05000361/LER-1982-146, Forwards LER 82-146/03L-0.Detailed Event Analysis Submitted

Forwards LER 82-146/03L-0.Detailed Event Analysis Submitted

ML20070L589
Person / Time
Site:	San Onofre
Issue date:	12/16/1982
From:	Morza H SOUTHERN CALIFORNIA EDISON CO.
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
Shared Package
ML20070L591	List: 05000361/LER-1982-146, Forwards LER 82-146/03L-0.Detailed Event Analysis Submitted 05000361/LER-1982-146-03, /03L-0:on 821116,while in Mode 1,auxiliary Feedwater Pump 2P-140 Declared Inoperable.Caused by Loosening of Switch Assembly 2ZL4705-2 from Valve Stem. Switch Assembly Realigned & Tightened
References
NUDOCS 8301030197
Download: ML20070L589 (2)

LER-1982-146, Forwards LER 82-146/03L-0.Detailed Event Analysis Submitted

Event date:
Report date:
3611982146R00 - NRC Website

text

N WD Southern California Edison Company IDIDECgg WE p;

S AN ONOFRE NUC LE AR GENER A TING S T A YtON P.O. B O X 120 s AN CLEMENTE, C ALIFORNI A 92672 O [/

H. B. R A Y

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tattawowe December 16, 1982

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U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region V 1450 Maria Lane, Suite 210 Walnut Creek, California 94596-5368 Attention:

Mr. R. H. Engelken, Regional Administrator

Dear Sir:

Subject:

Docket No. 50-361 30-Day Report Licensee Event Report No.82-146 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 the Auxiliary Feedwater (AFW)

System. A completed copy of LER 82-146 addressing this event is enclosed.

On November 16,1982 at 0130, while in Mode 1, turbine-driven AFW pump 2P-140 was declared inoperable due to failure of discharge valve 2HV4705 to stroke properly. Accordingly, Action Statement "a" of Limiting Condition for Operation (LCO) 3.7.1.2 was entered. This LC0 requires that while in Mode 1, 2 or 3, at least three independent AFW pumps and associated flow-paths must be operable.

If one train becomes inoperable, operation may continue provided the inoperable train is restored to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

During periodic surveillance, valve 2HV4705 failed to stroke fully open in the required 30 seconds (stroke time was 30.7 seconds).

Investigation revealed that the Switch Assembly 2ZL4705-2 had loosened from the valve stem. This resulted in the misalignment of the limit switch. The open indication contact was being rnaue beyond the point where the valve was fully open resulting in the apparently slow stroke time.

8301030197 821216 g 'y POR ADOCK 05000361 S

PDR gg

l R. H. Engelken December 16, 1982 The switch assembly was re-aligned and tightened. Surveillance testing was repeated with satisfactory results.

The valve, and therefore the AFW train associated with pump 2P-140, was declared operable at 1930 on November 16, 1982.

As a corrective measure to prevent recurrence, all valves of this type I

will be examined to verify proper switch alignment and tightness.

The public health and safety were not affected by this event since either one of the two remaining operable AFW pumps (each able to provide 100% of the required capacity) would have performed the necessary decay heat removal function, if required.

If there are any questions, please contact me.

Sincerely, hb

Enclosure:

LER 82-146 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 Infonnation and Program Control Institute of Nuclear Power Operations 1

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