The staid nuclear sector stalled for decades as natural gas and renewable energy came to dominate a power sector that feared nuclear for both safety concerns and its history of dramatic cost overruns. The only major U.S. expansion in nearly 30 years was the Vogtle project in Georgia, which took 15 years and cost over $35 billion—more the double the planned budget and timeline. That exercise hardly created an appetite for more.

“The U.S. (nuclear) safety record has been so good, but it created a culture where you were almost punished if you innovated,” TerraPower CEO Levesque said. “We were rewarded for doing everything the same way it was done last time, maybe 1% better. But don’t be a cowboy!”

When Levesque joined TerraPower from Westinghouse, a stalwart of the nuclear industry, he found a company guided by a different mindset: What does nature allow? What does science allow?

Roughly seven decades after the first nuclear power plant came online in the U.S., we may be witnessing a watershed moment for the industry as a new generation of small modular reactors (SMRs), along with surging demand from power-hungry AI data centers, and the Trump administration’s expedited regulatory process, converge to set the stage for what Energy Secretary Chris Wright heralds as “the next American nuclear renaissance.”

In January, Meta partnered with Gates’ TerraPower and Sam Altman-backed Oklo to develop about 4 gigawatts of combined SMR projects—enough to power almost 3 million homes—for “clean, reliable energy” both for Meta’s planned Prometheus AI mega campus in Ohio and beyond.

Analysts see Meta as the start of more Big Tech nuclear construction deals—not just agreements with existing plants or restarts such as the now-Microsoft-backed Three Mile Island.

“That was the first shot across the bow,” said Dan Ives, head of tech research for Wedbush Securities, of the Meta deals. “I would be shocked if every Big Tech company doesn’t make some play on nuclear in 2026, whether a strategic partnership or acquisitions.”

Ives pointed out there are more data centers under construction than there are active data centers in the U.S. “I believe clean energy around nuclear is going to be the answer,” he said. “I think 2030 is the key threshold to hit some sort of scale and begin the next nuclear era in the United States.”

Smaller SMR reactors can be built in as little as three years instead of the decade required for traditional large reactors. And they can be expanded, one or two modular reactors at a time, to meet increasingly greater energy demand from ‘hyperscalers,’ the companies that build and operate data centers.

“There’s major risk if nuclear doesn’t happen,” Oklo chairman and CEO Jacob DeWitte told Fortune, citing the need for emission-free power and consistent baseload electricity to meet skyrocketing demand.

“The hyperscalers, as the ultimate consumers of power are, are looking at the space and seeing that the market is real. They can play a major role in helping make that happen,” DeWitte said, speaking in his fast-talking, Silicon Valley startup mode. “We’re in a moment where we finally see this confluence of innovation in the industry to actually do things differently—kind of for the first time since the advent of nuclear power.”

Making nuclear grow again

Thanks to the shale drilling boom, natural gas-fired power generation has dominated the power sector for much of this century, now comprising over 40% of the U.S. grid. But with gas prices on the rise, and orders for combined-cycle gas turbines backlogged, hyperscalers are looking for alternative and, ideally, cleaner solutions for their long-term energy needs.

Wind and solar power, which make up more than 15% of the grid by electricity generation, have presented an attractive option for hyperscalers. But federal subsidies are ending and tariffs are further impacting costs.

So nuclear power—under 20% of the grid—reenters the equation thanks to new technologies, growing bipartisan support, and eased regulatory permitting. And, with U.S. electricity demand expected to surge anywhere from 50% to 80% between 2023 to 2050, depending on projections, the need for more sources of energy is critical.

“The electricity industry in general operates on a slower time constant than the tech industry, and the two industries are really crashing into each right now,” Levesque told Fortune about the nuclear race to meet AI’s demands. He contends his SMRs will compete economically with gas-fired power.

TerraPower is currently constructing its first 345-megawatt, nuclear SMR plant in Wyoming—the Kemmerer Power Station. It’s slated for completion in 2030 and to start providing power to the grid in 2031.

The company’s new deal with Meta calls for two reactors to come online as early as 2032, powering data center facilities at a yet-to-be-determined location. The agreement includes the option for six additional modular reactors supporting Meta operations—meaning there could be up to eight reactors totaling 2.8 gigawatts.

“It’s defining our order book,” Levesque said of the Meta agreement. “We have other discussions going on too, and we’re trying to scale as quickly as we can,” he said, noting that the company expects to have about a dozen plants under construction when Wyoming plant comes online in 2031. “Several of those could be these Meta units.”

Working with tech’s ‘hyperscalers’

Oklo, which was founded in 2013 by husband and wife Jacob and Caroline DeWitte, plans to start construction on its first nuclear reactors this year in Pike County, Ohio—about 85 miles from Meta’s future “Prometheus” data center campus in New Albany, Ohio. The first reactors are targeted to come online as early as 2030, with the “powerhouse” facility incrementally scaling up to 1.2 gigawatts of electricity on 200 acres of land by 2034.

In the meantime, Oklo already is building its first test reactor—dubbed the Aurora Powerhouse—with the Department of Energy’s Idaho National Laboratory as part of the White House’s executive order-created Nuclear Reactor Pilot Program. There are 11 such projects in the works at varying degrees of development and Oklo has three of them. No other company has more than one. Aurora is slated to come online in 2027 or 2028.

