The inspectors identified a finding of very low safety significance and an associated non-cited violation (
NCV) of
10 CFR Part 50, Appendix B, Criterion III, Design Control, for the failure to adequately verify the adequacy of the design of systems needed during a Design Basis Accident (
DBA). Specifically, the licensee failed to verify that the degradation identified during as-found inspections on the 21 and 22 Component Cooling (
CC) Water Heat Exchangers would not have prevented the heat exchangers (
HXs) from performing their safety functions if a
DBA had occurred. The licensee entered this issue into their corrective action program as
CAPs 1348544 and 1349624. The licensee concluded by additional analysis, and engineering judgment, that the Heat Exchangers had remained
operable. The licensee was also considering flushing the heat exchangers more frequently; inspecting and cleaning the
HXs more frequently; modifying the
CC heat exchangers to provide a more effective flush; and changing plant documents and/or programs to require opening, inspecting, and cleaning of the
HXs following major dredging near the plant intake. This issue was determined to be more than minor because it was associated with the
Mitigating Systems Cornerstone attribute of Design Control and impacted the objective of ensuring the capability of systems that respond to
initiating events to prevent undesirable consequences. The as-found condition of the
HXs challenged the capability of the
CC system to fulfill its safety function; however, the licensee did not fully evaluate the condition. The finding was of very low safety significance because the design deficiency did not result in a loss of operability or functionality. The inspectors determined the finding was cross-cutting in the Human Performance, Work Control, Work Practices area because the licensee did not properly ensure that supervisory and management oversight of work activities, including contractors, supported nuclear safety (
H.4(c)). Specifically, licensee personnel reviewing and approving Engineering Changes (ECs) 20044 and 20222 did not require the preparer to provide adequate technical support as part of the
past operability evaluation discussed in the ECs.
