The International Association of Classification Societies (IACS) has issued a significant position paper, "Nuclear Propulsion (Revision 0)," formally recognizing nuclear propulsion as a viable option for decarbonizing maritime transport and enhancing operational efficiency. The paper signals IACS's commitment to supporting the safe, secure, and environmentally responsible integration of nuclear power into ship design and operations, leveraging its expertise to help develop the necessary robust regulatory frameworks and technical standards.
The Path to Nuclear-Powered Commercial Shipping
The maritime sector is under increasing pressure to drastically reduce greenhouse gas emissions, driving a search for low-carbon energy alternatives. Nuclear power is emerging as a strong candidate, especially with advancements in technologies like Small and Advanced Modular Reactors (SMR/AMRs) and Floating Nuclear Power Plants (FNPPs), which offer high-capacity, low-emission power options for marine applications and port electrification.
Growing Global Interest and Proven Track Record
Globally, interest in nuclear energy is surging, with 31 countries signing the Declaration to Triple Nuclear Energy by 2050 as of March 2025. Nuclear power has a service record in naval vessels dating back to the 1950s and is now being adapted for commercial shipping. Recent initiatives from international bodies like the IAEA (Atomic Technology Licensed for Applications at Sea—ATLAS project), EMSA, and statements from the IMO Secretary-General underscore this growing potential. IACS members have been actively involved, participating in IAEA symposia and industry associations focused on safety and regulatory development.
Defining the Challenge and IACS's Role
While recognizing the potential, IACS acknowledges that deploying nuclear propulsion in commercial shipping introduces significant challenges, including:
- Public and political perception of nuclear energy.
- Considerations for insurance, liability, and port access.
- Requirements for emergency preparedness and international coordination.
- Handling safe decommissioning and waste disposal.
IACS defines nuclear-powered ships as self-propelled vessels using an onboard nuclear fission reactor for propulsion and auxiliary power. The organization is committed to supporting multi-stakeholder cooperation to address these issues, aligning solutions with IAEA guidance, IMO instruments, and flag state regulations.
Key Actions by IACS
To support the transition, IACS has outlined specific actions:
- Technical Support for IMO: IACS will assist the International Maritime Organization (IMO) in revising SOLAS Chapter VIII and IMO Resolution A.491 (XII), which haven't been changed since 1981, to incorporate SMR/AMR nuclear technologies.T
- Regulatory Framework Collaboration: It will collaborate with the IAEA, IMO, and flag states to establish a comprehensive regulatory framework.
- Future Technical Resolutions: IACS will later consider developing its own Technical Resolutions to ensure consistent safety and design requirements for nuclear-powered ships.
- IACS has already begun this work, supporting the IAEA Consulting Group on FNPPs since 2023, participating in related symposia, and engaging in industry working groups on safety and insurance.
A Nuclear Future for Shipping
The IACS position paper provides clear recognition and momentum to the development of nuclear propulsion for commercial shipping. By committing its technical expertise and focusing on the crucial regulatory and safety frameworks, IACS is positioning itself as a key partner in integrating this powerful, low-emission technology into the global fleet. The successful deployment of this technology will ultimately depend on coordinated international efforts to address the technical, regulatory, and societal hurdles outlined in the paper.
