United States Nuclear Regulatory Commission - Protecting People and the Environment

Morning Report for August 11, 2005

Headquarters Daily Report

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REGION II

Subject: Operability of Brunswick Emergency Diesel Generators and Restart of Units

Licensee/Facility:

CAROLINA POWER & LIGHT CO.
Brunswick 1, Brunswick 2
SOUTHPORT, North Carolina
Dockets: 05000325, 05000324
[1] GE-4, [2] GE-4
License No:
Notification:

MR Number: 2-2005-0009
Date: 08/09/2005

Call from SRI

Discussion:

As documented in Preliminary Notification PNO-II-05-004 and Event Notification EN 41895, Brunswick Units 1 and 2 were shutdown on August 6, 2005, due to a potential common cause degraded condition of all four emergency diesel generators (EDGs). Subsequent to this shutdown, Region II initiated a Special Inspection Team on August 9 to assess the circumstances surrounding the inoperability of the EDGs.

At approximately 2200 on August 9, the licensee convened a Plant Nuclear Safety Committee (PNSC) meeting to evaluate the readiness of Units 1 and 2 for restart. In reviewing issues associated with the operability of the EDGS, the licensee evaluated the existing differential current relay setpoints and subsequently replaced the existing relays with relays that have a higher setpoint. The licensee evaluated the issues associated with the potential transformers providing power to the EDG exciter and concluded that while the transformers were potentially underdesigned, the service conditions associated with the operation of the installed transformers (including operating temperatures) were within design limits. Finally, the licensee concluded that the lower than expected resistance readings found during inspection and testing of the EDG collector ring/brush assembly did not challenge the operability of the EDG. The special inspection team, with input from the NRR technical staff, reviewed the licensee's evaluations and determined that the evaluations supported the licensee's resolution of each of these issues.

At 0240 on August 10, the licensee declared the EDGs operable. Unit 1 startup was commenced at 0509. Unit 2 remains shutdown while undergoing other outage work unrelated to the EDGs. The special inspection to assess the circumstances surroung the EDG operability continues. The resident inspectors are monitoring the return to service of both units.

Accession Numbers:

Accession No Accession Date
ML052230068 08/09/2005

Contacts:

Name Office Abbrev Phone No E-Mail
FREDRICKSON, PAUL E R2 (404) 562-4530 PEF@nrc.gov
Page Last Reviewed/Updated Thursday, March 29, 2012