05000220/FIN-2008004-01
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Finding | |
|---|---|
| Title | Incorrect Risk Assessment for RCIC Unavailability |
| Description | An NRC-identified non-cited violation (NCV) of 10 CFR 50.65(a)(4) was identified for inaccurate risk assessments completed for August 5 and 6, 2008. Specifically, the unavailable reactor core isolation cooling (RCIC) system was not properly incorporated into the risk assessment. The cause was determined to be that an error had been made while entering a change to the risk monitor computer software, which resulted in RCIC incorrectly being assigned a zero risk importance. As corrective actions, the modeling of RCIC was corrected and a verification of all mapping codes used in the risk monitor was performed. The finding was greater than minor because the risk assessment for RCIC system maintenance was inadequate due to inaccurate information that was provided to the risk assessment tool. As a result, the overall elevated plant risk, when correctly assessed, put the plant into a higher licensee-established risk category. The finding was evaluated in accordance with IMC 0609, Appendix K, and determined to be of very low safety significance because the incremental core damage probability deficit (ICDPD) was less than 1E-6. The finding had a cross-cutting aspect in the area of human performance because NMPNS did not appropriately plan work activities by incorporating valid risk insights (H.3.a per IMC 0305). (Section 1R13) |
| Site: | Nine Mile Point  |
|---|---|
| Report | IR 05000220/2008004 Section 1R13 |
| Date counted | Sep 30, 2008 (2008Q3) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.13 |
| Inspectors (proximate) | E Knutson S Shaffer M Davis D Dempsey J Furia S Barr J Krafty E Huang |
| INPO aspect | |
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Finding - Nine Mile Point - IR 05000220/2008004 | |||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Nine Mile Point) @ 2008Q3
Self-Identified List (Nine Mile Point)
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