ML19310A355

LER 80-031/01T-0:on 800521,upon Finding Leaking RHR Sys Vent Valve Weld,Evaluation Commenced to re-energize RHR Isolation Valve in Case of Gross Failure.Caused by de-energized Process Control Signal & Vent Weld Leak

ML19310A355
Person / Time
Site:	Beaver Valley
Issue date:	06/04/1980
From:	Lacey W DUQUESNE LIGHT CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19310A350	List: ML19310A349 ML19310A355
References
LER-80-031-01T, LER-80-31-1T, NUDOCS 8006110126
Download: ML19310A355 (2)

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NRC FCCM 366 e U.s. NUCLEAR REGULATORY COMMISS4!N

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LICENSEE EVENT REPORT (PLEASE PRINT OR TYPE ALL REQUIREO INFORMATION)

CONTROL BLOClO l I

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EVENT DESCRIPTION AND PRC8ABLE CONSEQUENCES h 10121 l Upon finding a leaking Residual Heat Removal (RHR) System vent valve veld, an i I o l 31 i evolution was commenced to re-energize the RHR isolation valves in case of a gross l A 1 failure. The consequences were a total loss of RHR. but safety innlications were I t o i s 1 I minimal since the leakage was contained and the system was capable of total  !

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SEQUENTIAL R EPORT NO. CODE TYPE N O.

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44 47 CAUSE CESCRIPTION AND CORRECTIVE ACTIONS l t j o l l The cause of the loss of RHR was the re-energizing of the system isolation valves I I

m l which had a false high pressure signal due to a de-enercized nrneess control i,,7, l signal. The reason for the re-energizing of the RHR isolation valves was due to a I i,;3l l high point vent weld leak. See attachment for emergenev weld information. I l

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NAME OF PREPARER

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Attachment To LER 80-31/0lT Beaver Valley Power Station Duquesne Light Company Docket No. 50-334

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Cause Description And Corrective Actions (continued)

Emergen:y repair of the high point vent was called a temporary weld in the immediate report for LER 80-031/0lT because there was no formal work package.

The weld method, materials, data sheets were all received at a later date by the necessary parties and the Onsite Safety Committee. The recommendation of the OSC is that the weld qualifies as a permanent repair. Any pipe support modification considered necessary by the Duquesne Light Engineering Department will be noted in a follow-up report.

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