05000293/FIN-2011004-02
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Finding | |
|---|---|
| Title | Failure to Identify a Primary Containment System Maintenance Rule Functional Failure and Thereby Establish Monitoring Requirements for the System |
| Description | The inspectors identified a Green NCVof 10 CFR 50.65, paragraph (a)(1) and (a)(2), Requirements for Monitoring the Effectiveness of Maintenance of Nuclear Power Plants, because Entergy did not monitor the performance of the Primary Containment System (Drywell to Torus Vacuum Breaker Components) against license-established goals to provide reasonable assurance that these components are capable of fulfilling their intended functions. Specifically, Entergy did not identify a functional failure of the Drywell to Torus Vacuum Breaker Component portion of the Primary Containment System and thereby did not recognize that the system exceeded its unavailability performance criteria, requiring a Maintenance Rule (a)(1) evaluation. Entergy subsequently conducted an (a)(1) evaluation and concluded that the system should be classified as (a)(1), corrective actions specified, and system monitoring completed. The finding is more than minor because it is associated with the Barrier Performance attribute of the Barrier Integrity cornerstone, in that the issue affected the Primary Containment System reliability due to the failure to recognize the need to evaluate the system for goals, corrective actions, and monitoring. The inspectors determined the significance of the finding using IMC 0609-04, Phase 1 - Initial Screening and Characterization of Findings. The finding was determined to be of very low safety significance (Green) because the degraded condition had been corrected by the time of the failure to accurately evaluate the maintenance rule functional failure. As a result, this finding did not involve a design or qualification deficiency, did not result in a loss of system safety function, and did not screen as potentially risk significant due to external initiating events. The finding has a cross-cutting aspect in the Human Performance cross-cutting area, Decision Making component; in that, Entergy did not use conservative assumptions when evaluating the degraded Drywell to Torus Vacuum Breakers condition to correctly conclude that a functional failure had occurred. Specifically, Entergy did not consider that the function of these vacuum breakers would be required as soon as plant conditions exceeded 212F, and therefore, the procedural guidance for Technical Specification applicability not being exceeded was an incorrect basis for this decision |
| Site: | Pilgrim |
|---|---|
| Report | IR 05000293/2011004 Section 1R12 |
| Date counted | Sep 30, 2011 (2011Q3) |
| Type: | NCV: Green |
| cornerstone | Barrier Integrity |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.12 |
| Inspectors (proximate) | S Barr R Rolph B Smith M Schneider R Bellamy |
| CCA | H.14, Conservative Bias |
| INPO aspect | DM.2 |
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Finding - Pilgrim - IR 05000293/2011004 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Pilgrim) @ 2011Q3
Self-Identified List (Pilgrim)
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