A Green self-revealing non-cited violation of
10 CFR 50, Appendix B, Criterion XVI, Corrective Action, was identified for inadequate corrective actions which resulted in repetition of a significant
condition adverse to quality involving the spurious tripping of safety-related
molded case circuit breaker associated with the A
emergency diesel generator (
EDG) room ventilation cooling fan A due to asymmetrical in-rush starting current. The licensee documented this failure in their corrective action program and implemented breaker trip setpoint changes to preclude spurious tripping from this phenomenon. This finding is more than minor because it affected the equipment performance attribute of the
Mitigating Systems cornerstone and adversely affected the cornerstone objective of ensuring the availability, reliability and capability of systems that respond to
initiating events to prevent undesirable consequences. The finding is of very low safety significance because it did not result in a loss of safety function of one or more trains of the
EDGs and was not potentially risksignificant due to possible external events. The cause of this finding involved the thorough evaluation of identified problems aspect of the Problem Identification and Resolution cross-cutting area, in that, the extent of condition evaluation for the previous spurious trip of the A
EDG room cooling fan B failed to consider the need to readjust the trip setpoint of A
EDG room ventilation cooling fan A in order to mitigate the possibility of spurious tripping. (Section 1R15).
