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Northwest nuclear plant begins spring refueling

News Release

​Richland, Wash. – ​Yesterday evening, Energy Northwest operators disconnected Columbia Generating Station from the Northwest power grid commencing its 26th refueling outage. The biennial refueling is an opportunity to add fresh nuclear fuel to Columbia's reactor core, as well as perform maintenance projects that can be accomplished only when the reactor is offline.

The Northwest's only nuclear power plant, which produced a record 9.8 million megawatt-hours in 2022, is scheduled to be offline for 35 days.

“For the next several weeks, our focus will be safely completing the work to ensure Columbia continues to produce reliable and around-the-clock, carbon-free power for the region," said Grover Hettel, Energy Northwest executive vice president and chief nuclear officer.

Energy Northwest and the Bonneville Power Administration time the station's refueling to coincide with spring snow melt and runoff that maximizes power output from the region's hydroelectric dams and minimizes the impact of taking Columbia offline.

Mid-Columbia residents may notice the station's familiar water vapor plume absent from the sky while the station is offline. Before disconnecting from the power grid, Columbia achieved its second longest operating run in its 38-year history – 508 days online.

“I am incredibly proud of our team who operate a top-performing nuclear plant and our local community that supports us," Hettel said.

More than 1,200 skilled, temporary workers were hired locally and from across the country to support refueling and maintenance projects at Columbia. The added workers join EN's normal workforce of about 1,000 employees and bring substantial economic value to the region.

7,500 planned work tasks
During the refueling outage, crews will swap out 248 of the 764 nuclear fuel assemblies in Columbia's reactor core with new fuel. Fuel assemblies that have been in the reactor core for six years are removed and placed in Columbia's used fuel pool, which removes residual heat. After a minimum of five years in the pool, the assemblies are moved to Columbia's on-site dry-cask storage.

In addition to refueling, maintenance projects include inspecting the high-pressure turbine and moisture separator reheaters; replacing a reactor feedwater drive turbine and pump; replacing back-up transformer oil circuit breakers; and various valve replacements, refurbishments and diagnostic testing. In all, regular and temporary employees will complete more than 7,500 work tasks.

Concerted, rigorous planning efforts begin two years prior to each refueling, and long-lead planning starts many years in advance.

Columbia is located 10 miles north of Richland and will restart and reconnect to the Northwest power grid in mid-June.              

See also: Columbia Generating Station refueling outage fact sheet  

About Energy Northwest                                                                                                    

Energy Northwest is a Washington state public power joint operating agency and a premier provider of carbon-free electricity. Energy Northwest comprises 28 public power member utilities, serving more than 1.5 million customers, and provides its members and regional customers with safe, reliable, cost-effective, responsible power generation and innovative energy and business solutions. The agency owns and operates hydroelectric, solar, battery storage, wind and the Northwest's only nuclear power facility. Energy Northwest also explores transportation electrification and new generation projects to the benefit of public power. 


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