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            IMO-IAEA framework, with an essential   Not all ships are suitable for nuclear power. Large
            role played by the IAEA Safety Standards,     ocean-going containerships, tankers, bulk, and
            to solve issues of proliferation and   gas carriers are potential candidates due to the
            licensing. Second, significant forward   increased demand for bunkers, emissions reduction,
            investments, which necessitate subsi-  and bunkering operations requirements.
            dies and state commitment, as well as
            multi-layered insurance coverage with
            extensive safety and environmental lia-
            bility for radiation, will be required.
            From a technical point of view, more
            compact and lighter units and a fuel
            cycle compatible with maritime trade
            will be needed, which will have implica-
            tions for operating costs and the long life
            of reactor components (reflectors, heat
            exchangers, attached pumps) – especially
            those with very high design temperature.
            Additional requirements include a core
            material with consistent and verified
            thermophysical properties, and a pres-
            sure design that takes into account crit-
            ical emergency zones in meters rather
            than kilometres, ensuring the availability
            of suitable nuclear assessment tools
            for the proposed core designs.

            What are the key technical challenges
                in integrating nuclear power into
                commercial vessels?           of license holders, such as the US Nuclear
            No significant technical challenges are   Regulatory Commission (NRC), world-
            foreseen; however, the hull and cargo   wide that are familiar with nuclear ships’
            area design needs to take into account   port calls. This requires bilateral agree-
            the peculiarity of the nuclear reactor and   ments to be in place between recognised
            the ancillary systems as, due to the radi-  national licensing organisations. A world-
            ation shielding of the core, the reactor   wide common regulatory framework
            becomes heavier, and, therefore requires   developed within the framework of the
            structural reinforcement and careful   IMO and the IAEA will definitely expe-
            study of trim and stability, as well as the   dite nuclear ships allowed to call ports
            dynamic effect of the ship’s motion on   and cross the Suez and Panama canals.
            the operation and fixing arrangements.   There have been nuclear-powered naval
            Moreover, core accessibility, depending   and pilot ships (e.g., the NS “Savannah”
            on individual core design, is vital in order   and the  “Otto  Hahn”) that  regularly
            to minimise clashing in case of refuel-  received permission to visit civilian ports;
            ling or even removal of the unit. Finally,   however, the frequency and operation
            a minor technical inconvenience may   of these ships maintained a low social
            be the return of gas turbines in shipping   provocation level.
            following their gradual replacement by   Free trading may need to be a more
            internal combustion engines and the sub-  A-to-B sailing based on long-term con-
            sequent shortage of experienced crews.  tracts between specialised ports certi-
                                              fied for radiation exposure events.
            To what extent are flag states and port
                authorities prepared to handle   How does nuclear propulsion affect ship
                nuclear-powered ships?            design, maintenance, and crew
            In general, port authorities and flag   training requirements?
            states are poorly prepared to handle   Retrofitting a nuclear reactor will be
            nuclear-powered ships.            more difficult since hull design may
            There are, however, national regulators    require restructuring.

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