This issue is a performance deficiency because the licensee did not follow its approved
FPP for replacement of batteries in the
emergency lighting units to demonstrate conformance with the eight-hour capacity requirement on a continuing basis. The finding is more than minor because it is associated with the reactor safety,
mitigating systems, cornerstone attribute of protection against external factors (i.e. fire) and it affects the objective of ensuring reliability and capability of systems that respond to
initiating events. Because the finding adversely affected to some degree the ability to carry out local operator actions required to achieve and maintain a SSD condition following a severe fire, the Phase 1
Significance Determination Process (
SDP) for fire indicates that a Phase 2 analysis should be performed. To what degree the finding affected the ability to carry out operator actions depended on how long the
ELUs would have actually lasted. Preliminary evaluations by the team indicated that, if the
ELUs would have provided adequate illumination for 60 to 90 minutes, the finding would be of relatively low significance. Because there was insufficient objective evidence at the time of this report to determine whether the
ELUs would have provided adequate illumination for 60 to 90 minutes, the significance of the finding was considered indeterminate until that question can be resolved. The
ELUs which were replaced as a result of this finding have been retained by the licensee. Testing of these
ELUs could provide objective evidence important to resolving the issue. Since further information concerning the capacity of the
ELU batteries was needed to begin the
SDP, an unresolved item was established. It was identified as
URI 05000390/2007007-04,
Fire Protection Program did not Demonstrate Eight-Hour Emergency Light Unit Battery Capacity.
