ML19347C825

AO 73-22:on 730909,MSIV NS03B Tested for Leakage & Found to Exceed Tech Specs Limit.Cause Unknown.Prior to Disassembly of Valve,Stem Measurements Taken on All Valves to Check Conformity

ML19347C825
Person / Time
Site:	Oyster Creek
Issue date:	09/10/1973
From:	Richard Bright JERSEY CENTRAL POWER & LIGHT CO.
To:
References
AO-73-22, NUDOCS 8103040982
Download: ML19347C825 (2)

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BNORMAL OCCURRENCE 5

REPORT NO. 73-22

SUBJECT:

Violation of the Technical Specification, paragraph 1.15.E. ,

excessive Icakage through Main Steam Isolation Valve NS03B.

This event is considered to be an abnormal occurrence as defined in the Technical Specifications, paragraph 1.15.E. Notification of this event as required by the Technical Specifications, para-graph 6.6.2.a, was made to AEC Region I, Directorate of Regulatory Operations, by telephone on Monday, September 10, 1973, at 9:45 a.m. , and personally to Mr. E.' Greenm'an on Monday, September 10, 1973.

SITUATION: The reactor was shutdown (scrammed) on September 8,1973 at 0656. At 2255 on September 9,1973, NS03B was tested for leakage and found to be in excess of 100 SCFH. The limit, as detailed in the Technical Specifications, is 9.95 SCFH -(5% of Igo [20]). An estimate of the leak rate is now being formulated and is conser-vatively expected to be =200 SCFH. ,

l CAUSE: Unknown at this time.

REMEDIAL ACTION:

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Prior to disassembly of the valve, stem measurements are being l

! taken on all four. valves to check for confomity. In addition, l

the following organizations have been contacted, infomed of the i situation, and asked for coments. Their coments will be incor-porated into our decision on further action, ~

i f/OSo% W3 -

Abnormal Occurrence Report No. 73-22 September 9,1973

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r REMEDIAL ACTION (Con't)

Atwood-Morrill (vendor)

General Electric Company MPR Associates SAFETY SIGNIFICANCE:

The rate of pressure buildup in the reactor was compared to a graph of pressure buildup where at least one valve in each steam line was leak tight. These plots compared favorably. This implies that one valve in the "B" Main Steam Line (i.e. , NSO4B)

- was Icak tight. This was confirmed when pressure buildup between the valves was observed to be approximately th'e same as the reactor pressure. The redundancy feature will be ascertained only upon successful completion of the NSO4B Icak test.

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Prepared by: -

Date: 9/10/73

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