05000362/LER-2008-001, TS Required Shutdown Due to EDG Repair Beyond Allowed Outage Time

TS Required Shutdown Due to EDG Repair Beyond Allowed Outage Time

ML083020362
Person / Time
Site:	San Onofre
Issue date:	10/27/2008
From:	Hochevar A Southern California Edison Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LER 08-001-00
Download: ML083020362 (2)

LER-2008-001, TS Required Shutdown Due to EDG Repair Beyond Allowed Outage Time

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown
3622008001R00 - NRC Website

text

SOUTHERN CALIFORNIA EDISON" An EDISON INTERNATIONAL@ Company October 27, 2008 U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555-0001

Subject:

Docket No. 50-362 Licensee Event Report No. 2008-001 San Onofre Nuclear Generating Station, Unit 3

Dear Sir or Madam:

This submittal provides Licensee Event Report (LER) 2008-001, in accordance with 10 CFR 50.73(a)(2)(i)(A) to report the completion of a Technical Specification required shutdown. This shutdown was required to complete repair of the Emergency Diesel Generator, train "B", beyond the Allowed Outage Time.

Sincerely, Albert R. Hochevar Station Manager Unit 3 LER No. 2008-001 cc:

E. E. Collins, NRC Regional Administrator, Region IV G. G. Warnick, NRC Senior Resident Inspector, San Onofre Units 2 & 3 P.O. Box 128 San Clemente, CA 92674-0128

Abstract

On 9/1/08, at about 1035 PDT, with Unit 3 near full power, plant operators manually initiated a plant shutdown to complete repairs on Emergency Diesel Generator (EDG) 3G003. A condition identified while performing testing following the replacement of the generator, required the EDG to be inoperable longer than allowed by Technical Specification 3.8.1 (14 days). At 1403 PDT, SCE reported initiation of the shutdown on 9/1/08 (NRC Log No. 44456) under 10 CFR 50.72(b)(2)(i). Operators tripped the reactor on 9/1/08 at 14:47 PDT. SCE is submitting this report in accordance with 10 CFR 50.73(a)(2)(i)(A).

The Allowed Outage Time (AOT) began on 8/19/08 as planned maintenance that included replacement of bearings on Diesel fuel racks and an inspection of the generator. The inspection revealed cracks in the shorting ring, requiring replacement of the generator. Post-maintenance testing revealed anomalous readings that could not be resolved during the AOT. Subsequently, SCE determined that the readings were due to an improper fit of a newly replaced bearing, causing momentary binding of a fuel rack. The bearing was replaced, the Surveillance Requirements met and the EDG was returned to Operable status. The reactor returned to Mode 1 on 9/11/08 at about 22:22 PDT.

The shutdown was a normal, uncomplicated plant shutdown. Therefore, the significance of this event was minimal.