05000333/FIN-2013003-02
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Finding | |
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| Title | |
| Description | A self-revealing finding (FIN) was identified for a loss of decay heat removal (DHR) during refueling outage 20 (R20) that was the result of inadequately remediated DHR system degradation. Specifically, prior to using the system during R20, Entergy did not clean scale buildup in the DHR secondary cooling loop heat exchangers (HXs) causing low secondary system pressure, and Entergy did not address the resultant reduction in margin to the primary cooling loop pump automatic shutdown on low primary-to-secondary differential pressure. As a result, a spurious automatic DHR system shutdown occurred while it was functioning as the alternate method of DHR in place of residual heat removal (RHR) shutdown cooling. Entergys corrective actions included restarting DHR and initiating condition report CR-JAF-2012-06934. Entergy also initiated actions to evaluate corrective measures such as modifying the differential pressure trip, adding secondary loop water chemistry treatment, and cleaning of the HXs. This finding was more than minor because it was associated with 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 (i.e., core damage). Specifically, there was an unplanned shutdown of the DHR system for about 50 minutes when it was providing the shutdown cooling function. The inspectors determined the significance of the finding using IMC 0609, Appendix G, Shutdown Operations Significance Determination Process. Per Attachment 1, Shutdown Operations Significance Determination Process Phase 1 Operational Checklists for both PWRs [pressurized water reactors] and BWRs [boiling water reactors], Checklist 7, BWR Refueling Operation with RCS Level > 23, this finding impacted checklist item I.C, because at the time of the event the DHR system was functioning as the alternate method of DHR in place of RHR shutdown cooling. The finding was determined to be of very low safety significance (Green) because the finding did not require a quantitative assessment as described in checklist 7 of Attachment 1 to Appendix G, because checklist item I.C. is not listed as requiring phase 2 or 3 analysis, and the finding did not constitute a loss of control event per Appendix G, Table 1. The inspectors determined that the finding had a cross-cutting aspect in the Problem Identification and Resolution area, Corrective Action Program component, because Entergy staff did not take appropriate corrective actions to address the adverse trend in DHR system performance. |
| Site: | FitzPatrick  |
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| Report | IR 05000333/2013003 Section 4OA2 |
| Date counted | Jun 30, 2013 (2013Q2) |
| Type: | Finding: Green |
| cornerstone | Mitigating Systems |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 71152 |
| Inspectors (proximate) | S Rutenkroger J Laughlin E Knutson B Sienel R Rolph T Hedigan |
| CCA | P.3, Resolution |
| INPO aspect | PI.3 |
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Finding - FitzPatrick - IR 05000333/2013003 | |||||||||||||||||||||||||||||||||||||||||||
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Finding List (FitzPatrick) @ 2013Q2
Self-Identified List (FitzPatrick)
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