The inspectors identified an apparent violation (
AV) of
10 CFR 50, Appendix B, Criterion XVI, Corrective Action, for the licensees failure to promptly identify and correct a
condition adverse to quality (
CAQ) which resulted in a Unit 2
residual heat removal (
RHR) containment
sump suction valve failing to stroke full open during testing on April 29, 2006, and again on January 5, 2007. The licensee did not take corrective actions to address the high humidity condition inside the valve encapsulation which caused rust/corrosion accumulation on valve components and adversely impacted valve performance. After the valve failure on January 5, 2007, the licensee implemented interim corrective actions to support valve operability until long-term corrective actions were completed. This finding is more than minor because failure of a
RHR containment
sump suction valve to fully open impacts long-term core
decay heat removal (
emergency core cooling system sump recirculation) and therefore, affects the
mitigating systems cornerstone to ensure the availability, reliability, and capability of systems that respond to
initiating events to prevent undesirable consequences. Using the Phase 1 and Phase 2
significance determination process worksheets from NRC
Inspection Manual Chapter 0609, the finding was determined to have potential safety significance greater than Green. A regional Senior Reactor Analyst, with peer review from other qualified regional and headquarters personnel, performed a Phase 3 significance determination with a preliminary result of substantial safety significance. This finding has a crosscutting aspect in the area of problem identification and resolution because the licensee failed to thoroughly evaluate the
condition adverse to quality such that the resolution addressed the cause. (Section 4OA5.02.b)
