U.S. Nuclear output declines as South Carolina reactor shuts

U.S. nuclear-power production fell for the first time in three days after a reactor in South Carolina lost offsite power and shut down.

Generation decreased by 411 megawatts to 79,444, or 78 percent of capacity, according to filings with the Nuclear Regulatory Commission and data compiled by Bloomberg. Output was 4.3 percent above a year ago with 20 of 104 reactors offline.

Duke Energy Corp. declared an “unusual event,” the lowest of four categories in the NRC’s emergency classification system, as it shut the 1,129-megawatt Catawba 1 reactor in South Carolina when power was knocked out at 8:03 p.m. local time yesterday, according to a filing with the NRC.

Diesel generators supplied power until two offsite lines were restored by 1:35 a.m. today and the event declaration was lifted, the filing showed. Two other lines remained linked to generators and it was unclear when power would be restored to them, according to the filing.

“Plant operators and other plant staff are monitoring the situation and attempting to restore the power,” the federal agency said in an e-mailed statement today. “There was no radiation released or impact to plant workers or the public.”

The twin Catawba 2 at the plant 17 miles (27 kilometers) southwest of Charlotte, North Carolina, was shut March 11 for refueling and maintenance.

Ginna Slows

Constellation Nuclear Energy Group LLC’s 498-megawatt Ginna reactor in New York reduced generation to 80 percent of capacity from full power. Calls before regular business hours seeking comment from company spokesmen weren’t immediately returned.

Ginna is located on Lake Ontario, about 17 miles northeast of Rochester. Constellation Nuclear Energy is a joint venture of Constellation Energy Group Inc. and Electricite de France SA.

Energy Future Holdings Corp. started the 1,150-megawatt Comanche Peak 2 reactor in Texas after shutting it April 2 to replace a filter on the water cooling system, Ashley Barrie, a company spokeswoman in Dallas, said then by e-mail. It was operating a 2 percent of capacity.

The 1,200-megawatt Comanche Peak 1 is producing at full power at the plant 66 miles southwest of Dallas.

TVA Boosts Sequoyah

The Tennessee Valley Authority increased output at the 1,148-megawatt Sequoyah 1 unit 17 miles northeast of Chattanooga to 92 percent of capacity from 55 percent. The reactor was started April 2 after a refueling shutdown that began Feb. 27. The 1,126-megawatt Sequoyah 2 reactor was at 100 percent.

Entergy Corp. boosted output at the Indian Point 2 reactor in New York to 80 percent of capacity from 48 percent after repairing a malfunctioning static inverter used in power transmission.

The 1,020-megawatt unit on the Hudson River about 27 miles north of New York City was started April 2 after a scheduled 28- day refueling and maintenance shutdown. The 1,025-megawatt Indian Point 3 is at full power.

Reactor maintenance shutdowns, usually undertaken in the U.S. spring or fall when energy use is lowest, can increase consumption of natural gas and coal to generate electricity. The average refueling down time was 43 days in 2011, according to the Nuclear Energy Institute.