PNO-II-06-005
| ML063100681 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 11/06/2006 |
| From: | Randy Musser Division of Nuclear Materials Safety II |
| To: | |
| References | |
| PNO-II-06-005A | |
| Download: ML063100681 (1) | |
November 6, 2006PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO-II-06-005AThis 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 Region II staff (Atlanta, Georgia) on this date.FacilityLicensee Emergency ClassificationBrunswick Steam Electric PlantXNotification of Unusual EventUnit 2Alert Southport, NCSite Area Emergency Dockets/License: 050000324/DPR-62General EmergencyNot Applicable
Subject:
UNUSUAL EVENT DECLARED DUE TO LOSS OF OFFSITE POWER TO UNIT 2 4kVEMERGENCY BUSES (UPDATE)On November 1, 2006, at 6:37 p.m. EST, Brunswick declared an unusual event following a manual scram ofUnit 2 as a result of a loss of offsite power to the unit caused by a lockout of the Startup Auxiliary Transformer.
Emergency Diesel Generators (EDGs) 3 and 4 auto-started and re-energized the affected electrical buses.
EDGs 1 and 2 auto-started but did not tie to their respective buses as the buses remained powered from the Unit 1 Unit Auxiliary Transformer. At approximately 4:00 a.m. EST on November 2, EDG 1 tripped on low lube oil pressure. This condition coupled with an unavailable Unit 2 Startup Auxiliary Transformer required that Unit 1 be in hot shutdown by 4:00 a.m. EST on November 3.The licensee restored offsite power to Unit 2 by backfeeding through the Unit 2 Auxiliary Transformer, therebyterminating the unusual event at 5:45 p.m. EST on November 2. At 10:23 p.m. EST on November 2, the licensee commenced a shutdown of Unit 1 as required by Technical Specifications. At 1:52 a.m. EST onNovember 3, with reactor power at approximately 81 percent, the power reduction was stopped when the licensee restored the Unit 2 Startup Auxiliary Transformer service. This restoration transitioned Unit 1 to a 7-day Technical Specification Action Statement for EDG 1 being inoperable. During repair activities, the licensee identified a failed main crankshaft bearing. Repairs have been completed and the EDG is undergoing post-maintenance testing.The State of North Carolina will be informed. The information in this preliminary notification has beenreviewed with licensee management, and is current as of 2:00 p.m. EST on Monday, November 6, 2006.CONTACT:Randall A. Musser404-562-4603