05000271/FIN-2009005-01
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Finding | |
|---|---|
| Title | Inadequate Risk Assessment Associated with the Low Pressure Coolant Injection Subsystem |
| Description | The inspectors identified a non-cited violation (NCV) of 10 CFR 50.65 paragraph (a)(4), Requirements for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants, because Entergy did not assess and manage the increase in risk that resulted from maintenance activities that impacted the availability of the low pressure coolant injection subsystem (LPCI). On December 4, 2009, Entergy conducted a test of the high pressure coolant injection (HPCI) system as a retest following maintenance activities. Operations placed both trains of the residual heat removal (RHR) system in the torus cooling mode. This alignment impacted the ability of the LPCI subsystem to automatically perform its function in some design basis accident scenarios. However, the inspectors noted that the LPCI subsystem was not included as part of the risk assessment, and that subsystem was not maintained as available in accordance with Entergy procedures. Entergy entered this issue into the corrective action program (CAP), and initiated a preliminary investigation to review the effectiveness of Maintenance Rule accounting for LPCI unavailability while in the torus cooling mode. The finding is more than minor because Entergy\'s risk assessment did not consider risk significant structures, systems, and components (SSCs) (i.e. LPCI subsystem) that were unavailable during the maintenance activity. The finding is associated with the Configuration Control attribute of the Mitigating Systems cornerstone, and affects the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. The inspectors determined that the finding is of very low safety significance because the incremental core damage probability deficit was less than 1.0E-6. This finding has a cross-cutting aspect in the Human Performance cross-cutting area,Work Control component, because Entergy did not appropriately plan and incorporate risk insights. in work activities that impacted the availability of the LPCI subsystem. H.3(a) |
| Site: | Vermont Yankee  |
|---|---|
| Report | IR 05000271/2009005 Section 1R13 |
| Date counted | Dec 31, 2009 (2009Q4) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.13 |
| Inspectors (proximate) | D Jackson S Rutenkroger S Kennedy H Jones J Commiskey |
| CCA | H.5, Work Management |
| INPO aspect | WP.1 |
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Finding - Vermont Yankee - IR 05000271/2009005 | |||||||||||||||||||||||||||||||||||||||
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Finding List (Vermont Yankee) @ 2009Q4
Self-Identified List (Vermont Yankee)
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