Modular nuclear reactors sound great, but won’t be ready any time soon

The British government has announced its intention to build more than a dozen small nuclear reactors across the country, inaugurating what it calls a new “golden age” for nuclear energy. One of the ultimate objectives is to help the country finally depart from Russian energy within three years-but do tiny nuclear reactors have a sense of engineering and commercial sense, and can they even be built?

Before a visit of September 16 of London by the American President Trump, the United States and the United Kingdom announced a partnership between the British company Centrica and the American start-up X-Energy to build 12 small modular nuclear reactors with food centers, as well as a “microcular nuclear power plant” at DP World Gateway Port built by the American start-up of the American start-up.

However, no date has been given for the start of the projects, and the Ministry of Energy Security and Net Zero replied New scientists Request for more details.

The announcement corresponds to a trend in small nuclear reactors. Bruno Merk at the University of Liverpool in the United Kingdom said that Rosatom, the organization of nuclear energy in the State of Russia, recently completed the construction of a batch of small reactors for very specific use in nuclear propulsion icebreaker ships. Above all, they then continued to build more, showing either that there is demand for somewhere, or that Rosatom takes a risk and builds them as a commercial demonstration in the hope of selling more despite a series of energy sanctions imposed after its invasion of Ukraine.

China has also built a small nuclear reactor from Linglong, but it is not clear if it will still be a commercially viable product. And giant technology companies like Amazon, Google and Microsoft also invest in this type of nuclear technology.

David Dye at the Imperial College of London says that tiny reactors make sense for distant military installations or Arctic sites, but that it is skeptical about the use of tiny nuclear reactors to power the needs of these technology giants. He says it is much easier to build data centers near an energy supply ready for the place.

“If you are a technological visionary multi -loving and you want to believe … And you did your billion, what is it to throw $ 50 million in this cool technology? Said Dye.

A motivation could be surveillance, explains Michael Bluck to the Imperial College in London. “If you are a data center, you must be on 99.995% of the time,” explains Bluck. “It means you really want to control this electricity. You get the first dibs on this electricity. ”

Bluck says that there is no scientific engineering or reason, we cannot build tiny nuclear reactors and build them quickly. He underlines that the first experimental reactors were small, and many devices of a similar size operate in universities and military submarines around the world.

“Size is not the problem. It is modularity, it is construction on a production line, it is the normalization of components. It’s really practical. It’s standard engineering, ”explains Bluck.

But there are certainly a lot of drawbacks to miniaturize nuclear reactors. Merk says that for nuclear energy, the scale brings useful effectiveness both in cost and energy. The small and large reactors both require the same thickness of concrete shield to contain their reactions safely and, because the volume of a reactor develops faster than its surface when you enlarge it, larger reactors are cheaper by megawatt capacity. Smaller reactors also make less energy from the same amount of fuel due to ineffectiveness in the chain reaction of neutrons fission – smaller quantities of fuel lose more neutrons on the surface, rather than exploiting them to continue the reaction.

“You cannot avoid it. It’s physics, ”explains Merk. “Otherwise, you are a magician. And I don’t believe in magic. “

That said, Merk stresses that nuclear power plants take years to plan, the massive political will to finance and vast resources to build and maintain, which can make the options less effective more acceptable. “These animals have become so expensive,” says Merk. “It may be easier to build smaller.”

Design a new nuclear

Bluck says that there are two different approaches involved in the new government announcements: X-Energy has designed a gas cooled reactor called the XE-100 which uses a somewhat unusual design and a type of fuel that could take 10 years to obtain regulatory approval, while the type of PWR-20 nuclear power in Last Energy is a relatively familiar nuclear power plant, using the same fuel. The first could be the way to follow, but the latter could be able to come to the market earlier.

But even with standard fuel and familiar technology, Bluck says that Last Energy is probably five years from building a prototype reactor built in the United Kingdom. “Everyone would like it tomorrow,” he says. “But I think they are aware that energy is not like that.”

What will be vital for any plan to produce en masse and export these tiny reactors is regulatory approval, and this is something that must currently happen from zero in each country that will host them.

Bluck says that this is where the American and British announcement could be essential, because it promises to accelerate approval – at least between the two jurisdictions – by allowing a panel transfer. For example, Rolls Royce designed a small modular reactor, a much larger than those designed by many American startups, and more similar to a small traditional power plant. If it were approved by the United Kingdom, it could immediately be sold in the United States.

However, Bluck warns that the idea is not without political risk. “If you are anti -nuclear, you will certainly use this – you will say” What, we simply accept what they give us? We cannot trust them. ” This partnership can mitigate part of this concern. “He recognizes a problem, but it is the first time that I really see him between two important manufacturing countries,” he said.