05000410/FIN-2017004-03
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Finding | |
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| Title | Inadequate Operability Determination forImpairedInternal Flood Barrier |
| Description | An NRC-identified Green NCV of 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, was identified when Exelon failed to perform an adequate operability determination in accordance with OP-AA-108-115, Operability Determinations, Revision 20, upon identification of Unit 2 degraded internal flood barriers that support operability of emergency core cooling system (ECCS) equipment. Specifically, from November 21 until December 10, 2017, Exelon failed to properly evaluate the excavation of internal flood barriers and concluded there was a reasonable expectation for operability of the supported ECCS systems. Exelon entered this issue into the CAP as IR 04082686. Corrective actions included conducting a detailed evaluation of operability for the supported safety-related systems, additional training associated with TS 3.0.9, including a focus on the need for risk assessments when entering TS 3.0.9, and a procedure change to CC-AA-201, Plant Barrier Control Program, and CC-NM-201-1001, Plant Barrier Control Program Implementation, which is the NMPNS specific procedure to address the vulnerabilities associated with impairing multiple required barriers. This finding is more than minor because it is associated with the human performance attribute of the Mitigating Systems cornerstone and affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, from November 21 until December 10, 2017, Exelon failed to adequately evaluate the operability of a degraded internal flooding barrier and the potential impact on operability of the supported ECCS system equipment. The inspectors identified that the internal flood barrier was excavated such that there was not sufficient material to ensure adequate flood protection, and resulted in a reasonable doubt for the operability of the supported ECCS systems. This finding is also similar to example 3.j and 3.k of IMC 0612 Appendix E, Examples of Minor Issues, issued August 11, 2009, because the condition identified by the inspectors resulted in a reasonable doubt for the operability of the ECCS supported systems and additional analysis was necessary to verify operability. In accordance with IMC 0609.04, Initial Characterization of Findings, and Exhibit 2 of IMC 0609, Appendix A, The Significance Determination Process for Findings At-Power, issued June 19, 2012, the inspectors determined that the finding was of very low safety significance (Green), because the finding was not a design or qualification deficiency, did not represent a loss of system safety function, and did not screen as potentially risk significant due to vulnerability to external initiating events. This finding has a cross-cutting aspect in the area of Human Performance, Work Management, because Exelon failed to implement a process of planning, controlling, and executing work activities such that nuclear safety is the overriding priority. As a result, Exelon personnel failed to recognize that work activities that impaired internal flood barriers on both Division I and II low pressure ECCS pump rooms were executed simultaneously, which led to an unplanned entry into TS Limiting Condition for Operation (LCO) 3.0.9. [H.5] |
| Site: | Nine Mile Point  |
|---|---|
| Report | IR 05000410/2017004 Section 1R15 |
| Date counted | Dec 31, 2017 (2017Q4) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.15 |
| Inspectors (proximate) | M Catts B Sienel P Presby M Patel K Mangan M Hardgrove J Bream F Arner R Rolph G Stock E Miller H Lynn |
| Violation of: | 10 CFR 50 Appendix B 10 CFR 50 Appendix B Criterion V Technical Specification |
| CCA | H.5, Work Management |
| INPO aspect | WP.1 |
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Finding - Nine Mile Point - IR 05000410/2017004 | ||||||||||||||||||||||||||||||||||||||||||
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Finding List (Nine Mile Point) @ 2017Q4
Self-Identified List (Nine Mile Point)
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