Nuclear Output Falls a 9th Day on Byron 2 Plant Shutdown

U.S. nuclear-power generation dropped for a ninth day, the longest such streak since October 2010, as Exelon Corp. (EXC) unexpectedly shut the 1,136-megawatt Byron 2 reactor in Illinois.

Nationwide production slipped 1.1 percent to 78,213 megawatts, or 77 percent of capacity, the lowest level of output since Nov. 22, according to U.S. Nuclear Regulatory Commission data compiled by Bloomberg. Generation was 2 percent less than a year ago with 22 of 104 nuclear reactors offline.

Byron 2, about 85 miles (137 kilometers) west of Chicago, shut after a loss of generator cooling water caused a manual reactor trip, an event report filed with the NRC showed. The unit had been operating at full capacity.

The unplanned shutdown sent output in the Midwest, NRC’s Region 3, to the lowest level since May 2. Generation fell 6.4 percent to 16,675 megawatts.

The only other region to post a decline in production was the West, which slipped 0.1 percent to 16,500 megawatts after Entergy Corp. (ETR)’s Arkansas Nuclear 1 reactor slowed to 80 percent of capacity from 82 percent yesterday. The 843-megawatt plant is about 65 miles northwest of Little Rock.

Reactor maintenance shutdowns, usually undertaken in the U.S. spring or fall when energy use is at its 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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