05000346/FIN-2009004-01
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Finding | |
|---|---|
| Title | Loss of the Switchyard J Bus Due to a Faulted Coupling Capacitor Potential Device |
| Description | A Green self-revealed finding was identified for the failure to implement a maintenance strategy to replace a capacitive coupled potential device (CCPD) in a timely manner. The CCPD had been installed beyond the 25-year life expectancy and failed catastrophically on June 25, 2009, causing the loss of one offsite AC circuit and some burning debris. The licensee included this finding in their corrective action program as CR 09-61025. Corrective actions were initiated to trend secondary voltages on the remaining CCPDs that have been installed beyond 25 years. The six remaining CCPDs have been scheduled for replacement in November, 2009. This finding affected the initiating events cornerstone and could be reasonably viewed as a precursor to a significant event because a CCDP failure can subject the plant to a unit trip, loss of an offsite power source or startup transformer. This finding is greater than minor because it had an actual impact of causing one offsite AC source to become inoperable. The finding was not a LOCA initiator and did not contribute to both the likelihood of a reactor trip and the likelihood that mitigation equipment will not be available. The burning debris in the switchyard was extinguished within a short time period, and there was not an impact on operating plant equipment because one offsite power source and the emergency diesel generators remained available throughout the event. Therefore, the finding was determined to be of very low safety significance (Green). No violation of NRC requirements occurred. This finding has a cross-cutting aspect in the area of problem identification and resolution, corrective action program (P.1.d) |
| Site: | Davis Besse  |
|---|---|
| Report | IR 05000346/2009004 Section 4OA2 |
| Date counted | Sep 30, 2009 (2009Q3) |
| Type: | Finding: Green |
| cornerstone | Initiating Events |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 71152 |
| Inspectors (proximate) | J Rutkowski T Go A Wilson J Bozga J Cameron |
| CCA | P.3, Resolution |
| INPO aspect | PI.3 |
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Finding - Davis Besse - IR 05000346/2009004 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Davis Besse) @ 2009Q3
Self-Identified List (Davis Besse)
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