ML20086H324

AO 50-271/72-07:on 721010,alarm Annunciated in Main Control Room,Indicating Leak in Bellows Assembly of Main Steam Relief Valve D.Vendor Evaluating Problem

ML20086H324
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	10/11/1972
From:	Rosalyn Jones VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20086H319	List: ML20086H317 ML20086H321 ML20086H324 ML20086H336 ML20086H343 ML20086H345 ML20086H355
References
AO-50-271-72-07, AO-50-271-72-7, VYV-2276, NUDOCS 8401160380
Download: ML20086H324 (2)

Text

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1 CVENTY OCVCN OROvC STRCCT .

RUTLAND, hMONT 05701 '

fttPLY TO:

VYV-2276 p, o, gox i,7  :

VERNON. VERMONT 05354 j October 11, 1972 -]

i e

i United States Atomic Energy Commission j Directorate of Regulatory Operations, Region I j 9)G Broad Street i Newark, New Jersey 07102 5 5

REFERDICE Operating License DPR-28 _

bo Oc u ce No. A0-72-07 -

Gentlenent 4 An defined h>y Technical Specifications for the Vermont Yankee Nuclear Power Station, Section 6.7.A.c, we are reporting the following -

Abnormal Occurrence as AD-72-07 and confirming our telephone conversation  ;

4 with your office on this date.

i At 1831 hours0.0212 days <br />0.509 hours <br />0.00303 weeks <br />6.966955e-4 months <br /> on October 10, 1972 an alarm annunciated in the nain control roon indicating a leak in the bel 2cvs assembly of nain stean j relief valve "D". The failurc of the bellows could render the one relief _

valve incapable of automatically relievin, reactor steam pressure at its set point of 1080 psig (1080 psig 11% Technical Specifications Section 2.2.D).

This particular valve had experience 6 a similar failure on September 19, 1972 and was subsequently repaired during a scheduled plant a outage. The relief valve was restored to service on October 1,1972.

This relief valve unlike those on otean lines A, B, and C, has a silver f plated 0-ring installed between the bellowr.' and the preload spacer. j An identical 0-ring was determined to be the cause of the previous failure. -

2 The vendor representative is presently on site assisting in the evaluation of the probica and is preparing a reconnondation for review by appropriate j plant personnel. _.

$R 03BO 723gog .

S DDCK 05000g73 PDR 5 <> W// 4 v 9,&

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strectorate or negulatory operations, negion 1 i k E. October 11, 1972 1- -

Par. 2 o o The failed bellows in no way hinders the operation of the Autoinatic Depressurization System (ADS) or the reactor operator's ability to manually operate the relief valve.

Very truly yours, VE ONT YANKEE NUCLEAR POWER CORPORATION

/ ') , J s

+->

r Robert F. es Plant Superintendent DUE/rpb

.