How an AUKUS-Style Arrangement Could Help South Korea Produce Nuclear-Powered Submarines (The National Interest)

Last week, senior U.S. and South Korean officials met in Washington to hammer out how the United States might help build and fuel nuclear submarines for South Korea. The South Korean officials also urged the United States to give Seoul permission to enrich uranium and recycle plutonium to power South Korean civilian reactors.

As I explain in the attached piece from The National Interest, “How an AUKUS-Style Arrangement Could Help South Korea Produce Nuclear-Powered Submarines,” a critical problem these officials failed to mention publicly is the risk South Korea might get to the very brink of bomb-making once it made nuclear fuel on its soil. The timeline could be measured in weeks or months—not years.

The poster child for this problem is Iran. We are now fighting a war, in part, to get Iran to give up these nuclear activities.

This makes granting South Korea permission to do so awkward. Moreover, the economics of enriching uranium and reprocessing plutonium are negative in South Korea. Then there’s South Korea’s previous attempts to make nuclear fuels in violation of its Nuclear Nonproliferation Treaty pledge to keep its nuclear activities open to International Atomic Energy Agency (IAEA) inspections. Taken together, these considerations suggest that Washington should hold off on green-lighting civilian nuclear fuel production in South Korea.

As for helping South Korea fuel a future nuclear submarine fleet, the safest, quickest course would be to apply the model the United States has already established for helping Australia build nuclear boats: let Seoul build its submarines in South Korea, but fuel them with uranium enriched in the United States. What’s good enough for Sydney should be good enough for Seoul.

The South Koreans already have pledged to invest in a private U.S. firm that could do the enrichment—Centrus. President Trump’s preference is for South Korea to keep investing in Centrus and to have it supply South Korea with enriched uranium.

That would not only make economic, but security sense for both the United States and South Korea.

As always, I’m curious to get your thoughts on the attached.

As Ever,

Henry S.

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June 8, 2026

By: Henry Sokolski

How an AUKUS-Style Arrangement Could Help South Korea Produce Nuclear-Powered Submarines

Last week, South Korean envoys and US officials began hammering out how to build and fuel nuclear submarines for Seoul without bringing Seoul to the brink of bomb making. They haven’t yet sorted this out, but the AUKUS model could help avoid the worst by having Seoul build the submarines in South Korea and fuel them with uranium enriched in the United States.

President Donald Trump should tell Seoul to wait on making nuclear fuel for its civil reactors. Getting Iran and its neighbors to forswear these activities will be hard enough without egging South Korea on to lean into them

Seoul won’t like this. But letting it make its own nuclear fuel is neither necessary nor desirable.

South Korea’s Nuclear Submarine Ambitions Raise Old Questions

Last November, President Trump met with President Lee Jae-myung and announced a “50-50 joint venture” to build and fuel nuclear submarines. President Lee said it “would be preferable” if the submarines were fueled and built in South Korea. Trump’s take: Seoul should build its submarines in a shipyard that the South Korean corporation Hanwha just bought in Philadelphia and invest in a US enrichment firm, Centrus, to fuel the boats.

It’s unclear who will prevail. If Seoul gets its way, though, it could complicate the submarine project. South Korea insists that if it makes nuclear fuel on its soil, it will uphold the highest nonproliferation standards. History, however, is hardly supportive: Seoul attempted to make nuclear weapons covertly in the 1970s, toyed with secret enrichment and reprocessing activities in the 1980s, and in the early 2000s secretly tested laser enrichment processes. All of these pursuits violated South Korea’s International Atomic Energy Agency (IAEA) safeguard obligations under the Nuclear Nonproliferation Treaty (NPT).

South Korea, though, insists nuclear submarines are needed to counter North Korean nuclear ballistic missile boats. Perhaps. But there are far cheaper, quicker, and more effective ways to do this. The Nonproliferation Policy Education Center (NPEC) commissioned an analysis detailing these alternatives. The Naval War College Review showcased the study, and US and South Korean military analysts have since echoed the study’s recommendations—invest in advanced conventional submarines and unmanned anti-submarine warfare systems instead.

One military application for nuclear submarines, though, does make sense: using them as a stealthy platform for launching nuclear-armed missiles. Seoul knows this. That’s why its latest conventional submarine incorporates a High-performance Large Underwater Launch System—vertical launch tubes that can accommodate South Korea’s largest ballistic missile, the Hyunmoo-V. This missile can launch at least two tons—more than enough to deliver a nuclear warhead.

The AUKUS Model Offers a Better Path Forward for South Korea

So while the political decision to help South Korea make nuclear submarines is settled, the nuclear weapons proliferation dangers this might entail are not. Fortunately, there is a fix—the AUKUS model: defer to Seoul’s desire to build the submarines in South Korea and Trump’s wish for Seoul to pay to enrich the fuel in the United States.

This makes sense. South Korea will not only need nuclear fuel for its boats, but also US technology to fit them out. This, in turn, will require a separate Atomic Energy Act Section 91 agreement and technology transfers from the US Navy’s Team Submarine.

Washington should ask South Korea to invest in Centrus to make the fuel for its boats in exchange for the high technology bits they’ll need to outfit them. The United States has already established this precedent with Australia, under its AUKUS agreement. What’s good for Sydney should be good for Seoul.

As for Seoul’s desire to make nuclear fuel for its civil reactors, this would require a “subsequent agreement” to the existing US-South Korean civilian nuclear cooperative agreement, an executive understanding that would only have to sit before the US Congress for 15 legislative days to come into force.

Its adoption would be simple were it not for another nuclear headache—stopping Iran from making nuclear fuel and a separate nuclear cooperative agreement with Saudi Arabia geared to help it enrich uranium. Critics are already warning that it hardly makes sense to oppose nuclear fuel-making in Iran, only to green-light it for Saudi Arabia. By extension, what’s viewed as being bad for Tehran and Riyadh is unlikely to be seen as being good for Seoul.

As for the economics of recycling plutonium, they’re still quite negative, and investing in new enrichment capacity is rife with uncertainties. What’s smarter and more profitable, then, isn’t to push Seoul to go its own way on making nuclear fuel, but to increase US and South Korean nuclear interdependence.

This nuclear tough love won’t please the impulsive. But it assures nuclear nonproliferation, sound economics, and more security sense than green lighting of nuclear fuel making in Korea ever could.

To read the original piece, click here.