05000220/FIN-2012002-02
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Finding | |
|---|---|
| Title | Inadequate Torque Applied to Shutdown Cooling Isolation Valve Closure Bolts |
| Description | A Green self-revealing NCV of 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, was identified due to NMPNS failure to adequately implement Standard Design Specification SDS-006, Bolt-Torque Requirements for Unit 1 and Unit 2, to determine the amount of torque to apply to the bonnet bolts of shutdown cooling isolation valve IV-38-01. This resulted in a reactor coolant system (RCS) leak of one gallon per minute and a Unit 1 shutdown. NMPNS corrective actions included applying an appropriate torque to the body to bonnet bolts, performing an extent of condition review of similar valves in the drywell, and checking the torque of bolts on valve IV-38-02, located outside the drywell, that had similarly been modified in 2011. This finding is more than minor because it adversely impacted the equipment performance attribute of the Initiating Events Cornerstone objective to limit the likelihood of those events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. The inspectors determined this finding to be of very low significance (Green) because assuming the worst case degradation of the body to bonnet seal, the leak would not have exceeded the technical specification limit for identified reactor coolant system leakage. The finding has a cross-cutting aspect in the area of human performance, resources, because NMPNS design documentation regarding required torque values was not complete and accurate |
| Site: | Nine Mile Point  |
|---|---|
| Report | IR 05000220/2012002 Section 4OA3 |
| Date counted | Mar 31, 2012 (2012Q1) |
| Type: | NCV: Green |
| cornerstone | Initiating Events |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 71153 |
| Inspectors (proximate) | D Dempsey K Kolaczyk G Dentel B Dionne |
| CCA | H.7, Documentation |
| INPO aspect | WP.3 |
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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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