05000220/FIN-2013003-04
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Finding | |
|---|---|
| Title | Improper Bus Restoration Results in a Loss of Shutdown Cooling |
| Description | A self-revealing apparent violation of Technical Specification (TS) 6.4.1, Procedures, was identified at Unit 1 because CENG failed to properly recover from a loss of a vital direct current (DC) bus in accordance with station off-normal procedures resulting in an unplanned loss of all shutdown cooling (SDC) when time to boil was less than 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. Specifically, during the restoration from the loss of battery bus 12, operators failed to identify a SDC trip signal before attempting restoration of the DC bus, which ultimately lead to a SDC pump trip (i.e. loss of decay heat removal from the reactor). Corrective actions included conducting a prompt human performance event review, entering the issue into their corrective action program (CAP), and conducting a root cause analysis. Planned corrective actions include a review of all emergency, off-normal, and normal system operating procedures. The inspectors determined that CENGs failure to properly restore battery bus 12 in accordance with N1-SOP-47A.1, Loss of DC, Revision 00101, and N1-OP-47A, 125 VDC Power System, Revision 02500, was a performance deficiency that was reasonably within CENGs ability to foresee and correct and should have been prevented. The performance deficiency was determined to be more than minor because the inspectors determined it affected the configuration control aspect of the Initiating Events cornerstone and adversely affected the associated cornerstone objective to limit the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. The significance of the finding is designated as To Be Determined (TBD) until a Phase 3 analysis can be completed by the NRCs Senior Reactor Analysts. The inspectors determined this finding has a cross-cutting aspect in the area of Human Performance, Resources, because CENG did not ensure that personnel, equipment, procedures, and other resources were available and adequate to assure nuclear safety - complete, accurate and up-to-date design documentation, procedures, work packages, and correct labeling of components. Specifically, CENG procedures N1-SOP-47A.1 and N1-OP-47A did not contain adequate guidance to ensure recovery from a loss of a DC bus would not result in an unexpected plant transient. |
| Site: | Nine Mile Point  |
|---|---|
| Report | IR 05000220/2013003 Section 4OA3 |
| Date counted | Jun 30, 2013 (2013Q2) |
| Type: | AV: |
| cornerstone | Initiating Events |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 71153 |
| Inspectors (proximate) | W Schmidt B Bickett D Roberts D Schroeder E Monteith R Lorson R Zimmerman W Deanj Lilliendahlp Kaufman D Schroeder K Kolaczyk B Haagensen A Rosebrook J Krafty J Laughlin B Dionne E Miller B Scrabeck |
| CCA | H.7, Documentation |
| INPO aspect | WP.3 |
| ' | |
Finding - Nine Mile Point - IR 05000220/2013003 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Nine Mile Point) @ 2013Q2
Self-Identified List (Nine Mile Point)
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