On August 1, 2003, at
2118 hours0.0245 days <br />0.588 hours <br />0.0035 weeks <br />8.05899e-4 months <br />, the Perry Nuclear Power Plant experienced an actuation of several Division 2 Balance-of-Plant (
BOP) inboard isolation valves. At the time of the event, the plant was in Mode 1 (Power Operation). The isolation closed one or more valves in each of the following Division 2 subsystems: Liquid Radwaste
Sumps, Containment Vessel Chilled Water, Reactor Water Sampling, Drywell and Containment Radiation Monitoring, and Control Room Ventilation.
The event is considered an invalid system actuation, and is reportable under 10 CFR 50.73(a)(2)(iv)(A). The isolation was not initiated in response to actual plant conditions or parameters, and was not a manual initiation. It meets the criteria specified in 10 CFR 50.73(a)(2)(iv)(B)(2) as a general containment isolation signal affecting containment isolation valves in more than one system. Therefore, notification is being provided via 60-day optional phone call in accordance with 10 CFR 50.73(a)(1). All systems functioned as expected for a partial BOP (inboard) isolation.
Repositioning of the valves did not present operational concerns; they were re-opened per restoration procedures.
The BOP isolation was attributed to an electrical transient on 120 volt AC electrical bus EK-1-B1 as a result of a failed capacitor. The capacitor had been previously replaced during Refuel Outage 9.
This event was documented in the Corrective Action Program. Remedial actions include replacement of the defective capacitor. The capacitor will be sent out for failure analysis.
The licensee notified the NRC Resident Inspector.
