The inspectors identified a non-cited violation of
10 CFR 50, Appendix B, Criterion III, Design Control, for the licensees failure to verify the adequacy of the design of the control room
HVAC system. Specifically, the licensee failed to demonstrate the ability of control room
HVAC design to maintain the temperatures in the main control room below habitability and environmental qualification limits, for the duration of all accident scenarios. The licensee initiated Action Request 332565 to document the concern, issued night order 1662 to communicate the issue, aligned both control room air handling units to their respective chillers, created a quick card procedure to perform the chiller reset actions, and validated the quick card actions could be accomplished within 10 minutes. Additionally, the licensee determined that operators could restore the chillers during accident conditions within 90 minutes to prevent temperatures from exceeding equipment operability limits. The performance deficiency was more than minor because it adversely affected the design control attribute of the
Mitigating Systems Cornerstone objective to ensure the availability, reliability, and capability of systems that respond to
initiating events to prevent undesirable consequences. Using NRC
Inspection Manual Chapter 0609, Appendix A, Exhibit 2,
Mitigating Systems Screening Questions, the inspectors determined the finding was of very low safety significance because (1) the finding was not a deficiency affecting the design or qualification of a mitigating system; (2) the finding did not represent a loss of system and/or function; (3) the finding did not represent an actual loss of function of a single train for greater than its technical specification allowed outage time; and (4) the finding does not represent an actual loss of function of one or more non-technical specification trains of equipment designated as high safety-significant in accordance with the licensees
maintenance rule program for greater than
24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. This finding had a cross-cutting aspec
in the area of problem identification and resolution, evaluation, in that the licensee did not thoroughly evaluate issues to ensure that resolutions address causes and extent of conditions commensurate with their safety significance. Specifically, the licensee did not thoroughly evaluate the extent of condition from NRC-identified NCV 05000397/2013002-04, Failure to Obtain NRC Approval for Changes to Control Room HVAC Requirements, fo
the effect of this change on other station calculations [P.2].
