Korea’s Needs and Strategies for Civilian Enrichment and Reprocessing: Ensuring Sustainable Nuclear Energy and Energy Security

Bong-Geun Jun

jun2030@mofa.or.kr​

Visiting Research Fellow

Sejong Institute

1. Nuclear Energy for Carbon Neutrality and Energy Security

As climate change continues to worsen and geopolitical rivalries grow more intense, countries around the world are striving to achieve two critical objectives: strengthening energy security and ensuring a stable supply of carbon-free energy. These efforts toward energy transition are driven by mounting concerns that fossil fuels, such as oil, coal, and gas, may be phased out within the next generation to meet the global goal of carbon neutrality. Without securing a timely and sufficient supply of carbon-free energy, it will be difficult to sustain national economic development. In addition, the escalating competition between the United States and China, as well as between the United States and Russia, has disrupted global energy supply chains and triggered energy crises. As a result, energy security has become a central element not only of economic security but also of national security.

In general, the most economical and accessible approach to achieving carbon neutrality and energy security is widely considered to be the full utilization of carbon-free renewable energy sources, including solar, wind, hydro, and geothermal power. Countries with vast territories, consistent and strong winds, long hours of sunlight, and abundant water resources are well positioned to generate substantial amounts of carbon-free energy by leveraging these geographic and climatic advantages. However, much like fossil fuel reserves, renewable energy sources are unevenly distributed across countries. Indeed, many countries, including Korea, face significant geographic and climatic constraints that hinder the large-scale deployment of renewables. In such cases, nuclear power is increasingly recognized as a viable alternative carbon-free energy source for achieving carbon neutrality.

Nuclear power currently generates 413 gigawatts of electricity across 32 countries worldwide. It is estimated to reduce global carbon emissions by 1.5 gigatons annually and to replace approximately 180 billion cubic meters of natural gas consumption. In the absence of nuclear energy, the pace of climate change would have accelerated significantly. The International Energy Agency (IEA), in its June 2022 report 『Nuclear Power and Secure Energy Transitions』, highlighted the significance of nuclear energy in this context, emphasizing that expanding the role of nuclear power during the transitional period is essential to ensure a smooth shift from the traditional fossil fuel era to a future carbon-free energy system. The report also noted that, compared to renewable energy, nuclear power holds considerable potential as an alternative energy source due to its advantages in dispatchability and scalability.

Owing to its near-total lack of domestic energy resources, Korea has long prioritized investment in nuclear power. As a result, it now ranks as the fifth-largest country in terms of nuclear power generation capacity and has also become an exporter of nuclear power plants. Public acceptance of nuclear energy remains relatively high. Accordingly, Korea is in a more advantageous position than most countries when it comes to utilizing nuclear power to meet the challenges of carbon neutrality and energy security. However, there is a critical weakness that threatens the long-term sustainability and future viability of Korea’s nuclear energy program, namely the absence of domestic enrichment and reprocessing capabilities. Among the major nuclear energy-producing countries, Korea is the only one not only lacking enrichment and reprocessing facilities but also barred from accessing the relevant technologies.

In light of accelerating climate change and intensifying geopolitical competition, this paper argues that securing enrichment and reprocessing capabilities is essential to ensure the long-term sustainability of Korea’s nuclear energy program and to facilitate the introduction of small modular reactors (SMRs). Although Korea has so far developed world-class nuclear technologies without enrichment and reprocessing, its existing nuclear policy is no longer viable in the emerging international political and energy environment. Maintaining a nuclear energy ecosystem without these capabilities is likely to inflict serious damage on Korea’s economic development and energy security.

2. The Korea’s Case for Civilian Enrichment and Reprocessing

a. The Restructuring of the Global Nuclear Fuel Supply Chain and Korea’s Urgent Needs for Enrichment

The global supply of nuclear fuel is monopolized by a small number of advanced nuclear countries and nuclear-armed states. The conversion of uranium into uranium hexafluoride (UF₆), the preliminary stage before enrichment, is dominated by five countries, the United States, Canada, France, Russia, and China, with China and Russia together accounting for 40 percent of the world’s total conversion capacity. Uranium enrichment is controlled by four companies, Rosatom of Russia (40 percent), CNNC of China (12 percent), Urenco, a consortium of the United Kingdom, Germany, and the Netherlands (27 percent), and Orano of France (14 percent).

