TerraPower’s Natrium reactor has moved beyond the experimental stage, but its bigger test is still ahead: proving that an advanced nuclear design can be built repeatedly, financed commercially and delivered on schedule.
The Wyoming project received a U.S. construction permit in March and officially entered construction in April. Meanwhile, Meta has backed a potential fleet of up to eight Natrium plants as data-centre electricity demand rises.
The latest agreements with Korean industrial companies suggest TerraPower is now building not just one reactor, but the supply chain for a wider commercial rollout.
Natrium’s 345 MW Core
Natrium is a sodium-cooled fast reactor developed by TerraPower and GE Hitachi Nuclear Energy. Its nuclear generating capacity is 345 MWe. Unlike conventional reactors that rely on light water for cooling, Natrium uses liquid sodium and combines the reactor with a molten-salt energy-storage system.
That storage system is central to TerraPower’s commercial pitch. The company says it can increase the plant’s electrical output to 500 MW for more than five hours when required. The additional output comes from stored thermal energy, so 500 MW should not be confused with the reactor’s 345 MWe nuclear capacity.
The distinction matters because it gives the plant a way to respond to periods of higher electricity demand without increasing the reactor’s nuclear power output.
Wyoming Project Clears Hurdle
The first Natrium plant is being developed in Kemmerer, Wyoming, through TerraPower subsidiary US SFR Owner. On March 9, 2026, the U.S. Nuclear Regulatory Commission issued the construction permit for Kemmerer Power Station Unit 1. The NRC said it was the first construction permit it had issued for a commercial non-light-water power reactor.
TerraPower then announced the official start of construction on April 23. The project is supported by the U.S. Department of Energy’s Advanced Reactor Demonstration Program, under which DOE has committed up to $2 billion in cost-shared support.
The project is currently targeting commercial operation around 2030–2031. That remains a target rather than a guaranteed commissioning date, since the plant must still complete construction and obtain the separate regulatory approvals required to operate.
AI Creates New Power Demand
The commercial timing coincides with a major shift in electricity demand from data centres. The International Energy Agency’s latest outlook estimates global data-centre electricity consumption will roughly double from 485 TWh in 2025 to 950 TWh in 2030. Electricity consumption from AI-focused data centres is projected to grow even faster.
That demand is one reason large technology companies are increasingly looking at nuclear power. Nuclear plants can provide firm electricity without relying on weather conditions, while Natrium’s storage system is designed to add flexibility during periods of higher demand.
Meta has already put commercial backing behind the technology. Its January 2026 agreement with TerraPower covers up to eight potential Natrium units. Two initial units are intended to provide up to 690 MW of firm power, with delivery targeted as early as 2032.
The agreement also gives Meta rights to energy from as many as six additional units. Across all eight, the potential capacity is 2.8 GW of baseload generation, plus 1.2 GW of built-in storage.
These are development commitments, not eight reactors currently under construction.
Supply Chain Becomes Critical
The latest developments show TerraPower is addressing another challenge: whether advanced nuclear plants can be manufactured and constructed repeatedly rather than treated as one-off projects.
On August 14, TerraPower announced a framework agreement with Hyundai Engineering & Construction to support commercial deployment of up to eight future Natrium reactors. The arrangement includes completion, price and performance guarantees intended to support conventional commercial financing. HD Hyundai is also developing manufacturing capacity for major reactor components.
TerraPower separately signed a preliminary agreement with SK Innovation covering potential Natrium development and commercialisation in South Korea and international markets. Financial terms were not disclosed.
The significance is commercial rather than merely technological. Advanced nuclear projects have to overcome long construction timelines, complex supply chains, fuel requirements and substantial financing needs. Standardising design, manufacturing and construction could make future units easier to finance and deliver.
Commercial Test Still Ahead
Natrium’s regulatory progress gives TerraPower an important lead, but a construction permit is not an operating licence, and the first plant remains a first-of-a-kind project.
The company’s immediate challenge is therefore execution. If Kemmerer Unit 1 reaches operation close to its 2030–2031 target, TerraPower will have a working reference plant around which it can build the larger commercial pipeline. If delays or cost pressures emerge, the economics of subsequent projects could become harder to prove.
For now, the evidence supports a more measured conclusion than claims of a nuclear revolution. TerraPower has secured a construction permit, started building its first plant, attracted a major technology-company customer and, most recently, strengthened its Korean manufacturing and construction partnerships.
The next milestone is no longer whether Natrium can be licensed. It is whether the company can build it successfully and turn that first project into a repeatable business.
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