ML20153F008

Summary of 880330 Meeting W/Util to Discuss Justification for Continued Operation at Reduced Power Levels Due to Calculated Reduced ECCS Flowrate During Large Break Loca. Agenda Viewgraphs Encl

ML20153F008
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	05/02/1988
From:	Wang A Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
References
NUDOCS 8805100207
Download: ML20153F008 (22)

Text

_ _ . _ - - _ _.

NhY021988

. Docket No. 50-?13  :

i 4

j LICENSEE: Connecticut Yankee Atomic Pcher Cornpany i

FACILITY: Haddam Neck Plant I

SUBJECT:

StlWARY OF MARCH 30, 1988 PEETING REGARDING LARGE BREAK LOCA i  !

PERFORPAhCE W11H REDUCED ECCS FLOWRATE j i  !

i i i On l' arch 30, 1988, the staff met with Connecticut Yankee Atomic Pcher Coripany l (CYAPCO) to discuss their justification for continued operation (JCO) at  :

reduced power levels because of calculated. reduced ECCS flow during a large I i break LOCA. In a conference call on March 24, 1988, the staff agreed that  !

l CYAPC0 had adequate basis for providing a JC0 to operate at 40 percent power.  !

The staff felt a ccn.plete reanalysis of the large break LCCA with the reduced l flow was necessary to go to higher power levels. CYAPC0 on Parch 25, 1988  !

sutoitted a JC0 for 80 percent power operation. The staff reviewed the JC0 and concluded that operation at 40 percent power was warranted but not enough i technical justification was presented to respone to CYAPCO's request to operate l l at 80 percent power. 3 CYAPC0 requested this treeting to clarify their JC0 and provide the basis for the i

! conclusions in their JC0 allowing operation at power levels up to 80 percent.

l

! CYAPC0 stated, tased on a different single failure scenario than was used by I j Vestinghouse, the NSSS vendor, that the failure of tFSI isoletion valve during  ;

large break LOCA would reduce ECCS flow by abcut 20 percent. This 20 percent j i reduced ficw is expected to cause the peak clad tuterature to exceed the f

2300'F limit. CYAPC0 providec'. references to substantiate their asswption ,

i that, to reduce the peak clad tenterature by 100*F, a decrease in the linear l 1

teat generation rate by approxirnately 0.8Kw/ft was rceded. l

CYAPCO provided the follcwing as the t' asis for their JCO:  :

1  !

1) Tte naximum linear heat generation rate Ifmit was reduced by 1Kw/ft 1 from 14.3Xw/ft to 13.3kw/ft, i

}

q 2) The rr.axirrum pcwer was reduced by 70 percent even thcugh prelimirary l calculaticos indicate operation up to 90 percent is warranted in the i current configuration, and i 3) Based on the liriear heat generation rate limit, the axial offset limits l 1 were adjusted. Operating at 90 percent power assures the linear heat )

rate will te less then 12.6Kw/ft. I i  ;

l l

1 8805100207 880502

PDR ADOCK 05000213 I J P PDR l

1 l t

l

O

\

. -?-

The staff agreed that operation at 80 percent pewer is warranted. CYAPCO closed the teeting stating that a tevised JC0 would be prepared and that the Vestinghouse reanalysis of the large break LOCA whould be ccepleted in seven to 10 days. Assuming a favorable result from Westinghouse analysis, CYAPC0 proposed to operate at 100 percent pcwer by using ct;re restrictive adn:inistrative prtcedures until the TS anendnent can be processed. The st6ff stated this proposal was untenable and that a TS change would need to be approved before 100 percent power is authorized.

Enclosed is CYAPCO's handcut for the neeting and the attendance list.

M 673 Bff' Alan B. Wang, Project Panager Project Directorate I-4 Division of Peactor Projects I/II

Enclosures:

As stated cc: See next page w/ Enclosures DISTPIPU110N

-DocketJiTel At NPC & Local ~ PPPs J. Stol:

A. Wang OGC-WF E. Jordan J. Pertlow NPC Participants ACRS(10)

LA:PDI-4 FM:PD:;-4 D:PDI-4 SNc6 AWang @ d JStolz C4/$/08 Cy v/08 Of/,t/88

Mr. Edward J. Hroczka Connecticut Yankee Atomic Power Company Haddan Heck Plant CC:

Gerald Garfield, Esquire R. H. Kacich, Manager  :

Day, Berry and Howard Generation Facilities Licensing  !

