As America’s need for power evolves, nuclear energy is vying for a top spot.
AI data centers, extreme weather, intermittent renewable sources, and the electrification of vehicles and buildings all present complex challenges and opportunities for the power grid.
While politicians, utility executives, and industry groups squabble over rising electricity bills and a need for stable power sources, one resource is repeatedly cited as a solution: nuclear energy. Now, U.S. tech giants, from Amazon to Google to Meta, are jumping in, with billions of dollars in nuclear investments to power their energy-hungry data centers.
Amid high electricity costs and evolving U.S. energy needs, a utility that has long been an object of protest presents an alternative to fossil fuels. Small-scale nuclear reactors are drawing interest as stable, economically feasible power generators.
Despite lingering public angst around past nuclear accidents (Three Mile Island in 1979; Chernobyl in 1986), nuclear power already provides roughly 18% of the country’s electricity, ranking second only to gas as a single source of U.S. power generation.
This is partly because of new safety rules and processes. But it’s also because nuclear has proven itself the ultramarathoner of energy sources: slow to get going but steady and efficient for the long term. About 70% of the cost of a nuclear plant goes toward construction, which can sometimes take years. Once that plant is up and running, only six uranium fuel pellets, which cost about $25 each (or $150 total) and are burned to make nuclear energy, are needed to power an average American household for a year. Experts say the same year of power would require 12,000 pounds of coal ($300 to $1,300) or 78,000 cubic feet of gas ($212 for wholesale to $1,500 for residential retail).
Now, thanks to advancements that have shrunk reactors from the size of concrete plants to that of shipping containers, nuclear energy is seeing a revival in interest, largely to help power data centers, remote military bases, and clean-energy communities.
That means that small modular reactors (SMRs) and microreactors are starting to move, albeit slowly, from blueprints to U.S. construction sites.
Small nuclear reactors operate much like larger models. Fission – or the splitting of atoms (usually uranium) – produces energy that heats a liquid (usually water) into steam, which then spins a turbine, generating electricity. But unlike large nuclear plants, which typically span a square mile, the smaller units use only 5% to 10% of that space. While SMRs produce less electricity than bigger models, their components can be manufactured off-site en masse and shipped directly by truck, train, or ship to a desired location. Factory assembly, experts say, could give nuclear power a better chance of competing in the energy marketplace; shipping reactor components to remote parts of Alaska, for example, should be cheaper than building a new gas pipeline there.
“The goal is to build reactors more like airplanes than airports,” said Katy Huff, chair of the department of nuclear engineering and engineering physics at the University of Wisconsin-Madison. “Ideally, you bring things in mostly built and plug them together more like a Lego set.”
Proponents say new cooling systems and safety measures mean that SMRs and microreactors are safer and more efficient than larger nuclear reactors. Detractors argue that the SMRs scattered around the country would be harder to secure, and that dealing with nuclear waste across 50 states, not to mention the SMRs’ unproven scalability and possible cost overruns, makes them risky. Many SMRs are still in early stages of development. The U.S. has only two next-generation small reactors under construction, both by private firms: TerraPower near Kemmerer, Wyoming, and Koros Power in Oak Ridge, Tennessee.
Input costs are considered the biggest hurdle for investors.
Large reactors can cost around $10 billion to build and are more expensive upfront than coal, natural gas, solar, and wind operations. Small reactors are also expensive, typically costing between $1 billion and $6 billion per unit.
But mass production could drive down the cost per megawatt of SMRs. Experts and researchers say that achieving cost parity will require building at least 30, and perhaps several hundred, identical units. (Different models project vastly different electricity costs.)
Still, all nuclear reactors require a specialized supply chain. For example, reactor-grade uranium, the fuel needed for a nuclear chain reaction, is hard to obtain and secure. Though accounting for a small fraction of operating costs, it requires government licensing, contract agreements, and an extensive enrichment process.
