A finding of very low safety significance and associated
NCV of Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, was identified by the inspectors for the failure to have instructions of a type appropriate to the circumstances. Specifically, the instructions for testing a refurbished safety-related power supply did not contain acceptance criteria to ensure that the power supply voltage output did not exceed the maximum voltage requirements established by the vendor of the downstream level transmitter. Immediate corrective actions included evaluating the voltage output of operating power supplies to ensure the voltage at their associated transmitters was within vendor specifications. The finding was determined to be more than minor because the finding, if left uncorrected, had the potential to
lead to a more significant safety concern. Specifically, power supplies could have been placed back in service producing voltage levels at the downstream safety-related transmitters exceeding their vendor requirements. The inspectors concluded this finding was associated with the
Mitigating Systems Cornerstone. The inspectors determined the finding could be evaluated using the
Significance Determination Process (
SDP) in accordance with
IMC 0609,
Significance Determination Process, Attachment 0609.04, Initial Characterization of Findings, issued on October 7, 2016. Specifically, the inspectors used
IMC 0609 Appendix A SDP for Findings At-Power, issued June 19, 2012, Exhibit 2,
Mitigating Systems Screening Questions to screen the finding. The finding screened as of very low safety significance (Green) because the inspectors answered No to the screening questions. This finding has a cross-cutting aspect in the area of human performance, Design Margins, because the licensee did not ensure that design margins were carefully guarded. [H.6]
