Backgrounder: Energy Northwest Refueling and Maintenance Outage 23

John Dobken, Public Affairs, 509-377-8369
Anna Markham, Public Affairs, 509-377-8162

RICHLAND, Wash.Today, Columbia Generating Station, owned and operated by Energy Northwest, began its 23rd refueling and maintenance outage. Scheduled for no-more-than 40 days, the outage is an opportunity to add fresh nuclear fuel to Columbia’s reactor core, as well as perform maintenance projects that can best be accomplished only when the reactor is shut down. Outage projects are undertaken for a variety of reasons, including regulatory commitments, enhancing equipment reliability and improving Columbia’s value to the region.
Major R-23 Projects
• The agency received approval from the Nuclear Regulatory Commission to proceed with a measurement uncertainty recapture power uprate during the outage. This would allow Columbia to boost its thermal energy output from 3,486 megawatts thermal to 3,544 MWt. The reactor power uprate will result in additional electrical output for the station.
In 2015, EN installed leading edge flowmeter technology that improved the measurement accuracy of feedwater flow through the reactor core. This allows the reactor to run closer to regulatory limits because measurement of power levels is more precise.
• A new low pressure turbine rotor will be installed as part of Columbia’s turbine life-cycle plan, a multi-year, $32 million project to refurbish the three low pressure turbines to satisfy the plant's license extension to 2043. Forged in Fukuoka, Japan, the large metal ingot traveled through the Panama Canal to a machining facility in Charlotte, N.C., and then by rail to Columbia Generating Station, a total distance of more than 14,000 miles. The rotor fully assembled weighs about 275,000 pounds.
• Columbia's reactor building facade has stood virtually unchanged since 1980. As part of the station's Nuclear Regulatory Commission-guided post-Fukushima actions, workers will complete installation of a hardened containment vent system. The system includes a 140-foot vent pipe on the exterior of the building, providing a direct means of venting hydrogen gas from an area of primary containment known as the wetwell to outside secondary containment during severe, beyond-design-basis accident conditions. Most of this work was completed pre-outage.
In addition to these major projects, Columbia will replace 272 of 764 nuclear fuel assemblies. Every two years, approximately a third of Columbia’s fuel assemblies are removed from the core and placed in the used fuel pool after spending a total of six years in the reactor core. Energy Northwest continues to utilize a newer design in its fuel assemblies, which increases fuel efficiency, ultimately providing a cost-benefit during future refueling outages.
Since last year, the plant has been operating with four fuel defects in the core. The fuel bundles with the defects will be removed and replaced by bundles currently in the core.
In all, about 1,450 work orders involving more than 10,300 tasks will need to be completed during the 40-day outage. The total budget for the outage is approximately $135 million ($60 million for operations and maintenance, and $75 million for capital investments).
More than 1,350 skilled outage workers were hired locally and from across the country to support maintenance projects throughout the plant. The added workers join Columbia’s normal work force of about 1,100 employees and bring substantial economic value to the region.
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.
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