By Dustin Bleizeffer, WyoFile.com

Having already agreed to take on one nuclear power plant in Wyoming, western utility giant PacifiCorp will now consider adding five more to its electric generation fleet by 2035, by co-locating “small modular reactors” where it plans to retire coal-fired power plants in Wyoming and Utah.

PacifiCorp, which serves customers in six western states and operates as Rocky Mountain Power in Wyoming, will join nuclear energy developer TerraPower to study “the potential for advanced reactors to be located near current fossil-fueled generation sites, enabling the companies to repurpose existing generation and transmission assets for the benefit of [PacifiCorp’s] customers,” the companies announced in a joint statement Oct. 27.

Before choosing locations, “both companies will engage with local communities.”

“This is just a first step, as advanced nuclear power needs to be evaluated through our resource planning processes as well as receive regulatory approval,” Rocky Mountain Power President and CEO Gary Hoogeveen said in a prepared statement. “But it’s an exciting opportunity that advances us down the path to a net-zero energy future.”

PacifiCorp entered into a tentative agreement in 2021 to take ownership of TerraPower’s first-of-its-kind Natrium nuclear power facility slated for construction at the Naughton coal-fired plant site outside Kemmerer. The plant is scheduled to begin operations in 2028. PacifiCorp would take ownership sometime thereafter.

Nuclear power is emerging as a potential strategy to help PacifiCorp meet low-carbon emission standards — particularly in California, Oregon and Washington — while also meeting continuous power reliability and making use of its existing coal-fired power facilities.

The utility plans to convert fuel sources or retire at least six coal-burning units in Wyoming by 2035, taking offline about 2,691 megawatts of continuous “baseload” power capacity, or more than 36% of the state’s coal-fired power generating capacity, according to PacifiCorp data and WyoFile calculations. It plans to shut down its entire coal-fired power fleet in the state by 2039, according to its 2021 Integrated Resource Plan.

Aside from potentially replacing coal plants with nuclear reactors, PacifiCorp plans to add more than 3,700 megawatts of new wind power by 2040 throughout its six-state region, including in Wyoming, while adding commercial-scale solar power and battery storage.

Wyoming lawmakers have passed a suite of bills aimed at delaying coal-plant closures in the state by forcing regulated utilities like PacifiCorp to retrofit coal units with carbon capture utilization and sequestration technologies. But so far, the cost-benefit of CCUS retrofits haven’t penciled out for PacifiCorp or Black Hills Energy, according to the companies.

Legislators and the state’s top energy officials, however, are also enthusiastic about adding nuclear to the state’s power mix. Not only would it provide replacement jobs for coal-plant workers, but some hope it would also help revive Wyoming’s languishing uranium mining sector.

“Wyoming has been working hard to develop a nuclear industry — from the supply chain via our uranium reserves all the way through the value chain to produce zero-emissions electricity that can then be used as feedstock for other net-negative emission products,” Wyoming Energy Authority Executive Director Glen Murrell wrote WyoFile. “The news that [TerraPower and PacifiCorp are] taking on an additional feasibility study to potentially deploy more reactors in the area will strengthen the industry and create jobs and growth for Wyoming’s benefit.”

It makes sense to begin analysis and planning for multiple nuclear power reactors now because TerraPower needs to deploy the technology “at scale” if it’s going to prove the Natrium technology commercially viable, University of Wyoming energy economist Rob Godby said.

“You have to look that far down the road when you’re talking about this sort of technological change if you’re [selling nuclear plants to a utility],” Godby said. “So it makes sense for both TerraPower and PacificCorp.”

TerraPower, backed by Microsoft billionaire Bill Gates, selected PacifiCorp’s Naughton power plant at Kemmerer for its demonstration Natrium nuclear power plant in November 2021. Engineering and geologic sampling work is ongoing at the Kemmerer location. Construction is slated to begin in 2024 and bring 2,000 workers to the tiny community.

The company is looking to the U.S. Department of Energy to cover about half of the estimated $4 billion cost of the Kemmerer plant, contingent on a 2028 in-service date.

That schedule, however, was thrown into question after Russia invaded Ukraine earlier this year. TerraPower cut ties with the Russian state-owned Tenex — the only facility in the world with the capacity to supply commercial volumes of high-assay, low-enriched uranium fuel. The company is working with DOE and Congress to speed up the development of a domestic HALEU supply chain, including the potential to “downblend” weapons-grade uranium to meet initial fuel needs at Kemmerer by end of 2025, according to TerraPower.

Yet some doubt the viability of adding new nuclear power to the grid under such a time constraint. The Oregon Public Utility Commission in March declined to formally acknowledge PacifiCorp’s plans for Natrium to be a part of its future electrical generation portfolio.

TerraPower is confident of a speedy federal permitting process and that a domestic HALEU supply will come into play, however, and is moving forward with the project as scheduled, a company official told WyoFile.

Kemmerer and PacifiCorp’s Naughton power plant make an ideal location for TerraPower’s demonstration Natrium plant due to “local community support, the physical characteristics of the site, the ability to obtain a license from the U.S. Nuclear Regulatory Commission for the site, access to existing infrastructure, and the needs of the grid,” the company said.

Those same factors make other locations in Wyoming a prime target for Natrium facilities, according to the company.

In its initial analysis to choose a location for its demonstration plant now slated for Kemmerer, TerraPower had also considered the Jim Bridger plant near Rock Springs, the Dave Johnston plant in Glenrock and the Wyodak plant near Gillette — all owned by PacifiCorp.

“We have been impressed and humbled by our work with the Kemmerer community and PacifiCorp,” TerraPower President and CEO Chris Levesque said in a prepared statement. “We look forward to evaluating new potential sites for Natrium plants that have the same energy expertise and capabilities as our demonstration site.”