With such concentration in the global uranium enrichment market, there is a growing risk that the supply of enriched uranium could be weaponized amid intensifying geopolitical competition. In fact, following Russia’s invasion of Ukraine, the United States and other Western countries came to recognize the vulnerability of their energy security due to excessive reliance on Russian-enriched uranium. As a result, they have begun efforts to secure independent enrichment capabilities. These efforts also reflect an intention to cut off Russia’s foreign currency revenues by halting the purchase of Russian nuclear fuel. Recently, the U.S. Congress passed the Prohibiting Russian Uranium Imports Act, which will ban all imports of Russian uranium beginning in 2028. In turn, Russia has also become increasingly likely to use nuclear fuel supply as a means of political pressure in response to such actions by the West.

The U.S. government is concentrating its investment on the development and production of HALEU fuel to accelerate the deployment of small modular reactors (SMRs). At present, Russia’s TENEX is the only company in the world capable of supplying HALEU on a commercial scale. Consequently, even if the United States succeeds in developing next-generation reactors, it would lack the necessary fuel to operate them and would have to depend on imports from Russia. To address this issue, the U.S. Department of Energy launched the “HALEU Availability” program under the 「Energy Act of 2020」, aiming to ensure the timely production and supply of HALEU. In 2022, the government formed the HALEU Consortium and, in accordance with the 「Inflation Reduction Act of 2022」, plans to invest 700 million dollars in building the HALEU supply chain by September 2026.

Since the outbreak of the war in Ukraine, the global nuclear fuel supply market has been rapidly restructured, forming two major blocs: a Western-aligned supply chain comprising the United States, its allies, and Japan, commonly referred to as the “Sapporo Five,” and a rival bloc centered on Russia and China. This shift has raised serious concerns about the stability of Korea’s nuclear fuel supply. Korea currently relies on Russia for approximately 30 percent of its annual imports of enriched uranium. However, as a close ally of the United States, Korea participates in the international sanctions regime led by Washington against Russia. If these sanctions are further intensified, Korea’s ability to import Russian nuclear fuel may become increasingly unstable.

If the import of Russian nuclear fuel becomes infeasible in the future, it will be difficult to ensure the continued operation of nuclear power plants. The procurement of HALEU, the fuel required for small modular reactors (SMRs), also presents a serious challenge. Most next-generation SMR designs require HALEU enriched to levels between 5 and 20 percent, but currently, no country other than Russia is capable of supplying it. Although the United States is making efforts to establish a domestic supply chain, it is unlikely to meet international demand for the foreseeable future. Advanced nuclear countries are competing to gain early leadership in the SMR market, and without secure access to this critical fuel, they risk falling behind. Korea is currently confronted with precisely such a situation.

To prepare for such contingencies, the 2022 summit between the Republic of Korea and the United States produced an agreement to pursue “joint cooperation in securing energy supply chains, including enriched uranium.” In addition, the joint statement from the 2023 trilateral summit among the Republic of Korea, the United States, and Japan at Camp David declared an intention to “accelerate efforts to reduce dependence on Russian energy.” Nonetheless, no substantive intergovernmental cooperation has yet been undertaken in this regard. If geopolitical competition among major powers intensifies and nuclear fuel supplies become severely disrupted, Korea is likely to suffer the most serious consequences, given its lack of domestic enrichment capabilities. It is therefore imperative for Korea to urgently identify effective countermeasures, including the establishment of indigenous enrichment capabilities.

b. Trends in Spent Fuel Management and the Needs for Reprocessing

Spent nuclear fuel is generally classified either as waste intended for permanent disposal or as a recyclable energy resource. Approaches to spent fuel management differ significantly depending on national circumstances. Some countries adopt a direct disposal strategy by placing spent fuel in deep geological repositories. Others, particularly countries with a high dependence on nuclear energy such as France, Russia, Japan, India, and China, implement reprocessing and recycling policies. The majority of countries, including Korea, temporarily store spent fuel at reactor sites to maintain flexibility in future policy decisions. However, interim storage is inherently a provisional measure. In the long term, spent fuel must either be reprocessed for reuse or transferred to a permanent disposal facility.

Even in cases where direct disposal is adopted, spent fuel often requires treatment to reduce its volume and radiotoxicity, thereby facilitating safer and more efficient final disposal. This necessity is particularly pronounced in countries like Korea, where securing disposal facilities isolated from densely populated areas is constrained by limited land availability. Under such circumstances, reprocessing or pyroprocessing becomes essential prior to disposal. Furthermore, these processes are also critical for the production of transuranic (TRU) fuel intended for use in advanced non-light water small modular reactors (SMRs).

In response to the United States’ opposition to reprocessing, Korea has abandoned this approach and is instead advancing the development of pyroprocessing technology as an alternative. Considering the urgency of processing the growing volume of spent fuel stored on-site and the need to facilitate both the deployment and operation of non-light water small modular reactors (SMRs), the early adoption of pyroprocessing has become a critical national priority.

