As U.S. electrical energy call for rises and generation firms search to construct extra and bigger knowledge facilities to power synthetic intelligence methods, the principle query coming up is tips on how to generate all that energy.
Consistent with the Global Power Company, large-scale knowledge facilities world wide used about 460 terawatt-hours of electrical energy in 2022, a determine that analysts be expecting to proceed emerging years into the long run.
One attainable resolution being proposed is nuclear power – produced through current large-scale nuclear energy crops, reactivated outdated ones, new ones that could be built with govt subsidies, and different, smaller sorts of nuclear crops which can be in building and no longer but to be had.
The dialogue round powering AI knowledge facilities, specifically, has concerned one of those nuclear energy plant known as a small modular reactor. Consistent with the Global Atomic Power Company, there are about 70 other designs being researched and evolved world wide, together with reactors that would sooner or later serve small or faraway communities, army packages or even ships at sea or spacecraft.
Proponents say those reactor designs supply constant energy with out climate-changing carbon emissions. They may be able to even be positioned with regards to puts that want their power, decreasing dependence at the electrical energy grid. They’re nonetheless years from being commercially to be had: Demonstration initiatives would possibly start development ahead of 2030, with business ones achieving operation possibly through the mid-2030s. And there isn’t but a plan from the U.S. Division of Power to maintain the radioactive waste they’d generate.
I’m an engineer whose paintings specializes in the nuclear trade, together with waste dealing with and decommissioning of nuclear reactors. Right here’s what this kind of reactor is, the way it works and what it will possibly do:
Small modular reactors, on the most sensible, are in between the opposite two sizes of reactor, and serve other sizes of communities, on the backside.
A. Vargas/IAEA
The fundamentals
There are 3 basic sizes of nuclear reactors – most effective one in all which, standard nuclear crops, has been constructed commercially. Standard crops are inbuilt everlasting places on vast plots of land round reactor cores as tall as 30 toes (10 meters). They normally generate greater than 1,000 megawatts of energy, sufficient to offer 700,000 to at least one million houses.
The opposite varieties are nonetheless being researched and are significantly smaller. Microreactors have cores which can be sufficiently small to suit into the trailer of a semitruck. They may be able to be put in on land about as large as a soccer box and generate not up to 20 megawatts.
Small modular reactors are in between. Their cores are more or less 9 toes (3 meters) throughout and 18 toes (6 meters) tall. All of the operation occupies a space of about 50 acres and will generate as much as 300 megawatts of electrical energy.
As a result of the reactors’ measurement, they may be able to be inbuilt factories from more than a few parts after which be shipped through truck, rail or water to the site the place they’re assembled.
All of the various kinds of small modular reactors generate warmth the similar means: through splitting heavy atoms and shooting the warmth into a number of fabrics – like water, liquid steel or molten salt – that flow into via water to generate steam that drives a turbine.
They’re additionally designed with security features to scale back the chance and severity of injuries that may liberate radiation or radioactive subject matter into the environment. As an example, passive methods and the ones in line with elementary rules like gravity can terminate nuclear reactions ahead of they achieve ranges the place explosions or leaks may happen. Those reactors additionally produce much less warmth and feature a ways smaller quantities of nuclear subject matter than conventional vast reactors, which will scale back the radioactivity possibility as nicely.
The fairway-wrapped core module of a small nuclear reactor is readied for switch to a boat.
Liu Xuan/VCG by way of Getty Pictures
Building and deployment
Small modular reactors are well-suited to offer electrical energy in faraway puts or areas with out a big energy grid – puts the place vast nuclear energy crops are impractical.
Their compact design and versatile placements cause them to ultimate for small geographical areas or business installations, like desalination crops, or in international locations simply beginning to increase nuclear energy.
They may be able to be constructed and put into operation inside of two or 3 years – extra briefly than the last decade or longer it will possibly take to safe allows and development of same old nuclear energy crops and whole development of a giant nuclear plant.
There stays a spread of technical demanding situations ahead of small modular reactors can in truth be constructed and put into use. Those come with reasonably simple questions like what number of people are had to perform every reactor, and extra advanced selections about refinements to protection rules, each within the U.S. and across the world. It’s additionally no longer but transparent what one of the simplest ways is to regulate the delivery of radioactive fabrics, particularly for reactors that use coolants rather than water, which might produce new kinds of radioactive waste.
Figuring out the gasoline
Better nuclear energy crops use gasoline this is about 5% uranium-235, the component that splits in a nuclear response, freeing warmth. However many small modular reactor designs use a other gasoline, with between 5% and 20% uranium-235.
This other gasoline, known as “high-assay low-enriched uranium,” we could the reactors generate extra electrical energy from a smaller quantity of gasoline subject matter. And despite the fact that it comprises considerably extra uranium than same old nuclear gasoline, it stays a ways under the focus of 90% uranium-235 this is utilized in nuclear guns.
The extra concentrated gasoline additionally permits reactors to run longer between refueling and decreases the quantity of radioactive waste that continues to be after the gasoline is spent.
An engineer at a French analysis middle works on apparatus as a part of efforts to increase a small modular reactor.
Nicolas Tucat/AFP by way of Getty Pictures
US efforts
The U.S. Division of Power is operating to increase home production of this kind of uranium for small modular reactors, to keep away from being depending on international resources.
Below a central authority contract, a Maryland-headquartered nuclear gasoline corporate known as Centrus Power has produced just about 1 ton (920 kilograms) of that gasoline since 2023 beneath a freelance estimated to price taxpayers US$120 million. In mid-2025, Centrus gained a $110 million contract extension to provide that quantity once more through the center of 2026.
The Division of Power is distributing the gasoline Centrus has made to 5 firms for demonstrations and building initiatives.
Managing waste
All nuclear crops require protected dealing with of the gasoline and the ensuing waste. There is not any everlasting position to retailer nuclear waste within the U.S. Maximum nuclear waste is saved at the land across the reactors the place it was once generated.
The Division of Power says it is making an attempt to discover a position to quickly retailer waste from small modular reactors, however that procedure has been tied up within the courts for years and is probably not resolved anytime quickly.
Different business makes use of
Along with turning in electrical energy, small modular reactors too can at once generate vast quantities of warmth.
That may be helpful for desalination crops, which use each electrical energy and warmth to transform seawater into contemporary water for ingesting and irrigation. Faraway mining operations additionally continuously want each warmth and gear to perform apparatus, be certain that dwelling quarters are liveable and procedure minerals.
Small modular reactors can be helpful on college campuses. A microreactor deliberate for the College of Illinois will supply energy and steam to campus structures, whilst additionally instructing scholars tips on how to perform nuclear crops, and be offering analysis and demonstration alternatives for extra reactor enhancements one day.
