The NRC team identified a finding of very low safety significance (Green) involving a non- cited violation of
10 CFR 50, Appendix B, Criterion III, Design Control, because
FENOC staff did not establish measures to assure that the design bases were correctly translated into specifications, drawings, procedures, and instructions. Specifically, for the recirculation phase following a postulated small break loss -of-coolant accident, engineering staff determined the maximum differential pressure fo r motor- operated valves
MOV -1SI -863A and
MOV -1SI -863B to be the low head safety injection pump shutoff head, but the actual configuration could have resulted in a higher differential pressure at the valve due to allowable
reactor coolant system leakage past downstream pressure isolation valves . In response,
FENOC staff initiated corrective action program condition report s and assessed the deficiency , and concluded that affected motor -operated valves remained functional although with reduced valve thrust design margin . This finding was more than minor because it was associated with the Design Control attribute of the
Mitigating Systems cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to
initiating events to prevent undesirable consequences. In accordance with
IMC 0609.04, Initial Characterization of Findings, and Exhibit 2 of
IMC 0609, Appendix A, The
SDP for Findings At -Power, the team determined that this finding was of very low safety significance (Green) because it was a design deficiency confirmed not to result in the loss of operability or functionality. This finding was not assigned a cross -cutting aspect because the issue did not reflect current licensee performance.