05000416/FIN-2011007-04
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Finding | |
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| Title | Inadequate Corrective Actions To Assure Postfire Safe Shutdown |
| Description | The team identified a noncited violation of 10 CFR 50, Appendix B, Criterion XVI, for inadequate corrective actions to address the potential for fire induced hot shorts to impact the ability to trip a control rod group as described in Information Notice 2007-07. The licensees evaluation of Information Notice 2007-07 stated in part, provisions have been included in 05-1-02-II-1, Shutdown from the Remote Shutdown Panel, to trip the proper reactor protective system breakers to ensure that the reactor scram occurs. The team noted that Procedure 05-1-02-II-1 contained a conditional statement for the operator to determine if opening the reactor protective system breakers is required. The procedure did not provide assurance that all control rod groups insert since the control room indications to be utilized by the operator were not identified and confirmed to be reliable during fires requiring control room evacuation. The licensee entered this finding into its corrective action program under CR-GGN-2011-02780, implemented compensatory measures to ensure the operators de-energized the reactor protection system, and implemented a procedure change. The failure to take adequate corrective actions to address the potential for fire induced hot shorts to impact the ability to safely shutdown the plant following a fire is a performance deficiency. The performance deficiency was more than minor because it was associated with the reactor safety mitigating systems cornerstone attribute for protection against external events (fire), and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Since the finding involved control room evacuation, a Phase 3 SDP risk assessment was performed by a senior reactor analyst. Because a bounding change to core damage frequency was 9.58 x 10-7, and the finding was not significant with respect to large, early release frequency, this finding was determined to have very low safety significance (Green). The finding did not have a crosscutting aspect since it was not indicative of current performance. The licensee had incorrectly assessed the applicability of Information Notice 2007-07 more than three years prior to this finding. |
| Site: | Grand Gulf  |
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| Report | IR 05000416/2011007 Section 4OA2 |
| Date counted | Sep 30, 2011 (2011Q3) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71152 |
| Inspectors (proximate) | N O'Keefe J Mateychick E Uribe B Correll N Okonkwo |
| INPO aspect | |
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Finding - Grand Gulf - IR 05000416/2011007 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Grand Gulf) @ 2011Q3
Self-Identified List (Grand Gulf)
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