THE attention being paid to nuclear for shipping is far out of proportion to what it can deliver.

The industry has had more buzz since the Great Hydrogen Crash of 2025, and the deflation of hopes around other alternative fuels.

Cheerleaders led by British start-up Core Power say next-generation small modular reactors are the only alternative to fossil fuels, since hydrogen-based options would require far too much electricity to make at the scale needed.

But nuclear for decarbonising shipping raises too many unanswered questions around cost, regulation, insurance, decommissioning and public acceptance to be a serious proposition.

Next-gen reactors are still a long way off

Proponents argue that regulation and public acceptance are the biggest barriers to SMRs for maritime, not the technology.

Yet while the AI-generated imagery of reactors on ships has got more impressive, the technology is still way off.

Norwegian University of Science and Technology professor Jan Emblemsvag looked at 80 Gen-IV reactor designs. He and fellow researchers narrowed the field down to three top-scorers, none of which has yet been commercially deployed.  

University of Greenwich emeritus professor Steve Thomas wrote in February: “It is likely to be around the late 2030s before there is any experience worldwide for any of the available SMR designs, and all experience with nuclear power suggests that until there is that experience, it would be extremely risky to order SMRs.”

Most advanced nuclear designs use high-assay, low-enriched uranium (HALEU) fuel to get more power per unit of volume. HALEU is only commercially available from Russia at present, though the US and UK are trying to work out how to create their own supply chains.

The fact the industry hasn’t yet settled on a reactor design to mass-produce makes it hard to answer fundamental questions, which in turn makes it hard to estimate future costs and liabilities.

How frequently would such reactors need refuelling? How much waste will they produce and how radioactive will that waste be? And where will we put it for the next 1,000 years?

And what’s more, who is going to pay for all this?

There’s no business case, and no road to one

The big problem with nuclear power throughout its history has been cost, not safety.

The industry has been beset by cost overruns and delays on land, and trumpets SMRs as the way to reverse this.

It argues that modular production in a shipyard would reduce costs to a point where their power output could compete with fossil fuels, so that the “nth-of-a-kind” reactor costs far less than the “first-of-a-kind”.

Fair enough. But that still leaves the question of who is going to pay for the first, and however many subsequent reactors, before the costs can become  low enough to be interesting.

Whoever is going to build this shipyard-based reactor production line will need a lot of orders locked in to justify building it. Since the regulatory burden with nuclear is so high, that leaves only governments as customers.

The nuclear option would only be available to shipowner-operators, since a traditional owner would be on the hook for the high capex and liabilities, while charterers take all the benefit in the form of lower fuel opex.

Such costs will also have to include providing for decommissioning the reactor and storing the waste, perhaps for thousands of years.

Given there are no working Gen-IV reactors to test, promises that they’ll be cheaper to run than conventional nuclear, let alone fuel oil, are hard to swallow.

Open registries would be off limits; the ship would have to fly the flag of its nuclear-equipped home country. That means the US, China, UK, France or Russia.

There were no Russian or Chinese attendees at the Norwegian University of Science and Technology’s nuclear propulsion conference earlier this month, apparently on security grounds.

So how likely is it that relations between the West, Russia and China will improve to the point that bilateral deals will be in place to allow mutual nuclear safety inspections? Would such countries even agree on technology transfer, given the technology’s potential military uses?

If the answer is no, then where are nuclear ships supposed to trade? The Strait of Hormuz is presumably off limits, so that’s the source of most tanker work ruled out. An ultra-large containership that can’t call in China is likewise going to struggle for gainful employment.

The US-Europe LNG trade has been mooted as a potential nuclear shipping corridor. But that trade has plenty of ships coming in, and a world happy to burn LNG won’t pay an atomic premium on that already expensive fuel unless forced.

Politics and regulation

So what will force it? Core Power’s 2026 nuclear conference was remarkably quiet on the topic of the IMO Net-Zero Framework, though chief executive Mikal Boe used part of his keynote speech to lambast net zero policies for burdening economies.

A green transition away from fossil fuels for international shipping requires a global, market-based IMO regulation. Shipping nearly got one in the NZF, but that decades-long effort was derailed last year by the US, several petrostates and a coalition of Greek shipowners led by Maria Angelicoussis.

The NZF, or some variant of it, may live on. But the way the IMO works means it is only as ambitious on climate as its least ambitious member, so its chances of passing a carbon tax high enough to make nuclear viable are slim.

If the nuclear lobby has a proposal for an alternative global regulation to the NZF that can successfully transition the industry, while compensating developing countries and overcoming the opposition of the global oil and gas industry, I would love to hear it.

The IMO and the International Atomic Energy Agency would have to decide which regulator bears ultimate responsibility for nuclear shipping. Countries that accept nuclear-powered port calls would need to verify each other’s nuclear approvals, and many countries don’t even have nuclear regulators.

There is also no international convention on liability for insuring nuclear shipping. That could take 15 to 20 years for IMO states to agree, and another decade to enter into force.

So who is the nuclear lobby really selling to?

Nuclear is an unproven technology, with no business case, limited public acceptance, a difficult path to regulatory clarity and no means of insurance for decades. So what is going on?

Clues can be found in the sales pitch. Conferences are big on talk of energy independence, naval power and local manufacturing might. They usually blame regulation, not economics, for nuclear power’s poor track record on land.

Former military men boast of the rigorous training, expertise and safety culture cultivated by navies like that of the US, as if that’s in any way relevant to the discussion on Gen-IV reactors for commercial ships.

Retired US Navy Admiral John Richardson told the Core Power conference last week that a nuclear-powered aircraft carrier could steam for more than 20 years without refuelling.

“That’s not just a ship, that’s a mobile piece of sovereign territory — acres of sovereign territory projecting influence and presence across every ocean of the Earth,” Richardson said.

Rousing stuff for a conservative audience of engineers, scientists and defence buffs. Also appealing is the idea that simply tweaking the regulation could restore the UK and US industrial rust belts, giving them a technological edge over China while making criticism from greens go away.

It also ignores the difficulty of IMO politics and accompanying need to involve developing countries. All that’s needed, they argue, is for the government to pay for it all.

The real customers for SMRs would more likely be warships and submarines, where costs don’t matter as long as the government foots the bill.