An NRC-identified Green
NCV of
10 CFR 50, Appendix B, Criterion XVI, Corrective Action, was identified for the licensees failure to determine the cause of a significant
condition adverse to quality involving both trains of Control Room Area Chilled Water System (CRACWS) being out of service at the same time. This resulted in insufficient corrective action to preclude repetition. The licensee reopened the root cause investigation to determine the cause and was resolving the high cycle fatigue issue on the hot gas bypass line. The performance deficiency was more than minor because, if left uncorrected, it had the potential to
lead to a more significant safety concern in that failing to identify corrective actions to preclude repetition could result in the loss of safety function of more risksignificant equipment such as
emergency diesel generators. This finding was determined to be of very low safety significance (Green) because it did not contribute to both the likelihood of a
reactor trip and the likelihood that mitigation equipment or functions would not be available. This finding was associated with the cross-cutting aspect of supervisory and management oversight in the Work Practices component of the Human Performance area because managements establishment of the scope and reviews of the completed root cause evaluation failed to provide adequate oversight to ensure the cause of a significant
condition adverse to quality was determined and corrective actions were taken to preclude repetition.
H.4(c) (Section 4OA3
