IMO Begins Overhaul of Nuclear-Powered Ship Regulations　原子力推進船の国際規則、IMOが改正着手　

Formal rulemaking launched to support zero-emission ambitions as China and Russia advance; Maritime industries face regulatory and insurance hurdles

IMO Begins Overhaul of Nuclear-Powered Ship Regulations
Formal rulemaking launched to support zero-emission ambitions as China and Russia advance; Japan faces regulatory and insurance hurdles

原子力推進船の国際規則、IMOが改正着手

ゼロエミ対応で本格制度化　中国・ロシアが先行、海運業界に制度整備の課題

The International Maritime Organization (IMO) officially agreed on 26 June 2025, at the 110th session of its Maritime Safety Committee (MSC) held in London, to begin revising international safety regulations governing nuclear-powered ships. The revisions will target the “Code of Safety for Nuclear Merchant Ships (A.491),” adopted in 1981, and related provisions of the SOLAS Convention. The initiative marks the start of rulemaking aimed at incorporating next-generation technologies. As interest grows in nuclear energy as a zero-emission maritime fuel, China and Russia are already advancing technological development, while Japan and other Western nations are being urged to urgently establish regulatory frameworks and insurance mechanisms.

Speaking to Maritime Bridge Japan by 28 June, a senior executive from a major Japanese shipping firm noted, “Japan has historical and societal sensitivities surrounding nuclear power, but if China or Russia succeed in commercialising nuclear-powered merchant ships, Japan’s maritime sector will not be able to ignore it.” According to multiple sources, if Japan were to adopt nuclear propulsion, the focus would likely be on ultra-large container vessels of 16,000 TEU or more, as well as LNG carriers, with intended operation on long-distance routes that do not call at Japanese ports.

Photo courtesy, Core Power, IMO

Key Points of This Article
• What is the proposal submitted by UK-based Core Power to the IMO?
• What discussions have taken place among Japanese researchers on this issue?
• What kind of insurance framework is necessary to enable the commercial deployment of nuclear-powered vessels?

原子力推進船の国際規則、IMOが改正着手

ゼロエミ対応で本格制度化　中国・ロシアが先行、海運業界に制度整備の課題

　国際海事機関（IMO）は2025年6月26日、ロンドンで開催した海上安全委員会（MSC）第110回会合において、原子力推進船に関する国際安全規則の改正に正式に着手することを決定した。1981年に採択された「原子力商船の安全規程（A.491）」とSOLAS条約の関連条文を対象とし、次世代技術を反映した新たな制度づくりが始まる。海運のゼロエミッション燃料として原子力への関心が高まる中、中国やロシアが技術開発を進めている一方、日本を含む西側各国では制度基盤や保険の構築が急務となっている。

　６月２８日までにMaritime Bridge Japanの取材に応じた日本の海運大手幹部は、「日本は原子力に対して歴史的・社会的な敏感さを抱えているが、中国やロシアが国際海運市場で原子力推進の商業船を実現した場合、日本の海運業界も無視できないだろう」と語った。複数の関係者によると、日本が原子力推進船を導入する場合、1万6000TEUクラス以上の超大型コンテナ船やLNG船が対象になり、日本に寄港しない長距離航路での運用が想定される。

この記事のポイント

• IMOの採択で英コア・パワー社の提案とは何か。
• 日本の研究者たちの勉強会での議論とは何か。
• 原子力推進船を実現するために不可欠な船舶保険の制度とは。