TerraPower Targets AI Data Centers With Natrium Energy Storage
TerraPower plans a 2027 AI data center reactor project, using molten sodium storage to flex its 345 megawatt Natrium plant as power demand swings for GPUs.
Summary
TerraPower, founded by Bill Gates, plans to announce its first data center project by the end of 2026, Bloomberg reported on August 19. The undisclosed customer’s plant is expected to break ground in 2027 and become TerraPower’s second, after a project already under construction in Wyoming. Meta agreed in January to buy eight Natrium plants, but TerraPower has not linked Meta to this project.
The 345 megawatt, molten salt cooled Natrium reactor keeps fission running steadily while storing surplus heat in a giant vat of molten sodium, then uses that heat to make extra steam when AI demand spikes. U.S. nuclear plants generate at maximum power 92.5% of the time, but existing reactors adjust output by only about 5% of rated capacity per minute, versus about 10% for small modular reactors, according to the National Laboratory of the Rockies. Natrium’s storage, originally designed to balance intermittent wind and solar, could follow volatile GPU loads without throttling costly nuclear equipment or adding large battery banks. That matters because AI demand swings have damaged natural gas turbines, nuclear has the highest capital expenditure among generation technologies, and proposed savings from mass manufacturing small modular reactors remain unproven and could take a decade or more.
Positives
- Meta agreed in January to buy eight Natrium plants, providing TerraPower with a substantial order before its first data center project is disclosed.
- The 345 megawatt Natrium design stores surplus reactor heat in molten sodium and releases it when AI power demand rises.
- U.S. nuclear plants operate at maximum power 92.5% of the time, offering the constant generation sought by data centers.
- TerraPower expects its first data center project to break ground in 2027 as its second power plant.
- Storage designed to balance wind and solar could let Natrium serve volatile GPU workloads without reducing reactor output.
Risks & concerns
- TerraPower has not identified the data center customer or connected the project to Meta’s agreement for eight Natrium plants.
- AI workload swings are demanding enough to damage natural gas turbines and can require costly large battery banks.
- Nuclear has the highest capital expenditure among generating technologies, making reduced operation particularly uneconomic.
- Mass manufacturing has not yet proved it can lower small modular reactor costs, and any benefits could take a decade or more.
- Existing reactors change output by about 5% per minute, while newer small modular reactors reach only about 10%, according to the laboratory.