South Korea’s Ministry of National Defense (MoND) announced a formal plan to develop and domestically build nuclear-powered submarines on May 26, with Defense Minister Ahn Gyu-back targeting a first vessel launch in the mid-2030s and operational deployment by the late 2030s.
The program, designated the Jangbogo-N Project after the Republic of Korea Navy’s (ROKN) first submarine, the ROKS Jangbogo, will use low-enriched uranium (LEU) fuel sourced from the United States under the 2015 Atomic Energy Peaceful Uses Agreement. President Donald Trump approved U.S. fuel support for the program in October 2025.
📌「대한민국 핵추진잠수함 개발 기본계획」 발표
국방부는 5월 26일(화)에 「대한민국 핵추진잠수함 개발 기본계획」을 발표했습니다.
「대한민국 핵추진잠수함 개발 기본계획」은 대한민국이 핵추진잠수함을 체계적으로 개발하기 위한 추진 방향을 국내·외에 최초로 제시하는 문서로서 주요 내용은… pic.twitter.com/jkVjS3soQt
— 국방부 (@ROK_MND) May 26, 2026
The announcement arrives with safeguard negotiations unsettled. International Atomic Energy Agency (IAEA) Director-General Rafael Grossi, during a Seoul visit in April 2026, stated the program requires “ironclad guarantees” against diversion and confirmed formal talks with South Korea were already underway. Seoul’s plan commits to a joint IAEA safeguard framework, but terms remain unresolved.
Seoul’s stated rationale centers on neutralizing North Korea’s submarine-launched ballistic missile (SLBM) capability. The 31-page MoND document envisions nuclear attack boats shadowing Korean People’s Navy submarines from port and neutralizing subsurface nuclear launch capability before weapons leave the water. The boats will also carry precision strike missiles supporting Seoul’s Korea Massive Punishment and Retaliation (KMPR) doctrine.
President Lee Jae-myung convened the inaugural Future Defense Strategy Committee at Jinhae to mark the announcement, calling the program “a symbol of our will to take responsibility for peace and security on the Korean Peninsula.”
The MoND expects the project to create more than 40,000 jobs spanning South Korea’s shipbuilding, nuclear, and defense sectors. Shares in Hanwha Ocean and HD Hyundai Heavy Industries closed up 10.2% and 9.6% on the announcement.
The announcement follows the ROKN’s first Pacific deployment of the KSS-III Dosan Ahn Chang-ho, South Korea’s most advanced conventional submarine, which arrived in Canada late this month following a historic two-month trans-Pacific transit.
