Modular nuclear reactors sound great, but won’t be ready any time soon
The UK government has announced a raft of tiny nuclear power projects, while Russia, China and a host of tech giants are also betting big on small nuclear reactor designs. Does the idea make sense and can they really be built any time soon?
By Matthew Sparkes
15 September 2025
A proposed Xe-100 plant in the US from X-Energy uses similar technology to one planned in the UK
Centrica
The UK government has announced plans to build more than a dozen small nuclear reactors across the country, ushering in what it calls a new “golden age” for nuclear power. One of the ultimate goals is to help the country to finally divest from Russian energy within three years – but do tiny nuclear reactors make engineering and commercial sense, and can they even be built?
Ahead of a 16 September London visit by US President Trump, the US and UK announced a partnership between British firm Centrica and US start-up X-Energy to build 12 small modular nuclear reactors to power data centres, plus a “micro modular nuclear power plant” at DP World’s London Gateway port built by US start-up Last Energy.
However, no dates were given for the beginning of any of the projects, and the Department for Energy Security and Net Zero did not respond to New Scientist’s request for more detail.
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Chinese nuclear reactor is completely meltdown-proof
The announcement fits a trend of smaller nuclear reactors. Bruno Merk at the University of Liverpool in the UK says Rosatom, Russia’s state nuclear energy organisation, recently finished building a batch of small reactors for a highly specific use in nuclear-powered icebreaker ships. Crucially, they then continued building more, showing either that there is demand from somewhere, or that Rosatom is taking a risk and building them as a commercial demonstration in the hope of selling more despite a raft of energy sanctions imposed after its invasion of Ukraine.
China, too, has built a Linglong One small nuclear reactor, but it is not clear whether it will yet be a commercially viable product. And giant technology firms like Amazon, Google and Microsoft are investing in these sorts of nuclear technologies, too.
