In Kemmerer, Wyoming, a town of roughly 2,400 people best known for a shuttering coal plant, TerraPower has begun the long, regulated work of building the first utility-scale advanced reactor in the United States. The Nuclear Regulatory Commission issued the construction permit for the Natrium demonstration plant in 2025 [Department of Energy, 2025], and the Wyoming Industrial Siting Council followed with approval [ANS Nuclear Newswire, 2026]. Operations are targeted for 2030 [TerraPower website, October 2025].
The bet
TerraPower, founded in 2006 by Bill Gates, Nathan Myhrvold, and John Gilleland, sells one core product: the Natrium reactor, a 345-megawatt sodium-cooled fast reactor paired with a molten-salt energy storage system that can boost output to 500 megawatts. The pitch to utilities is dispatchable carbon-free power. Beyond the demonstration plant, TerraPower has a second business line in medical isotopes [TerraPower website].
The commercial wedge widened considerably this year. TerraPower entered an agreement with Meta covering eight Natrium plants [TerraPower website]. The company also signed a 10-year offtake agreement for high-assay low-enriched uranium (HALEU) reported at $3.5 billion [LinkedIn, Nick Lawson].
Why it could be big
Hyperscaler power demand is rising faster than utilities can build generation. TerraPower's 2024 raise of roughly $650 million pulled in NVentures, HD Hyundai, and SK Group [Crunchbase, 2024].
| Metric | Value |
|---|---|
| Total disclosed funding | $650M |
| Meta offtake (8 plants, announced) | 8 reactors |
| HALEU offtake agreement | $3.5B |
| Kemmerer permanent jobs | 250 jobs |
If Kemmerer comes online near schedule and the Meta units follow, TerraPower would be one of very few companies with a deployed, permitted, fueled advanced reactor design and a backlog of identified sites. The Natrium design has also entered the UK's Generic Design Assessment process [World Nuclear News].
The team and traction
Chris Levesque is President and CEO [TerraPower website]. John Gilleland serves as Chief Technical Officer and a board member [Craft.co]. Nathan Myhrvold is Vice Chairman of the Board. Active hiring includes a Principal Fuel Fabrication Engineer, a Nuclear Security Systems Resident Engineer, and a Quality Assurance Manager [Greenhouse / TerraPower].
Utility partnerships extend beyond PacifiCorp. TerraPower and Evergy signed an agreement with the State of Kansas to explore Natrium deployment [TerraPower website], and a separate agreement with Southern Company covers a fast-spectrum molten salt research reactor [TerraPower website].
The honest counterfactual
Critics argue TerraPower's path to a commercial reactor by the early 2030s is aggressive [E&E News by POLITICO], and sodium's reactivity with water and air remains a long-running question [The Boston Times, 2026]. The bull answer is specific: the Natrium design separates the nuclear island from the power and storage island, runs at near-atmospheric pressure, and has passed an NRC final safety evaluation [ANS Nuclear Newswire, 2025; Department of Energy, 2025].
What to watch
The next twelve months are about execution on three fronts: construction progress at Kemmerer, conversion of the Meta agreement's two early-development units into a firm site selection, and the first deliveries against the HALEU offtake. The Kemmerer pour is the milestone that matters most.
Technical breakdown
Natrium is a pool-type sodium-cooled fast reactor rated at 345 MWe baseload, coupled to a molten salt thermal storage loop that can deliver 500 MWe. Sodium operates as coolant at near-atmospheric pressure. Fuel is HALEU at enrichments up to 19.75 percent U-235.
What could go wrong at scale
A single demonstration plant on schedule does not prove an eight-unit fleet on schedule. Fast reactor programs in France, Japan, and Russia have hit multi-year delays driven by sodium handling incidents, fuel qualification, and supply-chain bottlenecks. Scaling from one to nine is where most reactor programs in history have stalled.