The U.S. Nuclear Regulatory Commission is beginning to return to normal inspection coverage for nuclear power plants in the Northeastern United States in the path of Hurricane Sandy. Heightened coverage will continue at Oyster Creek, a plant in Lacey Township, N.J., still in an “Alert” due to high water levels in its water intake structure.
In addition to the event at Oyster Creek, three reactors experienced trips, or shutdowns, during the storm. They were Indian Point 3, in Buchanan, N.Y.; Salem Unit 1, in Hancocks Bridge, N.J.; and Nine Mile Point 1, in Scriba, N.Y. All safety systems responded as designed.
At Oyster Creek, the Alert – the second lowest of four levels of emergency classification used by the NRC – remains in effect as plant operators wait for the water intake levels to drop to pre-designated thresholds. The water level rose due to a combination of a rising tide, wind direction and storm surge. Oyster Creek was shut down for a refueling and maintenance outage prior to the storm and the reactor remains out of service. Water levels are beginning to subside to more normal levels, but the plant remains in an Alert status until there is enough confidence levels will remain at more normal levels. Offsite power at the plant is in the process of being restored.
Meanwhile, three plants – Millstone 3, in Connecticut, Vermont Yankee, in Vermont, and Limerick, in Pennsylvania, – reduced power in advance of or in response to the storm. Millstone 3’s power was reduced to about 70 percent in advance of the storm to minimize potential impacts on its circulating water system due to the storm. Vermont Yankee reduced power to 89 percent in response to a request from the grid operator due to the loss of a transmission line in New Hampshire. Limerick Unit 1’s power was reduced to about 50 percent and Limerick Unit 2’s to about 25 percent in response to low electrical demands on the grid because of storm-related power outages.
Besides potentially affected nuclear power plants, the NRC also monitored any possible impacts on nuclear materials sites it oversees but did not identify any concerns.
NRC inspectors were onsite at all of the nuclear power plants expected to experience the greatest effects of the storm. Those inspectors were tasked with independently verifying that operators were following relevant procedures to ensure plant safety before, during and after the storm.
The NRC will continue to coordinate with other federal and state agencies prior to the restart of the affected plants.