A reactor at Connecticut’s Millstone nuclear plant that shut last weekend due to a faulty water pump is powering up again, federal regulators said.
Millstone unit 2 in Waterford, CT, was at 11 percent power last Wednesday on its way to going back to full power, said Neil Sheehan, a spokesman for the Nuclear Regulatory Commission (NRC). Nuclear power plants typically begin supplying the grid at about 30 percent power, he said.
The turbine-driven auxiliary water pump that led to the shutdown ended up tested and its flow rate is acceptable, Sheehan said. The cause of low flow from the pump was due to a piece of metal in an opening. The object is now under analysis.
The NRC said it does not have any immediate safety concerns with Millstone’s unit 2 resuming operation.
The CT plant was one of three that shut down unexpectedly last weekend.
Unrelated mechanical problems shut down two other reactors.
At one facility in Florida, workers at Florida Power and Light’s St. Lucie plant isolated a small leak in a safety injection tank outlet vent valve at unit 2, according to a report filed with the NRC. With the tank out of service, the unit powered down per the plant’s technical specifications shortly after midnight on July 26.
On July 27, operators manually tripped unit 1 at Southern Co.’s Plant Vogtle in Georgia. The plant reported to the NRC that operators noted a drop in steam generator water levels and the speed of a main feed pump during testing of the pump’s trip mechanism.