ML20085G928

AO BFAO-50-260/7417W:on 741007,HPCI Inoperable Due to Head Gaskets Leaking on Gland Steam Condenser,Causing Flooding of HPCI Turbine Sump & Gland Steam Condenser Hotwell Pump. Caused by High Pressure on Condenser.Gaskets Replaced

ML20085G928
Person / Time
Site:	Browns Ferry
Issue date:	10/17/1974
From:	Eric Thomas TENNESSEE VALLEY AUTHORITY
To:	Case E US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20085G930	List: ML20085G928 ML20085G940
References
NUDOCS 8308290521
Download: ML20085G928 (2)

Text

.

' l

- " TENNESGHE VAL: / AUTHO AIT/ r~ P "j l CH ATTA N C C G.ra., TENNESEEE

,_. . 37401 o - \

- N .. -; ___T s <<1 w >

October 17, 1974 G .$!, Lb ): L-sFie'sNf!W,

,)

' ey 4 N_h ,,' j Y.

purrre m ss;p

~ Q x,P s' \t ,

v; ,

p-(4 g@ T. L.. O ^;. , .'

Mr. Edson G. Case - -

u ^I' Acting Director of Licencing  ; 'j [ (, s' Office of Regulation  ?,'

• U.S. Atonic Energy Co icsion Washington, DC 20545 ' v "'

Dear Mr. Case:

TERIESCEE VAIJ2EY AUTHORITI - BRO'CS FERRY HUCLEAR FIAUT UNIT 2 -

DOCKET EO. 50-260 - FACILITY OPE?.ATIHG LICDISE DPR ASHORMAL OCCURICCE REPORT EFAO-50-260/7417U The enclosed report is to provide detaile concerning the HPCI systen which beccre inoperable due to head gaskets leaking on the gland stenn condenser, and thic caused flooding of the HPCI turbine su=p and the gic.nd steca condenser hotvell puno and is subnitted in accordance with Appendir A to Regulatory Guide 1.16, Revision 1 October 1973. This3 event occurred on Ercuns Ferry Huclear Plant unit 2 on October 7, 1974 Very tru2;f yours, TEMIESSEE VALLEY AUTHORITY

-/ <

' ,, L fj. E Q%vy E. F. Thomas Director of Power Production Enclosure CC ( helesure): ,

Mr. Hornan C. Mocclcy, Director Region II Regulatory Operationc Office, USAEC 230 Peachtree Street, IRT. , Suite 818 Atlanta, Georgia 30303 3

8308290521 741017 PDR ADOCK 05000260 S PDR 10808 Axe

• t *h COPY SENT REGION #

m m -_ _ _ . _ . . _ _ _ _ _ . . m_ _ . . _ _ . _ _

f (' ')

. L)J _

l ABNORMAL OCCURRI2CE REPORT  !

l I

i Report No.: BFAO-50-260/7417W Report Date: October 17, 1974 Occurrence Date: October 7, 1974 Facility: Browns Ferry Nuclear Plant unit 2 Identificatien of Occurrence The HPCI system became inoperable due to head gaskets leaking on the gland steam condenser ifnich caused flooding of the HPCI turbine sung and the gland steam condenser hotwell pump.

Conditions Prior to Occurrence The unit was in hot shutdown condition.

Description of Occurrence The HPCI was manually initiated following a reactor scram at 1456 hours0.0169 days <br />0.404 hours <br />0.00241 weeks <br />5.54008e-4 months <br /> on October 7, 1974 Reactor water .hvel was restored as intended with no indication of troubic. A rcutine inspection of the crea was in progress following the operation of the 15CI uhen the upper and lower gaskets on the gland steam condenser vere found to be leaking. Sc=e flooding at the sunn surrounding the HPCI turbine had occurred with consecuent flooding of the gland steam condenser hotvell purn notor.

Denicnction of Imnarent Cause of Occurrence The apparent cause of the failure of the upper cnd lower head gaskets on the gland steen condenser was the high pressure created on the condenser when the unit started due to the location of the cooling water flow control orifice.

This orifice is located dounstream of the condenser, and thus the excharger in subjceted to high pressure when the HPCI pump starts.

Analysis of Occurrence Failure of the upper head gasket on the gland stcem condenser which caused HPCI s

to become inoperable did not jeopardize unit operation or create a hazard to the public. Other core cooling systems were operabic.

Corrective Action

1. The upper cnd lower head gaskets to the gland steam condenser were replaced.

Tne ginnd stecn condenser hotwell pump motor was dried out and meggered catisfactorily.

2. A modification which relocates the flow control orifice upstream in the j cooling unter supply line and reduces the pres::ure that the gland condenser experiences has been approved and tuplemented.

i l

( =

L. -

cx t ) /', l

Ij x -

l CorrectiveAction(continued) 3 HPCI was tested and returned to cperable condition.

Failure Data A cinilar failure cecurred Septe=ber 21, 1971, 1 4 reported on Abnormal Occurrence-ReportNo.3FAO-50-260/7416W.

1 s

9