Navigating the Future: Nuclear Propulsion in Maritime Decarbonization

A Challenging Landscape for Maritime Decarbonization

2025 has presented significant challenges for the maritime industry as it pushes toward decarbonization. Despite increased engagement in low-carbon technologies, reports revealed that international shipping emissions have reverted to levels not seen since 2008. However, a flicker of optimism emerged with the introduction of FuelEU Maritime (FEUM) in January. This landmark legislation aims to promote the integration of low-carbon alternative fuels, marking one of the most comprehensive regional emissions regulations to date.

Following FEUM, the International Maritime Organization (IMO) unveiled its proposed Net Zero Framework, representing a critical step in consolidating fragmented regional emissions regulations. However, the framework’s delay, resulting from an extraordinary meeting by the Marine Environment Protection Committee (MEPC) in October, has left the industry grappling with regulatory uncertainty, alongside a complicated patchwork of regional regulations.

Commitment to the 2050 Net-Zero Target

Amid this turbulence, the maritime industry remains resolved to achieve the IMO’s 2050 net-zero goal. One of the most intriguing prospects is the potential for nuclear technology in maritime applications. A recent technical report by Bureau Veritas Marine & Offshore (BV) detailed how advancements in Generation IV nuclear reactors could usher in the deployment of Small Modular Reactors (SMRs) in the maritime sector. These reactors could begin operating in national near-shore projects by the mid-2030s, paving the way for broader global adoption by 2045.

The Power of Small Modular Reactors

The development of SMR technology, particularly Generation IV or Advanced Modular Reactors (AMRs), marks a pivotal moment for nuclear propulsion in marine environments. These reactors, characterized by their compact size (15 to 300 MWe), are designed for factory production and transportation to shipyards ready for integration. Types of AMRs include high-temperature gas reactors, molten-salt reactors, and liquid-metal reactors.

AMRs are not just small; they carry inherent safety advantages that enhance their commercial viability. Public skepticism surrounding nuclear technology often stems from fears of catastrophic incidents. Generation IV SMRs mitigate these concerns with passive safety designs that utilize natural processes to maintain reactor core integrity. They can reach a “walk-away-safe” condition during emergencies without external power, significantly improving their safety profile.

Additionally, these safety features could theoretically result in a smaller Emergency Planning Zone (EPZ) compared to conventional water-cooled reactors. Historically, strict definitions around EPZs have posed challenges to the integration of nuclear technologies on commercial vessels, particularly concerning public perception and operational constraints in busy ports.

The Need for Regulatory Realignment

Despite technological advancements, the fragmented regulatory landscape surrounding nuclear propulsion technology presents significant obstacles. While nuclear regulation often occurs at the national level, maritime regulation operates internationally. This divide has created a pressing need for cohesive regulatory frameworks that accommodate the civil applications of nuclear technology while addressing overlapping jurisdictional concerns.

Existing frameworks, such as the 1962 Brussels Conventions, which aimed to establish liability for nuclear-powered ships, never took effect due to a lack of ratifying nations. Similarly, the International Atomic Energy Agency (IAEA) guidelines on radioactive material transport fall short in defining regulations for fuelled nuclear reactors. The IMO’s 1981 Nuclear Ship Code is antiquated and does not reflect the innovations in nuclear propulsion technology.

Driving Forward with Collaboration

Recognizing the importance of resolving these regulatory inconsistencies, the IMO has tasked its Sub-Committee on Ship Design and Construction (SDC) to create a roadmap for updating the Nuclear Ship Code. This revision aims to be presented for vote at the next Maritime Safety Committee meeting.

To support the safe development of nuclear propulsion technologies, industry bodies are stepping up their engagement. BV plays a leading role in this effort, participating in the International Association of Classification Societies (IACS) working group on nuclear propulsion and contributing to initiatives under the IAEA. Recently, BV co-signed the Declaration for Accelerating Nuclear for Maritime Applications, an initiative launched during the World Nuclear Exhibition in Paris that aims to unify stakeholders across the nuclear, maritime, research, financial, and regulatory communities.

Navigating Complex Challenges

The pathway to integrating viable commercial applications of nuclear propulsion technology is multifaceted and complex. Nevertheless, emerging market signals from regulatory and industry bodies indicate a pivotal moment for this technology. With a renewed focus on aligning regulations and dispelling misconceptions surrounding nuclear propulsion, the maritime sector stands on the brink of harnessing nuclear technology’s net-zero potential—a development that could set a benchmark for other industries seeking sustainable energy solutions.

Jose Esteve Otegui is Offshore Gas & Power Market Leader, Bureau Veritas Marine & Offshore, and Federico Puente Expel is Maritime Nuclear Strategy Leader, Bureau Veritas Marine & Offshore.

The opinions expressed herein are the author’s and not necessarily those of The Maritime Executive.