The U.S. Nuclear Regulatory Commission did on March 4 what it hasn’t done in nearly a decade: it unanimously voted to let a commercial nuclear plant break ground.
The winner is TerraPower, the Bellevue, Washington company founded by Bill Gates. Its Natrium reactor in Kemmerer, Wyoming, now has a construction permit for the nuclear island, the first approval for any new commercial reactor since the mid-2010s and the first-ever for a non-light-water design under the NRC’s standard licensing process.
The details matter. This isn’t another conventional light-water plant. Natrium is a 345-megawatt sodium-cooled fast reactor paired with a molten-salt storage system that can spike output to 500 MW for hours at a time. Think of it as a nuclear plant with a built-in battery, designed to flex alongside renewables or feed the kind of steady, high-volume power that hyperscale data centers are now demanding.
TerraPower filed its construction permit application in March 2024. The NRC docketed it in May and wrapped the entire safety review in 18 months, five months faster than its original schedule. Commissioners authorized staff to issue the permit “soon,” and the company says nuclear-specific construction will begin within weeks. Non-nuclear site work has already been underway since 2024 next to a retiring coal plant.
For an industry that has spent years complaining about regulatory gridlock, the speed is notable. TerraPower’s CEO Chris Levesque called it “a historic day for the United States’ nuclear industry.” The project remains part of the Department of Energy’s Advanced Reactor Demonstration Program, which has already committed hundreds of millions in cost-share funding.
But speed on paper is one thing; execution is another. The original Department of Energy target for first power was 2028. That slipped. The current plan points to fuel loading around 2030 and commercial operation in 2030 or 2031, with an operating license application planned for late 2027 or early 2028. The total price tag is now estimated at up to $4 billion. That’s expensive for 345 MW, but the bet is that follow-on plants will cost far less once the supply chain, workforce, and regulatory precedents are in place.
The bigger picture is what makes this approval feel different from past nuclear restarts. Electricity demand in the United States is rising for the first time in years, driven almost entirely by data centers powering artificial intelligence. Tech companies, including Microsoft, which Gates co-founded, are openly scouting for firm, carbon-free power that doesn’t depend on the weather. Sodium-cooled designs like Natrium promise higher thermal efficiency, passive safety features, and the ability to load-follow in ways traditional reactors struggle with.
TerraPower isn’t alone. Companies such as Oklo, NuScale, and X-energy are also chasing advanced reactor approvals, but most are still years behind in the licensing queue. The fact that TerraPower cleared the construction permit hurdle first gives it a real first-mover advantage in proving that the NRC can actually move at something approaching commercial speed.
Still, the road ahead is long. The plant must be built without the cost overruns that have plagued every recent U.S. nuclear project. It will need high-assay low-enriched uranium (HALEU) fuel, which the domestic supply chain is only now beginning to scale. And it will face the usual local and environmental scrutiny once concrete starts pouring.
For Gates, who has poured personal money and credibility into TerraPower for more than 15 years, this is validation of a long-held thesis: nuclear power, done differently, can be part of the climate solution without the delays and drama of the past. For the rest of the industry, it’s a test case. If Natrium gets built on anything close to its current schedule and budget, it could unlock a wave of follow-on deployments. If it slips, the skeptics who argue advanced nuclear is perpetually “just a decade away” will have fresh ammunition.
The permit itself is just ink on paper. The real story starts now, in the high desert of Wyoming, where a company backed by one of tech’s most patient billionaires is about to find out whether the next generation of nuclear can actually deliver.
