For more than 50 years, Chapter VIII “Safety of Nuclear-Powered Merchant Ships” remained the single chapter of the International Convention for the Safety of Life at Sea (SOLAS) that had never been amended since its adoption in 1974. While every other chapter received multiple updates to reflect new technologies, risks, and operational realities, the nuclear ship regulations stayed frozen in time. The companion document, the 1981 Code of Safety for Nuclear Merchant Ships, also gathered dust as a purely recommendatory instrument.

That era of regulatory hibernation has officially ended.

Driven by the global push for maritime decarbonisation and the rapid advancement of next-generation nuclear technology, the International Maritime Organization (IMO) has placed the complete modernisation of Chapter VIII and its associated Code at the top of its agenda. Work on substantive amendments will begin in January 2026, with adoption targeted around 2030.

Why Now?

The sudden revival of interest is directly linked to the emergence of compact, fourth-generation reactor designs, particularly small modular reactors (SMRs) and molten-salt reactors (MSR) that promise:

1. Inherently safe passive cooling
2. Lower pressure operation
3. Smaller footprint suitable for merchant vessels
4. Ability to load-follow and integrate with hybrid propulsion
5. Potential for factory-built, sealed units that reduce on-site construction risks

Major classification societies, ship designers, and technology companies in Europe and North America are already running funded projects to adapt these reactors for marine use. Although no commercial nuclear merchant ship has been ordered yet, the pipeline of concept and approval-in-principle studies is growing fast.

What Will Change?

The upcoming revision will address decades of technological and regulatory gaps:

1. Alignment with current IAEA safety standards and post-Fukushima requirements
2. New risk-assessment methodologies (probabilistic instead of purely deterministic)
3. Updated requirements for emergency planning, radiation protection, and liability
4. Provisions for advanced reactor types (Generation IV, SMR, floating nuclear power plants when used as bunker stations)
5. Harmonisation with the 2024 edition of the SOLAS structure and modern goal-based standards

The future chapter is expected to move from highly prescriptive rules written for 1960-1970s pressurized water reactors to a more flexible, performance-based framework that can accommodate innovation while maintaining the highest safety levels.

What Seafarers Need to Know Right Now

Even though the amendments are still years away, officers studying for higher certificates should already be aware of the following:

1. The current Chapter VIII and the 1981 Code remain fully in force for any nuclear-powered ship
2. Familiarity with basic nuclear safety principles (ALARA, defence-in-depth, multiple barriers) is increasingly appearing in oral examinations
3. New training modules on advanced marine nuclear propulsion are being developed by maritime academies in cooperation with classification societies
4. Future STCW requirements may include specific nuclear-awareness endorsements for senior officers on nuclear vessels

Timeline at a Glance

1. January 2026: Sub-Committee on Ship Design and Construction (SDC) starts detailed work
2. 2027-2029: Correspondence group and intersessional meetings
3. 2030: Expected adoption at Maritime Safety Committee (MSC)
4. 2032-2034: Likely entry into force (standard SOLAS cycle)

The maritime industry is preparing for a world where zero-emission nuclear propulsion may become a realistic option for deep-sea shipping before the end of this decade.