US-based nuclear technology company TerraPower and South Korea’s HD Hyundai have begun a strategic collaboration to develop the global manufacturing supply chain for Natrium reactor components. Bill Gates, founder and chairman of TerraPower, and Kisun Chung, Executive Vice Chairman of HD Hyundai, attended the signing ceremony.

Terrapower’s Natrium technology features a 345 MWe sodium-cooled fast reactor with a molten salt-based energy storage system. The Natrium demonstration project is being constructed near a retiring coal facility in Wyoming. Non-nuclear construction on the project began in June 2024.

The aim of the collaboration is to build new supply chain capacity to enable large-scale production and global deployment of Natrium plants. The agreement with HD Hyundai Heavy Industries, an affiliate of HD Hyundai specialising in shipbuilding, provides the manufacturing foundation necessary for full commercial deployment beyond the first project that is currently under development. The partnership builds upon the existing relationship first established in 2024 when HD Hyundai Heavy Industries was competitively selected to develop the reactor vessel for the first Natrium plant in Wyoming.

“TerraPower is committed to delivering our first Natrium plant in the United States, as well as rapidly deploying additional units at competitive prices during the next decade in the US and around the world,” said TerraPower President & CEO Chris Levesque. “HD Hyundai Heavy Industries manufacturing capabilities are world-renowned, and I look forward to working with them to establish the commercial-scale production capacity that will be essential for successful deployment of multiple Natrium units globally.”

Kwang-shik Won, Senior Executive Vice President & COO of HD Hyundai Heavy Industries said: “With our extensive experience in high-precision manufacturing and large-scale industrial production, we are uniquely positioned to apply our proven expertise to support TerraPower’s vision for commercial deployment. This agreement marks a transformative collaboration that will accelerate the commercial viability of next-generation nuclear energy solutions and help shape the future global energy landscape.”

The US Nuclear Regulatory Commission (NRC) in May 2024 accepted TerraPower’s construction permit application for review, marking the first time in more than 40 years that the NRC has docketed this type of application for a commercial non-light water reactor. In his blog, Gates said he expects the NRC review process to take a couple of years. “So in the meantime, TerraPower will continue to build the non-nuclear parts of the facility”. Construction will begin next year on the so-called “energy island,” which is where the steam turbines and other machinery that actually generate power will sit. (The reactor will eventually be part of a “nuclear island,” and the team hopes to start building that in 2026.)”

However, while the TerraPower website provides some details of work done with molten salt, it contains very little information about the reactor technology. It is also notable that none of the contracts signed with suppliers relate to the reactor itself.

Basically, the Natrium reactor is a sodium-cooled fast reactor. Currently, the only commercially operating liquid metal-cooled fast reactors are in Russia, using sodium as the coolant. Development of these reactors took decades supported by full government support. In the US and Europe research on fast reactors took place in the 1960s and 1970s. However, by the early 1990s the US, the UK and Germany had closed down their programmes. France continued with projects for a few more years, finally closing Superphénix in 1998 and Phénix in 2009, In 2019, France also cancelled the Generation IV ASTRID sodium-cooled fast reactor demonstrator design project. Although interest is now reviving in Europe and the USA, it remains at the early design phase and is probably decades away from implementation.