05000361/LER-1982-149, Forwards LER 82-149/03L-0.Detailed Event Analysis Submitted

Forwards LER 82-149/03L-0.Detailed Event Analysis Submitted

ML20064H867
Person / Time
Site:	San Onofre
Issue date:	12/23/1982
From:	Kay H SOUTHERN CALIFORNIA EDISON CO.
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
Shared Package
ML20064H870	List: 05000361/LER-1982-149, Forwards LER 82-149/03L-0.Detailed Event Analysis Submitted 05000361/LER-1982-149-03, /03L-0:on 821123,during Mode 1,while Attempting to Shift Steam Generator Feedwater from Auxiliary Feed to Main Feed,Containment Isolation Valve 2HV4730 Would Not Close. Caused by Failure of Limit Switch.Switch Adjusted
References
82-466, NUDOCS 8301170447
Download: ML20064H867 (2)

LER-1982-149, Forwards LER 82-149/03L-0.Detailed Event Analysis Submitted

Event date:
Report date:
3611982149R00 - NRC Website

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Southern California Edison Companyg,g C p _$, E S AN ONOFRE NUC LE AR GENER A TING S T A TION

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P.O. B O x 12 8 S A N C LE, MENT E C ALIFOR NI A 92672 8

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December 23, 1982

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U. S. Nuclear Regulatory Commission Office of Inspection and Entorcement Region V 1450 Mario Lane, suite 210 Wolnut Creek, California 94596-t368 Attention:

Mr. R. H. Engelken, Regional Administrator

Dear Sir:

l

Subject:

Docket No. 50-361 30-Day Report 3

Licensee Event Report No.82-149 San Onofre Nuclear Generating Station, Unit 2 Pursuant to Section 6.9.1.13.b of Appendix A, Technical Specifications to Operating License NPF-10, for San Onofre Unit 2, this submittal provides the required 30-day written report and copy of Licensee Event Report (LER) for an occurrence involving a containment isolation valve.

A completed copy of LER 82-149 addressing this event is enclosed.

On November 23,1982, at 0300 with the plant in Mode 1, while Operators were attempting to shift steam generator feedwater flow from auxiliary feed to main feed, containment isolation valve 2HV4730 failed to close.

The valve was declared inoperable and Limiting Condition for Operation (LCO) 3.6.3 was entered. The Action statement "a" of LC0 3.6.3 allows operation to continue for up to four hours before the valve is restored to operable status.

The failure of the valve to close has been determined to have been caused by a limit switch in the valve control circuit. The limit switch is operated by a cam driven from the valve gear train such that when the valve reaches the full open position, the limit switch closes providing a permissive for the valve close circuit.

Adjustment of the contacts in the limit switch corrected the problen, the valve was tested several times successfully, and the valve was declared operable at 0500 on November 23, 1982.

This was an isolated incident, therefore, no corrective measures to prevent recurrence are planned. The public health and safety were not affected by this event since containment isolation was maintained by a second closed valve in the same line.

830117T447 821223 PDR ADOCK 05000361 S

PDR 18-21 y-4(clo

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Mr. R. H. Engelken December 23, 1982 I

If there are any questions, please contact me.

Sincerely, Hf;h/@NA Enclosure: LER 82-149 cc:

A. E. Chaffee (USNRC Resident Inspector, San Onofre Unit 2)

U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Office of Management Information and Program Control l

Institute of Nuclear Power Operations 4

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