Multilateral cooperation on nuclear fuel offers the United States a faster, more secure path to expanding its domestic nuclear energy program and reducing supply risks.
The U.S. Challenge: Ambitious Goals, Structural Constraints
On May 23, President Donald Trump signed a series of executive orders on nuclear energy. The orders aim to quadruple nuclear power within the next twenty-five years by promoting nuclear power plant construction on federal lands and expanding uranium mining and enrichment in the United States.
Nuclear power, a stable and low-carbon energy source, is a timely and strategically sound solution to the U.S. energy problem. However, constructing large reactors in the United States presents substantial logistical, regulatory, and financial challenges. In particular, the United States must be prepared for the high construction costs associated with new large-scale nuclear plants. The case of Vogtle Units 3 and 4 is a cautionary tale: the project’s costs doubled to $30 billion, and construction was delayed by nearly seven years. Without significant reform, similar setbacks may recur.
South Korea’s Potential Risk: Nuclear Power Expansion Amidst Fuel Supply Instability
South Korea currently operates twenty-six nuclear reactors and is constructing four more. By 2038, the government plansto add two additional large reactors and one small modular reactor (SMR). According to my calculations, annual demand for uranium concentrate (U3O8) and enrichment services is projected to rise from 4,456 tons and 2,912 tons of separative work units (tSWU) in 2024 to 6,020 tons and 4,126 tSWU, respectively, by 2038. Furthermore, with the commercialization of small modular reactors (SMRs), South Korea will require high-assay low-enriched uranium (HALEU). South Korea currently imports all of its uranium concentrates and enriched uranium.
Given global trends, uranium supply constraints are expected to intensify. As more countries pursue nuclear energy, demand for uranium will continue to grow. A pivotal moment came at the 28th Conference of the Parties to the United Nations Framework Convention on Climate Change in 2023, where twenty-two countries —including the United States and South Korea—pledged to triple their nuclear energy capacity by 2050.
According to the OECD Nuclear Energy Agency, global demand for natural uranium will quadruple from 50,000 tons in 2021 to 200,000 tons by 2050. Enrichment needs are expected to increase from 60,000 to over 170,000 tSWU. HALEU demand alone is projected to reach 520 tons annually by 2050.
Yet the enrichment market remains concentrated. Currently, Russia’s TENEX controls forty-four percent of global enrichment capacity. South Korea depends on Russian supply for roughly one-third of its enriched uranium needs. The HALEU market is even more fragile: currently, only Russia has commercial-scale HALEU production. Centrus Energy operates the only HALEU facility in the United States, producing an annual output of just 900 kilograms. Replacing Russia’s share of the market will demand significant time and investment.
If this market instability persists, countries with enrichment capabilities may prioritize domestic supply, further limiting international availability. South Korea could face the risk of reactor shutdowns due to a lack of fuel. In the long term, chronic uranium shortages could push nations to pursue indigenous enrichment capabilities, raising proliferation concerns, which could undermine the global nonproliferation regime.
A Multilateral Sanctuary Approach: A Practical Path Forward
To reconcile the two key priorities of ensuring nuclear fuel security and preventing proliferation, the international community has increasingly turned to multilateral frameworks. Since 2003, various proposals—by states and international organizations—have advocated mechanisms such as international fuel banks and multilateral fuel cycle centers.
One promising concept is a sanctuary, a special territory initially proposed as part of Germany’s multilateral enrichment initiative. This model offers a flexible and secure platform for international nuclear cooperation. It could be adapted to address the challenges faced by both the United States and South Korea.
Proposal 1: Construction Sanctuaries in the United States
The United States could designate certain federal sites as “construction sanctuaries” for new reactor projects undertaken by companies from both countries. Within these zones:
- Nuclear safety and industrial regulations would adhere to U.S. standards;
- Construction could follow South Korea’s proven project management protocols;
- Labor and operational frameworks could reflect South Korean practices to promote workforce stability and cost efficiency.
These hybrid zones would accelerate licensing and construction, reduce cost overruns, and foster integrated U.S.–Korea supply chains. Constructing two to four plants under this model could spur a shared industrial ecosystem that benefits both nations and the global clean energy transition.
Proposal 2: Enrichment Sanctuaries in South Korea
To address South Korea’s nuclear fuel security challenges while upholding nonproliferation goals, both the United States and South Korea should consider establishing a U.S.-managed enrichment facility in a sanctuary zone in South Korea. This facility would:
- Operate under Korean nuclear safety regulations while maintaining U.S. technological and operational control;
- Employ a “black-box” model to limit South Korean access to sensitive enrichment technology;
- Guarantee a stable nuclear fuel supply without triggering proliferation concerns.
Such a facility could serve as a regional enrichment hub, enhancing fuel assurance across Asia in alignment with the 2015 U.S.–South Korea nuclear cooperation agreement.
Proposal 3: Joint Uranium Development with Mongolia
A trilateral supply chain initiative involving the United States, South Korea, and Mongolia could further diversify sources and stabilize nuclear fuel markets. Mongolia holds significant untapped uranium reserves, with France already having established a presence in the region. The United States and South Korea should take the following steps:
- Jointly developing uranium mines and concentrate production facilities;
- Establishing a logistics route through Russia’s Trans-Siberian Railway to the port of Vladivostok;
- Integrating the mined material into the proposed South Korea-based enrichment facility to support Asia’s nuclear fuel demands.
Conclusion: Multilateralism as the Most Realistic Solution
Global demand for enriched uranium is surpassing supply, exacerbated by Russia’s geopolitical isolation. This imbalance not only threatens the viability of future nuclear projects but also could undermine the nonproliferation regime by incentivizing domestic enrichment efforts.
The multilateral sanctuary model offers a pragmatic solution. It balances sovereignty with cooperation and technical innovation with political realism. If the United States and South Korea jointly pioneer this model—through construction sanctuaries, enrichment partnerships, and diversified supply chains—they can stabilize the nuclear fuel market and advance the global clean energy transition.
About the Author: Joohyun Moon
Joohyun Moon is a Professor of Energy Engineering at Dankook University. He serves as the President of the Board of Directors at the Institute for Korea Spent Nuclear Fuel. He is also the Vice President of both the Korean Nuclear Society and the Korea Institute of Nuclear Materials Management. Additionally, he has served as a member of the Nuclear Safety Advisory Committee for the Nuclear Safety and Security Commission. He earned his Ph.D. in Nuclear Engineering from Seoul National University in 1996.
Image: The White House/WikiMedia Commons
