The inspectors identified a finding with an associated violation involving
10 CFR Part 50, Appendix B, Criterion III (Design Control), and
10 CFR Part 50, Appendix B, Criterion XVI (Corrective Actions). The finding involved the degraded performance of 22 breakers that were installed in the plant during May and June 2001. Sixteen of these breakers had active safety functions for Division I and II components. The licensee failed to properly verify the design adequacy of replacement
Westinghouse DHP-VR 350 breakers equipped with a SURE CLOSE mechanism to operate in the existing configuration. The design change did not address the substantially reduced closing force available to operate the mechanism operated cell switch between the previous and current designs. Subsequently, the plant experienced four breaker malfunctions involving the Division II standby
service water system and
emergency diesel generator from June 2001 through February 2002. On June 29, 2001, and November 19, 2001, the Division II standby
service water system pump breaker failed, in that the mechanism operated cell switch failed to reposition. In addition, on January 17, 2002, the Division II
emergency diesel generator breaker mechanism operated cell switch malfunctioned. For these three malfunctions or failures, the licensee did not identify the cause, the generic aspects of the problem, or take effective actions to prevent repetition. This issue was considered to be more than minor because it impacted the operability of two safety-related systems with the potential to impact others. Using the NRCs Phase 3
Significance Determination Process, this finding was determined to have low to moderate safety significance based on the overall change in core damage frequency and
large early release frequency. The licensee captured these problems in Problem Evaluation Request 202-0456 and 202-0927 (Sections 02.03 and 02.04, respectively). The condition that resulted in the breaker failures, the malfunction and the overall degradation of the 22 breakers has been corrected.
