The Nuclear Regulatory Commission has issued its first commercial nuclear construction permit in almost ten years, marking a significant milestone for the American nuclear energy sector. On March 4, 2026, the commission unanimously approved TerraPower’s application to build the Natrium advanced reactor at the Kemmerer Power Station Unit 1 in southwestern Wyoming. TerraPower, which receives backing from Bill Gates, announced that construction activities will begin within the coming weeks.
This development is particularly noteworthy for the United States, which currently has zero nuclear reactors under construction, placing it behind countries like China with 38 reactors being built, and Russia and India with six each. The approval represents the first construction permit for a non-light-water commercial reactor in more than four decades, signaling a potential shift in America’s nuclear energy landscape.
The Natrium reactor differs substantially from conventional nuclear technology. It operates as a sodium-cooled fast reactor with a pool-type design, integrated with a molten-salt energy storage system. This configuration enables the reactor to adjust its power output similarly to natural gas peaker plants while maintaining consistent baseload operations. The system uses High-Assay Low-Enriched Uranium fuel, enriched to approximately 15-20 percent U-235, which permits smaller and more efficient reactor cores. The facility will generate 345 megawatts of electricity, with the storage capability potentially increasing output for enhanced grid flexibility.
The NRC completed its review of TerraPower’s application in just 18 months, significantly faster than the initially projected 27-month timeline. The company submitted the application in March 2024, and the accelerated approval process reflects growing urgency around meeting increasing energy demands, particularly from artificial intelligence and data center operations, while facing coal plant retirements.
TerraPower CEO Chris Levesque characterized the approval as a historic moment for the nation’s nuclear industry. The company has already commenced preliminary work on non-nuclear components since 2024, including the energy island infrastructure, following earlier exemptions and state permits from Wyoming’s Industrial Siting Council granted in 2025. The project targets full commercial operation by 2030, with total costs estimated at up to $4 billion for this demonstration facility. Funding includes up to $2 billion from the Department of Energy’s Advanced Reactor Demonstration Program, with matching contributions from TerraPower and its partners.
The project’s momentum extends beyond this single installation. Earlier this year, TerraPower secured a substantial agreement with Meta to develop up to eight Natrium facilities, potentially delivering gigawatts of carbon-free baseload power to support AI infrastructure requirements. This partnership reflects the technology sector’s search for reliable power sources to avoid blackouts or reliance on diesel generators at data centers.
The design addresses several challenges facing modern electricity grids. Advanced features include modular construction capabilities, passive safety systems, and improved cost and schedule discipline compared to traditional nuclear projects that have experienced significant overruns and extended construction timelines. The Natrium design specifically tackles intermittency issues associated with wind and solar power without requiring massive battery storage
installations.
Additional small and mobile modular reactor companies, including Oklo and Nano Nuclear, are developing technologies expected to support behind-the-meter data center power needs, addressing what analysts estimate as a 100-gigawatt shortfall in coming years.
The Wyoming project will replace a retiring coal facility and demonstrates how private capital combined with regulatory cooperation can advance American energy innovation. The facility represents more than infrastructure replacement; it establishes a model for
transitioning electricity grids toward dispatchable, high-density power generation that maintains grid reliability without imposing excessive costs on consumers.
This approval signifies renewed momentum for nuclear energy
development in the United States, particularly for advanced reactor designs that offer improvements over legacy light-water reactor technology.