Plans for nuclear-powered merchant ships face safety challenges
Nuclear energy emerges as a solution for maritime decarbonization but raises significant safety concerns.
1Maritime decarbonization targets
The shipping industry requires low-carbon fuel alternatives to achieve net-zero emissions by 2050. While batteries suit short distances, they're impractical for long voyages. Methanol faces sustainable production challenges, ammonia poses toxicity issues, and hydrogen presents storage difficulties at sea, leaving nuclear as a potential solution.
2Advantages of nuclear power
Nuclear reactors offer zero direct CO2 emissions and eliminate the need for massive onboard fuel storage, creating more cargo space. This technology reduces voyage times by removing refueling stops and enabling higher speeds. Ship owners could save tens of millions annually in fuel costs and carbon taxes, making nuclear an economically attractive option.
3Global developments and plans
The US Maritime Administration sought public input in May 2024 on modular nuclear reactor systems for marine use. London-based Core Power plans to open orders for mass-produced floating nuclear plants by 2028. China's state-owned Jiangnan Shipyard aims to build the world's first thorium-powered container ship by 2035, signaling growing industry interest.
4Market projections
A 2023 US report estimates several hundred nuclear-powered merchant vessels (mainly container ships, bulk carriers, and tankers) could operate globally by 2050, capturing 2-5% market share. However, these mobile nuclear facilities require exceptional safety measures, raising concerns about hijacking, grounding, or missile attacks in conflict zones.
5Regulatory efforts
The IAEA plans to launch its ATLAS initiative in August 2024, bringing together nuclear and maritime regulators. The IMO began revising its 1981 Nuclear Merchant Ship Safety Code in June 2025, with the updated version expected by 2030. These efforts aim to create comprehensive safety frameworks for this emerging technology.
6Historical context
Nuclear power has a long naval history, with the US Navy operating the world's largest nuclear fleet - 77 warships including 66 submarines. Since 1955, US nuclear vessels have logged over 300 million kilometers. However, commercial nuclear ships have seen limited success, with only four ever built, none achieving commercial viability.
7Commercial implementation challenges
Unlike military applications under sovereign control, commercial ships operate in a multinational system. Design, construction, flag registration, insurance, and maintenance often span multiple countries, while ships visit various foreign ports. This complexity creates significant nuclear safety challenges absent in controlled military environments.
8Past failures
The 1959 NS Savannah, part of Eisenhower's Atoms for Peace program, proved commercially unviable due to complex port entry permits. Germany's Otto Hahn operated for nine years before conversion to conventional power in 1982. Japan's Mutsu faced public opposition after a 1974 neutron leak during testing, keeping it docked for years despite no catastrophe.
9Safety concerns
Nuclear merchant ships face threats like hijacking, grounding, or missile attacks. A maritime nuclear accident could cause environmental disasters. Current fragmented international regulations and varying national standards complicate creating effective global safety frameworks. The industry must address these before large-scale adoption becomes feasible.
10Technological advancements
Small Modular Reactors (SMRs) offer safer, more flexible solutions than traditional nuclear plants. Their compact designs and passive safety systems better suit marine environments. Companies like Core Power propose floating nuclear plants to power commercial ships, potentially overcoming some historical limitations of nuclear maritime technology.
11Call for global coordination
Safe operation of nuclear merchant ships requires IAEA and IMO to integrate reactor licensing, ship certification, port entry, and emergency response into one framework. Without this, incompatible national systems could lead to maritime nuclear accidents. International cooperation will be crucial as the industry moves toward this potentially transformative but high-stakes technology.
Original article: Nature — Nükleer enerjili ticaret gemileri için planlar ve riskler