Nationwide generation fell 1.1 percent from yesterday to 84,936 megawatts, or 83 percent of capacity, the biggest decline since May 18, according to Nuclear Regulatory Commission data compiled by Bloomberg. Output was 0.9 percent less than a year ago with 13 of 104 plants offline.
North Anna 2, about 40 miles (64 kilometers) northwest of Richmond, was manually shut yesterday because of decreasing steam generator levels, according to a commission filing. The unit had been running at 98 percent of capacity. North Anna 1 was not affected.
“Procedures directed operators to manually shut down the reactor to ensure water levels were maintained in the steam generators,” Richard Zuercher, a company spokesman based in Richmond, said in an e-mail.
The closing dropped Southeastern nuclear-power generation to 28,047 megawatts, 2.9 percent less than yesterday. The Northeast also posted a decline after Constellation Energy Group Inc. and Exelon (EXC) Corp. slowed two reactors. The area’s nuclear output slid 1.3 percent to 19,528 megawatts.
Constellation cut output to 65 percent of capacity at the 1,140-megawatt Nine Mile Point 2 plant in order to carry out maintenance on a feedwater system and control rods, said Jill Lyon, a company spokeswoman based in Scriba, New York.
While the unit is operating at reduced rates, crews expect to remove a pump from service in order to investigate abnormal indications on a water-level control valve, she said. Lyon declined to comment on the duration of the maintenance.
Nine Mile Point, located near Oswego, New York, operated at full power yesterday.
Exelon’s New Jersey-based Oyster Creek 1, which has the capacity to generate 619 megawatts, reduced power to 70 percent of capacity while personnel make repairs to a water flow regulator valve, said Suzanne D’Ambrosio, a plant spokeswoman.
Reactor maintenance shutdowns, usually undertaken in the U.S. spring or fall when energy use is lowest, may increase consumption of natural gas and coal to generate electricity. The average refueling down time was 46 days in 2012, according to the Nuclear Energy Institute.
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