South Korea saw progress in its long-running quest to secure rights to enrich uranium and reprocess used nuclear fuel for peaceful purposes, after the US affirmed its support. The agreement was reached during the meeting between US President Donald Trump and South Korean President Lee Jae Myung at the APEC summit in Gyeongju in October. It approved South Korea’s quest to build nuclear submarines and opened the door for Korea to secure rights to develop enrichment and reprocessing capabilities.
A joint fact sheet, which outlined the agreements reached covering commitments on a range of key trade and security issues, includes a clause on enrichment and reprocessing. The factsheet reaffirms a $350m strategic trade and investment deal announced in July and outlines commitments on a range of trade and security issues, with South Korea saying it welcomes US support for its civil and naval nuclear power programmes.
“Consistent with the bilateral 123 agreement and subject to US legal requirements, the United States supports the process that will lead to the ROK’s [South Korea’s] civil uranium enrichment and spent fuel reprocessing for peaceful uses,” the document noted.
Under the 1974 123 agreement on peaceful nuclear energy cooperation, South Korea has very limited authority to reprocess used fuel or enrich uranium for civilian purposes, with such activities requiring US consent through bilateral consultations under the relevant treaties, laws and regulations governing both countries.
The agreement only allows South Korea to enrich uranium up to less than 20% based on US consent, with US concerns over nuclear proliferation cited as the primary reason. It was revised once in 2015 for a 20-year term, to accommodate Korea’s request for future rights to reprocess fuel and enrich uranium, but effectively barred Korea from producing its own civilian nuclear fuel. The procedure, which requires approval from a high-level bilateral commission and a formal written agreement, is so complex that South Korea has never been able to conduct enrichment in practice. Reprocessing is entirely prohibited under the pact.
Both capabilities are considered vital by South Korea, which relies heavily on nuclear power and seeks to strengthen its position as a global nuclear reactor exporter.
Reprocessing helps manage the country’s growing stockpile of spent nuclear fuel and enables the recycling of valuable uranium. The spent-fuel storage pools which cater for its 26 commercial reactors are expected to be full in 2030. Expertise in spent-fuel treatment and disposal would also give South Korea a significant advantage in exporting nuclear power plants.
Uranium enrichment rights would bolster energy security by stabilising the nuclear-fuel supply chain against geopolitical risks. South Korea currently depends entirely on imports for the low-enriched uranium used in its reactors. Enrichment rights are also essential for obtaining high-assay low-enriched uranium (HALEU) which is crucial for the commercial development and global competitiveness of small modular reactors.
Announcing the result of the summit, Lee said US support for Korean uranium enrichment and used fuel reprocessing was a “significant advancement”. He added: “The door is now wide open for a South Korea-US alliance renaissance, in which both nations can achieve a true win-win outcome.”
Korea’s foreign ministry described the agreement on enrichment and reprocessing as “a strategic upgrade” of bilateral nuclear energy cooperation. “We have publicly secured US backing for (uranium) enrichment and spent fuel reprocessing for the first time,” the ministry said.
“On the nuclear agreement issue, we have secured broad agreement (with the US) and set the direction,” National Security Advisor Wi Sung-lac said during a press briefing. “The direction is now set toward granting South Korea the authority to carry out enrichment and reprocessing, and follow-up consultations will proceed on that basis.”
However, South Korea faces a long and complex journey to advance these efforts, as implementing the agreement is likely to require a lengthy and challenging negotiating process. The US will need to decide whether to allow enrichment and reprocessing within the current 123 agreement framework, or to revise the agreement. “It will require extensive discussions,” Wi said following the joint fact sheet announcement. “How much adjustment is needed will depend on the results of these consultations.”
First Vice Foreign Minister Park Yoon-joo indicated that the government is considering a revision. “We are in talks with the US with a revision in mind,” he told lawmakers during a parliamentary session. South Korea and the US established a high-level bilateral commission under the 123 agreement and talks could start by reactivating this platform.
Korea will also need to dispel US nuclear proliferation concerns. It took more than two weeks after the Lee-Trump summit for the joint fact sheet to be released, apparently due to extended coordination among the relevant US government agencies. Wi said that the delay had much to do with the enrichment and reprocessing issues.
“The bulk of the final discussions had focused on uranium enrichment and reprocessing,” he told reporters at the briefing. “In any case, we believe the agreement will need some form of adjustment.”
South Korea formally relinquished possessing uranium enrichment and nuclear reprocessing facilities in January 1992 by signing the Joint Declaration of the Denuclearisation of the Korean Peninsula. However, South Korea had an active nuclear weapons programme in the 1970s, which included research into laser isotope separation. This was discontinued in 1975 under US pressure, when South Korea acceded to the Nuclear Non-Proliferation Treaty (NPT).
Despite the 1992 declaration and its NPT commitments, it was revealed in 2004 that South Korean scientists had secretly conducted small-scale, undeclared uranium enrichment experiments in 2000, as well as other undeclared nuclear activities in the 1980s. South Korean officials stated these experiments were for “speculative curiosity” and were not government-directed.
Undoubtedly, this history will have figured in the US internal discussions during the finalisation of the fact sheet, which delineated very close political and security relations with South Korea.
In the fact sheet, the South Korea and the US reaffirmed their commitment to “the complete denuclearisation of North Korea” with South Korea agreeing to increase defence spending to 3.5% of GDP for the modernisation of the Korea-US alliance, to purchase US weapons worth $25bn by 2030, and to provide comprehensive support worth $3bn over 10 years for US forces stationed in South Korea.
“The Korea-US alliance has developed into a true future-oriented strategic partnership that covers national security, the economy and high tech. The door has opened for a renaissance in our alliance that will be beneficial for both our countries,” President Lee said announcing the fact sheet. In the Q&A session that followed, Lee was asked why the fact sheet’s release was delayed.
“The US government’s general position had already been confirmed during the summits, but very different terms were proposed when the detailed document was being drafted,” he said. “We meticulously examined the specifics of the agreement and sharply debated every detail…. As many have guessed, I think the issues of uranium enrichment and nuclear reprocessing had to be mulled over inside the US government.”
AS National Security Adviser Wi noted, “Many discussions will be required moving forward.”
