Roughly 800 kilometres east of Cape Shiriya near the island of Honshu, radiation began leaking out of the Mutsu, Japan’s first nuclear-powered merchant ship, during her maiden voyage on September 1, 1974.
The failure of the nuclear reactor’s shielding while it was running at just 1.4 per cent of capacity was embarrassing enough — but the humiliation did not stop there.
Fearful that scallop beds in the bay could be contaminated, local fishermen refused to let the Mutsu return to port. Emergency repairs had to be made at sea, the reactor reportedly being patched up using a thick layer of sticky boiled rice. Only when the government handed over $4.6 million in what was termed “compensation”, did the fishermen relent.
Debate has raged for decades over the feasibility of using nuclear power in merchant ships. Despite many warships employing the technology, safety and security fears, combined with poor economics, have largely put the kibosh on commercial use.
Now a UK consortium is planning to breathe new life into nuclear-powered shipping.
FTSE 100 engineer Rolls-Royce, defence giant Babcock and shipping classification society Lloyd’s Register have joined forces with international law firm Stephenson Harwood, specialist marine insurer NorthStandard and consultancy Global Nuclear Security Partners.
The consortium’s aim? To have their first ship setting sail by the early 2030s. “We want to build a supply chain and ecosystem to enable Britain to be at the forefront of nuclear in maritime,” said Mark Tipping, a director at Lloyd’s Register.
“It’s all sitting under our noses,” added Mike Salthouse of NorthStandard. “We can be a shipping superpower again.”
Nuclear-powered commercial ships are not a new concept. The first vessel of its kind was launched in 1959. There are now nine active civil nuclear-powered ships in the world; all are Russian, eight are icebreakers and one is a cargo ship.
The reason for the renewed push is a desire to combat global warming and tackle the horrendous carbon footprint of oil-fuelled shipping.
Green power
Depending on who you ask, maritime trade is responsible for 2 to 3 per cent of the world’s carbon emissions, putting the sector on a par with aviation. Similarly to air travel, this proportion will only increase as actions are taken in other sectors to curb their carbon footprints.
New, greener technologies exist such as liquefied natural gas, biofuels and ammonia. Yet the first still emits some carbon dioxide. Wind is also an option; a study by the International Chamber of Shipping in 2023 found that 11 per cent of industry executives felt wind-assisted power — essentially, adding modern-day sails to fossil fuel-powered ships — was a viable energy source within the next decade, while 9 per cent supported the use of nuclear power.
Russia’s nuclear-powered icebreaker, 50 Years of Victory
ALAMY
Bringing in new fuels such as ammonia would require significant retraining of staff, however. And those in the nuclear lobby argue that if shipping companies have to do this, they may as well be trained to handle a nuclear-powered vessel that can, they say, operate with zero emissions.
Baroness Charlotte Vere, a former shipping minister now working for Core Power, an advanced nuclear energy technology company, is adamant that the shipping sector cannot achieve the International Maritime Organization (IMO)’s net-zero emissions target by 2050. “You can’t make progress on net zero emissions without us,” she said.
Baroness Charlotte Vere works for Core Power as vice-president of international relations
UK PARLIAMENT
The benefits extend beyond the environment, say advocates. “Instead of a ship refuelling once every two weeks or so, nuclear alternatives, depending on size and use, could last years, or even decades before needing to be refuelled,” explained Tipping. This shortens port turnaround times and allows vessels to travel up to a third faster.
But the question on many people’s lips will be whether the nuclear ships of the future could be turned into floating atom bombs. “No,” said Tipping. “It’s low enriched nuclear fuel, which is not weapons usable
Beyond this, scenarios such as the meltdown that beset the Mutsu will be a major worry to many.
But there is a crucial difference with the reactors the British consortium wants to stick in its ships. It wants to operate what are known as “Generation IV” reactors. Unlike previous iterations, which primarily used a metal casing to keep the nuclear fuel contained, newer technologies put protection inside the fuel itself.
Take Triso fuel, which comprises tiny particles of uranium the size of a grain of pepper or a poppy seed. The grains are encased in several layers of ceramic and carbon able to withstand temperatures as high as 1,600 degrees Celsius: far higher than a reactor would reach if it were to fail.
Modern reactors are also designed to protect themselves automatically. When something goes wrong, the reaction slows; the heat is then allowed to naturally bleed off, rather than having to be removed by pumping cold water, as is the case in older technologies.
A molten salt reactor (MSR) is an example of this. Here the fuel is not radioactive rods but molten salt containing the radioactive material. A drain sits at the bottom of the reactor, plugged by solid salt. If the reactor overheats or loses power, the liquid fuel melts the plug and, thanks to gravity, drains into a tank, where the nuclear reaction stops and the heat begins to dissipate.
Other technologies work in a similarly way to a lava lamp, experts explain. When a liquid is heated it becomes lighter and rises. As it cools, it becomes heavier and sinks. In these reactors, the fuel heats the coolant, so the coolant rises away from the core. It gives up that heat to the ship’s systems to make steam or electricity, cools down, then sinks back to pick up more heat. The result is a continuous loop that runs on heat alone, not on mechanical pumps.
Rules of the sea
In some ways there are greater hurdles to building nuclear ships than safety or security concerns. More prosaic considerations include establishing a global regulatory framework.
This week, members of the IMO will meet in London to begin drafting new rules and standards for how a nuclear-powered merchant fleet should function.
Hopes were raised last September when President Trump and Sir Keir Starmer signed the Atlantic Partnership for Advanced Nuclear Energy, which could pave the way for a nuclear shipping corridor.
Donald Trump and Sir Keir Starmer signed the Tech Prosperity Deal at Chequers last September
EPA/CHRIS J RATCLIFFE
Insurance expertise is also vital, which is why NorthStandard has been brought into the UK consortium, but also why the expertise of Lloyd’s of London insurance market can be leveraged.
Nuclear power could even be extended to cruise ships. Sir Richard Branson is not ruling out nuclear reactors on board Virgin Voyages vessels, for example.
A spokesman said: “Virgin Voyages is actively reviewing its energy mix and the full range of decarbonisation pathways across its fleet. The team recognises that transforming the shipping sector won’t come from a single breakthrough but from collaboration, learning and practical action.”
As with most things, cost will likely be the determining factor. The upfront price of an oil-powered ship is in the range of $150 million to $200 million. This can vary significantly depending on size. A nuclear-powered vessel could be 3.5 to 4.5 times this price.
But Tipping claims that when spread over the life of the vessel, nuclear power will be cheaper — although he is tight-lipped by how much.
Economics proved the undoing of the world’s first nuclear-powered merchant ship. The NS Savannah was a product of President Eisenhower’s “Atoms for Peace” programme that sought to demonstrate peaceful uses of nuclear energy. It launched in 1959 before being taken out of service in 1971 and is now moored up in the Port of Baltimore as a floating museum.
For some it is a symbol of what might have been. The British consortium will be hoping its plans do not end up in the history books as a missed opportunity.