Energy Northwest 1,207-MW nuclear plant reconnects to grid

Energy Northwest’s 1,207-megawatt Columbia Generating Station recently reconnected to the Northwest power grid on June 21 following its 24th nuclear refueling.

Energy Northwest noted that during the last several weeks, Energy Northwest employees, with support from more than 1,200 temporary workers, also completed thousands of individual maintenance improvements and upgrades to sustain the nuclear station’s generation efficiency and electricity output.

Biennial refueling is necessary to add fresh nuclear fuel to Columbia’s reactor core, but also an opportunity to perform maintenance projects that can best be accomplished only when the reactor is offline. In addition to replacing 260 of the 764 nuclear fuel assemblies in Columbia’s reactor core, work crews installed a 34-foot, 133-ton refurbished low-pressure turbine rotor.

Equipment replacements, refurbishments and upgrades have increased Columbia’s gross generation capacity from 1,150 MW in 2010 to 1,207 MW beginning in 2017.

During the last two years the station set nine monthly generation records, and five annual generation records during the last seven years. During 2018, the plant sent more than 9.7 million megawatt-hours of electricity to the grid, a record for its 34-year operating history.

Energy Northwest and the Bonneville Power Administration time the biennial refueling to coincide with spring time snow melt and runoff that maximizes power output from the region’s hydroelectric system and minimizes the impact of taking the nuclear station offline. Together, nuclear and hydro provide the region’s only fulltime clean energy resources.

All of the electricity produced at Columbia Generating Station, located 10 miles north of Richland, is sold at-cost to BPA.

Columbia’s refueling began on midnight, May 10, and reconnected to the grid June 21.

Columbia is the third largest electricity generator in Washington, behind Grand Coulee and Chief Joseph dams. Columbia is the only commercial nuclear energy facility in the region.

Columbia began delivering power to the region in 1984.