Counselors at Law Northeast Utilities Service Company '

City Place Post Office Box 270 Hartford, Connecticut 06103-3499 Hartford, Connecticut 06141-0270 W. D. Romberg, Vice President D. O. Nordquist Nuclear Operations Manager of Quality Assurance Northeast Utilities Service Company Northeast Nuclear Energy Company Post Office Box 270 Post Office Box 270 Hartford, Connecticut 06141-0270 Hartford, Connecticut 06141-0270 Kevin McCarthy, Director Regional Administrator Radiation Control Unit Region i Departnent of Environmental Protection U. S. Nuclear Regulatory Commission State Office Building 475 Allendale Road ,

Hartford, Connecticut 06106 King of Prussia, Pennsylvania 19406 Bradford S. Chase, Under Secretary Board of Selectmen Energy Division Town Hall Office of Policy and Management Haddam, Connecticut 06103 80 Washington Street Hartford, Connecticut 06106 J. T. Shedlosky, Resident inspector Haddam Neck Plant D. B. Miller, Station Superintendent c/o U. S. Nuclear Regulatory Commission Haddam Neck Plant Post Office Box 116 Connecticut Yankee Atomic Power Conpany East Haddam Post Office RfD 1, Post Office Box 127E East Haddam, Connecticut 06423 East Hanpton, Connecticut 06424 G. H. Bouchard, Unit Superintendent Haddam Neck Plant RFD #1 Post Office Box 127E i East Hampton, Connecticut 06424 l

1

e l

ATTEND-_ A A.C.E..L.I.S.T.

CONNECTICUT YANKEE A10MIC POWER COMPANY MARCH 30,_1,98,8, NAME ORGANIZATION PHONE l

J Steve Vick Northeast Utilities (GFL) 203 665-5537 j

Fred Sears John Blaisdell NU NU (l203 l

I 665-3758 203 665-5669 Plerre Litteureux CYAPC0 ,203 267-2556 Bill Herwig NU (203 665-3198 Bob ilones NRR 301 492-1307 .

Walt Putler NRR 301 492-1425 l Wayne Hodges NRR 301 49?-0895 l

Alan k'ang NRR 301 492-1313 Bob Ferguson NRR 301 492-1307 i

1' On Ocnference Line Lee Betthenhausen Pegion I Tcm Shedlosky Senior Resident #

i l

i<

i l

I i i

1 l l

I i

I 1  :

l i

t f

i i

HADDAM NECK PLANT DOCKET NO. 50 213  !

i l l

i MEETING WITH NRC STAFF l ON l LARGE BREAK LOCA PERFORMANCE WITH REDUCED ECCS FLOWR ATE l

l l

i j ,

j MARCH 30,1988  !

ROCKVILLE, MD.

l \

l

) '

i j

.I I

I I

I l l

1

l l

l l

i l

l NORTHEAST UTILITIES REPRESENTATIVES 1

C.F. SEARS VICE PRESIDENT, NUCLEAR AND ENVIRON.

I MENTAL ENGINEERING i J. A. BLAISDELL MANAGER, SAFETY ANALYSIS  ;

4 P. F. L'HEUREUX CONNECTICUT YANKEE ENGINEERING SUPER-VISOR i W. M. HERWIG REACTOR ENGINEERING t

S. D. VICK GENERATION FACILITIES LICENSING i

I I

i i l l

)

PAGE 2 1

a .

l t

l i

i OUTLINE OF MEETING i

l lNTRODUCTION AND OVERVIEW OF NU EFFORTS FRED SEARS i

DISCUSSION OF PROBLEM JOHN BLAISDELL  ;

BACKGROUND '

INTERIM ACTION SOLUTION SINGLE FAILURE EVALUATION CONCLUSIONS FRED SEARS COMPELLING ARGUMENTS  !

CONSERVATISMS IN JCO l

i JUSTIFICATION OF 80% POWER OPERATION l

i i

i l

i i

PAGE 3 i

1

l I r i  !

l i

j

• j PURPOSE OF MEETING  !

