Nine Mile Point 2 was shut down early this morning after losing power from a supply unit in the plant.
Neil Sheehan, a public affairs officer for the Nuclear Regulatory Commission, said the loss of power effected cooling flow to both of the plant's reactor recirculation pumps.
"The operators at the plant, in turn, manually scrammed or shut down the reactor," Sheehan said. "And that means they inserted all the control rods, halted the fissioning process and, therefore, the plant was no longer heating up water and generating electricity."
Sheehan said two NRC inspectors assigned to Nine Mile Point 2 are reviewing the incident, including troubleshooting the loss of power, operator actions and the performance of safety systems.
He added that the plant is in hot shutdown, meaning the reactor and reactor safety systems are still heated and pressurized and can be started up again fairly quickly.
UPDATE: The unit was returned back to full power Sunday afternoon.