UCL Study Finds Nuclear-Powered Container Ships Depend on IMO Net-Zero Framework for Cost Competitiveness

Summary

A study by University College London (UCL), published on 27 October 2026, finds that nuclear-powered container ships could become the most cost-effective propulsion option from 2040, provided reactor costs decline substantially and the International Maritime Organization’s (IMO) Net-Zero Framework (NZF) is implemented. Without the framework, nuclear-powered vessels would remain more expensive to operate than conventional ships, even at the lowest reactor cost assessed. The research also identifies insurance and regulatory challenges, with a mature insurance regime potentially taking 15 to 20 years to develop.

Article

Nuclear Propulsion Economics Depend on Reactor Costs and IMO Climate Policy

Nuclear propulsion could become a cost-competitive option for large container ships from 2040, but its commercial viability will depend on lower reactor costs and the implementation of international maritime climate measures, according to new research from University College London.

Published on 27 October 2026, the study compares nuclear-powered container ships with conventional fuel oil-powered vessels and ships using dual-fuel ammonia engines. Its findings indicate that nuclear propulsion would cost more to operate without the IMO’s proposed Net-Zero Framework, even under the most favourable reactor-cost assumptions examined.

The research assessed reactor costs ranging from $2,600 to $12,400 per kilowatt of electrical capacity (kWe). At the lower end of this range, nuclear propulsion could emerge as the least-cost option under the scenarios assessed. At the upper end, it was not economically competitive in any of the scenarios examined.

The findings highlight the importance of reactor development costs in determining whether nuclear propulsion can become a viable option for commercial shipping.

IMO Net-Zero Framework Could Improve Nuclear Propulsion Economics

The study identifies the IMO’s Net-Zero Framework (NZF) as a factor that could improve the economic case for nuclear-powered vessels.

Under the framework scenarios examined, nuclear-powered ships could potentially generate additional income by selling surplus compliance units to other vessels. This revenue opportunity could improve their relative economics compared with ships using conventional fuels or ammonia.

However, the advantage could diminish as the framework’s greenhouse gas fuel-intensity targets become more stringent. The commercial benefits would therefore depend on the framework’s final design, the applicable targets and the treatment of surplus units.

Without the NZF, the study finds that nuclear-powered ships would not achieve lower operating costs than conventional vessels, even when reactor costs are assumed to be at the lowest level assessed.

The findings suggest that nuclear propulsion’s economic prospects are linked not only to technology development but also to the international policy environment governing maritime emissions.

Insurance and Regulatory Barriers Remain

Beyond reactor costs and emissions policy, the study identifies insurance and regulatory arrangements as significant challenges for commercial nuclear shipping.

Developing a mature insurance regime for nuclear-powered commercial vessels could take 15 to 20 years, according to the research. This timeframe could affect investment decisions, project financing and the pace at which shipowners consider adopting nuclear propulsion.

The development of suitable regulatory frameworks and risk-management arrangements will also be important as the industry assesses the feasibility of deploying nuclear reactors on commercial ships.

These requirements add another layer of uncertainty to projects that already depend on substantial reductions in reactor costs.

UCL Researcher Calls for Strong International Climate Policy

Dr Tristan Smith, Professor of Energy and Transport in UCL’s Shipping and Oceans Research Group, said nuclear propulsion should not be treated as a reason to weaken maritime climate policy, arguing that the technology itself depends on such policy.

He said those supporting reactor development programmes should also support a stringent international greenhouse gas policy and a credible global framework.

His comments underline the study’s central finding that the economic case for nuclear-powered shipping is closely connected to the rules governing emissions and compliance in international maritime transport.

IMO Net-Zero Framework Faces Further Decisions at MEPC 85

The policy debate comes as the IMO prepares for the 85th session of its Marine Environment Protection Committee (MEPC 85), scheduled for 30 November to 3 December 2026. The session could provide another opportunity to reach agreement on the Net-Zero Framework, following the postponement of its adoption last year.

The United States has been a prominent opponent of adopting the framework while also supporting several projects exploring nuclear propulsion for shipping. This creates a policy contrast between interest in developing nuclear-powered vessels and opposition to the international emissions framework that the UCL study identifies as important to their economic competitiveness.

The outcome of MEPC 85 could therefore have implications for shipowners, reactor developers and investors evaluating nuclear propulsion as a potential pathway for maritime decarbonisation.

What the Findings Mean for Shipowners and Investors

The study identifies two major conditions for nuclear-powered container ships to become commercially competitive: a substantial reduction in reactor costs and an international emissions framework that improves their relative economics.

Even if reactor costs decline, insurance arrangements, regulatory requirements and the final design of the IMO framework will influence investment decisions. Shipowners and investors will need to assess these factors alongside the comparative economics of conventional fuels, ammonia and other low-emission propulsion options.

MEPC 85 is the next significant policy milestone, while the development of reactor technology and nuclear-specific insurance arrangements will remain longer-term considerations.

FAQs

Could nuclear-powered container ships become the cheapest propulsion option?

Yes. The UCL study finds that nuclear propulsion could become the least-cost option for large container ships from 2040 under favourable assumptions, particularly if reactor costs fall substantially and the IMO Net-Zero Framework is implemented.

What reactor costs did the study examine?

The research assessed reactor costs ranging from $2,600 to $12,400 per kWe. Nuclear propulsion could be the least-cost option at the lower end, but it was not competitive in any scenario assessed at the upper end.

Why is the IMO Net-Zero Framework important for nuclear shipping?

The framework could improve nuclear propulsion economics by allowing ships to earn income from selling surplus compliance units to other vessels. Without the framework, nuclear-powered ships would remain more expensive to operate than conventional vessels under the study’s assumptions.

How long could it take to establish nuclear ship insurance arrangements?

The study indicates that developing a mature insurance regime for nuclear-powered commercial shipping could take 15 to 20 years.

When will the IMO discuss the Net-Zero Framework again?

The IMO’s Marine Environment Protection Committee is scheduled to hold its 85th session from 30 November to 3 December 2026. The framework could be agreed at the meeting, although the outcome remains uncertain.

What are the main barriers to nuclear-powered commercial shipping?

The main challenges identified include reactor costs, insurance availability, regulatory requirements and the international emissions policy framework. Their combined effect will influence whether nuclear propulsion becomes commercially competitive with conventional fuel oil and dual-fuel ammonia.