PRESENT DETAILS ON REDUCED ECCS FLOW 3 ATE PROBLEM

.l .

ANSWER QUESTIONS ON THE JCO  !

l ,

DESCRIBE OUR ONGOING ACTIVITIES i

j OBTAIN NRC CONCURRENCE TO OPERATE AT 80% POWER i

i l i i l i

J i

} .

.i PAGE.4 4

-,,..-,--.------.------...-----n., . , . - - - . , . , . , _ , . . .- .

.-,n.--- n.,,., , ,. ,_- , . , . . n,,.. ,-- - - .- ,._ .- , ,.,- _,n ---

i i

i CHRONOLOGY OF REDJSQED ECCS FLOWRATE PROBLE_M i

POTENTIAL PROBLEM DISCUSSED WITH NRC 3/23/88 CONFERENCE CALL WITH THE NRC 3/24/88 PROMPT REPORT TO NRC AND STATE 3/24/88 JCO FOR 80% POWER SUBMITTED 3/25/88 QUESTIONS ON JCO RECEIVED 3/28/88  !

i MEETING WITH NRC TO RESOLVE 3/30/88 .

a l

CONCURRENCE FOR 80% POWER 3/30/88 SUBMITTAL OF WESTINGHOUSE REANALYSIS week of RESULTS AND AUTHORIZATION FOR 100% 4/4/88 i POWER OPERATION 1

l l I i

1 PAGE 5 l

l

R l

1 l

'i i

i i Qy,ERVIEW OF NU SAFETY ANALYSIS EFFORTS FOR HADDAM NECK [

1 1

SUBMITTAL

+ 'u?a',L BREAK LOCA REANALYSIS JUL '84 -

LEVEL 1 PRA FEB '86 - l NON LOCA TRANSIENT edd?l.YSIS JUN '86 -  !

LARGE BREAK LOCA ANALYSIS MID '89 --

Aw a tr y % 44 l 1 /.1 6 H Q n M l

1 4

PAGE 6

, s 53W 30m30 3v03 t m e a " D y A ( ,

o o <

g t 9=

3 's R 8

g g=

v 3 e o

• i

+ I 2 p -

-5

$$ $ $N

_ _i, bf d

v ~5- AW

^

k h

• ve-a a hk<

0.8o m -e d

W -- W "

g Eg

$U X uz zo _ea C

!, S Xf -

1 1 q -Uq g " a G--Yt $$-

s~l

~

dU $ 8

.E2 i I bS 8$

s-m N I.a O, A

~ft

. . ._ . o m

j s.

0 w 3 e 5 $b

; 7,, ._ . _

E I :s. g w a Os w s O i6 I g"* Is Eje']

i #_

ger i_l 65 6 a " 9 I= It s

i II 8 y a I n -g_

e 0

k b p

O

l 1

l OVERVIEW OF HADDAM NECK ECCS (ON RECEIPT OF SIS)

HPSI AND LPSI PUMPS AUTO-START CHARGING PUMPS AUTO-START IF OFFSITE POWER AVAILABLE FOUR HPSI INJECTION VALVES OPEN TWO CORE DELUGE VALVES OPEN CVCS VALVES REALIGN AND DIVERT CHARGING PUMo SUCTION FROM VCT TO RWST HPSI, TAKING SUCTION FROM RWST, DELIVERS TO FOUR COLD LEGS LPSI, TAKING SUCTION FROM RWST, DELIVERS TO THE UPPER HEAD VIA CORE DELUGE CHARGING (OFFSITN POWER AVAILABLE), TAKING SUCTION FROM RWST, DELIVERS TO LOOP 2 COLD LEG PAGE 7

l THE PROBLEM ECCS DELIVERY CURVES WERE DEVELOPED IN-HOUSE TO l SUPPORT THE PLANNED IN-HOUSE LOCA CALCULATIONS SIMILAR TO THE 1972 WESTINGHOUSE DELIVERY FLOWS, ECCS DELIVERY WAS EVALUATED FOR ALL POTENTIAL SINGLE FAILURES IN HOUSE CALCULATIONS SHOWED THAT THE LIMITING SINGLE FAILURE WAS ONE LPSI INJECTION MOV l

