Entergy Corp. cut output to the 989-megawatt River Bend 1 reactor in Louisiana early today, dragging nuclear production from the highest level in 16 weeks.
Total U.S. generation dropped almost 0.1 percent to 94,245 megawatts, or 92 percent of capacity, after reaching the highest level since Sept. 9 yesterday, according to U.S. Nuclear Regulatory Commission data compiled by Bloomberg. Output was 3.1 percent less than a year earlier period with six of 104 plants shut.
Entergy slowed River Bend 1 to 81 percent of capacity from full power yesterday. The unit, 24 miles (39 kilometers) northwest of Baton Rouge, reduced power to perform regularly scheduled control rod adjustments, Katie Damratoski, a company spokesman based in St. Francisville, Louisiana, said in an e-mail today.
A control rod is used to control the power of a nuclear reactor by absorbing neutrons and preventing them from causing further fissions, according to the commission’s glossary.
Grand Gulf 1, an Entergy-operated plant in Port Gibson, Mississippi, that can generate 1,297 megawatts, operated at 86 percent of capacity early today, down from 91 percent yesterday. The unit is also making control rod adjustments after shutting Dec. 29 because of a turbine trip, according to Mike Bowling, a company spokesman based in Jackson, Mississippi.
The Entergy units led production lower by 1.3 percent to 19,652 megawatts in the NRC’s Western region, which spans from Washington state to Louisiana, and includes the Grand Gulf reactor. That was the only decline among U.S. regions.
Nuclear generation in the Southeastern region, referred to as the NRC’s Region 2, gained 0.4 percent to 29,079 megawatts, the highest level since Aug. 5. The Tennessee Valley Authority’s Sequoyah 2 headed the advance after the company boosted output to 15 percent from 4 percent yesterday.
The 1,126-megawatt unit is coming online after completing a refueling outage that began Oct. 15. During the downtime, crews completed a $316 million project that included the replacement of four steam generators, according to Ray Golden, a company spokesman based in Knoxville, Tennessee.
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 43 days in 2011, according to the Nuclear Energy Institute.