Last week, South Korean President Lee Jae-myung described his proposed nuclear submarine and nuclear fuel-making projects as a, “50-50 joint venture,” with the United States. As I argue in the attached RealClearDefense op-ed, “Make South Korean Nuclear Fuel and Subs in America,” how that 50-50 split is made matters plenty.
President Trump has got it right. Insisting that the nuclear fuel-making and submarine construction be done on U.S. soil not only brings South Korean investment to America but keeps Seoul from exploiting the deal to acquire nuclear-weapons. South Korea tried to get nuclear arms covertly in the 1970s and toyed with it again in the ’80s. Korean political leaders have been recommending that the government to so again.
As I argue in the piece, America can support supplying Korea with nuclear fuel and nuclear attack submarines without helping it get the bomb but to do so it needs to insist that these efforts be made on American soil.
As always, I’m curious to get your take.
As Ever,
Henry S.
December 10, 2025
By: Henry Sokolski
Make South Korean Nuclear Fuel and Subs in America
Earlier last month, President Donald Trump visited South Korea and proposed a U.S.-ROK deal to make nuclear fuel and nuclear submarines for Seoul. South Korean President Lee Jae-myung described the deal as a “50-50 joint venture,” indicating that, although “it would be preferable if we [South Korea] could do it at home,” making nuclear fuel on South Korean soil wasn’t essential to his government. President Trump has been more insistent: He wants Seoul to invest in facilities in the United States to produce both nuclear fuel and submarines.
Trump is right. If the fuel-making and submarine construction is done properly, it not only will attract hundreds of billions in South Korean investment to the United States, but also prevent Seoul from developing a nuclear weapons option — something it seriously toyed with in the 1970s and 1980s and is still tempted to do.
Despite President Lee’s preference for enriching nuclear-weapons grade highly enriched uranium (HEU) on South Korean soil, a White House fact sheet on the deal suggests America’s preference is different. The sheet claims U.S.-based Centrus Energy Corporation, Korea Hydro and Nuclear Power, and South Korean POSCO International Corporation have all “agreed to support the expansion of Centrus’ uranium enrichment capacity in Piketon, Ohio.” If this is true, any uranium enrichment activity the deal called for would be conducted in the United States.
Seoul has also asked for Washington’s consent to recycle South Korea’s spent civilian reactor fuel. If this proposal is accepted, Seoul should foot the bill to recycle its spent fuel in U.S. facilities. In return, the U.S. government or U.S. private firms should purchase any of the plutonium-based fuels these plants generate to fuel American advanced reactors operating in the United States.
Why? First, recycled plutonium can be extracted to make nuclear weapons. If the proposed recycling is conducted in the United States, it won’t. Second, South Korean officials claim the reason they want to recycle plutonium is to manage the nuclear waste. Some question this claim. However, if the United States buys South Korea’s recycled plutonium byproducts and sends back the rest of the waste, South Korea’s waste management goal is addressed without unnecessary nuclear weapons proliferation risks. Finally, having Seoul pay for recycling its material in the States would spare America’s nuclear industry and our government the hassle of having to do so for America’s planned advanced reactor projects.
As for nuclear submarines, Seoul says it needs them to detect and neutralize enemy subs. However, nuclear submarines are hardly optimal for that purpose, especially when operating in the closed and shallow waters surrounding the Korean Peninsula. Instead, these boats are ideal for serving as stealthy platforms to launch nuclear-armed ballistic missiles, but that presumes Seoul is going nuclear. We shouldn’t.
Certainly, Seoul goes nuclear, Japan, Taiwan, Australia, and others will have to reconsider their nuclear options. President Trump is well-founded in his opposition to nuclear proliferation. Rather than helping Seoul go nuclear, the United States should take a different course.
In October, Trump said South Korea would invest $5 billion to build the proposed submarines at the Hanwha Philly Shipyard that South Korea owns in Philadelphia. Constructing the boats there could prevent their construction with vertical ballistic missile launchers necessary to launch nuclear ballistic missiles (something South Korea is planning to develop).
It could also assure the boats don’t run on nuclear weapons-grade HEU. French nuclear submarines run quite well on more affordable low and medium-enriched uranium. South Korean subs should too.
With all these proposed activities, the United States should maintain its usual controls over its nuclear fuel-making technologies as sensitive proprietary information. Any sensitive U.S. submarine-related know-how incorporated into South Korean submarines should remain subject to the usual levels of U.S. classification.
These measures may seem ambitious, yet the Trump administration has already taken the essential first steps. Now, the White House and Congress need to follow through to make sure the deal benefits not just South Korea, but the United States.
To read the full piece, click here.