05000293/FIN-2012005-04
From kanterella
Jump to navigation
Jump to search
Finding | |
|---|---|
| Title | Failure to Evaluate Extent of Condition for B-15 Safety-Related Bus After Identifying an Overload Condition on the B-14 Safety-Related Bus |
| Description | The inspectors identified a finding of very low safety significance (Green) involving a non-cited violation (NCV) of 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, because Entergy did not identify an overload condition on the B-15 bus after a similar overload condition was known to exist on the opposite train B-14 bus. Entergy specified an extent of condition review to be performed as a corrective action but was not successful in completing this review to identify the similar vulnerability to B-15. Entergys corrective actions included immediately reducing loading on the B-15 bus and revising procedures to prohibit overloading the B-15 bus. Entergy has captured these issues in condition reports CR-PNP-2012-2015, CRPNP- 2012-4185 and CR-PNP-2012-4884. The performance deficiency was determined to be more than minor because it is associated with the Equipment Performance attribute of the Mitigating Systems cornerstone, and adversely affected the cornerstones objective to ensure the availability of systems that respond to initiating events to prevent undesirable consequences. During certain accident scenarios, equipment electrically powered from the B-15 bus (Reactor Building Closed Cooling Water and Salt Service Water) would have been unavailable to mitigate the consequences of an event. The inspectors used IMC 0609.04, Phase 1 Initial Screening and Characterization of Findings and Inspection Manual Chapter (IMC) 0609 Appendix A, Exhibit 2, Mitigating Systems Screening. In accordance with Exhibit 2 of IMC 0609, this performance deficiency required a detailed risk analysis since the issue resulted in an actual loss of function of at least a single train for greater than its Technical Specifications (TS) allowed outage time. The Senior Risk Analyst performed a detailed risk evaluation and determined the finding to be of very low safety significance (Green) with a change in core damage frequency of 1.1E-7. This finding has a cross-cutting aspect in the Problem Identification and Resolution cross-cutting area, Corrective Action Program component, because Entergy did not thoroughly evaluate the problem with B-14 such that the resolution addressed the extent of condition for the same vulnerability to B-15. |
| Site: | Pilgrim |
|---|---|
| Report | IR 05000293/2012005 Section 1R15 |
| Date counted | Dec 31, 2012 (2012Q4) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.15 |
| Inspectors (proximate) | T Moslak J Lilliendahl G Meyer S Pindale T Fish B Smith M Schneider R Bellamy M Orr |
| CCA | P.2, Evaluation |
| INPO aspect | PI.2 |
| ' | |
Finding - Pilgrim - IR 05000293/2012005 | |||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Finding List (Pilgrim) @ 2012Q4
| |||||||||||||||||||||||||||||||||||||||||||||