Columbia Generating Station reconnected to the regional power grid at approximately 2:30 p.m. Saturday following nearly 13 days offline. The nuclear facility shutdown Aug. 20 when an air removal valve located in the station's turbine building closed, causing a loss of vacuum pressure necessary to pull steam through a condenser.
As part of Columbia's generation process, 80,000 gallons of water flow through nuclear fuel rods, which boil the water into steam. The high-pressure, fast-moving steam turns a series of turbines in a separate building to generate up to 1,207 gross megawatts of electricity - enough energy to power a city the size of Seattle. As part of the plant's closed cooling system, the steam is then condensed back into water and returned to the station's reactor building to repeat the boiling process.
Columbia Generating Station is the third largest generator of electricity in Washington state. All of its electricity is sold at-cost to the Bonneville Power Administration, and 92 Northwest utilities receive a percentage of its output. During the spring plant workers conducted maintenance and installed equipment that boosted the facility's output by more than 25 megawatts, contributing to a monthly generation record in July.
About Energy Northwest
Energy Northwest develops, owns and operates a diverse mix of electricity generating resources, including hydro, solar and wind projects - and the Northwest's only nuclear energy facility. These projects provide enough reliable, affordable and environmentally responsible energy to power more than a million homes each year, and that carbon-free electricity is provided at the cost of generation. As a Washington state, joint action agency, Energy Northwest comprises 27 public power member utilities from across the state serving more than 1.5 million ratepayers. The agency continually explores new generation projects to meet its members' needs.