Despite the successful application of nuclear power for US military vessels since the 1950s, its adoption for civilian maritime purposes has never moved beyond a few experimental designs. This is largely due to concerns about safety and high initial capital costs. Recently however, innovations in nuclear technology, combined with an industry-wide push to declutter the civilian maritime space, offer a chance to revitalize the concept at commercially viable rates.
The US Navy’s plethora of nuclear-powered warships have proven the safety of these reactors, which have operated without significant reactor-related incidents. By somewhat ironically, the US has been home to only a single nuclear-powered merchant ship–the N.S. Savannah. Meant to prove the nuclear concept, the Savannah ran smoothly from 1959 to 1972, but eventually stopped due to its limited cargo and passenger capacity.
Despite these early ups and downs, nuclear propulsion offers key benefits over traditional fuel sources. A nuclear-powered vessel can run for years without stopping for refueling and is less dependent on volatile fuel price changes. The energy density of nuclear fuel also eliminates the need to store millions of gallons of fuel oil, saving valuable space that can be purposed for cargo instead.
Nuclear-powered ships don’t risk fuel tank rupture and the resultant environmental damage in case of a maritime accident. In fact, a July 2023 study by the American Bureau of Shipping confirmed that by using nuclear reactors in certain configurations, cargo capacity and operational speed could be enhanced.
Beyond these practical benefits, nuclear power is also much cleaner than the conventional bunker oil fuel, contributing no carbon dioxide or particulate matter emissions.
Recent advancements in reactor technology could potentially accelerate the adoption of nuclear-powered vessels. Technological developments such as micro- and small-modular reactors (SMRs) offer a standardized design and thus the economy of scale, making SMRs cost-effective. Although these designs were intended for onshore power generation, they prove useful onboard commercial vessels.
Future advancements into advanced reactor designs cooled by molten salts or liquid metal may provide a reactor type better suited for maritime transportation. Due to their operation at ambient pressure and the fact that they solidify if the reactor stops, these reactor types pose little risk of environmental contamination.
The development of the next generation of advanced nuclear reactors is already underway, and these reactors can be comfortably adapted for civilian maritime use. This harbors the promise of a safe, reliable, clean, and cost-effective energy source.
This opinion piece was authored by Patrick R Pennella, an associate at Morgan, Lewis & Bockius, Alex Polonsky, a partner at the same firm and member of the Civil Nuclear Trade Advisory Committee, and Jane Accomando, also a partner at Morgan, Lewis & Bockius and co-leader of the firm’s global energy industry team.