A self-revealing finding was identified for the licensees failure to follow procedures while restoring auxiliary building evaporative air coolers to service. Although a violation of regulatory requirements was not identified, this failure was a performance deficiency with respect to licensee procedure PRO-NGGC-0200, Procedure Use and Adherence, Rev. 10, which requires all personnel who use procedures to understand the impact of their actions on personnel or equipment before taking action. As a result, the A
emergency diesel generator (
EDG) was declared unavailable and
inoperable. At the end of this inspection period, the licensee had not yet completed their evaluation of this finding, and had consequently not yet developed corresponding corrective actions. This finding is in the licensees corrective action program as
AR 332970332970 This finding is more-than-minor because it affected the Equipment Performance attribute of the
Mitigating Systems cornerstone, and affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to
initiating events to prevent undesirable consequences, in that this finding resulted in unplanned unavailability of an
emergency diesel generator. Using Attachment 4 of
IMC 0609, the significance of this finding was determined to be of very low safety significance (GREEN), because although the finding could degrade the Emergency
AC power function in the
Mitigating Systems cornerstone, the finding was not a design or qualification deficiency confirmed not to result in loss of operability or functionality, did not represent a loss of system safety function, did not represent actual loss of safety function of a single train for longer than its TS Allowed Outage Time, did not represent an actual loss of safety function of one or more non-TS Trains of equipment designated as risk-significant, and did not screen as potentially risk significant due to a seismic, flooding, or severe weather initiating event. This finding has a cross-cutting aspect in the Work Practices component of the Human Performance area because the licensee did not communicate human error prevention techniques such that work activities were performed safely, in that the licensee did not communicate instructions for the sequence of valve operations during the pre-job brief and the licensee proceeded in the face of uncertainty by operating system components when the current system alignment was not verified. (
H.4(a)) (Section 1R15.1
