US-based TerraPower has signed key agreements with Hyundai Engineering & Construction (HDEC) and SK Innovation. This followed a series of high-level talks in South Korea between Terrapower’s founder & Chairman Bill Gates and TerraPower President & CEO Chris Levesque with Korean Prime Minister Han Seong-sook, Industry Minister Kim Jung-kwan as well as leaders from the Export-Import Bank of Korea, HD Hyundai, HDEC and SK Innovation.
Gates and Kim discussed ways to integrate Korean suppliers into the US nuclear developer’s global SMR supply chain. “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,” Kim noted. “With over 50 years of experience building and operating nuclear facilities, Korea has established a ‘foundry-grade’ manufacturing and construction ecosystem, making it the ideal partner for TerraPower.” He urged TerraPower to leverage Korea’s advanced manufacturing resources, including both major conglomerates and highly specialised small-to-medium suppliers, as a key global production base and supply chains.
Gates noted: “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. I look forward to the cooperation between the two sides serving as a catalyst for the global clean energy transition and entry into third-country markets.”
The partnerships with HDEC and SK Innovation establish a robust framework for building Terrapower’s Natrium reactors at commercial-scale across the US, South Korea, and other international markets. The Natrium plant features a 345 MWe sodium-cooled fast reactor integrated with a molten salt-based energy storage system. The storage technology allows the facility to temporarily boost its power output to 500 MWe for over five hours, enabling it to follow daily electricity load changes and integrate with renewable energy sources.
Construction of the first Natrium plant is underway at Kemmerer in Wyoming after the US Nuclear Regulatory Commission (NRC) granted the first-ever construction permit for a commercial-scale advanced NPP in March. Completion is targeted for 2030. TerraPower has an existing commercial pipeline agreement with Meta to explore up to eight Natrium plants in the US by 2035. The reactor is also undergoing General Designed Assessment with UK regulators.
The two new agreements signed in Seoul split critical deployment and commercial responsibilities to establish an efficient global nuclear rollout. Under the framework agreement with HDEC, TerraPower selected the company as its engineering, procurement & construction (EPC) contractor to build up to eight future Natrium reactors. HDEC will provide completion, price, and performance guarantees to help projects secure conventional commercial financing.
The term sheet agreement signed with SK Innovation establishes an intent to develop South Korea’s very first commercial Natrium plant and scale the business internationally. TerraPower and SK Innovation will also collaborate on next-generation engineering tools, focusing on digital twin technology and artificial intelligence to optimise long-term operations and reactor maintenance. SK Innovation is a core subsidiary and the primary energy affiliate of SK Group – South Korea’s second-largest conglomerate (known locally as a chaebol). It operates as a massive corporate umbrella holding company over dozens of distinct, interconnected businesses.
These milestone agreements tie into a wider partnership with Hyundai and SK Group that began in August 2022. HD Hyundai (via HD Korea Shipbuilding & Offshore Engineering) at that time made a $30m anchoring equity investment into TerraPower. In December 2024, TerraPower placed its first physical equipment order with HD Hyundai, contracting them to manufacture the cylindrical reactor vessels for the Wyoming demonstration project. Fabrication is currently underway at HD Hyundai’s dedicated SMR facility in Ulsan.
In March 2025, the two companies signed a “Strategic Agreement for Manufacturing Supply Chain Expansion” launching a technical joint study evaluating manufacturing feasibility, cost competitiveness, and factory delivery schedules. Following the successful conclusion of the study in March 2026, HD Hyundai was awarded preferred bidder status for the broader, commercial-scale primary equipment and enclosure system components. With the latest agreement, alongside HDEC being named general EPC contractor, the partnership was integrated into a multi-party alliance to begin planning fleet-scale serial production for future markets, including the planned US plants tied to the Meta data centre pipeline.
The relationship with SK Group began in May 2022 when an initial memorandum of understanding (MOU) with TerraPower to jointly evaluate next-generation SMR technologies. In August 2022 SK Group and SK Innovation together closed a $250m equity investment, officially becoming a primary backer, second only to Bill Gates. In March 2023, SK Innovation expanded the alliance by signing a tripartite agreement with TerraPower and KHNP to co-manage the physical demonstration phase of the Natrium reactor. In January 2026, SK Innovation transferred a portion of its equity stake to state-backed utility Korea Hydro & Nuclear Power (KHNP). Despite this divestment, SK Group retained its second-largest shareholder status. With the August 2026 agreement SK Innovation converted its financial position into concrete construction planning to deploy Natrium technology globally.
SK Group’s capital allocation aligns with its broader corporate restructuring goals to transition from fossil fuels to clean energy and bio-tech. The investment is driven by SK Group Chairman Chey Tae-won’s strict corporate mandate to cut 200m tonnes of carbon emissions by 2030. The financial terms granted SK Group the exclusive business rights to co-develop and commercialise TerraPower’s advanced nuclear reactors across Korea and Southeast Asia. Beyond power grids, SK Group targeted TerraPower’s medical division. TerraPower uses nuclear byproducts to manufacture Actinium-225 used in cancer treatments. This technology creates immediate synergies with SK Group’s growing pharmaceutical and biotech portfolio.
“Today marks a pivotal moment for TerraPower as we embark on a new chapter of international collaboration with Korea’s leading organisations,” said Terrapower’s Chris Levesque. “Combining TerraPower’s innovative advanced nuclear technology with Korea’s nuclear construction and operational expertise will strengthen our global cooperation and accelerate the deployment of a Natrium fleet that will transform the world’s energy landscape.”
In addition, other Korean firms such as Doosan Enerbility are participating in equipment manufacturing, construction and operational roles for TerraPower’s domestic and global projects. Doosan Enerbility is South Korea’s premier nuclear equipment manufacturer and functions as TerraPower’s main components partner. In August 2026, Doosan signed a major manufacturing agreement to supply the physical core for the Wyoming demonstration plant. Doosan is tasked with fabricating the primary reactor containment vessel, the reactor guard vessel, and the heavy internal support structures that hold the fuel blocks in place. This contract followed a detailed year-long joint engineering study launched in December 2024 to verify the factory manufacturability of the complex sodium-cooled components.
