The team identified a Green non-cited violation of
10 CFR Part 50, Appendix B, Criterion III, Design Control, which states, in part, that measures shall be established to assure that applicable regulatory requirements and the design basis, as defined in 50.2 and as specified in the license application, for those structures, systems, and components to which this appendix applies are correctly translated into specifications, drawings, procedures, and instructions. Specifically, prior to March 16, 2012, the licensee failed to translate the site extreme maximum outside air temperatures, as stated in the updated safety analysis report, into calculations that determined the combustion air temperature available for the Unit 2
emergency diesel generators. This finding was entered into the licensees corrective action program as Condition Reports CR-ANO-2-2012-00436 and CR-ANO-2-2012-00486. The team determined that the failure to translate the updated safety analysis report design basis for site extreme maximum temperature into combustion air temperature calculations was a performance deficiency. 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 of ensuring the availability, reliability, and capability of systems that respond to
initiating events to prevent undesirable consequences. Specifically, the licensee failed to evaluate the effects of increased combustion air temperature on the load capacity of the Unit 2
emergency diesel generators, when outside air temperature reaches the design basis extreme maximum temperature. In accordance with NRC
Inspection Manual Chapter 0609, Attachment 4, Phase 1 Initial Screening and Characterization of Findings, the finding was determined to have very low safety significance (Green) because it was a design or qualification deficiency confirmed not to result in a loss of operability or functionality. Specifically, the team confirmed that historical outside air temperature was never in a condition that resulted in the loss of required diesel load capacity during accident conditions. This finding did not have a crosscutting aspect because the most significant contributor did not reflect current licensee performance.
