5-MW swappable nuclear reactor for offshore vessels prepares for ship integration trials

Nuclear-powered offshore vessels have moved a step closer to reality. A Norwegian project has secured fresh state funding to build and test atomic engines for commercial ships. The Research Council of Norway has awarded $2 million to the Marine Nuclear Propulsion System (MarNuPS) project. The consortium plans to develop and deploy small, modular nuclear reactors designed specifically to replace fossil fuels in offshore shipping. The reactors are intended to deliver high power output and long operating range without frequent refueling stops. Engineers will not start by placing active nuclear materials straight onto the water. Instead, the team is building an integrated land-based testing facility at Stette, near Ålesund, with trials scheduled to begin in 2027. The Stette facility will run a full-scale replica of a ship’s power plant. To assess safety and performance without radiation risks, engineers will heat the system with electricity rather than atomic fuel. “Testing will cover normal operation, rapid changes in power demand, transient and stress conditions, system performance and crew interaction,” explained the company. Using the Gem microreactor The system will use the Gem Microreactor. It is a 5-megawatt unit developed by Emerald Nuclear. The design uses TRISO fuel pellets, which coat enriched uranium in layers of ceramic and carbon. “The MarNuPS Pilot will integrate Emerald Nuclear’s 5 MWe Gem Microreactor technology with energy storage, power conversion, vessel power management, automation and bridge control systems,” noted the firm. This structure withstands extreme heat without melting, preventing the radioactive releases associated with older reactor technologies. The reactor will convert heat into electricity through specialized power conversion systems supplied by Peregrine Turbine Technologies. Under the current plan, the reactor operates inside a sealed unit that is swapped out every five to 15 years, avoiding the need for complex refueling procedures inside ports. Commercial sea deployment Norwegian shipowner Island Offshore intends to be the first operator to take the system to sea. The company plans to install an operational Gem reactor aboard an offshore service vessel between 2031 and 2032, paving the way for commercial atomic shipping across the North Sea. “Nuclear energy has the potential to provide a new route to decarbonizing offshore vessels without compromising the power, endurance and operational flexibility these ships require,” said Tommy Walaunet, CEO of Island Offshore. “Our role is to ensure that the system is developed around real offshore operations and the people who will ultimately use it.” Leading the industrial consortium Emerald Nuclear Norway leads the industrial consortium alongside several prominent European maritime and engineering organizations. Shipbuilder VARD Group will manage vessel design and naval architecture, while Vard Electro handles power distribution and control networks. Academic partners are running the underlying simulations. The Norwegian University of Science and Technology (NTNU) is modeling reactor physics and thermal hydraulics, while Imperial College London examines structural integrity under dynamic sea conditions. Engineering firm Maskindynamikk will oversee condition monitoring and system diagnostics. Partners have committed substantial private capital alongside the state award. The initial development phase carries an estimated budget of $15.6 million.Get the latest in engineering, tech, space & science - delivered daily to your inbox.An active and versatile journalist and news editor. He has covered regular and breaking news for several leading publications and news media, including The Hindu, Economic Times, Tomorrow Makers, and many more. Aman holds expertise in politics, travel, and tech news, especially in AI, advanced algorithms, and blockchain, with a strong curiosity about all things that fall under science and tech.