IN THIS CASE, 2 LPSI PUMPS DELIVER THROUGH 2 OF THE 4 HEAD PENETRATIONS AND 2 HPSI PUMPS DELIVER THROUGH 4 INJECTION VALVES (1 PATH SPILLS TO CONTAINMENT)

WESTINGHOUSE ECCS DELIVERY FLOW FOR CASE OF FAILED LPSI MOV WAS NOT LIMITING (E - 1140 LB/SEC NU - 866 LB/SEC)

LIMITING FAILURE PREDICTED BY WESTINGHOUSE WAS ONE EMERGENCY BUS IN THIS CASE,1 LPSI PUMP AND 1 HPSI PUMP DELIVER THROUGH ALL 6 INJECTION MCVs (E - 1060 LB/SEC NU - 1050 LB/SEC)

IN HOUSE CALCULATED FLOW IS POTENTIALLY 103. LESS THAN LIMITING WESTINGHOUSE FLOW PAGE 8

. - - _ _ _ . ~ . _ _ _ _ - . -.___.__ . - . . . _ . . _ . _

9 8

h -eN 4 3 '

~

o ,g um an d go sw , < s ,.

y u ,

t i e E $

= = =? x 3 3 3 - is 0

% 2 8 3

g 2 p

a _ -y j ix IX GX EX j,

_ v!

fr

• k's I d v AW ul!

$ $o8' r- s 50 ss J d $UO Of n

5 vo- 0.8o

@3 as eo" W -X- ,

a M i i

$z ri pde( !9 3 Ek* 0-X 5$

sI i s(

z "

1 a -

3G i -

A ; l_ -

's sw , . ,

g

,, e h- - V gjf w a r s g * ,s Os @~Xi &*-XI L #_ ~ j gjik "u

9 65 6 m l@-K X; E

13 >=

a i

-g "g I e d-5 n-g_9 h-

^5 a

_ . _ _ - , - - - - _ - - - - - . _ . . , . , -,.,,_,-_--.n. -- . - - - . - _ . , _ . _ . . - - , . - -

HADDAM NECK '

ECCS INJECTION LINEUP u - '*

nw -

M M I

gysy g$(NEW) e NWB y ,

SI-Wov-904 SI-MOV-903 l NEW WOV-24 ,

MW) C g, h- ,

SI-WOV-854 A ll g [

SI-MOV-901)@ puups y 5 u o 12 ONI NEW (NEW ) " [

~

SI-uoV-8548 ll SI-MOV-902 o @)

- - ^--- W w . nyo s S N LPSI SI-V-lG2 Nu - b6G ' S O

PUMPS (2 DN) p L} h L A gg TO LOOP 2 CL NONuAL mm SI-MOV-873 edEWI CONTAINRENT RH-RCV-602O ICLOSEDI M SI-MOV-871A 2 3/y } h Suur tC - ,

_g_ o .

RH-WOV-22 "h E~

pf"1mo11tEO g

,, N-( -

6 g

) ) tw5

> > - g rnou o 10 CHARGING O

u. >< N- "P t-

"S RH-V-8064

m. Si-=0V- na (CLD5Edl HX'S .

t e

n -- -

,pd

~ h % ,,

l l

\

IMPACT ON LARGE BREAK LOCA LICENSING ANALYSIS i

)

REDUCTION IN FLOW RESULTS IN A 10 SEC DELAY IN FILLING THE LOWER PLENUM PRIOR TO REFLOOD AND j A CORRESPONDING INCREASE IN HOT SPOT CLAD TEMPERATURE OF LESS THAN 100 F PRIOR TO REFLOOD

. THE RESULTING PEAK CLAD TEMPERATURE IS ESTIMATED TO BE i 2388 F (IAC LIMIT IS 2300F) l 7 4 C. -

PW ] ,

[% & L a p A f4 k ,

i PAGE.9

,a HADDAM NECK DECLG, CD = 1.0 g' g 2500 -

i o. .

egeo .

