The inspectors identified a Green
NCV of
10 CFR 50, Appendix B, Criterion XVI, Corrective Action, because Entergy did not promptly identify
conditions adverse to quality related to the
service water system. Specifically, observable
through-wall leaks that were reasonably able to be identified existed in
service water piping supplying the
emergency diesel generators (
EDGs) cooling system for an extended period of time without being identified. In addition, the affected
service water piping was not appropriately scheduled for treatment and replacement given known conditions favorable to microbiologically induced corrosion (
MIC). Entergys corrective actions to restore compliance consisted of performing complete walkdowns of all accessible safety-related
service water piping, performing ultrasonic inspections of the three leak locations and fifteen extent of condition locations, conducting structural analyses to determine structural integrity of the piping with the measured thinning, and performing daily leak rate monitoring and frequent periodic ultrasonic inspections of no more than 30 day intervals. This finding is more than minor because if left uncorrected it has the potential to
lead to a more significant safety concern. Specifically, the
through-wall leaks were unmonitored degraded conditions with reasonable doubt on the operability of the
service water and alternate cooling systems before the results of ultrasonic inspections and new structural analyses were obtained. The inspectors determined the significance of the finding using
IMC 0609, Appendix A, The
Significance Determination Process (
SDP) for Findings At- Power. The finding was determined to be of very low safety significance (Green) because the finding was a deficiency affecting the design and qualification of the
service water and alternate cooling systems and the systems maintained their operability. The inspectors determined that the finding has a cross-cutting aspect in the area of Human Performance, Resources, because Entergy did not ensure that the combination of piping replacements, chemical treatments, guidance and procedures for walkdowns, and camera coverage were adequate to support nuclear safety.
