05000206/LER-1981-025, Forwards LER 81-025/01X-1.Detailed Event Analysis Submitted

Forwards LER 81-025/01X-1.Detailed Event Analysis Submitted

ML20053C196
Person / Time
Site:	San Onofre
Issue date:	05/19/1982
From:	Ray H SOUTHERN CALIFORNIA EDISON CO.
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
Shared Package
ML20053C197	List: 05000206/LER-1981-025, Forwards LER 81-025/01X-1.Detailed Event Analysis Submitted
References
NUDOCS 8206010565
Download: ML20053C196 (2)

LER-1981-025, Forwards LER 81-025/01X-1.Detailed Event Analysis Submitted

Event date:
Report date:
2061981025R00 - NRC Website

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Southern California Edison Company Qi I.

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.m m mo U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region V 1450 fbria Lane, Suite 210 Walnut Creek, California 94596-5368 t-tontion:

Mr. R. H.

Engelken, Regional Administrator

Dear Sir:

Subject: Doc ke t No. 50-206 Licensee Event Report No.81-025, Rev. I San Onofro Nuclear Generating Station, Unit No. I

References:

1.

Letter, H. B. Ray to R. H.

Engelken, dated October 26, 1981.

2.

Letter, H. B. Ray to R. H. Engelken, dated November 3, 1981 (LER 81-025 enclosed).

The submittal dated November 3, 1981 outlined the problems experienced with two containment isolation valves, CV-534 and CV-107, which failed to operate automatically during testing.

In each case the problem was traced to sticking relays. The relays were replaced and the valves returned to service.

LER No.81-025 promised an investigaiion to determine the exact cause of relay failure.

That investigation has been completed.

In both cases, the failure has been traced to midpositioned contacts on the Containment isolation Relays (Agastat Magnetic Latch Relays Mod. No.

EMLD001).

Insertion of an arming contact in series with the reset winding of the Containment isolation Relays led to the failure of the relays. Corrective action consists of (1) making a circuit change to bypass the arming contact of the Agastat relay and (2) removing, inspect-ing, and testing each Agastat Magnetic Latch Relay to verify that each is in proper operating conditlon.

This corrective action is currentIy underway and all Agastat relays will nave been reworked in this fashion before the end of the current outage.

Please find enclosed LER 81-025, Revision 1.

This Licensee Event Report has been revised to reflect the results of our investigation.

if you need further information please do not hesitate to call me.

Sincerely,

[

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Enclosure:

LER No.81-025, Revision I

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820 6 010 $(,$

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Mr. R. H. EngoIFen May 19, 1982 cc:

U. S. fluclear Regu latory Cctrrni ssion Offico of inspection & Enforcerent U. S. fluclear Regulatory Cormission Offico of Management Inforration and Program Control institute of fluclear Power Operation (IfiPO)

L. F. Miller (USNRC Resident inspector - San Onofre Unit 1) i i