05000302/FIN-2011008-03
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Finding | |
|---|---|
| Title | Motor Operated Valves Not Protected From Hot Shorts That Could Bypass Torque Switches |
| Description | The failure to ensure that one train of systems necessary to achieve and maintain hot shutdown conditions was free of fire damage as required by 10 CFR Part 50, Appendix R, Section III.G is a performance deficiency. The noncompliance is considered to be more than minor because it is associated with the protection against external factors attribute (i.e. fire) and it degraded the reactor safety Mitigating Systems cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent consequences. The risk significance of the finding was determined utilizing the guidance of IMC 0609, Appendix F, Fire Protection Significance Determination Process. Pursuant to IMC 0609, Appendix F, the finding category was Post-fire Safe Shutdown . The finding was assigned a high degradation rating because the Post-fire SSD analysis was incomplete with regard to analyzing the effects of fires in MCCs and the potential impacts on MOVs. Because the finding was assigned a high degradation rating it did not screen in Phase 1 requiring a Phase 2 analysis. The MCCs affected by this finding were located in the auxiliary building in fire zones AB-95-3B, AB-95-3C, AB-95-3G and AB-119-6E, AB-119-6J, AB-119-6Q on elevations 95 and 119, respectively. All but one of the fire zones have fixed suppression, all have detection. The fire zone that does not have fixed automatic suppression is FZ AB-119-6Q. However, the valve fed from the MCC located in the zone is only required for cold shutdown which would screen to Green in Phase 1 of the SDP. For fires external to the MCCs there is a high likelihood that the fires will be detected and suppressed prior to damaging the components inside the MCC cabinet. For fires that start internal to the MCC cabinets it is more likely that damage will occur before the fire can be suppressed so no credit is given for manual or automatic suppression. However, independent of other factors, including fire suppression credit, the frequency of fires in electrical cabinets coupled with the probability of spurious operation is of sufficiently low likelihood that it is concluded that this finding is not associated with a finding of high safety significance (i.e. red). The inspectors determined the performance deficiency does not have a cross-cutting aspect because it does not represent current licensee performance since the analysis was completed prior to 2000. |
| Site: | Crystal River  |
|---|---|
| Report | IR 05000302/2011008 Section 4OA5 |
| Date counted | Jun 30, 2011 (2011Q2) |
| Type: | Violation: Severity level Enforcement Discretion |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | |
| Inspectors (proximate) | N Merriweather M Thomas J Munday L Suggs J Dymek |
| INPO aspect | |
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Finding - Crystal River - IR 05000302/2011008 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Crystal River) @ 2011Q2
Self-Identified List (Crystal River)
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