A 15,000-TEU container ship powered by a small modular reactor could operate at 39% lower cost than a conventional vessel, eliminating up to $68 million in annual operating expenses related to fuel and carbon penalty fees. That is the central finding of a report published by Lloyd’s Register and LucidCatalyst for Seaspan Corporation — a document that puts hard numbers behind what the maritime industry has been debating for years: nuclear propulsion is an economically viable option for the global merchant fleet.
The ecosystem of players moving in this direction has expanded rapidly throughout 2025. In September, ABB signed a memorandum of understanding with Swedish firm Blykalla to bring the lead-cooled SEALER reactor line into the maritime sector — building on a 2024 MoU focused on the Swedish energy market. The SEALER is a compact reactor featuring passive safety systems capable of maintaining stability without external intervention. In parallel, South Korean shipbuilder HD Korea Shipbuilding & Offshore Engineering received Approval in Principle from ABS for a 15,000-TEU SMR-powered container ship, which has also undergone a HAZMAT study by DNV. Italian classification society RINA has put forward proposals for applying SMRs to superyachts. Norway’s NuProShip project has selected three fourth-generation reactor technologies — Kairos Power’s molten salt reactor, Ultra Safe Nuclear Corporation’s gas-cooled reactor, and Blykalla’s SEALER — for its NuProShip II development phase.
On the regulatory front, progress has been equally tangible. In June 2025, the IMO‘s Maritime Safety Committee — MSC110 — launched a review of the rules governing nuclear-powered ships, tasking the Sub-Committee on Ship Design and Construction with building a regulatory framework aligned with the 2050 net-zero goals. The new code will go beyond direct-cycle PWR systems to encompass architectures such as fully electric ship designs. The Nuclear Energy Maritime Organization (NEMO) secured NGO status at the IMO by July 2025 — a remarkably swift recognition for a body founded just one year earlier — and was invited by the IAEA to participate in General Conference sessions under the ATLAS programme, which aims to develop regulatory structures for nuclear propulsion at sea. In the United States, the Maritime Administration (MARAD) issued a Request for Information to gather industry proposals on integrating SMRs into the American commercial fleet, in line with Trump administration executive orders on energy and maritime supremacy.
The deeper regulatory challenge remains unresolved: nuclear safety rules were built for fixed installations, while maritime regulations were designed for conventional ships. Neither framework contemplates a mobile nuclear plant transiting international waters and approaching commercial ports. A report published in November 2025 identified this structural gap as the priority to address before any nuclear merchant vessel can receive commercial authorization. The IACS — the International Association of Classification Societies — has committed to supporting the IMO in updating SOLAS Chapter VIII and Resolution A.491(XII), both unchanged since 1981. Meanwhile, Lloyd’s Register is working alongside Deployable Energy to develop safety cases and qualification pathways for micro-reactors intended for installation on commercial vessels, with pilot deployments expected in the near term.
According to DNV’s long-term forecasts, nuclear propulsion will not reach commercial scale until around 2045, with a potential share of up to 10% of the global maritime energy mix by 2060. Yet the pace at which agreements, feasibility studies, and regulatory updates are multiplying suggests that the window for the first concrete moves — single fleets, bilateral routes, favorable jurisdictions — could open considerably sooner. Those building the regulatory framework and supply chain today will hold an advantage that will be very difficult to close.
