05000483/FIN-2014002-02
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Finding | |
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| Title | Failure to Implement Corrective Actions to Preclude Repetition |
| Description | The inspectors identified a non-cited violation of 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Actions, involving the licensees failure to prevent repetition of a significant condition adverse to quality. Specifically, the licensee failed to implement corrective actions to prevent repletion that were identified for a significant condition associated with the uncoupling of an essential service water system valves and their motor operator. The condition had been identified during similar failures in 1990 and 1993, but the planned corrective actions were never implemented. As a result, another service water valve failed in the same manner in 2012. This issue was entered into the licensees corrective action program as Callaway Action Request 201401188. Corrective actions included updating the preventative maintenance instructions to include torque checks on the coupling bolts and verify all valves with similar couplings are checked by December 2014. The inspectors determined the failure to prevent repetition of a significant condition adverse to quality was a performance deficiency. This performance deficiency was more than minor because it adversely affected the equipment 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. The inspectors assessed the finding in accordance with NRC Inspection Manual 0609, Appendix A, Exhibit 2, Mitigating Systems Screening Questions, and determined the finding required a detailed risk evaluation because it involved the failure of a safety related valve (a single train) for longer than the technical specification allowed outage time. Therefore, a senior reactor analyst performed a bounding Phase 3 significance determination. The analyst determined that the finding was of very low safety significance (Green). The bounding change to the core damage frequency was approximately 4.5E-8/year. The dominant core damage sequences associated with the failed valve included losses of offsite power, failure of the redundant valve in the same train, random failures of the opposite train pump, failure to recover offsite power in 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, and a consequential reactor coolant pump seal loss of coolant accident. Equipment that helped mitigated the risk included the redundant essential service water isolation valve in the same train as well as the auxiliary feedwater system and the steam generators. This finding did not have a cross-cutting aspect because the issue occurred in 1993 and is not indicative of current plant performance. |
| Site: | Callaway  |
|---|---|
| Report | IR 05000483/2014002 Section 4OA3 |
| Date counted | Mar 31, 2014 (2014Q1) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71153 |
| Inspectors (proximate) | N O'Keefe P Elkmann T Hartman Z Hollcraft |
| Violation of: | 10 CFR 50 Appendix B Criterion XVI Technical Specification |
| INPO aspect | |
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Finding - Callaway - IR 05000483/2014002 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Callaway) @ 2014Q1
Self-Identified List (Callaway)
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