Entergy Corp. replaced a damaged transformer at the 852-megawatt Fitzpatrick 1 reactor in Scriba, NY, after a failure caused a fire and shut down the plant Nov. 11.
The reactor connected to the grid early this week and got up to 38 percent of power the next day after crews installed a spare transformer that was on site, said Tammy Holden, a company spokeswoman.
An investigation into the cause of the equipment failure is under way, Holden said.
“Preliminary results suggest the fire was caused by an internal fault,” said Holden, who is at the plant. “The failed equipment will be disassembled and a complete investigation conducted to identify the origin of the fault.”
The reactor, about 6 miles northeast of Oswego, has experienced two automatic production halts this month. Fitzpatrick 1 shut once when a main turbine tripped and again after the equipment malfunction.
The transformer that failed is one of two that take electrical power produced by the plant’s generator, step up the voltage and then send it out to the grid, said Neil Sheehan, the U.S. Nuclear Regulatory Commission’s (NRC) spokesman for the Northeast region.
If a reactor experiences three such halts in a period of 7,000 operating hours, the NRC must heighten the level of oversight at the unit.