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A view of Columbia Generating Station’s reactor core from the refuel floor during the station’s spring refueling outage. Energy Northwest takes the station offline once every two years to replace one-third of the core with new fuel assemblies.  

Operators at Columbia Generating Station reconnected the nuclear power plant to the Northwest power grid today at 4:30 a.m. following the station's 26th refueling, and just in time to meet the summer's higher demand for electricity.

During the last several weeks, Energy Northwest employees, with support from more than 1,200 skilled temporary workers, completed thousands of individual work tasks – including equipment maintenance and refueling the reactor core – to increase the nuclear station's generation efficiency and sustain reliability. 

“The team completed a tremendous amount of work over the past several weeks," said Grover Hettel, Energy Northwest chief nuclear officer. “Getting Columbia back online after refueling is always a significant achievement – and we're pleased to be back online producing 1,200 megawatts of clean electricity for the region."

Biennial refueling is necessary to add fresh nuclear fuel to Columbia's reactor core so that it can operate for a two-year cycle. Operators replaced 248 of the 764 nuclear fuel assemblies in Columbia's reactor core with new fuel. The fuel that had been in the reactor core for six years was placed in the adjacent used fuel pool, where the assemblies will await being moved to Columbia's on-site dry cask storage.

Refueling outages are also an opportunity to perform maintenance tasks that can be accomplished only when the reactor is offline. Crews inspected a high-pressure turbine and moisture separator reheaters; refurbished a feedwater drive turbine; replaced the roofing material on the turbine building; repaired a reactor feedwater valve; and many other inspections and diagnostics.

Crews assist with reassembling Columbia Generating Station’s reactor pressure vessel in early June after refueling the reactor core. Workers replaced 248 of 764 nuclear fuel assemblies with new fuel during the station’s biennial refueling outage. ​

“Outage work is a rigorous, complex sequence of 24/7 activity. It requires several years of planning and a highly skilled team to complete," Hettel said. “We appreciate the support and efforts of our employees, contractors, labor unions and vendors. We took the time to complete outage work with quality, and we're bringing the station back with increased reliability," Hettel said.

Prior to taking the station offline May 5, the plant achieved its second longest operating run – 508 days – and set a new generation record in 2022 for producing 9.8 million megawatt-hours.

Energy Northwest and the Bonneville Power Administration time the biennial refueling to coincide with spring snow melt and runoff that maximizes power output from the region's hydroelectric system and minimizes the impact of taking the nuclear station offline. The electricity produced at Columbia Generating Station, located 10 miles north of Richland, is sold at-cost to BPA. 

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Contact: media@energy-northwest.com