Part of a nuclear power plant was shut down while another plant - the oldest in the U.S. - was put on alert after waters from superstorm Sandy
rose six feet (1.8 meters) above sea level.
Conditions were still safe all U.S. nuclear plants, said the Nuclear Regulatory Commission, which oversees plant safety.
One of the units at Indian Point, a plant about 45 miles (72 kilometers) north of New York City, was shut down around 10:45 p.m. Monday because of external electrical grid issues, said Entergy Corp., which operates the plant. The company said there was no risk to employees or the public, and the plant was not at risk due to water levels from the Hudson River, which reached 9 feet 8 inches (2.97 meters) and was subsiding. Another unit at the plant was still operating at full power.
One unit at the Salem plant in Hancocks Bridge, New Jersey, near the Delaware River, was shut down Tuesday because four of its six circulating water pumps were no longer available, according to PSEG Nuclear. The pumps are used to condense steam on the non-nuclear side of the plant. Another Salem unit has been offline since Oct. 14 for refueling, but the nearby Hope Creek plant remained at full power. Together, the Salem and Hope Creek plants produce enough power for about 3 million homes per day.
The oldest U.S. nuclear power plant, New Jersey's Oyster Creek, was already out of service for scheduled refueling. But high water levels at the facility, which sits along Barnegat Bay, prompted safety officials to declare an "unusual event" around 7 p.m. About two hours later, the situation was upgraded to an "alert," the second-lowest in a four-tiered warning system.A rising tide, the direction of the wind
and the storm's surge combined to raise water levels in Oyster Creek's intake structure, the NRC said. The agency said that water levels are expected to recede within hours and that the plant, which went online in 1969 and is set to close in 2019, is watertight and capable of withstanding hurricane-force winds.
In other parts of the East Coast, nuclear plants were weathering the storm without incident.