PNO-IV-05-004, SONGS - Shutdown to Repair Component Cooling Water Valve

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PNO-IV-05-004: SONGS - Shutdown to Repair Component Cooling Water Valve
ML050490181
Person / Time
Site: San Onofre Southern California Edison icon.png
Issue date: 02/18/2005
From: Hay M
Division of Nuclear Materials Safety IV
To:
References
PNO-IV-05-004
Download: ML050490181 (1)


February 18, 2005 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -- PNO-IV-05-004 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without verification or evaluation, and is basically all that is known by the Region IV, Arlington, Texas, staff on this date.

Facility Licensee Emergency Classification San Onofre Nuclear Generating Staion Notification of Unusual Event Unit 2 Alert San Clemente, CA 92674-0128 Site Area Emergency Docket: 50-361 General Emergency License: NPF-10 X Not Applicable

SUBJECT:

SHUTDOWN TO REPAIR COMPONENT COOLING WATER VALVE DESCRIPTION:

On February 15, 2005, the San Onofre Nuclear Generating Station Unit 2 reactor was shut down following identification of an abnormal flow condition on a Unit 2 Train B component cooling water valve on the discharge of the shutdown cooling heat exchanger.

The licensee identified the leaking valve on February 10, 2005, during operator rounds when abnormal flow noise was heard in the area of the valve with the valve closed. Radiography and acoustic monitoring were used on the valve to attempt to determine the cause of the leakage with limited success. The valve was not easily isolable and, although repairs may have been possible on line, the licensee elected to shut down Unit 2 to correct the abnormal flow condition. The shutdown was commenced at 9:55 p.m. on February 14, 2005, and the unit was taken offline at 2:41 a.m. on February 15. The unit has been cooled down to Mode 5 conditions. The licensee is evaluating repair methods.

Region IV received notification of the abnormal flow condition from the licensee at 6:30 a.m. on February 11, 2005. The state of California has been notified by telephone.

The information presented herein has been discussed with the licensee and is current as of 8 a.m. on February 18, 2005.

ADAMS ACCESSION NUMBER: ML050490181 CONTACT: Michael C. Hay, 817-860-8144, mch@nrc.gov