Regulatory Challenges in the Transition to Small Modular Reactor Powered Merchant Vessels

The integration of Small Modular Reactors (SMRs), particularly Molten Salt Reactors (MSRs) and High-Temperature Gas Reactors (HTGRs), into maritime propulsion systems represents a significant step toward decarbonizing the commercial shipping sector. These reactors, part of the third-generation nuclear technology, are compact, safer, and operate at lower pressures compared to conventional Pressurized Water Reactors (PWRs) and Boiling Water Reactors (BWRs), which are used in military vessels. Despite their advantages, SMRs are still in the development phase, with limited deployment in Russia and China. One major obstacle to their wider adoption is the regulatory framework, which remains underdeveloped for nuclear-powered commercial ships. Leading maritime classification societies, such as the American Bureau of Shipping (ABS) and the Russian Maritime Register of Shipping, are beginning to draft rules for nuclear propulsion, but the lack of established global standards complicates the transition. Although investments in regulatory research are growing, the implementation of these technologies faces significant hurdles, both in terms of safety concerns and logistical challenges. This work will explore these regulatory barriers and discuss how international collaboration and standardization will be crucial in overcoming the challenges to the broader adoption of nuclear energy in merchant vessels. The gradual progress in this area shows that nuclear propulsion is not a distant vision but a near-future reality for the maritime industry, provided that key regulatory frameworks can be developed and implemented.