Workers at the Ginna nuclear power plant in upstate Wayne County, NY, spent Wednesday trying to determine the cause of a turbine problem that led to plant’s shutdown the night before.
The reactor powered down automatically and there was no problem on the nuclear end of the operation, said Maria Hudson, a spokeswoman for Constellation Energy Nuclear Group, the plant’s owner. “Everything operated as designed. The plant is stable,” she said.
The problem arose just before 11:30 p.m. Tuesday when the turbine suddenly stopped, Hudson said. The turbine spins from the steam generated by Ginna’s nuclear reaction, and imparts its energy to a generator that produces electricity.
Hudson said late Wednesday afternoon Constellation workers were still trying to determine why the turbine stopped and when the plant can resume operation. The turbine itself did not appear to suffer damage, she said.
The shutdown occurred due to a turbine auto-stop valve closure, the U.S. Nuclear Regulatory Commission said in a report. “The reactor tripped due to a RPS actuation signal from a turbine trip, which was caused by a turbine auto-stop signal,” the company said.
There was no requirement for Constellation to declare an emergency, Hudson said. “It appears to be a fairly straightforward event at this point,” said Neil Sheehan, a spokesman for U.S. Nuclear Regulatory Commission. He said Ginna did not have a recent track record of unplanned reactor shutdowns such as the one that occurred Tuesday night.
The Ginna plant, in the town of Ontario on the shore of Lake Ontario, can generate 581 megawatts of electricity, or enough to meet the needs of about 400,000 residents. Nearly all the plant’s electricity sells to Rochester Gas and Electric Corp., which built the plant and operated it until selling it to Constellation in 2004.
Ginna, placed in service in 1970, is the fourth-oldest commercial nuclear plant in the United States.