05000293/FIN-2015007-01
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Finding | |
|---|---|
| Title | Inadequate Past Operability Assessment of C Safety Relief Valve |
| Description | The team identified a Green NCV of Title 10 of the Code of Federal Regulations (10 CFR) 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, when Entergy staff performed an inadequate past operability determination that assessed performance of the C safety/relief valve (SRV), which did not open as expected when called upon to function. Specifically, following the January 27, 2015 reactor scram, operators placed an open demand for the C SRV twice during post-scram recovery operations, but the valve did not respond as expected and did not perform its pressure reduction function on both occasions. Entergys subsequent past operability assessment for the valves operation incorrectly concluded that the valve was fully capable of performing its required functions during its installed service. In response to the teams past operability concerns, Entergy subsequently re-evaluated the past operability of C SRV and concluded that it was inoperable and placed the issue into the corrective action program (CAP) as CR-PNP-2015- 02051. The team determined the failure to adequately assess past operability of the C SRV was a performance deficiency that was reasonably within Entergys ability to foresee and correct. This NRC-identified performance deficiency is more than minor because it is associated with the equipment performance attribute of the Mitigating Systems cornerstone and affects the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent core damage. The team evaluated the finding using IMC 0609, Appendix 0609.04, Initial Characterization of Findings, which directed the use of IMC 0609, Appendix A, The Significance Determination Process for Findings At-Power. Using Exhibit 2, Mitigating Systems Screening Questions, of IMC 0609, Appendix A, the team determined this finding was not a design or qualification deficiency and was not a potential or actual loss of system or safety function, and was therefore of very low safety significance (Green). The finding had a cross-cutting aspect in Human Performance, Conservative Bias, because Entergy did not use decision making practices that emphasized prudent choices over those that are simply allowable. Specifically, Entergy did not appropriately evaluate unexpected and unsatisfactory performance of the C SRV in consideration of the entire pressure range that the SRV, including its automatic depressurization system (ADS) function, was required to be operable. |
| Site: | Pilgrim |
|---|---|
| Report | IR 05000293/2015007 Section 4OA5 |
| Date counted | Mar 31, 2015 (2015Q1) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 93812 |
| Inspectors (proximate) | C Cahill D Schroeder E Burket E Dipaolo H Nieh J Lilliendahl S Pindale T Dunn |
| Violation of: | 10 CFR 50 Appendix B Criterion V |
| CCA | H.14, Conservative Bias |
| INPO aspect | DM.2 |
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Finding - Pilgrim - IR 05000293/2015007 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Pilgrim) @ 2015Q1
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