Workers prevented a potential problem with safety equipment at the Waterford nuclear plant during a recent refueling outage, the Nuclear Regulatory Commission reported Friday.
Maintenance at the plant near New Orleans revealed that a replacement emergency feedwater valve component was configured incorrectly. According to an NRC event report, plant staff noticed that a pneumatic actuator they were planning to install in the EFW-to-steam-generator primary-control valve was in a fail-closed instead of a fail-open configuration, as specified by the manufacturer.
"Two of these actuators were received and accepted as Masoneilan model 47 Sigma-F (fail-open) actuators in September of 2010. Both of which were labeled as such, yet configured in the fail-closed action," the report read. "Entergy concluded that for those potential applications of this valve operator model in the EFW system, had they been installed without correcting the deviation, it could have resulted in a substantial safety hazard in that it could have prevented fulfillment of EFW safety function."
Plant personnel reconfigured the component before its installation and notified the manufacturer.