A fault in a drive motor forced the Vermont Yankee nuclear power plant to reduce its power output by nearly two-thirds on Monday.
At 1 p.m. Monday there was a reported electrical failure in one of the plant’s two motor generator sets, which control the reactor’s power by varying the flow of the reactor cooling water, said Vermont Yankee spokesman Rob Williams.
Williams said the plant is operating at 38 percent power output and will stay at that level until they make repairs to the “Alpha” set.
Williams said the malfunction is not safety related and the public is not in any danger.
“We’re making preparations to lift the motor generator set out and have it refurbished,” Williams said.
“It appears likely the motor will need to be replaced,” said Neil Sheehan, a spokesman for the Nuclear Regulatory Commission (NRC).
At the time the motor stopped worked, operators observed “some smoking” near the motor generator sets’ lube oil pump, but there was no fire detected, Sheehan said.
“Our resident inspectors assigned to Vermont Yankee were immediately made aware of the issue and have been monitoring the company’s actions in response,” Sheehan said. “They have not identified any immediate safety concerns, but we do expect plant personnel to get to the bottom of the problem involving the motor generator sets as soon as possible.”
There is no timeline as to when the reactor could be back to full capacity, Williams said.
“This is not related to plant safety,” Williams said. “The plant will remain online at the reduced power output until the investigation of what happened is complete and proper repairs are made.”
On Sept. 30, 2011, the plant had to reduce its power output after one of its recirculation pumps had an electrical problem.
Williams said it’s unclear at this time if it’s the same pump or not.