Finding | |
|---|---|
| Title | Inadequate Risk Assessment for Emerency Maintenance on A5 Emergency Bus Undervoltage Relays |
| Description | The inspectors identified a Green non-cited violation (NCV) of 10 CFR 50.65(a)(4) for Entergy\'s failure to conduct an adequate risk assessment for emergent maintenance on the A5 Emergency Bus undervoltage relays. Specifically, the inspectors noted that Entergy had downgraded an on-line risk assessment from Red to Green without a valid technical basis and did not recognize the unavailability of the automatic function of the Emergency Diesel Generator (EDG); as a result, Entergy did not evaluate or specify risk management actions. This finding is more than minor because the risk assessment had incorrect assumptions that changed the outcome of the assessment. The inspectors conducted a screening in accordance with IMC 0609, Significance Determination Process, Appendix K, Maintenance Risk Assessment and Risk Management Significance Determination Process. The finding was determined to be of very low safety significance (Green) because the Incremental Core Damage Probability Deficit for the timeframe that the relays were removed from service was significantly less than 1E-6 due to the short amount of time the EDG was unavailable in the automatic mode and the reasonable assurance that operators could manually tie the EDG to the bus in the event of a Loss Of Offsite Power. This finding has a cross-cutting aspect in the area of Human Performance, Decision Making, because Entergy did not use a systematic process to make a risk-significant decision, when faced with an unexpected plant condition. H.1(a) (Section 1R13 |
| Site: | Pilgrim |
|---|---|
| Report | IR 05000293/2008002 Section 1R13 |
| Date counted | Mar 31, 2008 (2008Q1) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.13 |
| Inspectors (proximate) | G Johnson J Schoppy T Burns N Sieller R Powell B Norris R Rolph M Schneider G Newman |
| CCA | H.13, Consistent Process |
| INPO aspect | DM.1 |
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Finding - Pilgrim - IR 05000293/2008002 | |||||||||
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Finding List (Pilgrim) @ 2008Q1
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