Korea's nuclear submarine project faces hurdles despite key approval
The Republic of Korea Navy's Seo Hui submarine, the second vessel of the Jangbogo-III Batch-II program, is unveiled during a launching ceremony at Hanwha Ocean's Okpo shipyard in Geoje, South Gyeongsang Province, Tuesday. Yonhap
Reactor fuel deal with Washington remains uncertain amid congressional scrutiny
South Korea’s plan to build nuclear-powered submarines has cleared a key domestic hurdle, but securing reactor fuel from the United States remains unresolved, with legal requirements and closer congressional scrutiny threatening to complicate the project.
The Defense Acquisition Program Administration (DAPA) approved the basic acquisition strategy for the Jangbogo N program Friday, setting a 2027 start date targeting deployment of the first submarine in the late 2030s. The decision establishes how the project will proceed, not how Seoul will obtain the nuclear fuel it needs.
A defense acquisition official said Seoul believes it can secure submarine fuel without needing to revise its existing nuclear cooperation agreement with Washington. Instead, the government is pursuing a separate arrangement under Section 91 of the U.S. Atomic Energy Act, which provides for military nuclear cooperation.
The official cited the AUKUS partnership, under which the U.S. and Britain are helping Australia acquire nuclear-powered submarines, as a precedent for a separate agreement.
But negotiations have yet to produce a deal. The two countries have held one vice ministerial consultation involving the foreign ministry, according to the official, who declined to disclose further details of the ongoing talks.
Seoul has yet to secure the fuel and cooperation needed to keep the project on schedule.
Leif Eric Easley, a professor at Ewha Womans University, said U.S. President Donald Trump’s backing for South Korean nuclear submarines did not eliminate obstacles to implementation.
“Trump’s support for South Korean nuclear-powered submarines, civilian uranium enrichment and spent-fuel reprocessing is significant, but implementation involves complicated technical, legal and nonproliferation requirements that will face congressional scrutiny,” Easley said.
Those three areas involve distinct arrangements, and the precise congressional procedures for submarine fuel cooperation will depend on the agreement Washington and Seoul pursue.
The political climate in Washington could add another complication after Democrats won control of both chambers of Congress in last week’s midterm elections.
“There are many nonproliferation advocates among Democrats, so additional constraints could emerge for the nuclear-powered submarine project and efforts to revise the nuclear cooperation agreement,” said Shin Beom-chul, a Sejong Institute researcher and former vice defense minister.
That does not mean the Democrats have adopted a position against South Korea’s proposed nuclear submarines. Asked about the possible impact of congressional scrutiny, a defense official pointed instead to longstanding bipartisan support for the alliance.
Yu Ji-hoon, a research fellow at the Korea Institute for Defense Analyses, said the Democratic-controlled Congress could subject nuclear fuel cooperation and related legal arrangements to closer scrutiny, given the party’s traditionally cautious approach to nuclear technology transfers.
He said Seoul should make the case that its nuclear submarines would help counter North Korea’s growing maritime nuclear threats while strengthening combined allied defenses and security in the Indo-Pacific.
“South Korea needs to strengthen its engagement with lawmakers from both parties while maintaining policy cooperation with the Trump administration,” Yu said. He also called for closer shipbuilding and defense industry cooperation with Washington.
Frederick Fleitz, a former chief of staff of the U.S. National Security Council, raised a separate concern Wednesday, before DAPA’s decision.
Commitments made by Trump and President Lee Jae Myung on nuclear submarines and other issues “seemed to have stalled,” he said, urging Lee to press for progress in future talks with Trump.
Even if the fuel question is resolved, the domestic timetable presents challenges. A defense acquisition official said designing and building a nuclear submarine would likely take longer than a conventional vessel. South Korea aims to launch its first boat in the mid-2030s, followed by testing before deployment later that decade.
The price tag also remains unsettled. A detailed cost review is underway, with the total price expected to be discussed with budget authorities early next year. The newly approved strategy does not cover procurement of follow-on submarines, which will require separate decisions.