05000293/FIN-2011004-01
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Finding | |
|---|---|
| Title | Failure to Verify the Adequacy of the Design for the \'C\' Salt Service Water Pump |
| Description | The inspectors identified a Green NCV of 10 CFR Part 50, Appendix B, Criterion III, Design Control, because Entergy\'s design control measures did not ensure two-over-one seismic protection of the \'C\' Salt Service Water (SSW) Pump. Specifically, Entergy did not ensure that a Class I to Class II interface would not result in a failure of a Class I component (\'C\' SSW Pump). Corrective actions included installing a temporary modification (Le., water shield), to protect the pump motor from potential spray effects of a Class II piping failure and performing an extent of condition review. The inspectors performed a review of Inspection Manual Chapter (IMC) 0612, Appendix E, Examples of Minor Issues, and did not find a similar more than minor example. The finding was determined to be more than minor because it was associated with the Protection Against External Events (Le., seismic) attribute of the Mitigating Systems Cornerstone, and adversely affected the cornerstone\'s objective to ensure the reliability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the \'C\' SSW pump motor was vulnerable to water spray from a failed Class II pipe during a seismic event which could have rendered the pump inoperable. The inspectors used IMC 0609.04, Phase 1 - Initial Screening and Characterization of Findings, and determined that further evaluation was required since the finding was potentially risk significant due to a seismic initiating event. As a result of this screening, a Phase 3 evaluation was conducted by a regional Senior Reactor Analyst (SRA). The condition was assessed as Green, with a change in core damage frequency (CDF) calculated to be 1.29E-8. Since the finding was assessed to have a CDF of less than 1E-7, large early release frequency was not required to be assessed. The finding does not have a cross-cutting aspect since the failure to verify the adequacy of design with respect to ensuring two-over-one seismic protection for the \'C\' SSW pump is not indicative of current licensee performance. In addition, current Entergy design procedures require rigorous Class II-over-I criteria for all new modifications. |
| Site: | Pilgrim |
|---|---|
| Report | IR 05000293/2011004 Section 1R06 |
| Date counted | Sep 30, 2011 (2011Q3) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.06 |
| Inspectors (proximate) | S Barr R Rolph B Smith M Schneider R Bellamy |
| INPO aspect | |
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Finding - Pilgrim - IR 05000293/2011004 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Pilgrim) @ 2011Q3
Self-Identified List (Pilgrim)
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