The failure to assess the increase in risk is a performance deficiency as defined in
IMC 0612, Power Reactor IRs, Appendix B, Issue Screening. The inspectors determined that the finding was more than minor because it is similar to example 7.e of
IMC 0612, Appendix E, Examples of Minor Issues and resulted in the qualitative shutdown
probabilistic risk assessment (
PRA) risk crossing the threshold into a higher licensee-established risk category. Therefore, the performance deficiency is associated with the
Mitigating Systems Cornerstone attribute of Equipment Performance and adversely impacted the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to
initiating events to prevent undesirable consequences. The finding was reviewed for significance in accordance with
IMC 0609, Appendix K, Maintenance Risk Assessment and Risk Management
Significance Determination Process. Appendix K directs that for licensees who only perform qualitative analyses of plant configuration risk due to maintenance activities, as is the case during shutdown for this licensee, the significance of the deficiencies must be determined by an internal NRC management review using risk insights where possible in accordance with
IMC 0612. The NRC management review concluded that this finding was of Green safety significance because missing risk management actions did not result in loss of key shutdown risk functions and plant TS continued to be met for the plant conditions at the time.
