As well as signing the framework agreement with HD Hyundai Heavy Industries making it TerraPower’s strategic manufacturing partner, a separate memorandum of understanding was agreed between Terrapower, HD Hyundai and Hyundai Engineering and Construction “to collaborate on the design, manufacturing, supply chain, construction, commercial structure and delivery of multiple units of TerraPower’s Natrium technology”.
HD Hyundai said this would “establish a robust foundation for Engineering, Procurement, and Construction execution and the supply of major equipment, enabling an aggressive response to the global next-generation nuclear power market, including in the US”.
TerraPower’s Natrium technology features a 345 MWe sodium-cooled fast reactor with a molten salt-based energy storage system. The storage technology can temporarily boost the system’s output to 500 MWe when needed, enabling the plant to follow daily electric load changes and integrate seamlessly with fluctuating renewable resources. TerraPower began non-nuclear construction for its first Natrium plant, in Kemmerer, Wyoming, in June 2024, and expects construction of the plant – which it says will be the first commercial-scale, advanced nuclear project in the USA – to be complete in 2030. The first Natrium project is being developed through the US Department of Energy’s Advanced Reactor Demonstration Program. The Natrium reactor is a TerraPower and GE Vernova Hitachi Nuclear Energy technology.
Chris Levesque, president and CEO of TerraPower, said: “By combining our strengths, we are creating a new era of energy infrastructure – one where advanced reactors like Natrium are unleashed at scale to meet growing demand, strengthen supply chains, and deliver reliable, resilient, affordable power.”
Kwang-shik Won, senior executive vice president and COO of HD Hyundai Heavy Industries, said the framework agreement was a “critical foundation for our entry into the global nuclear market”. He added: “Through our agreement, we will strive to ensure the timely supply of Natrium reactor equipment and establish a serial production base to secure a formidable global competitive edge.”
In TerraPower’s announcement, it said the collaboration aims to “leverage American innovation and Korean industrial expertise for advanced reactor deployments, supporting a global shift toward innovative, next-generation nuclear technologies”.
It added that the agreement with HD Hyundai Heavy Industries “secured a scalable supply chain for serial production of Natrium reactors” and followed a “thorough review of its fabrication capabilities, large-scale industrial production expertise and proven track record in precision manufacturing for the energy sector”.
HD Hyundai noted that the agreement was an extension of the Strategic Agreement for Manufacturing Supply Chain Expansion for the Commercialization of Natrium Reactors signed in March 2025. It added that over the past year, the two companies had conducted a joint study to evaluate the manufacturing feasibility, cost competitiveness, and delivery schedules for the Natrium reactor.
In addition to the first Natrium plant under construction, TerraPower – which is chaired by Microsoft co-founder Bill Gates – has an agreement with Facebook and Instagram owner Meta for up to eight Natrium plants by 2035. In January South Korea’s SK Innovation .
