Entergy Corp. replaced a damaged transformer at the 852-megawatt Fitzpatrick 1 reactor in New York after a failure that caused a fire and shut down the plant Nov. 11.
The reactor connected to the grid yesterday and operated at 38 percent of power early today 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, said Holden.
“Preliminary results suggest the fire was caused by an internal fault,” Holden, who is based at the plant, said in an e-mail responding to questions. “The failed equipment will be disassembled and a complete investigation conducted to identify the origin of the fault.”
The reactor, about 6 miles (10 kilometers) 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 spokesman for the Northeast region.
If a reactor experiences three such halts in a period of 7,000 operating hours, the commission is required to heighten the level of oversight at the unit.