As demand for electricity in the United States grows, driven in part by the expansion of data centers powering artificial intelligence systems, questions are emerging about how to meet this rising need. The International Energy Agency reported that large-scale data centers worldwide consumed approximately 460 terawatt-hours of electricity in 2022, and analysts expect this figure to continue increasing.
Nuclear energy is being considered as a possible solution. This includes existing nuclear plants, reactivated facilities, new large-scale projects with government support, and smaller reactors currently under development. Among these options are small modular reactors (SMRs), which are being discussed as a way to supply consistent power without producing carbon emissions.
According to the International Atomic Energy Agency, there are around 70 different SMR designs under research and development globally. These reactors could potentially serve remote communities, military uses, ships at sea, or even spacecraft. Proponents argue that SMRs can be located close to where their energy is needed, reducing reliance on broader electrical grids. However, commercial availability is still years away; demonstration projects may begin construction before 2030 and commercial operations might not start until the mid-2030s. The U.S. Department of Energy has yet to establish a plan for managing the radioactive waste generated by these reactors.
Leonel Lagos, Associate Professor of Construction Management and Director of Research at Florida International University’s Applied Research Center, explained: “Here’s what this type of reactor is, how it works and what it can do.”
There are three general sizes of nuclear reactors: conventional plants (the only type built commercially so far), microreactors (still in research), and small modular reactors. Conventional plants typically generate over 1,000 megawatts—enough for up to one million homes—and require large plots of land for installation. Microreactors have much smaller cores that fit into a semitruck trailer and produce less than 20 megawatts.
Small modular reactors fall between these two types in size and capacity. Their cores measure about nine feet across and eighteen feet tall; they occupy roughly fifty acres and can generate up to three hundred megawatts of electricity. Their compact design allows them to be manufactured in factories from various components before being transported by truck or rail for assembly on site.
All SMRs operate by splitting heavy atoms to produce heat that generates steam for turbines—using materials such as water, liquid metal or molten salt as coolants. Safety features include passive systems based on gravity or other principles designed to shut down reactions before dangerous levels are reached. Compared with traditional large reactors, SMRs use less nuclear material and produce less heat.
These features make SMRs suitable for remote locations or areas lacking extensive power grids—where building large nuclear plants would not be practical—or industrial installations like desalination facilities or countries beginning nuclear programs. They can be constructed more quickly than standard nuclear plants: within two or three years compared with a decade or longer for larger facilities.
However, several technical challenges remain before SMRs can be widely deployed—including staffing requirements per reactor unit and regulatory adjustments both domestically and internationally regarding safety standards and transport of radioactive materials.
Fuel used in many SMR designs differs from that used in larger plants; it contains between five percent and twenty percent uranium-235 (known as high-assay low-enriched uranium). This allows greater electricity generation from smaller volumes while enabling longer intervals between refueling cycles.
The U.S. Department of Energy is working toward domestic production of this fuel type to reduce dependence on foreign sources. Under federal contracts since 2023 totaling $230 million so far—including a recent $110 million extension—a Maryland-based company called Centrus Energy has produced nearly one ton of high-assay low-enriched uranium for distribution among five companies engaged in demonstration projects.
Safe handling of spent fuel remains an issue: there is no permanent repository for nuclear waste in the U.S., so most waste stays onsite at generating facilities. The Department of Energy continues efforts to identify temporary storage solutions but faces ongoing legal obstacles.
Beyond electricity generation, SMRs could also provide direct heat for processes such as seawater desalination or mining operations needing both power and thermal energy for equipment operation or mineral processing.
University campuses may benefit as well; the University of Illinois plans a microreactor project intended both to supply campus energy needs and serve educational purposes by training students in plant operation while supporting further research into reactor technology improvements.
“This article is republished from The Conversation under a Creative Commons license.”
