• The U.S. Nuclear Regulatory Commission approved a construction permit for TerraPower’s Natrium reactor in Wyoming, the first commercial scale advanced nuclear plant to receive such authorization.
• The 345 MW sodium cooled reactor, paired with molten salt energy storage capable of boosting output to 500 MW, aims to provide flexible, dispatchable clean power.
• The project is backed by the U.S. Department of Energy’s Advanced Reactor Demonstration Program and is expected to come online by 2030.

U.S. Approves First Commercial Advanced Reactor Construction

The U.S. Nuclear Regulatory Commission has approved a construction permit for TerraPower’s Natrium reactor in Kemmerer, Wyoming, clearing the way for what could become the first utility scale advanced nuclear power plant built in the United States.

The decision authorizes construction of Kemmerer Unit 1, a commercial demonstration of TerraPower’s Natrium technology, which combines a sodium-cooled fast reactor with integrated molten salt energy storage. Regulators’ approval marks the first time a commercial-scale advanced nuclear reactor has received a construction permit from the NRC.

Chris Levesque, president and CEO of TerraPower, said the approval represents a breakthrough moment for the U.S. nuclear sector. “Today is a historic day for the United States’ nuclear industry. We are beyond proud to receive a positive vote from the Nuclear Regulatory Commissioners to grant us our construction permit for Kemmerer Unit One. This is the first commercial-scale, advanced nuclear plant to receive this permit. Our team has worked relentlessly for over 4 years with the NRC staff to get to this moment. We had extensive pre-application engagement with the NRC; and we submitted a robust and thorough construction permit application almost 2 years ago. We have spent thousands of manpower hours working to achieve this momentous accomplishment. We plan to start construction on the Natrium plant in the coming weeks and look forward to bringing the first Natrium reactor and energy storage system to market in the great state of Wyoming.”

A Faster Regulatory Path for Advanced Nuclear

TerraPower submitted the construction permit application in March 2024, becoming the first developer to file for approval of a commercial advanced reactor under the current U.S. regulatory framework. The NRC formally docketed the application in May 2024 and initially set a 27-month review schedule.

The review concluded in roughly 18 months, faster than anticipated, reflecting what both regulators and industry participants describe as unusually strong coordination during the licensing process.

According to TerraPower, the company’s regulatory strategy emphasized early technical engagement with the NRC and detailed documentation of the reactor’s design and safety features during both the pre-application and formal review stages.

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Policy support also played a role in accelerating the review timeline. Congressional backing through the Nuclear Energy Innovation and Modernization Act, combined with executive actions from President Donald Trump supporting domestic nuclear development, helped streamline the evaluation process.

For policymakers and investors, the permit represents a key regulatory test for the next generation of nuclear technology that the United States hopes will help meet rising electricity demand while reducing emissions.

Natrium’s Hybrid Reactor and Energy Storage Model

The Natrium design differs from traditional large-scale nuclear reactors by integrating grid-scale energy storage directly into the plant.

At its core is a 345 megawatt sodium-cooled fast reactor capable of producing steady baseload electricity. The system is paired with a molten salt energy storage unit that allows the plant to increase power output to as much as 500 megawatts when electricity demand spikes.

The configuration is intended to address one of the central challenges of modern power systems: balancing intermittent renewable generation with reliable dispatchable power.

Unlike conventional nuclear plants that operate at a constant output, the Natrium system is designed to maintain stable baseline generation while releasing stored thermal energy to increase electricity production during peak demand periods.

Developers argue this flexibility could allow advanced nuclear plants to complement large fleets of solar and wind power while preserving grid reliability.

Federal Backing and Strategic Energy Goals

The Kemmerer project is being developed under the U.S. Department of Energy’s Advanced Reactor Demonstration Program, a public-private initiative designed to accelerate commercialization of advanced nuclear technologies.

The program pairs federal funding with private sector investment to demonstrate new reactor designs capable of delivering low-carbon electricity at scale.

If completed on schedule, the Wyoming facility would become the first utility-scale advanced nuclear reactor deployed in the United States, with operations targeted for 2030.

For energy policymakers, the project represents more than a single plant. It serves as a proof of concept for a new generation of nuclear technologies that could play a larger role in decarbonizing electricity systems while supporting industrial demand and electrification.

As electricity consumption rises across data centers, manufacturing, and electrified transport, governments are increasingly evaluating advanced nuclear designs as a stable, carbon-free power source that can operate alongside renewables.

The NRC’s decision places the Natrium project at the center of that strategy. If the reactor performs as expected, it could shape how regulators, utilities, and investors approach the next wave of nuclear deployment both in the United States and globally.

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