05000206/LER-1980-028, Forwards LER 80-028/01T-0

Forwards LER 80-028/01T-0

ML13331B419
Person / Time
Site:	San Onofre
Issue date:	07/01/1980
From:	Ottoson H SOUTHERN CALIFORNIA EDISON CO.
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
Shared Package
ML13331B420	List: 05000206/LER-1980-028, Forwards LER 80-028/01T-0 05000206/LER-1980-028-01, /01T-0:on 800612,during IE Bulletin 79-14 Insp, Inadequate Pipe Guides Discovered in Safety Injection Sys Injection Lines.Caused by Improper Installation.Guides Will Be Modified Before Return to Svc
References
NUDOCS 8007080403
Download: ML13331B419 (2)

LER-1980-028, Forwards LER 80-028/01T-0

Event date:
Report date:
2061980028R00 - NRC Website

text

Southern California Edison Company P. 0. BOX 800 2255 WALNUT GROVE AVENUE ROSEMEAD. CALIFORNIA 91770 July 1, 1980 U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region V 1990 North California Boulevard Suite 202, Walnut Creek Plaza Walnut Creek, California 94596 Attention: Mr. R. H. Engelken, Director

Dear Sir:

Subject: Docket No. 50-206 San Onofre Nuclear Generating Station Unit 1

Reference:

Letter dated June 12, 1980 from SCE (J. M. Curran) to NRC (R. H. Engelken)

The referenced letter provided prompt written notification to your office of (1) a damaged pipe guide, and (2) a pipe guide which was inadequately designed and constructed, both involving the Safety Injection System. In accordance with IE Bulletin No. 79-14 and our Technical Specification 6.9.2, this letter is submitted as the required 14-day report. In addition, a completed copy of Licensee Event Report No.80-028 is enclosed concerning this incident.

In the conduct of the field verification/inspection in accordance with IE Bulletin No. 79-14, a damaged pipe guide and a pipe guide which was inadequately designed and constructed were discovered on the Safety Injection System injection lines 6006-6"-1501R and 6007-6"-1501R. As described in the referenced letter, the damaged pipe guide will be repaired and the pipe guide which was inadequately designed and constructed will be modified prior to return to service from the current refueling outage to conform the piping systems to the seismic analysis input information.

At07 0 8 0 5

U. S. Nuclear Regulatory Commission 2 -

July 1, 1980 Based on the results of the two day engineering evaluation, the damaged pipe guide did not satisfy deflection criteria in the restraint direction as assumed in the seismic analysis, and the pipe guide which was inadequately designed and constructed did not provide adequate lateral support

(+ Z movement) as assumed in the seismic analysis. With the damaged pipe guide, the maximum stress would be approximately 25,950 psi during an earthquake as defined in the Final Safety Analysis Report which is in excess of the code allowable stress of 22,320 psi. With the inadequately designed and constructed pipe guide, the maximum stress would be approximately 25,730 psi during an

- earthquake as defined in the Final Safety Analysis Report which is also in excess of the code allowable stress of 22,320 psi. However, since these stresses would be substantially below the minimum ultimate tensile stress of 70,000 psi, it is unlikely that the piping would have failed with the improper pipe guides during an earthquake.

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

Very truly yours, X-1 H. L. Ottoson Manager of Nuclear Operations Enclosure: Licensee Event Report No.80-028 cc:

Director, Office of Inspection and Enforcement (40)

Director, Office of Management Enforcement & Program Control (3)

Director, Nuclear Safety Analysis Center L. Miller, USNRC Resident Inspector