UK-based Lloyd’s Register (LR) has announced Approval in Principle (AiP) for a hybrid nuclear ready power concept developed with Australian ship design group, Seatransport Pty Ltd. The AiP follows several years of close collaboration between LR and Seatransport.
The design envisages combining nuclear micro modular reactors (MMRs) with conventional diesel-electric systems for 73-metre and 90-metre amphibious stern landing vessel (SLV) designs to deliver long-range vessels with significantly reduced fuel dependence and emissions.
A recently launched 73m conventionally powered SLV was used as the trial platform, which confirmed the design assumptions used in the MMR concept, providing strong technical assurance that the design is both practical and robust.
Seatransport’s SLV platform is already well established, with more than 25 years of successful operations. By incorporating a hybrid nuclear-ready capability, the vessels gain effectively unlimited operational range, significantly reduced reliance on conventional fuels, and extended endurance for sustained missions. This approach also enhances operational flexibility, delivers low-emission performance, and enables reliable operation in demanding environments, such as landing and logistic support on unprepared or remote beaches.
The MMRs under consideration range from 1.2-2.6 MWe and are undergoing rigorous technical and regulatory assessment. LR is working closely with national authorities to ensure that safety, compliance and operational standards are fully addressed. Wider adoption is anticipated in the early 2030s.
“Achieving Approval in Principle for hybrid nuclear power is an exciting step for LR and the wider maritime industry,” said Jez Sims, Technical Authority for Nuclear, Lloyd’s Register. “We are proud to provide independent technical assurance, drawing on decades of expertise in regulatory compliance, vessel design and nuclear safety. Our role is to help the industry move forward with confidence, turning pioneering ideas into safe, practical solutions.”
Stuart Ballantyne, CEO Seatransport, said: “This AiP marks a pivotal moment for amphibious vessel design. By working closely with LR, we’ve integrated nuclear MMR capability into our proven SLV platform, future-proofing it for extended endurance, operational flexibility and low-emission performance. We do believe that for all shipowners, this is a paradigm shift in marine technology greater than sail to steam.”
In April 2025, Seatransport and Texas-based Deployable Energy announced a collaboration with LR to develop nuclear power generation for maritime applications focused on integrating advanced reactor technology into specialised vessels. The project utilises Deployable Energy’s Unity Nuclear Battery (UNB), a factory-built MMR designed to fit in a standard 20-foot shipping container. By using two to five MMRs, these vessels are projected to operate for 8-10 years without refuelling and are capable of feeding power back into shore grids to support local recovery efforts.
The UNB is 1 MWe gas-cooled MMR requiring minimal on-site construction and using existing industrial supply chains to avoid exotic materials. It utilises standard 5% Low Enriched Uranium (LEU) fuel with an actively cooled helium primary loop.
