PNO-IV-06-004, San Onofre, Unit 3, Shutdown of San Onofre Unit 3 to Investigate Safety Injection Tank Gaskets

From kanterella
Revision as of 09:49, 18 September 2019 by StriderTol (talk | contribs) (Created page by program invented by StriderTol)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search
PNO-IV-06-004 - San Onofre, Unit 3, Shutdown of San Onofre Unit 3 to Investigate Safety Injection Tank Gaskets
ML060880230
Person / Time
Site: San Onofre Southern California Edison icon.png
Issue date: 03/29/2006
From: Troy Pruett
NRC/RGN-IV/DRP/RPB-D
To:
References
PNO-IV-06-004
Download: ML060880230 (2)


March 29, 2006PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -- PNO-IV-06-004This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interestsignificance. 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. FacilitySan Onofre, Unit 3Southern California Edison Co.

San Clemente, CA Docket No: 50-362 License No: NPF-15Licensee Emergency Classification Notification of Unusual Event Alert Site Area Emergency General Emergency X Not Applicable

SUBJECT:

SHUTDOWN OF SAN ONOFRE UNIT 3 TO INVESTIGATE SAFETY INJECTION TANKGASKETS DESCRIPTION: On March 29, 2006, San Onofre Unit 3 entered a Technical Specification 3.0.3shutdown action statement at 2:01 a.m. (CST) when the licensee declared both trains of emergencycore cooling systems inoperable due to potentially degraded gasket material on all four safety injectiontank manway covers which could impact safety injection system operation. Plant operators began theUnit 3 shutdown at 2:50 a.m. (CST) with the unit required to be in Mode 3 by 9:01 a.m. (CST). Unit 3 was at 100 percent power and Unit 2 was in a refueling outage preparing for startup. OnMarch 27, the licensee discovered gasket material used to seal one of the Unit 2 safety injection tank manway covers in one of the safety injection tank outlet check valves. This gasket material prevented the check valve from fully seating. During inspections of the remaining three Unit 2 safety injection tank manway covers, the licensee found the gaskets degraded but intact; therefore, the licenseedetermined the same condition could exist on the Unit 3 safety injection tanks. The state of California will be informed.

The information presented herein has been discussed with the licensee and is current as of1100 a.m. (CST) on March 29, 2006. This preliminary notification is issued for information only and the resident inspector staff will follow theresolution of the degraded safety injection tank gaskets.ADAMS ACCESSION NUMBER: ML060880230 CONTACTS:Troy Pruett, ChiefProjects Branch D Division of Reactor Projects 817-860-8173 twp@nrc.gov