3. Policy Recommendations

a. Establishing a National Policy on Civilian Enrichment and Reprocessing

In order for Korea to introduce enrichment and reprocessing capabilities, it must first establish a “national enrichment and reprocessing policy” as part of its overall nuclear energy policy. This policy should encompass the intended uses and necessity of enrichment and reprocessing, public consensus and national commitment to advancing such capabilities, agreement among relevant stakeholders regarding their introduction, a clear timeline and scale for implementation, reaffirmation of the nation’s commitment to nuclear nonproliferation, and concrete measures to enhance nuclear transparency.

Over the past several decades, various domestic institutions and experts have repeatedly called for the development of enrichment and reprocessing capabilities to ensure a stable nuclear fuel supply, strengthen energy security, promote the treatment and disposal of spent fuel, and prepare for the era of fast reactors. However, there is still no clearly articulated government policy addressing these issues. In view of Korea’s prior commitment under the 1991 Joint Declaration on the Denuclearization of the Korean Peninsula, the government has faced significant constraints in openly promoting enrichment and reprocessing initiatives. As a result, this lack of a coherent and officially endorsed national strategy has led the United States to largely disregard Korean officials’ repeated appeals for the recognition of such capabilities.

Although an exception was made for joint research between Korea and the United States on the pyroprocessing of spent nuclear fuel, the project has remained limited in scope and has seen little progress. This lack of advancement is largely due to the U.S. government’s increasingly reserved stance, citing the sensitivity of pyroprocessing technology. With this context in mind, any future attempt by the Korean government to pursue enrichment and reprocessing should be approached with particular caution, taking into full account the United States’ long-standing opposition to cooperation and technology transfer in this domain.

As the Korean government considers formulating a national policy on enrichment and reprocessing, it must be able to provide clear and convincing answers to several critical questions. First, does Korea truly need enrichment and reprocessing capabilities, and if so, why are they now considered essential when the country has functioned without them for decades? Second, to what extent is Korea prepared to bear the political, diplomatic, and economic costs involved in pursuing these technologies? Given that Korea’s previous efforts have been repeatedly thwarted by strong opposition from the United States, does the Korean government now possess the political will and justification necessary to overcome such resistance? Third, has the country achieved public consensus on this matter? In the past, divergent views among stakeholders have hindered agreement, but is there now sufficient public support to proceed? Finally, how will Korea address the primary concern that has led the United States to oppose enrichment and reprocessing, namely the perceived risk of nuclear weapons development? What specific measures can Korea take to alleviate these concerns, and how can it credibly demonstrate its commitment to nonproliferation and enhance transparency in a way that persuades the United States of its reliability?

b. Overcoming “Domestic Nuclear Armament” Discourse and Raising Nonproliferation Awareness

The United States has consistently prioritized nuclear nonproliferation as a core objective of its international security policy, both during and after the Cold War. In May 1974, following India’s successful nuclear test under the codename “Smiling Buddha,” which was conducted using a nominally peaceful reprocessing program, the U.S. government began to rigorously restrict the dissemination of enrichment and reprocessing technologies to prevent the emergence of additional nuclear-armed states. Around the same time, President Park Chung-hee of Korea pursued the introduction of a reprocessing facility from France. In response, the United States intervened and exerted direct pressure on both the Korean and French governments, ultimately forcing the cancellation of the plan. Since then, the U.S. has maintained a consistent position of prohibiting Korea from developing enrichment and reprocessing capabilities, with the explicit objective of ensuring Korea's continued denuclearized status.

Considering the United States’ long-standing commitment to nuclear nonproliferation, Korea’s strong public support for nuclear armament will undoubtedly pose a significant obstacle to the adoption of enrichment and reprocessing capabilities. To obtain U.S. consent for such a policy shift, the Korean government must first undertake efforts to reshape domestic public opinion and reduce the prevailing preference for nuclear armament.

The Korean public’s aspiration for nuclear weapons is well established. Recent public opinion polls consistently indicate that more than 70 percent of Koreans support nuclear armament. However, is nuclear armament truly the optimal means of securing national security? This paper contends that domestic nuclear discourse tends to overstate the uncertain benefits of acquiring nuclear weapons while downplaying the substantial costs and risks involved. In particular, it significantly underestimates the influence of U.S. nonproliferation policy and the robustness of the international nonproliferation regime.

