05000336/FIN-2008002-03
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Finding | |
|---|---|
| Title | Failure to Identify a Service Water Bypass Flow Path following a Failed IST (Section 1R22) |
| Description | Green. The inspectors identified a non-cited violation (NCV) of 10 CFR 50, Appendix B, Criterion XVI, Corrective Action, for Dominions failure to identify a condition adverse to quality after the B service water (SW) pump failed a Technical Specification in-service test (IST). Specifically, on March 9, 2008, Dominion declared the B Service Water (SW) pump operable, despite a failed IST flow surveillance. Dominion based this declaration on the incorrect assumption that the failed pump differential pressure (dp) was indicative of faulty test equipment vice an actual equipment issue. On March 10, 2008, Dominion determined that the unacceptable B SW dp was caused by back pressure from the running C SW pump through the shut B swing pump cross connect valve (2-SW-79B). The inspectors identified that Dominion did not have a reasonable basis to consider the IST invalid based on the information available at the time. Corrective actions for this issue included implementing an alternate plant configuration to ensure train separation, performing an assessment to evaluate past operability and to establish a bounding service water temperature at which the B service water pump would be considered inoperable, and incorporating the 2-SW-97B leakage repair in the 2R18 refueling outage. This finding was more than minor because it was associated with the equipment performance attribute of the Mitigating System cornerstone, and affected the cornerstones objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences (i.e., core damage). Specifically, Dominion concluded that the B SW pump IST containing unacceptable dp data was invalid based, in part, on an inability to justify the results (i.e. high dp and nominal flow). Consequently, the B SW pump was inappropriately declared operable and the actual degraded condition was not promptly identified and corrected. This finding is of very low safety significance (Green) because it did not result in a confirmed loss of service water train operability. This finding has a cross-cutting aspect in the area Human Performance, Decision Making Component, because Dominion did not use conservative assumptions in restoring B SW pump operability following a failed IST surveillance H.1(b). (Section 1R22 |
| Site: | Millstone  |
|---|---|
| Report | IR 05000336/2008002 Section 1R22 |
| Date counted | Mar 31, 2008 (2008Q1) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.22 |
| Inspectors (proximate) | L Scholl B Haagensen J Benjamin J Krafty R Powell S Shaffer J Ayala C Sanders |
| CCA | H.14, Conservative Bias |
| INPO aspect | DM.2 |
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Finding - Millstone - IR 05000336/2008002 | |||||||||||||||||||||||||||||||||
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Finding List (Millstone) @ 2008Q1
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