2000 -

i i

1500 -

N '

e 1000 .. o u N G M l 500 refill  : reflood ---

l l

l

I I I I I l 0 I 0 20 40 60 80 100 120 time after break - sec l Wh

% s wM hE 040 h 4 W h

1 INTERIM ACTIONS - JCO W. SENSITIVITY STUDIES WITH HADDAM NECK'S LICENSING MODEL INDICATE THAT THE 100 F REDUCTION IN PCT CAN BE ACHIEVED BY REDUCING THE LINEAR HEAT RATE BY 0.8 KW/FT (REFERENCES)

THE REDUCTION IN LINEAR HEAT RATE REQUIRED TO ENSURE THAT THE PCT STAYS BELOW 2300 F WAS CONSERVATIVELY

(

ASSUMED TO BE{KW/FT)

(CURRENT LIMIT - 14.3 KW/FT INTERIM LIMIT - 13.3 KW/FT)

THE AXlAL OFFSET LIMITS WERE EVALUATED TO DETERMINE 2 REQUIRED REDUCTION IN OPERATING MARGIN IT WAS DETERMINED ThAT 100% POWER IS ACHIEVABLE WITH TIGHTER AXIAL OFFSET LIMITS. AXIAL OFFSET LIMITS REQUIRE NO MODIFICATION BELOW 90% POWER.

h .

AN INTERIM MAXIMUM POWER OF BHS WAS PROPOSED FOR CONSERVATISM. }

THIS ENSURES LINEAR HEAT RATE WILL BE LESS THAN 12.6 KW/FT v ,

SUMMARY

OF CONSERVATISMS l l

INCREASED ASSUMED HEATUP RATE BY 10%

INCREASED SENSITIVITY TO REQUIRED LINEAR HEAT RATE REDUCTION BY 20%

REDUCED MAXIMUM POWER BY 20%

AXIAL OFFSET LIMITS PROVIDE FURTHER CONSERVATISM REFERENCES D. C. SWITZER TO R. A. PURPLE, DATED 6/23/75 W. G. COUNSIL TO W. A. PAULSON, DATED 8/31/84 D. L. FULLER TO J. A. BLAISDELL, DATED 3/29/88 PAGE 10

- Fnou, i PowEn LEVEL VS AXIAL OFFSET LIMITS, .

0-250 EFPD. FOUR LOOP SPERATION Iso 1

. i

> +

. __. i 1 e i i i

, i i 1 2

. 4_. y.h 4

_q .4 u.

' i ie c.w,wo) i I'r.r.*.; 4 .p %

u -. . 2 too . ,

(-15.100) r . 2m 1 -

s-i-

(10.100) e * , 1J ,a ' i '

] h1 il + 1 h* I.; n'

- i r '.

\ > 11 i i r. 1 i i .

. 7 1_,._- i ,

r

-, y' ' I !

-i n t. .

M .( tt.8,98)g_

, , 1 ,.,,f

, , , i;

% , i d%-i;(11% $8) M .

~~

u ' 5 .i ._LM I I  !- 5 2 X5

.. m _ .. -. p.... _ . - . - - - -

_ _ u ... ._ -

7.

so

-- u  ;, .g .-.___., + . ; 4. __ - . . . .-- e y .

. . ._4 ,

1 - i -

i~ 1 __ . m i. A -

b ' r

. u

.- L (20,70) 3 > (.3o'yo) u' _. s_ a'.1 .

1. . ...

~ . - ,

f 1 0 8 l 0 i -_3 f I 8 1 I I 1  ! 0 ( f e 4

{ 9 8 y g e > + , i . .

g j __e f a 8 '

i 8

, 1 1 ,

,4e_ ,

d '

E l!i- il l

^

i;+ , , +- j i --w -,-  ; . .

,', ,i i - i

~~ 3

, i , j  !

~

-4  :

4

. : 4 ^

• *. -  !

• 11

!- ! ! a  ! t 4. e i 9 .

> , . i . i ! i . 1 .

,i ,

1 Iii 3j6 1 I l i i **1 2 i

l _ i ._ i I 1

%  : . (-3o,4o) ! ; i ehM4+ - (20,4o) N +

. . . . +. -

. i

' "T .

i , ,-  : i ,,4 1 1eiii Ii  ! ' i e - 1 iii! i ,

al 1 j -

- - i l?

I 1

l _.

1 A

1

..-- 4-1 i

?

l ! -

.L i

,_. _.'ii'

t1 -

' ; ;i

' ;. A, i i

, _j_

i : i i

.i' ,;..

