Firefighters at Arizona's Palo Verde nuclear plant extinguished flames near a feedwater pump Monday that prompted a brief emergency declaration but did not trip safety systems.
Arizona Public Service Co. issued an unusual event declaration at 7:26 p.m. when a security guard reported smoke near the pump, according to a report filed with the Nuclear Regulatory Commission. Unit 2 personnel encountered one-foot flames coming from lagging material that the fire team extinguished a half hour later, according to the report. Oil-soaked lagging reignited twice as workers removed it. Subsequent inspection revealed a small oil vapor leak from a high-pressure bearing seal that was then remedied, the NRC reported. The plant cancelled the emergency declaration at 11:45 p.m.
The pump itself continued to work, and the reactor continued to operate at full power. According to APS, the event had no adverse safety consequences and did not trigger any of the plant's engineered safety features. Palo Verde near Phoenix is the largest nuclear plant in the U.S., with three Combustion Engineering System 80 pressurized water reactors.