05000206/LER-1982-005, Forwards LER 82-005/03L-0.Detailed Event Analysis Submitted

Forwards LER 82-005/03L-0.Detailed Event Analysis Submitted

ML20050B763
Person / Time
Site:	San Onofre
Issue date:	03/25/1982
From:	Ray H SOUTHERN CALIFORNIA EDISON CO.
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
Shared Package
ML20050B764	List: 05000206/LER-1982-005, Forwards LER 82-005/03L-0.Detailed Event Analysis Submitted 05000206/LER-1982-005-03, /03L-0:on 820228,during Normal Power Operation, Containment Isolation Valve SV-70ZC Failed to Close on Demand.Possibly Caused by Contaminants in Valve Soft Goods. Solenoid Valve or Soft Goods to Be Replaced
References
NUDOCS 8204070346
Download: ML20050B763 (4)

LER-1982-005, Forwards LER 82-005/03L-0.Detailed Event Analysis Submitted

Event date:
Report date:
2061982005R00 - NRC Website

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SAN CLEMENTE, C ALIFORNI A 9267:

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U. S. Nuclear Regulatory Commission

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Office of Inspection and Enforcement N

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1450 Maria Lane, Suite 210 g 9,q G y

Walnut Creek, California 94596-5368 6}

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Attention:

Mr. R. H. Engelken, Director g

s Docket No. 50-20 v

San Onofre - Unit 1

Dear Sir:

This letter describes a reportable occurrence involving failure of Containment Isolation Valve SV-702 C to close on demand. Submittal is in accordance with the reporting requirements of Section 6.9.2 of Appendix A to Provisional Operating License DPR-13. This report was due on March 24, 1982; however, it was delayed until March 25, 1982 as discussed between our Mr. P.A. Croy and Mr. J. Zwetzig of your office.

On February 22, 1982, nonnal operator surveillance of the status and configuration of plant systems identified Containment Isolation Valves SV-702 A, B, C and D to be open. These valves are continuous duty, energized to open, solenoid operated valves located on the 3/4 inch vent lines from the B and C loop safety injection lines; SV-702 A and B are located on the C loop vent while SV-702 C and D are located on the B loop vent. These solenoid valves are periodically opened to remove air pockets from the safety injection lines in order to prevent water hammer in the unlikely event that safety injection is initiated.

This venting operation is performed monthly while the unit is in Modes 1 through 4.

Although the SV-702 valves are nonnally kept closed, there is no Technical Specification requirement that they be closed. However, Technical Specification Section 3.6.2 requires that they be operable.

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. Following discovery of the four valves in open positions, an attempt to close all valves was made. SV's 702 A, B, and D all closed insnediately while SV 702 C did not. 'In accordance with Technical Spec-ification Section 3.6.2, the affected containment penetration was veri-fied to be isolated by local inspection and tagging of a downstream manual block valve in the closed position. There are no system opera-bility problems in isolating this containment penetration with this manual block valve as the subject venting is done on a periodic basis and is not required just prior to initiating Safety Injection.

Subsequent investigation failed to. determine why the valve failed to close on demand. The valve functioned properly on all tests conducted after the initial discovery.

The manufacturer of this valve has been contacted for technical consultation. Yhe manufacturer stated that the most likely cause of failure is contaminants in the "sof t goods" (0-ring seals, polymer seats, etc.) area of the valve.

Investigation is continuing into the valve failure.

It is anticipated that corrective action will entail replacement of the " soft-goods" which will be completed by the return to power from the current outage.

Should our investigation indicate that other corrective action is warranted, an additional report will be prepared and submitted.

Relative to the discovery of the four v'alves in an open position, our review indicates that it is not possible to positively establish whether the va' tes were in fact properly closed following the most recent monthly venting; however, closure was properly do umented in the procedure checklist. In addition, there is no evidence of an electrical or mechanical fault which would cause these four valves to be opened.

Consequently, corrective action will be taken in the fonn of continued emphasis in orerator training to careful adherence to procedural require-merts. Adher Ace to procedural requirements will ensure documentation of operator actions (such as valve closure) is based in fact, and operator actions (such as valve opening) is not accomplished unless procedurally required.

Additionally, should safety injection have initiated during the time the valve was inoperable, there would have been no adverse affect on public safety.

Solenoid valve SV-702 D, which is in series with SV-702 C, also closes automatically on a containment isolation signal which is in turn initiated on safety injection. Thus, there would be no loss of safety injection flow should SV-702 C fail to close concurrent with initiation of safety injection.

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. If you have any questions or desire further information on this matter, please contact me.

Very truly yours,

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Enclosure (LER82-005) cc:

L. Miller (NRC Resident Inspector - San Onofre Unit 1)

Director, Office of Management Information and Program Control Director, Nuclear Safety Analysis Center 4

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PACroy:cng bcc: L. T. Papay (2)

NARC Members R. Dietch OSRC Members A. Arenal H. L. Ottoson H. B. Ray B. Katz/M. A. Wharton C. R. Kocker/J. A. Beoletto K. P. Baskin W. H. Ray /J. L. Anaya J. P. Albers H. E. Morgan G. T. McLandrich G. R. Mills J. M. Curran /J. D. Dunn G. W. Mcdonald M. P. Short (STA)

J. Reeder/W. McGhee J. G. Haynes W. C. Moody R. W. Krieger P. A. Croy W. C. Marsh W. W. Strom C. K. Balog F. Briggs CDM Files CC & C Files Engineering Files D.R. Piggot, Esq. (Orrick, Herrington & Sutcliffe)

D.W. Gilman (San Diego Gas & Electric Company)

R.L. Erickson (San Diego Gas & Electric Company) t i

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