Royal Navy considers nuclear-powered surface warships

Defence industry asked to explore technology which could enable ships to stay at sea for years

The Royal Navy is considering nuclear-powered surface ships that could stay at sea for years.
As part of what is understood to be a “long-term” plan, the Navy has asked the defence industry to explore nuclear power on its surface ships.
In the UK, nuclear propulsion is only used on submarines, however the Ministry of Defence (MoD) has issued a Request for Information (RFI) for updates on the use of Generation IV, an advanced nuclear technology.
The request will look at how Generation IV nuclear technologies, including larger nuclear reactors and micro-modular reactors, could power surface fleets.
The US has a number of nuclear-powered aircraft carriers, including Nimitz and Gerald R. Ford-class ships. France’s Charles de Gaulle carrier is also nuclear-powered.
At a cost of $13 billion (£10 billion), the nuclear-powered USS Gerald R. Ford was commissioned in 2017 and is the US navy’s newest and costliest warship.
The Royal Navy’s two aircraft carriers, HMS Queen Elizabeth and HMS Prince of Wales, cost £3 billion each. Commissioned in 2017, they are powered by gas and diesel engines. 
Both ships have been hit by malfunctions since they launched. HMS Queen Elizabeth was forced to pull out of the largest Nato exercise since the Cold War in February due to an issue with a propeller shaft.
In 2022, HMS Prince of Wales was forced to pull out of exercises with the US Navy after breaking down off the Isle of Wight due to a similar malfunction.
Tom Sharpe, a former Navy commander, described the RFI as “prudent planning” by the MoD, although cautioned the costs behind such a development.
“It isn’t about building a fleet of nuclear-powered cruisers any time soon,” he said. “That there is someone in a corner of the Naval Headquarters looking this far ahead, and not getting consumed by the day-to-day running of the fleet, is good news.”
He added: “Nuclear power in ships is all about cost vs operational gains. 
“In submarines, the gains are massive, which is why many are powered that way. In surface ships the operational gain is much less and so cost comes in earlier.”
The Government’s “Net Zero Strategy”, published in 2021, reinforced the importance of nuclear in the UK’s energy as it transitions to net zero by 2050.
The MoD’s request is an information-gathering exercise conducted in line with the Defence and Security Industrial Strategy (DSIS), according to the UK Defence Journal.
The RFI, which has a deadline of Oct 9 this year, adds: “The primary objective is to gather detailed information on GEN-4 nuclear-reactor designs, their feasibility for large surface ships (including support vessels and surface combatants), and the potential benefits and challenges associated with their use.”
Mr Sharpe added: “There is a gross tonnage above which this ratio changes in favour of nuclear propulsion, and it’s about 80,000 tons. This is why US carriers at 100,000 tons have it and ours, at 65,000 tons do not.”
He added that the Charles de Gaulle, which sits at 42,000 tons, is an expensive anomaly to be nuclear-powered.
“However, if Gen IV reactors are that much smaller, safer, more powerful and with less waste as the brochure suggests, then it’s possible the tonnage point at which nuclear propulsion becomes viable could change substantially,” Mr Sharpe said.
The RFI also highlights the need for detailed technical information. It says: “The Royal Navy is seeking information regarding integrating Generation-4 nuclear technologies for surface ship employment. Exploring scopes for alternative energy paradigms, the Royal Navy is gathering information on energy solutions for powering large surface ships.”
Pete Sandman, a Navy expert who runs the Navy Lookout blog, said he doubted the UK will see a nuclear-powered vessel in the near future, due to the “enormous overheads” that would come with instilling and maintaining such advanced technology.
“Nuclear propulsion comes with enormous overheads, maintenance, regulations and once you go nuclear things become way more expensive and complicated,” he said.
“You have nuclear regulatory bodies, people have to be trained to a very high standard and have 24-hour watches. Although infinite power comes with lots of downsides, for a surface ship, the case is less clear cut.”