A non-cited violation of
10 CFR 50, Appendix B, Criterion XVI, Corrective Action, was identified by the inspectors for the failure to promptly identify and correct a
condition adverse to quality (
CAQ) involving alignment of the safety-related refueling water storage tank (
RWST) to a non-seismic spent fuel purification (SF) system. The licensee entered the problem into their corrective action program as condition report 12-06193. The inspectors determined that the failure to promptly identify and correct the
CAQ for the alignment of the
RWST to the SF system was a performance deficiency (
PD). The inspectors reviewed Inspector Manual Chapter (IMC) 0612, Appendix B and determined the
PD was more than minor and therefore a finding, because it affected the
Mitigating Systems cornerstone objective to ensure the availability, reliability, and capability of systems that respond to
initiating events to prevent undesirable consequences and the respective attribute of configuration control because the alignment of the safety-related
RWST to the non-seismic SF system created a
CAQ and rendered the
RWST inoperable. The inspectors evaluated the finding in accordance with NRC
IMC 0609,
Significance Determination Process, Attachment 4 and Appendix A and determined that the finding required a phase 3 evaluation by a senior reactor analyst using the NRC
SPAR model. A one year exposure period was used and no recovery credit was assumed in the analysis. The non-seismic
RWST purification piping was assumed to fail at the same seismic input as that assumed for a loss of offsite power. The dominant sequence was a seismically induced loss of offsite power leading to a station blackout with failure of the emergency power system and failure to recover offsite power or the
EDGs. Subsequent battery depletion and operator failure to control the
TDEFW pump would
lead to core damage. The risk was mitigated by the low probability of a seismic event. The analysis determined that the risk increase of the performance deficiency was an increase in core damage frequency less than
1E-6/year a GREEN finding of very low safety significance. The cause of the finding involved the cross-cutting area of problem identification and resolution, the component of corrective action program, and the aspect of complete and thorough evaluation,
P.1(c), because the licensee failed to determine that the alignment of the safety-related
RWST to the non-seismic SF system was a
CAQ.