, i i i i iI 77 Y li3 ~~

no ij  ! .

+4 1 i

. .! iII.

-H i -- -

M l' li'j,

, .- 9 I  ;

i , _ j_

_-._..., l

! -,-- - -~ -

~

- I g . ,

3 -40 -Bo e as 40 RXIM. OFFSET (1) 8

?

g e i ,

I I

e

.i O

h

'I

• • • • • =-*-

_. wgpy,- . , . , -

---A ,. .-,,.m gg=4, ,, y 4 9 2,y=.;=,a= * *g , ,, .,

NEAR TERM CORRECTIVE MEASURES WESTINGHOUSE IS CURRENTLY REANALYZING THE LIMITING BREAK ASSUMING N 18% REDUCTION IN ECCS FLOW Q w o n (A WESTINGHOUSE IS ECALCULATING ECCS DELIVERY ASSUMING 1 LPSI MOV FAILURE g , n, / g 9, f, WESTINGHOUSE WILL PERFORM ADDITIONAL LARGE BREAK LOCA ANALYSES IF NECESSARY REQUIRED CHANGES TO TECHNICAL SPECIFICATIONS WILL BE MADE TO ENSURE COMPLIANCE WITH IAC.

INTERIM ADMINISTRATIVE CONTROLS WILL ENSURE PLANT LIMITS ARE NOT EXCEEDED LONG TERM CORRECTIVE MEASURES LARGE BREAK LOCA WILL BE REANALYZED IN HOUSE USING CUR R ENT-D AY METHODS (MID '. < 19) 9.EL& P $ 4 00 % Q-k&f X

,CdLRRENT EX_PECTATIONS _ ARE THAT REANALYSIS WILL RESULT IN PEAK CLAD TEMPERATURES MUCH LOWER THAN CURRENT ANALYSES ~

f A. cAA ~ p o o W:

PAGE 11

e SINGLE FAILURE ANALYSES (REFERENCE)

A DETAILED SINGLE FAILURE ANALYSIS OF ALL PUMPS AND VALVES REQUIRED TO CHANGE STATE TO MITIGATE LOCAs WAS PERFORMED IN 1987. THIS INCLUDED CONSIDERATION OF THE FOLLOWING:

2 LPSI PUMPS 2 CHARGING PUMPS 2 HPSI PUMPS 2 RHR PUMPS 24 MOVS NO NEW LIMITING SINGLE FAILURES WERE IDENTIFIED. HOWEVER, THE WESTINGHOUSE ECCS FLOWS WERE USED TO ASSESS THE  !

IMPACT OF THE FAILURE OF THE CORE DELUGE MOV. SINCE NO PIPING CHANGES HAVE BEEN MADE IN THE LPSI SYSTEM, THERE WAS NO REASON TO QUESTION THE WESTINGHOUSE RESULTS.

REFERENCE E. J. MROCZKA LETTER APRIL 1,1987

% Q&& Q PAGE.12

~

=

s 's CONCLUSIONS THIS IS NOT A ' SINGLE FAILURE' PROBLEM. OUR COMPRE-HENSIVE EVALUATION OF SINGLE FAIL.URES (APRIL 1,1987) l REMAINS VALID l THIS IS AN APPARENT CALCULATIONAL ERROR FOR AN INPUT TO AN ANALYSIS PERFORMED ALMOST TWO DECADES AGO. IT IS NOT A REQUIREMENT TO RECALCULATE INPUTS USED IN APPROVED, LICENSING BASIS ANALYSIS THE PROBLEM WAS IDENTIFIED BECAUSE OF OUR THOROUGHNESS IN VALIDATING INPUTS FOR OUR IN HOUSE SAFETY ANALYSES THERE IS AMPLE CONSERVATISM TO JUSTIFY OPERATION AT 80 %

POWER

\

REANALYSIS IN PROGRESS TO PROVIDE ANALYTICAL R ASIS FAR_

100 % POWER OPERATION 1

WITH THE COMPLETlON OF THE LARGE BREAK LOCA ANALYSIS l (SCHEDULED FOR MID 1989L THE HADDAM NECK SAFETY ANALYSIS UPGRADE WILL BE COMPLETED PAGE 13