Lloyd’s Register has granted Approval in Principle for a hybrid nuclear-ready power concept developed by Australian ship design firm Seatransport Pty Ltd, the classification society announced on 26 February.

The design enables nuclear micro modular reactors (MMRs) to be combined with conventional diesel-electric systems for 73-metre and 90-metre amphibious stern landing vessel (SLV) designs. The approval follows several years of collaboration between the two organisations.

According to Lloyd’s Register, the concept demonstrates how licensable MMRs can be integrated with diesel-electric systems to deliver vessels with reduced fuel dependence and emissions. A recently launched 73-metre SLV was used as the trial platform, with sea trials of the conventionally powered vessel confirming the design assumptions used in the MMR concept.

Seatransport’s SLV platform has been in operation for more than 25 years. The hybrid nuclear-ready capability is intended to provide effectively unlimited operational range, reduced reliance on conventional fuels, and extended endurance for sustained missions. The design also aims to enable operation in demanding environments, including landing and logistic support on unprepared or remote beaches.

The MMRs under consideration range from 1.2 MW to 2.6 MW and are undergoing technical and regulatory assessment. Lloyd’s Register said it is working with national authorities to address safety, compliance and operational standards. 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 at 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 of Seatransport, commented: “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.”