US targets nuclear-powered cargo ships by 2028: Will it transform commercial shipping?

For decades, nuclear power at sea has been largely the preserve of aircraft carriers, submarines and icebreakers. Now, the US wants to take the technology into commercial shipping.

The latest move: the US Maritime Administration (MARAD) has signed an agreement with nuclear technology developer CORE POWER to explore how US-flagged cargo ships powered by small modular reactors (SMRs) could become a reality.

The agreement does not mean nuclear cargo ships are ready to enter service. Instead, it tackles the less visible but critical barriers that stand between a reactor design and a working commercial vessel — from regulation and port access to insurance, financing and crew training.

US pushes nuclear power into commercial shipping 

MARAD and CORE POWER (US) Inc. have signed a Memorandum of Cooperation to develop a pathway for nuclear-powered commercial vessels.

The framework will examine several issues that would need to be resolved before such ships could operate, including:

• Regulatory approvals and nuclear safety requirements 
• Port operations and access 
• Crew training and credentialing 
• Nuclear fuel supply 
• Reactor maintenance and lifecycle services 
• Insurance and liability 
• Financing of nuclear-powered vessels 

The agreement is the third initiative signed by the US Department of Transportation since Transportation Secretary Sean Duffy launched a maritime SMR initiative in May.

Earlier agreements with the ports of Long Beach and Corpus Christi established potential testing areas and frameworks for exploring nuclear-powered ships and shoreside nuclear applications.

Why does the US want nuclear cargo ships? 

The biggest attraction is endurance. Conventional cargo ships carry large quantities of fuel, consuming it continuously as they cross oceans.

A nuclear-powered vessel could instead use a compact reactor capable of generating enormous amounts of energy over an extended period. That could potentially free up space otherwise used for fuel storage, while reducing the need for refuelling stops.

Duffy has claimed nuclear-powered cargo ships could carry more cargo, travel up to 75% faster and operate for as long as 20 years without refuelling. He has also said the first nuclear-powered vessel could be built in 2028.

Those figures represent the administration's stated ambitions; actual performance would depend on the reactor and ship designs eventually selected.

What is an SMR? 

A small modular reactor is a compact nuclear reactor designed to generate electricity or heat at a smaller scale than conventional nuclear power plants.

For shipping, the attraction is its potentially compact footprint.

Instead of burning diesel or other marine fuels, the reactor would use nuclear fission to generate heat. That heat can produce steam, drive turbines and ultimately generate the power required to propel the vessel.

The fundamental advantage is energy density: a relatively small amount of nuclear fuel can produce vastly more energy than conventional marine fuels.

Nuclear-powered ships already exist 

The technology itself is not experimental. Nuclear reactors have powered military vessels for decades, allowing submarines and aircraft carriers to remain at sea for long periods without conventional refuelling.

Russia also operates nuclear-powered icebreakers, where long endurance is particularly useful in the Arctic.

The difficult part is bringing that technology into commercial shipping, where a vessel has to work within a complex global network of ports, insurers, regulators, shipowners and cargo operators.

Biggest hurdles are not just technological 

A nuclear cargo ship would need to satisfy nuclear safety rules as well as maritime regulations.

Ports would need procedures for receiving nuclear-powered vessels. Crews would require specialised training. Operators would need reliable arrangements for nuclear fuel, maintenance and eventual reactor decommissioning.

Insurance could be another major challenge because nuclear accidents involve potentially enormous liabilities.

Financing could also prove difficult. Nuclear vessels are likely to carry higher upfront costs than conventional ships, even if their operating economics eventually prove attractive.

And then there is public acceptance: bringing nuclear reactors into busy commercial ports could face resistance even if the technology meets safety standards.

Could nuclear shipping cut emissions? 

Nuclear propulsion could significantly reduce the direct carbon emissions associated with running ships because reactors do not burn fossil fuels during operation.

That makes the technology particularly interesting for long-distance shipping, one of the sectors where replacing fossil fuels remains difficult because of the enormous amount of energy required.

But nuclear power is not impact-free. The nuclear fuel cycle, reactor construction, radioactive waste management and eventual decommissioning all bring their own environmental and safety considerations.

The China factor

Washington is also looking beyond emissions and fuel costs. Duffy has openly framed the nuclear shipping push as part of the US effort to "DOMINATE China" in maritime competition.

China has become a major force in global commercial shipbuilding, while the US has struggled to maintain its position in the sector.

Faster, longer-range and potentially more fuel-efficient nuclear vessels could therefore form part of a broader US strategy to rebuild its commercial maritime and shipbuilding capabilities.