Proponents of nuclear armament argue that “only nuclear weapons can deter nuclear weapons,” and that “the U.S. nuclear umbrella is a torn umbrella that will fail to open when needed,” thereby making nuclear armament inevitable. This line of reasoning, however, fails to recognize the reality that Korea cannot simultaneously pursue independent nuclear weapons development and maintain the U.S.-ROK alliance. Moreover, the mistrust these advocates express toward the alliance and its extended nuclear deterrent is not substantiated by evidence. Over the past 70 years, the U.S.-ROK alliance and its nuclear umbrella have reliably safeguarded Korea’s peace and prosperity.

In contrast, the security benefits of South Korea’s nuclear armament remain highly uncertain. Rather than promoting stability, such a development could heighten the risk of (nuclear) conflict on the Korean Peninsula. The India–Pakistan case demonstrates that mutual nuclear deterrence has not prevented frequent armed clashes or reduced the likelihood of nuclear escalation. The more intense and volatile nature of inter-Korean relations makes it unlikely that stable deterrence would emerge, even if South Korea were to possess nuclear weapons.

Advocates of nuclear armament also argue that developing nuclear weapons would elevate Korea to the status of a great power and enhance its international standing. In reality, however, as demonstrated by the cases of North Korea and Iran, nuclear development results in severe sanctions and international isolation. Should Korea pursue nuclear weapons, it would not gain recognition as a nuclear-armed major power but rather risk forfeiting its current status as an advanced economy, a responsible middle power, and an exemplary member of the Nuclear Non-Proliferation Treaty (NPT), instead being regarded as a rogue state.

c. Formulating a Negotiation Strategy for Enrichment and Reprocessing and Laying the Domestic Groundwork for Negotiations with the U.S.

To establish a negotiation strategy for engaging the United States, Korea must begin by developing arguments to directly counter the justifications that the U.S. offers for opposing Korea’s enrichment and reprocessing efforts. These justifications are as follows. First, Korea voluntarily renounced the possession of enrichment and reprocessing facilities in the “Joint Declaration on the Denuclearization of the Korean Peninsula,” and this declaration remains in effect. Second, if the U.S. allows Korea to acquire enrichment and reprocessing capabilities, it will lose the grounds to oppose similar developments in other countries. Third, there are doubts about the objective necessity and economic viability of enrichment and reprocessing in Korea. Fourth, permitting Korea’s enrichment and reprocessing would undermine diplomacy aimed at the denuclearization of North Korea. Fifth, Korea’s credibility in nonproliferation is low due to its past nuclear weapons program and strong public support for nuclear armament. Moreover, the persistent desire for nuclear weapons driven by the inter-Korean standoff and the unstable security environment in Northeast Asia further reinforces this perception. Since the United States will likely continue to cite these justifications, Korea must be thoroughly prepared with counterarguments to respond.

Next, Korea must establish a diplomatic structure capable of effectively advancing its efforts to persuade and negotiate with the United States. For instance, in the case of the 1988 revision of the U.S.-Japan Nuclear Agreement, Japan is said to have spent nearly 30 years preparing for the negotiations at a national level. The Ministry of Foreign Affairs significantly strengthened and expanded its departments related to international security and nuclear affairs, with ample governmental support. Japan also pursued all-out diplomacy, with the Diet, industry, academia, and the public united in emphasizing the principles of nonproliferation and asserting the necessity of enrichment and reprocessing. Then–Prime Minister Yasuhiro Nakasone personally took charge of diplomacy with the United States, leveraging his close personal relationship with President Ronald Reagan. Korea, by contrast, finds itself in the position of the challenger, seeking to alter the current provisions of the U.S.–ROK agreement, while the United States seeks to maintain the status quo. As it is often said that an offensive effort requires three times the strength of the defense to succeed, Korea must also ensure thorough preparation and mobilize strong diplomatic capacity.

Strengthening its negotiating leverage with the United States requires the Korean government to elevate both its nuclear energy capabilities and its strategic value, thereby positioning itself as a mature and credible partner in nuclear cooperation. Korea has already accumulated substantial technical expertise and a strong nonproliferation record, qualifying it to be recognized by the United States as a responsible and trustworthy counterpart. In fact, what Korea seeks is not preferential treatment but fair treatment that reflects its international standing and nuclear capabilities. Since the early 2010s, Korea has emerged as a prominent middle power, having hosted the G20 Summit and the Nuclear Security Summit, and has joined the ranks of global rule-makers. Korea stands as a major nuclear energy country, both in terms of domestic utilization and reactor exports. Notably, Korea is the most trusted and strategically valuable U.S. ally in East Asia, playing a frontline role in advancing U.S. interests under the Indo-Pacific Strategy. By actively leveraging its advanced nuclear capabilities and strategic importance in its nuclear diplomacy with the United States, Korea may, for the first time, open a path toward securing enrichment and reprocessing rights.