South Korea Plans Nuclear Submarine by Mid-2030s

South Korea unveiled a roadmap on 26 May 2026 to launch its first domestically built nuclear submarine by the mid-2030s. The project is designated as the Jangbogo N Project and is linked to South Korea’s shipbuilding and reactor technologies.

Jangbogo N Project

The Jangbogo N Project is South Korea’s programme for a nuclear-powered submarine built within the country. The submarines are planned for active service in the late 2030s or later. The project was announced at the inaugural meeting of the Committee on Future Defense Strategy in Changwon, South Gyeongsang Province.

Technical Features of the Submarine Plan

The planned submarines will use low-enriched uranium, defined as uranium enriched to less than 20% uranium-235. The reactors are designed for extended operational cycles, which reduces the frequency of refuelling. South Korea plans to develop the submarines with domestic reactor technology and domestic shipbuilding capability.

Strategic and Diplomatic Context

The stated purpose of the nuclear-powered submarines is to counter North Korea’s submarine-based nuclear and missile threats. South Korea has said that it will uphold nuclear non-proliferation obligations and will work with the United States on fuel sourcing. South Korea also plans cooperation with the International Atomic Energy Agency on safeguards-related matters.

United States Approval and Industrial Impact

The United States approved South Korea’s construction of nuclear-powered submarines in a Joint Fact Sheet issued on 13 November 2026. The approval followed a summit on 29 October between President Lee Jae Myung and then-US President Donald Trump. Shares of Hanwha Ocean and HD Hyundai Heavy Industries rose after the announcement on 26 May 2026.

Important Facts for Exams

• Nuclear-powered submarines use a nuclear reactor for propulsion and can remain submerged for longer periods than conventional diesel-electric submarines.
• Low-enriched uranium contains less than 20% uranium-235 and is used in many civilian nuclear applications.
• The International Atomic Energy Agency is the United Nations body responsible for nuclear safeguards and verification.
• South Korea is one of the world’s major shipbuilding countries, with firms such as Hanwha Ocean and HD Hyundai Heavy Industries.