U.S. nuclear-power production fell for the first time in five days after a Duke Energy Corp. reactor in North Carolina was taken offline for repairs.
Nationwide generation slipped 0.3 percent to 80,801 megawatts, or 79 percent of capacity, according to Nuclear Regulatory Commission data compiled by Bloomberg. Output was 5.5 percent less than the year-earlier period with 19 of 104 reactors offline.
Duke shut its 900-megawatt Harris 1 unit, about 20 miles (32 kilometers) southwest of Raleigh, because of an “unacceptable flaw” discovered during data review of the reactor vessel, according to the NRC’s daily Event Notification report. The unit operated at 95 percent of capacity yesterday.
The 0.26-inch flaw was caused by a nozzle that overlaps a weld, which “exhibits characteristics of primary water stress corrosion cracking,” the NRC said. There is no evidence of leakage and the unit was shut for repairs, the report showed.
Entergy Corp.’s 989-megawatt River Bend 1 reactor, 24 miles northwest of Baton Rouge, Louisiana, cut output to 89 percent of capacity from full power yesterday.
The 1,410-megawatt South Texas Project Unit 1 restarted after being shut over the weekend for planned maintenance to prepare for summer, the peak demand period for electricity, according to NRC data and Buddy Eller, a spokesman at the plant. The reactor, about 80 miles southwest of Houston, was operating at 12 percent of capacity early today.
The South Texas Project Nuclear Operating Co., which has two equal-sized reactors at the facility, is co-owned by NRG Energy Corp. and the municipal utilities for Austin and San Antonio.
Constellation Energy Group Inc. increased output for the 621-megawatt Nine Mile Point 1 reactor in New York to 25 percent of capacity from 6 percent yesterday. The plant is about 6 miles northeast of Oswego.
Duke raised production for the 937-megawatt Brunswick 2 reactor, about 130 miles south of Raleigh, to 96 percent of capacity from 76 percent.
The 1,166-megawatt Wolf Creek 1 reactor, a Great Plains unit about 55 miles (88 kilometers) south of Topeka, Kansas, increased to full power from 80 percent yesterday. The plant shut last week for repairs related to safety equipment and increased temperatures, according to Cassie Bailey, a spokeswoman at the site.
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.