The U.S. Energy Dept. found no significant impacts in its final environmental review of infrastructure planned to support the estimated $4-billion next generation nuclear energy plant proposed by developer TerraPower at the site of a retired coal fired power plant in Wyoming. 

TerraPower’s Natrium plant is a proposed 345-MW sodium cooled fast nuclear unit with a molten salt energy storage system.

Bechtel, TerraPower’s engineering, procurement, and construction partner, broke ground on the project in mid 2024. It is set to employ about 1,600 workers will be for construction at project peak. Construction is set to span five years. 

North America’s Building Trades on March 3 said it signed a project labor agreement with TerraPower for construction of the Natrium reactor, marking “a massive step forward for America’s nuclear industry,” Union President Sean McGarvey said in a statement.

The federal agency also said it plans to authorize funds for site preparation and support infrastructure work, including non-structural backfill, construction of multiple buildings, installation of underground services, laying foundations, installation of stormwater management ponds and establishing temporary power.

Support infrastructure construction is set to begin this month, but construction of the nuclear unit would not begin until the U.S. Nuclear Regulatory Commission issues a construction permit, which is expected in September 2026 after it completes an expected 18-month long environmental impact statement and a record of decision.  The approved infrastructure construction would not involve radioactive material or nuclear safety-related systems, “and no safety-related structures would be built,” DOE said.

The commission said in late February that it completed its draft safety evaluation for the plant and expects to complete the final safety evaluation in June 2026, needed before a construction permit can be granted. 

The proposed infrastructure funding would come under the DOE’s seven-year, $2 billion matching agreement signed in 2020 under its Advanced Reactor Demonstration Program.

TerraPower said in January that it received approval from Wyoming authorities for construction and operational activities that are not under commission jurisdiction., 

The state approval allows construction of the energy island that will house the molten-salt energy storage tanks and turbines. “With this permit complete, TerraPower will continue its aggressive construction schedule; and plans to start construction on both the Kemmerer Training Center and the energy island in 2025, as well as continue work on the sodium test and fill facility that began in 2024,” the company said.

The state permit was the first by any state awarded to a commercial-scale advanced nuclear project. “The regulatory process to bring new nuclear plants to fruition is robust, and our team has been working relentlessly to successfully maneuver through a complicated, multi-jurisdictional environment to bring the first Natrium plant to market,” TerraPower CEO Chris Levesque, said in a statement. 

TerraPower is the only advanced nuclear developer that has submitted a permit application for a commercial advanced reactor to the commission, done one year ago. The unique Natrium design, a collaboration between TerraPower and GE Hitachi Technology, allows the company to start non-nuclear construction onsite during the NRC review, the company said. 

Expected to be completed by 2030, the Natrium plant will be a “fully functioning commercial power plant,” TerraPower said. Its energy storage system allows the plant to integrate easily with renewable resources, said the developer, which was founded by Bill Gates in 2008.

he company estimates that 250 people will support day-to-day activities, including plant security, once the plant operates. 

In mid-February, TerraPower and nVision Energy, an affiliate of utility-scale energy project developer, NOVI Energy, agreed to establish a framework to deploy a model for developing Natrium reactor and energy storage system plants across the U.S.

In January, TerraPower and data center developer Sabey Data Centers signed a memorandum of understanding to develop a strategic collaboration to leverage Natrium plants into the developer’s current and future data center operations.