Northwest’s only nuclear power plant shut down after problem detected

The Northwest’s only commercial nuclear power plant, the Columbia Generating Station, was manually shut down early Thursday morning due to a mechanical problem.

Energy Northwest workers shut the plant down at 2:49 a.m. after both of its recirculation pumps shut down. If they did not shut down the plant, it would have automatically shut down, according to Energy Northwest.

There is no estimated time when the plant may return to operations and be reconnected to the electric grid.

It remains in a safe and stable condition, according to Energy Northwest.

“Safety is always our top priority, and our team took conservative steps consistent with our commitment to protecting the plant and the public,” said Dawn Sileo, Energy Northwest’s chief nuclear officer.

“While an unplanned outage is not our desired operating state, this response reflects our dedication to being a reliable and top-performing energy provider for the region,” she said.

The recirculation pumps push water into the core that boils as fuel rods undergo controlled chain reactions and release heat.

The heat boils the water, turning it into steam that spins a turbine connected to a generator to produce electricity.

The plant can operate with a single recirculation pump, but both went offline, according to Energy Northwest.

The Columbia Generating Station is a 1,207‑megawatt electric nuclear power plant 20 miles north of Richland in Eastern Washington. It is the third largest electricity generator in Washington state, behind the Grand Coulee and Chief Joseph dams.

The nuclear power plant had been online for 227 days after returning to service after a May 2025 outage to refuel.

The last time it stopped producing power — that was not related to a refueling outage and restart — was December 2021.

That was considered a planned outage because after an issue was observed with balance weights on each end of a turbine installed earlier that year, Energy Northwest was able to coordinate a time with Bonneville Power Administration when the impact of a shutdown could be minimized.

The last unplanned outage was in May 2018 when one of the plant’s main power transformers automatically disconnected from the transmission system following a grid disturbance. That caused the main generator also to trip and the plant to stop operating.

This story was originally published February 12, 2026 at 3:42 PM.