ional R. Balent (2) S. Golan

Babcock & Wilcox Company (Box 1260, Lynchburg, Va 24505)

M. W. Croft

Babcock fc Wilcox Company (Barber ton , Ohio)

P . B. P r o b e r t

Ba ldwin-Lima-Hami l ton Corp. ( Industr ia l Equip. Div. , Eddystone, Pa)

J . G. Gaydos R. A. Tidball

Bat tel le Memor i a l Inst i tute (Columbus, Ohio)

AEC L ib ra ry

Brookhaven National Labora tory O. E. Dwyer D. Gurinsky (2) K. Hoffman C. Klamut L. Ne'wman A. Romano

Combustion Engineer ing, Inc. (Box 500, Windsor, Conn)

W. P . Staker W. H. Zinn

Detroi t Edison Company W. R. Olson H. A. Wagner

Genera l E lec t r i c Company (175 Cur tner , San J o s e , Calif 93125)

K. P . Cohen (3)

Genera l E lec t r i c Company (310 DeGuigne, Sunnyvale, Calif 94086)

A. Gibson

Gulf Gene ra l Atomic , Div. of Gulf Oil Co. (San Diego, California)

P . F o r t e s c u e

M. W. Kellogg Company (711 Thi rd , New York, New York)

E. W. J e s s e r

Lewis Flight P r o p . Lab . , NASA (21000 Brookpark , Cleveland, Ohio)

C. A. B a r r e t t

Lub .Alamos Scientific Labora tory D. n . Hall (2) G. Waterbury W. R. Wykoff

•M.'-iA R e s e a r c h Corp. (Gal lery . Pa 14024)

C. H. Staub

X'lu-lear Ma te r i a l s 8t Equipment Corp . (Apollo, F'ennsylvania)

7 . M. Shapiro

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Di rec to r

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F. L. Culler J . H. Devan D. Gard iner J . White

Oak Ridge National Labora to ry (Box Y, Oak Ridge, Tennessee)

R. E. M a c P h e r s o n , J r .

Pacific Northwest Labora to ry , BMI E. Astley (5)

Power Reac to r Development Company (1911 F i r s t S t ree t , Det ro i t , Mich. 48226)

A. S. Griswold

Southwest Atomic Energy Assoc ia t e s (Box 1106, Shrevepor t , La 71102)

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United Nuclear Corpora t ion (Box 1583, New Haven, Conn)

A. S t r a s s e r (2)

West inghouse E lec t r i c Corpora t ion (Box 1-8. Madison, Pa 15663)

,r. C. R. Kelly. J r . (2)

Westinghouse E lec t r i c Corpora t ion (Box 158, Madison, P a 15663)

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J . Stephenson (12)

USAEC-EURATOM Exchange EURATOM S3, Rue Bel l iard Brus se l s 4, Belgium

A. deStordeur (10)

CNEN Via Mazzmi 2 Bologna, Ital>

F . P ie ran toni (4)

CEN Saclav Boite Pos ta le 2 Gif-Sur-Yvette (Set 0) F r a n t e

G. Vendrves (10)

Kernforschungszent rum Kar ls ruhc 7500 K a r l s r u h e , Germany

W. Haefele (10)

Oak Ridge National Labora tory (RDT L ib ra ry , 1000 Bmldmg)

M. Bender