05000220/FIN-2012002-01
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Finding | |
|---|---|
| Title | DID Not Correctly Implement Procedure During Power Supply Transfer |
| Description | A Green self-revealing finding was identified for the failure of Nine Mile Point Nuclear Station (NMPNS) to properly implement procedure N1-OP-30, 4.16 kV, 600V and 480V House Service, Revision 02800 when shifting the power supply for power board (PB) 101 from the south reserve transformer to the north reserve transformer on January 3, 2012. As a result, power was momentarily interrupted to PB 101 which caused the 13 reactor recirculation pump to trip resulting in an unplanned reactor power reduction from 100 to 84 percent. NMPNS immediate corrective actions included removing the control room supervisor and plant operator who were involved in the event from shift activities, conducting a prompt investigation, and installing warning placards on the exterior cabinets to the potential transformers that state de-energizing the potential transformers could cause a loss of power to PB 101. The finding is more than minor because it was associated with the configuration control attribute of the Initiating Events Cornerstone and adversely impacted cornerstone objective of limiting the likelihood of those events that upset plant stability and challenge critical safety functions during power operations. The finding was determined to be of very low safety significance (Green), because the finding did not contribute to both the likelihood of a reactor trip and the likelihood that mitigation equipment or functions will not be available. This finding has a cross-cutting aspect in the area of Human Performance, decision making because NMPNS operators did not use conservative assumptions in decision making when questions arose regarding how to implement procedure N1-OP-30 |
| Site: | Nine Mile Point  |
|---|---|
| Report | IR 05000220/2012002 Section 1R13 |
| Date counted | Mar 31, 2012 (2012Q1) |
| Type: | Finding: Green |
| cornerstone | Initiating Events |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 71111.13 |
| Inspectors (proximate) | D Dempsey K Kolaczyk G Dentel B Dionne |
| CCA | H.14, Conservative Bias |
| INPO aspect | DM.2 |
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Finding - Nine Mile Point - IR 05000220/2012002 | |||||||||||||||||||||||||||||||||||||
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Finding List (Nine Mile Point) @ 2012Q1
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