Korea Hydro & Nuclear Power (KHNP) and French nuclear fuel cycle company Orano have signed a Letter of Intent (LOI) to advance long-term cooperation in uranium enrichment. The agreement was signed at the Élysée Palace in Paris during a state visit by South Korean President Lee Jae Myung.
Through the agreement, KHNP secures alternative Western enrichment sources amid global supply chain uncertainty while Orano solidifies its commercial foundation for upcoming uranium enrichment ventures. The deal builds on an initial Memorandum of Understanding (MOU) signed in April covering the complete nuclear fuel cycle. KHNP maintains its 2.5% equity stake in Orano’s Georges Besse 2 enrichment plant, which it has held since 2009.
“Amid growing uncertainty in the global nuclear fuel market, it is critical to proactively secure reliable sources of supply,” KHNP President & CEO KIM Hoe Chun said. “This LOI will serve as an important opportunity to expand cooperation between the two companies and further strengthen the stability of our nuclear fuel supply.”
Claude Imauven, the Chairman of the Board of Directors of Orano, noted: “This cooperation with KHNP represents an important opportunity to further strengthen the relationship between the two companies. We look forward to continuing our cooperation in the front end of the nuclear fuel cycle.”
South Korea’s wider nuclear energy strategy targets aggressive global export expansion, the adoption of advanced reactor designs, and achieving absolute domestic energy security. Historically, the country operated a model based entirely on importing enriched fuel and storing spent fuel on-site. However, recent global supply chain disruptions and geopolitical shifts have forced Seoul to transition toward active domestic uranium enrichment and spent-fuel fuel-cycle management.
South Korea operates 26 commercial nuclear reactors supplying over 30% of its electricity, but it remains heavily dependent on foreign fuel sources. The original US-South Korea 123 Agreement was signed in 1974, placing strict, long-term limits that banned South Korea from enriching uranium or reprocessing spent nuclear fuel.
In April 2015, Washington and Seoul finalised a revised 20-year civil nuclear pact that formally moved the relationship toward an equal partnership. It opened the door to civilian uranium enrichment by creating a framework for ongoing consultations with the US to achieve low-level enrichment (up to 20% U-235). It also granted South Korea permission to conduct advanced research into pyroprocessing (used fuel recycling). However, enrichment progress remains at the discussion stage.
In late 2025, Korea paid a high price to achieve a breakthrough. Building on the framework of the 123 Agreement, the US formally affirmed support for South Korean uranium enrichment and approved a process allowing South Korea to acquire and fuel its own nuclear-powered attack submarines using low-enriched uranium (LEU).
In return for the concession on uranium enrichment and nuclear-powered attack submarines, the Trump administration secured a highly lucrative, transactional $350bn trade, defence, and investment package from South Korea. To settle a tense tariff dispute and achieve the military breakthrough South Korean President Lee Jae Myung agreed to major financial and industrial concessions.
South Korea pledged to invest $150bn in the struggling US shipbuilding sector. This includes a directive for South Korean conglomerates to build the new nuclear-powered attack submarines directly at US shipyards in Philadelphia. South Korea committed $200bn toward other vital US national security and economic supply chains, such as semiconductors and advanced technology infrastructure. Seoul agreed to a $25bn purchase of American military hardware and allocated $33bn to support US bases in the Korean Peninsula.
To ensure Washington retains oversight, the US required that any future commercial enrichment facility must operate as a 50-50 joint venture between the two nations. South Korea agreed to use strictly LEU for its submarines and civil energy.
South Korea’s near-term goal is to secure independent rights to enrich uranium up to 5% U-235 purity levels. This threshold is specifically tailored to satisfy the fuel needs of its current fleet of large, third-generation commercial reactors.
However, securing further enrichment rights is essential to source high-assay low-enriched uranium (HALEU) domestically. HALEU (enriched up to 19.75%) is highly critical for South Korea’s next-generation small modular reactors (SMRs) and would be more appropriate for its planned domestic nuclear-powered attack submarines.
South Korea will remain completely dependent on foreign imports for HALEU unless the US grants programmatic consent to exceed the standard LEU 5% cap.
While the text of the revised 2015 123 Agreement technically permits South Korea to enrich uranium up to 20% via bilateral consultation, Washington still holds strict “advance consent” veto power over the physical implementation.
Because the 2025 “submarine and energy” breakthrough relies strictly on LEU or closely monitored US-sourced fuel, South Korean energy conglomerates are actively forming purchasing agreements and investing heavily in Western facilities, such as Orano’s upcoming Oak Ridge plant, to secure their future HALEU imports.
