TerraPower bullish on Natrium plant construction
TerraPower officials said last week to expect “dirt moving” at its Wyoming site come June—and for operations to begin there as early as 2030—as it advances plans to build new nuclear in the United States. But 40-plus pages of initial commentary from the Nuclear Regulatory Commission, in the form of a preapplication readiness assessment report, may slow TerraPower’s plans.
The Bill Gates-backed company filed preapplication materials for Kemmerer Power Station Unit 1, which will utilize TerraPower’s Natrium sodium fast reactor technology and will be built near the site of one of Wyoming’s retiring coal plants. TerraPower’s preapplication filing was part of a voluntary process to get early feedback from the NRC.
What’s next? Chris Levesque, chief executive of TerraPower, told the Financial Times that his firm will start building at the Kemmerer site in June. If the proper NRC permit is not approved by then, the company may start initial work on nonnuclear parts of the demonstration project.
TerraPower is confident that it will submit its official construction permit application to the NRC within the next week. Company officials said that, with no “category A issues” identified in the NRC readiness feedback, they expect the NRC to docket the application for review.
The NRC’s response to TerraPower’s application suggests there are still gaps around the technical and licensing processes for Natrium reactor approval. “References to reports for which the reviews have not yet been completed represent a potential application review schedule risk,” the NRC said in its letter.
The specs: The Natrium reactor demonstration project is a 345-MW sodium-cooled fast reactor design with a molten salt–based energy storage system. The demonstration plant is intended to validate the design, construction, and operational features of Natrium technology and HALEU fuel.
The reactor would generate 345 MW of electricity, but actual electricity generation will vary between 100 MW and 500 MW, depending on wholesale prices on the grid. The longer-term idea is that this will depend on whether the sun is shining and the wind is blowing.
Natrium is one of two advanced reactor demonstration projects selected for competitive funding through the Department of Energy’s Advanced Reactor Demonstration Program. (X-energy’s Xe-100 is the other.) TerraPower also received $1.6 billion in funding from the Bipartisan Infrastructure Law signed by President Biden in November 2022, which is to be used to ensure the completion of the plant. The company also raised over $1 billion in private funding.
The technology: Gates helped found TerraPower in 2006 and has been its chair ever since. The company’s aim is to provide the world with a more affordable, secure, and environmentally friendly form of nuclear energy. The Natrium plant is roughly one-third the size of the larger U.S. operating plants and is even a smaller footprint, compared with other advanced reactors.
TerraPower touts the cheaper cost and safety attributes of using liquid sodium rather than water to cool its Natrium reactors. Liquid sodium has a significantly higher boiling point—882°C—than water, which is used to cool most conventional reactors.
But the use of sodium has raised some concerns due to its explosive reaction if it touches water. There has not been a sodium-cooled reactor in the U.S. since several experimental reactors were attempted in the 1960s and 1970s. After several failures, including a partial meltdown of Fermi-1 in Michigan in 1966, all these reactors were decommissioned, and most were replaced with conventional light water reactors.
Natrium’s design also relies on natural forces, like gravity and thermodynamics, to cool the reactor if an unexpected shutdown occurs.
