Columbia Generating Station, the Northwest Territories’ only commercial nuclear power station, was manually shut down early Thursday morning due to mechanical failure.
Northwest Energy crews shut down the plant at 2:49 a.m. after two recirculation pumps shut down. According to Northwest Energy, if they don’t shut down the plant, it will shut down automatically.
There is currently no estimate of when the plant will resume operations and be reconnected to the grid.
It remains in a safe and stable condition, according to Northwest Energy.
“Safety is always our top priority, and our team took conservative steps that are consistent with our commitment to protecting the plant and the public,” said Dawn Sileo, Northwest Energy’s chief nuclear officer.
“While unplanned outages are not the operating state we want, this response reflects our commitment to being the region’s reliable and best-performing energy provider,” she said.
Northwest Energy’s Columbia Generating Station near Richland is the Northwest’s only commercial nuclear power plant. The contrast between the dark sky and the morning light behind the water vapor clouds in the reactor cooling tower caught the attention of Judy Hastings, who took the photo at 4:20 a.m. on the day the reactor was fully operational. It is currently offline due to issues with the recirculation pump.
(Courtesy of Judy Hastings)
A recirculation pump pushes water into the core, where it boils as the fuel rods undergo a controlled chain reaction and release heat.
The heat boils the water, turning it into steam, which spins a turbine connected to a generator to produce electricity.
According to Northwest Energy, the plant could operate with a single recirculation pump, but both pumps were offline.
Columbia Generating Station is a 1,207-megawatt nuclear power plant located 20 miles north of Richland in eastern Washington state. It is the third largest generator in Washington state, behind Grand Coulee Dam and Chief Joseph Dam.
The nuclear power plant resumed operation after a fuel supply interruption in May 2025 and has been operating for 227 days.
The last time it stopped generating electricity (unrelated to refueling outages and restarts) was in December 2021.
This was considered a planned outage because after problems with balancing weights on either end of the turbines installed earlier this year, Northwest Energy was able to coordinate with the Bonneville Power Authority on a time to minimize the impact of the outage.
The last unexpected power outage was in May 2018, when one of the plant’s main power transformers automatically disconnected from the transmission system due to a grid disturbance. This caused the main generator to also trip and the plant to cease operations.
