Small nuclear reactors are starting to leave PowerPoint

For years, small modular reactors, known as SMRs by their acronym in English, have existed in an ambiguous zone between technological promise and industrial reality. For their supporters, they are a key component that can help generate clean, consistent electricity in a world with more data centers, increased electrification, and greater grid strain. For critics, they remain an expensive technology, slow to license, and still far from proving that they can be mass-produced.

New data from the OECD Nuclear Energy Agency show that the race is starting to move. The United States ranks as the country with the most announced sites for future SMRs, with 28 identified locations. Followed by Canada with 9; the United Kingdom with 7; Russia with 5; and China, Finland, France, and Poland with 4 each.

This figure warrants a cautious interpretation. An announcement of a site does not mean that a reactor is already under construction or that it will be connected to the grid within a few years. It indicates that there is a publicly associated location with a project, and a significant step has been taken in a process that will later require licensing, funding, permits, supply chain, construction, and operation.

Still, it’s not an insignificant number. Major energy technologies do not arrive all at once. First come designs, then testing, followed by site selection, power purchase agreements, regulatory processes, and finally, construction. Regarding SMRs, activity is beginning to show a broader global portfolio than it appeared a few years ago.

United States Gains Lead in the SMR Race

The U.S. position is not entirely surprising. The country combines national laboratories, electric utilities, universities, private developers, large industrial consumers, and a demand for electricity that is resurging strongly driven by AI, data centers, electrification, and reindustrialization.

According to a tally compiled from the OECD-NEA panel, national laboratories lead site announcements in the U.S., with seven locations. Next come electric companies, universities, and SMR developers, with five each. This diversity matters because it reduces dependence on a single approach. There is no single type of client or reactor model trying to break through.

The most interesting insight relates to the potential types of demand that could emerge. SMRs are usually envisioned as reactors up to 300 MW electrical, smaller than conventional nuclear reactors, which often range from 1,000 to 1,400 MW. This smaller scale would — at least on paper — enable more flexible deployment and repeatable module manufacturing.

One of the great promises here is to produce reactors as an industry more similar to mass manufacturing than to a one-off civil project. If achieved, costs could decrease through repetition. If not, SMRs might end up sharing some of the traditional nuclear’s challenges: long timelines, cost overruns, complex licensing, and difficulty attracting private investment.

Why Data Centers, Industry, and Power Grids Are Interested

The debate around SMRs has accelerated for a very specific reason: firm electricity is once again a strategic matter. For years, much of the energy conversation centered on solar and wind growth. Today, that conversation now also includes storage, transmission, gas, interconnections, hydrogen, and nuclear.

Artificial intelligence has sped things up. Data centers require a lot of electricity but also need continuity, predictability, and long-term energy contracting. Renewables are cost-competitive and will continue to grow, but they do not always deliver power when demand needs it. Batteries help, but don’t fully resolve all long-term backup needs on their own.

SMRs promise low-carbon, continuous electricity. That’s why they’re appearing in conversations about data centers, energy-intensive industries, remote mines, coal plant replacements, isolated grids, and urban heating in cold countries. Not all these applications will be feasible, but they explain why governments and companies are revisiting nuclear with fewer prejudices than a decade ago.

There’s also a geopolitical angle. Those who manage to license, build, and export SMRs at scale could gain a significant industrial foothold. It’s not just about selling electricity, but about mastering design, fuel, components, safety, operation, maintenance, and service over decades. The U.S., Canada, the UK, France, Russia, China, and South Korea recognize there’s a strategic technological and diplomatic race here.

Announcements Are Not Reactors: The Test Will Be Building

Caution remains essential. The OECD Nuclear Energy Agency tracks 129 SMR designs, but only a subset appears publicly on its digital panel. Others are designs whose promoters have asked not to be listed yet, or technologies not actively in development, lacking sufficient resources, canceled, or indefinitely paused.

This data tempers enthusiasm. The sector has many designs, but not all will reach the market. In early-stage industries, many proposals tend to disappear. The key question isn’t how many designs exist, but how many succeed in securing funding, licenses, supply chains, and actual construction.

SMRs also face the same challenges as traditional nuclear. They require regulators capable of evaluating new technologies without compromising safety. They need fuel, skilled personnel, waste agreements, social acceptance, physical security, and credible business models. They must also demonstrate that modularity reduces costs in practice, not just on paper.

This point is critical. A small reactor isn’t automatically cheaper per megawatt. It may be easier to finance per project, better suited to certain sites, and reduce some construction risks. But if it’s not manufactured in series and each installation becomes nearly unique, the economic advantage diminishes.

The SMR race is entering a more serious phase, but it has not yet won the industrial battle. The U.S. leads in site announcements, Canada and the UK are progressing, Europe is starting to move, and Asia maintains multiple lines of development. The trend exists. Certainty, however, remains elusive.

The fundamental question isn’t whether SMRs are a promise or a definitive solution. It’s more about which countries will be the first to move from announcements to concrete construction, from concrete to operation, and from the first unit to a repeatable reactor chain.

That’s where it will be decided whether small nuclear reactors will genuinely change the energy map or remain another promising technology that arrived too late, too slowly, or too costly.

Frequently Asked Questions

What is a small modular reactor or SMR?
A smaller nuclear reactor, typically up to 300 MW electric, designed for modular construction and adaptable to various energy uses.

Which country is leading SMR development?
Currently, the U.S. leads in site announcements, with 28 locations identified per OECD-NEA data.

Does an announcement mean the reactor is already being built?
No. It indicates a site is associated with a project, but licensing, funding, permits, supply chain, and construction may still be pending.

Why are SMRs of interest to data centers?
Because data centers require reliable, high-capacity electricity. SMRs promise low-carbon, steady power, though they still need to prove costs, timelines, and commercial viability.

Will SMRs replace renewables?
Not necessarily. Their most probable role is to complement solar, wind, storage, and grids, especially where constant power is needed.

via: oecd-nea.org and motive-power