TerraPower Signs Korean Construction and Reactor Deals to Scale Up Natrium Nuclear Fleet

TerraPower announced two agreements with South Korean companies on August 14, 2026, aimed at scaling up its Natrium sodium-cooled reactor technology beyond the single demonstration plant currently under construction in Kemmerer, Wyoming.

The first deal is a framework agreement with Hyundai Engineering & Construction, known as HDEC. TerraPower named HDEC as its engineering, procurement and construction contractor for up to eight future Natrium reactors, according to PRNewswire and World Nuclear News. The agreement includes completion, price and performance guarantees, which TerraPower says will make it easier to secure conventional commercial financing for the reactor fleet rather than relying solely on government-backed programs.

The second deal is a term sheet with SK Innovation to develop South Korea's first commercial Natrium plant. Nuclear Engineering International reported the two companies also plan to collaborate on digital twin technology and artificial intelligence tools for plant operations and maintenance.

Both agreements followed a day of meetings in Seoul between TerraPower founder Bill Gates, CEO Chris Levesque, South Korean Prime Minister Kim Min-seok, Industry Minister Kim Jung-kwan, and executives from the Export-Import Bank of Korea, HD Hyundai, HDEC and SK Innovation, according to World Nuclear News. It was the first meeting of top executives from the three companies since HD Hyundai, TerraPower and HDEC signed a trilateral memorandum of understanding in May to cooperate on sodium reactor projects.

Kim Jung-kwan made the case for why Korea matters here. "To lower costs and standardise SMR deployment worldwide, combining TerraPower's standardised reactor design with Korea's highly reliable mass-manufacturing supply chain is essential," he said, according to Nuclear Engineering International. He pointed to Korea's 50-plus years of nuclear construction experience as a "foundry-grade" manufacturing base.

Gates framed the deal in similar terms. "The outstanding nuclear power plant manufacturing and construction capabilities of Korean companies and the customised financial support from the Export-Import Bank of Korea are key driving forces that will accelerate the commercialisation of TerraPower's SMRs," he said.

Where the Wyoming project actually stands

TerraPower's first Natrium plant, in Kemmerer, is being built under the Department of Energy's Advanced Reactor Demonstration Program, a public-private partnership. The U.S. Nuclear Regulatory Commission granted the first-ever construction permit for a commercial-scale advanced nuclear plant in March, according to Nuclear Engineering International. Completion is targeted for 2030.

The Natrium design pairs a 345 megawatt sodium-cooled fast reactor with a molten salt energy storage system that can push output to 500 megawatts for more than five hours during peak demand, according to Nuclear Engineering International and Power Engineering. This flexibility is the selling point: base-load nuclear output that can still ramp to cover gaps when wind and solar drop off.

TerraPower already has a commercial pipeline agreement with Meta to explore up to eight Natrium plants in the U.S. by 2035. The reactor design is also going through a General Design Assessment with UK regulators.

The AI power crunch is driving the money

Nvidia's venture arm, NVentures, joined a $650 million funding round for TerraPower as part of a broader scramble by tech companies to lock down carbon-free power for data centers, according to Breitbart. Microsoft has a deal with Constellation Energy to restart the Three Mile Island plant. Google, Meta and Amazon have all signed nuclear agreements of their own in recent years.

Breitbart's coverage leaned heavily into personal jabs at Gates rather than the substance of the deal, but the underlying fact that Nvidia is betting real money on nuclear to power AI infrastructure checks out against Bloomberg's reporting.

What's actually locked in versus what isn't

The HDEC deal is a framework agreement, not a signed construction contract for eight specific plants. The SK Innovation deal is a term sheet, meaning the two companies have agreed on terms they intend to formalize, not a completed joint venture. SK Innovation itself said in its statement, carried by World Nuclear News, that it plans to "comprehensively review regulatory, industrial, and power grid conditions" before specifying next steps for what it's calling a "K-Sodium" business model.

These are cooperation agreements and manufacturing pipelines being built now, with actual construction contingent on financing, regulatory approval in each country, and Wyoming's demonstration plant actually working as designed.

The Wyoming reactor's 2030 completion date is itself a demonstration project timeline, not a proven commercial track record. High-assay low-enriched uranium fuel availability has already shaped that project's schedule, a supply chain constraint that will apply equally to any Korean-built Natrium units. Whether HDEC's price and completion guarantees hold up once construction starts on the first commercial units, beyond the demonstration plant, is the open question the industry will be watching over the next several years.