On 11/2/04 at 1400, Seabrook Station determined that a potential scenario involving a fire could result in the loss of the Train A and Train B centrifugal charging pumps (
CCP). During a fire, inadequate cable separation could result in the spurious closure of one of two series volume control tank (
VCT) outlet valves. This would result in a loss of suction to the operating
CCP and eventual loss of the pump. The second
CCP is assumed to be lost as a result of the same fire. This condition was concluded to be reportable pursuant to
10CFR50.72(b)(3)(ii)(B) as a condition that resulted in the plant being in an
unanalyzed condition that significantly degrades plant safety.
Compensatory measures include establishing a roving fire watch in the affected fire zones, operator briefings, and limiting combustible material in the affected fire zones.
The licensee notified the NRC Resident Inspector.