U.S. Approval for South Korean Enrichment of Uranium Would Be a Serious Mistake

South Korea may soon have uranium enrichment technology. “We agreed to a 50-50 joint venture,” South Korean President Lee Jae-myung said, disclosing that when President Donald Trump visited South Korea in October, he proposed a joint plan to enrich uranium for nuclear reactor fuel. The planned commercial enrichment facility is to be built either on U.S. or South Korean soil, Lee said at a December 3 press conference. Washington also greenlit Seoul operating nuclear submarines.

Lee’s disclosure suggests a concerning American willingness to ease its long-standing policy against the proliferation of sensitive technology. Uranium enrichment and plutonium reprocessing are essential for producing both reactor fuel and nuclear weapons.

What South Korea Wants

The October agreement authorizes South Korea to acquire nuclear-powered attack submarines — which are typically fueled by highly enriched uranium (HEU) — and grants future U.S. permission for Seoul to conduct domestic enrichment and reprocessing. Lee indicated he seeks U.S.-supplied HEU to power the submarines.

At the press conference, Lee said he would prefer the planned enrichment facility be built in South Korea. However, a White House fact sheet issued on October 29 highlighted trilateral cooperation involving U.S.-based Centrus Energy Corporation, Korea Hydro Nuclear Power, and POSCO International, stating that the three companies “agreed to support the expansion of Centrus’s uranium enrichment capacity in Piketon, Ohio.” This suggests the joint facility may ultimately be located on U.S. soil. That does not preclude a future enrichment plant in South Korea, and the planned collaboration could give Seoul valuable access to enrichment technology.

Growing Nuclear Cooperation with the United States

Lee said he wants South Korea to produce its own enriched uranium fuel for the country’s 26 domestic nuclear reactors, cutting 30 percent of its dependence on Russian-supplied fuel. Domestically or jointly produced fuel could also supply Seoul’s growing portfolio of reactor exports.

Washington and Seoul have deepened their commercial nuclear partnership in recent months. In January, the two governments signed a new memorandum of understanding on joint nuclear reactor exports and cooperation. At the same time, they resolved a long-running legal dispute over U.S. Westinghouse intellectual property (IP) and royalties — IP that underpins South Korea’s pressurized water reactor designs.

The agreements clear the path for continued and expanded reactor projects by Westinghouse and Korea in the United Arab Emirates, Saudi Arabia, Ukraine, and the Czech Republic.

Deal Sets Potentially Dangerous Precedent

These developments mark a sharp reversal of decades-long U.S. nonproliferation policy that has blocked South Korean enrichment and reprocessing — restrictions rooted in the 1974 bilateral nuclear cooperation agreement and its 2015 successor, both of which require prior U.S. consent for such activities. Granting Seoul domestic enrichment and reprocessing capabilities, along with access to American enrichment technology, would effectively bring South Korea to the threshold of a nuclear weapons option. Within South Korea, a growing chorus of officials and analysts is openly urging the government to develop its own deterrent in response to North Korea’s arsenal.  

More broadly, the move risks setting a precedent that U.S. adversaries could exploit by offering similar sensitive technologies to their own allies. It is also likely to trigger demands for equal treatment from other U.S. partners, including Saudi Arabia, Turkey, the United Arab Emirates, Egypt, Vietnam, Poland, and beyond.

Congress and the media should press the Trump administration — and Energy Secretary Chris Wright in particular — to clarify why the United States is now prepared to ease its nonproliferation standards, and how it intends to contain the inevitable repercussions. A viable path forward would be for Washington to supply enriched uranium fuel to Seoul through joint investment in Centrus, while carefully withholding the underlying technology and know-how from South Korea.

Andrea Stricker is a research fellow and deputy director of the Nonproliferation Program at the Foundation for Defense of Democracies (FDD). For more analysis from the author and FDD, please subscribe HERE. Follow Andrea on X @StrickerNonpro. Follow FDD on X @FDD. FDD is a Washington, DC-based, nonpartisan research institute focused on national security and foreign policy.