05000219/FIN-2015004-01
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Finding | |
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| Title | Preconditioning of the Standby Liquid Control Relief Valves |
| Description | The inspectors identified an NCV of 10 Code of Federal Regulations (CFR) 50, Appendix B, Criterion XI, Test Control, because Exelon conducted unacceptable preconditioning of the standby liquid control (SLC) relief valves prior to American Society of Mechanical Engineers (ASME) code testing. Specifically, Exelon performed a SLC system functional test prior to performing the SLC relief valve as-found testing. Exelons immediate corrective actions included completing the as-found test prior to the functional test. Exelon entered this issue into their corrective action program (CAP) as issue report 2566036 to track the resolution of the issue. The 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 availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences (i.e., core damage). Additionally, if left uncorrected, the performance deficiency could have the potential to lead to a more significant safety concern. Specifically, completion of the functional test prior to the replacement of the SLC relief valves masks the actual as-found condition by solidifying the valve internals. As a result, the as-found condition of the SLC relief valves have not been conducted and in the worst case scenario, could open below the design setpoint, which would divert flow back to the liquid poison tank instead of into the vessel to shut down the reactor during an anticipated transient without scram (ATWS) condition. The inspectors evaluated the finding using IMC 0609, Attachment 4, Initial Screening and Characterization of Findings, and determined the finding was of very low safety significance (Green) because the structure, system or component (SSC) maintained its operability. The finding has a cross-cutting aspect in the area of Problem Identification and Resolution, Evaluation because Exelon did not thoroughly evaluate issues to ensure that resolutions address causes and extent of conditions commensurate with their safety significance. Specifically, Exelon did not evaluate the effect of performing the SLC system functional test prior to conducting the ASME code as-found test on the SLC relief valves. |
| Site: | Oyster Creek |
|---|---|
| Report | IR 05000219/2015004 Section 1R15 |
| Date counted | Dec 31, 2015 (2015Q4) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.15 |
| Inspectors (proximate) | A Patel B Dionne E Andrews J Deboer M Scheetz S Haney S Kennedy |
| Violation of: | 10 CFR 50 Appendix B Criterion XI |
| CCA | P.2, Evaluation |
| INPO aspect | PI.2 |
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Finding - Oyster Creek - IR 05000219/2015004 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Oyster Creek) @ 2015Q4
Self-Identified List (Oyster Creek)
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