Sailors board the ROKS Dosan Ahn Chang-ho, a 3,000-ton South Korean naval submarine, at a naval port in Changwon, South Gyeongsang Province, South Korea, 25 March 2026. The submarine is departing across the Pacific for the first time to take part in joint drills with Canada in June aimed at bolstering maritime security and defense industry cooperation. Photo by YONHAP / EPA
May 24 (Asia Today) — South Korea is preparing to publicly unveil a development roadmap for a nuclear-powered attack submarine program after the successful Pacific deployment of the domestically built Dosan Ahn Chang-ho submarine, according to military and defense officials.
The move signals Seoul’s effort to strengthen what officials describe as the strongest conventional strategic deterrence available to a non-nuclear weapons state in response to North Korea’s advancing nuclear and missile capabilities and growing maritime competition in the region.
Senior military officials said the Ministry of National Defense and the Defense Acquisition Program Administration have completed technical reviews for a South Korean nuclear-powered submarine program and are now coordinating with related ministries, including the Foreign Ministry, on a diplomatic and regulatory strategy.
The report follows the recent Pacific deployment of the 3,000-ton Dosan Ahn Chang-ho submarine, which sailed about 14,000 kilometers, or 8,700 miles, from Jinhae through Guam and Hawaii using only domestically developed lead-acid batteries, diesel engines and an air-independent propulsion system.
South Korean officials said the deployment significantly reduced the need for snorkeling operations, in which submarines surface or raise air intake masts to recharge batteries, and demonstrated the vessel’s long-duration underwater operational capability and hull durability.
Officials also said the submarine successfully demonstrated stable operation of its submarine-launched ballistic missile vertical launch system in rough Pacific conditions. The Dosan Ahn Chang-ho class is the world’s first diesel-electric submarine class equipped with vertical launch tubes for submarine-launched ballistic missiles.
Defense experts said the mission simultaneously highlighted the operational limitations of conventional diesel submarines and the strategic advantages of nuclear propulsion.
While diesel-electric submarines must operate at relatively slow underwater speeds to maintain endurance, nuclear-powered submarines can remain submerged for much longer periods and travel underwater at speeds exceeding 40 kilometers per hour, allowing broader operational flexibility, officials said.
The foreign affairs and security publication The Diplomat reported Thursday that South Korea’s pursuit of a nuclear-powered submarine would become “a major test case of non-nuclear deterrence” for a country that does not possess nuclear weapons.
Chung Sung-chang, head of the Korea Nuclear Strategy Forum and a senior researcher at the Sejong Institute, said the submarine under discussion would be a non-nuclear attack submarine that would not carry nuclear weapons.
Chung said South Korea plans to retain the hull design and submarine-launched ballistic missile strike capability proven through the Dosan Ahn Chang-ho program while replacing the diesel propulsion system with a small nuclear reactor.
He said South Korea should first publicly present its nuclear submarine development roadmap before negotiating a bilateral nuclear submarine cooperation agreement with the United States and securing approval from the U.S. Congress.
Chung also said Seoul would need a separate agreement with Washington to secure low-enriched uranium fuel for naval reactors derived from downgraded highly enriched uranium.
Officials are reportedly studying the AUKUS security partnership among the United States, Britain and Australia, under which Australia received access to nuclear-powered submarine technology while remaining within the international nonproliferation framework.
South Korean officials said the success of the Dosan Ahn Chang-ho deployment demonstrated that the country’s technical preparations for a future nuclear-powered submarine program had reached a mature stage, shifting the focus toward diplomatic negotiations and international coordination.
— Reported by Asia Today; translated by UPI
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Original Korean report: https://www.asiatoday.co.kr/kn/view.php?key=20260524010006872