“Obviously, Idaho is the first one, but Ohio is where we’re planning a pretty major presence,” DeWitte said. “We’re going to be building a lot more there. We’re eager to position ourselves to really double down and put down significant roots and start building there.”

It’s a major milestone for the DeWittes, who met at the nuclear engineering department at the Massachusetts Institute of Technology. He hailed from the New Mexico nuclear environment while she grew up around oil and gas technology in Oklahoma.

They met Sam Altman the same year they founded Oklo, when Altman was still with the startup incubator Y Combinator and had not yet started OpenAI. They became fast friends, especially since Altman was a believer in power demand growth and the need for clean, next-gen nuclear power.

Altman became an investor and fundraiser and served as Oklo’s chairman from 2015 until April 2025—Oklo went public in 2024. Altman still maintains an almost 4% ownership stake, but no longer leads the board—a move meant to help Oklo sign more deals with hyperscalers who compete with OpenAI.

“Hyperscalers are really good partners to help get new power generation built and on the grid sooner, because they’re willing to move faster and they’re willing to bring resources to bear,” DeWitte said. “That helps all of us de-risk project certainty so it gets built, which translates to having power online sooner. That brings more capacity online, which is great, but that then helps us drive our costs down so that we can build more plants.”

Oklo now has a market cap hovering above $11 billion, up almost 50% in 12 months despite sizable fluctuations.

How it all works

Tried-and-true, old-school nuclear plants typically function with light-water reactors—using ordinary water both to create pressure and serve as the reactor’s coolant.

TerraPower and Oklo both utilize differing versions of sodium-cooled reactors instead of water. The sodium transfers heat better, and their low-pressure systems require much less containment. After all, much of the cost of nuclear plants is for the massive amounts of concrete and steel needed for reactor containment.

Levesque said the steel, concrete, and labor per megawatt is more than double what TerraPower’s sodium system—dubbed natrium—requires.

“It’s still fission. We’re still breaking uranium atoms to release heat, and then we make the electricity with the turbine,” Levesque said. “Be we’re moving to a plant that’s cooled with liquid metal—sodium—instead of water, which lets us have a low-pressure plant, meaning everything in the plant is lighter—lighter components, less piping, less structural concrete and steel.”

The sodium design also takes advantage of air-cooled chimney systems to keep the reactor safe when it’s shut down, instead of requiring off-site electric and water systems for emergencies.

Russia, China, and India have been more aggressive over the years in pursuing sodium-cooled reactor projects, but the U.S. is currently catching up.

The sodium designs are loosely based on the 60-year-old designs of the Argonne National Lab’s Experimental Breeder Reactor-II (EBR-II) in Idaho that first showed sodium-cooled fast reactors could work. But, by then, the traditional water reactors were well accepted, and no one commercially was going to risk anything else—until now.

“To put it bluntly, the industry got used to making things really expensive because it could,” DeWitte said.

TerraPower even incorporated molten-salt energy storage, which essentially operates as a “thermal battery” to store excess power that can be deployed when electricity demand spikes. Levesque argued that eliminates the need for gas-fired peaker power plants commonly used to add extra power during demand surges.

TerraPower’s dual reactors offer 690 megawatts of baseload power, but Levesque said the storage addition allows them to deploy up to 1 gigawatt of dispatchable electricity on the hottest days or when other power plants suffer outages.

Apart from all the construction supplies and labor constraints, another major expense for the plants is the enriched uranium that sources the nuclear fuel, especially when Russia dominates almost half of the global uranium enrichment market.

The U.S. is actively working to build up its own uranium supply chains—both from a mining and processing perspective—but Oklo also is focused on nuclear fuel recycling to eventually eliminate much of those concerns. Only about 5% of the energy is used by a reactor, meaning the used nuclear fuel has the potential to be recycled.

Oklo is working on fuel fabrication and building a $1.7 billion nuclear fuel recycling facility in Oak Ridge, Tennessee to come online as soon as 2030. Of course, the technology still must be perfected.

Oklo may use plutonium as a bridge fuel and, in the meantime, even has a partnership with Energy Secretary Wright’s previous oil and gas services company, Liberty Energy, to provide temporary, gas-fired power to data centers until Oklo’s SMRs scale up.

“Recycling is the big game changer in many ways because it enables you to actually extend the resource considerably,” DeWitte said. With recycling, “The entire (uranium) reserves in the United States could power the country for over 150 years.”

Rising regulatory fears

The rebirth of the nuclear industry, and the way it’s happening, has not been universally cheered.

The White House’s goal is to dramatically expand nuclear capabilities in the U.S. from about 100 gigawatts today to 400 gigawatts by 2050—enough to power almost 300 million homes (keep in mind that there are about 150 million homes in the entire country today).

To meet the ambitious goal and accelerate development of next-generation nuclear technologies, Trump’s new reactor program is combining with a federal rewriting of the nuclear safety rules—placing more under the purview of the Department of Energy instead of the Nuclear Regulatory Commission.

The DOE contends it is eliminating unnecessary excess regulations without sacrificing safety. But, while there’s truth to overly burdensome bureaucracy, the Union of Concerned Scientists (UCS) and other outside observers remain concerned that safety is falling by the wayside to better serve the global AI race.

OSHIKAZU TSUNO/POOL/AFP via Getty Images

“The Energy Department has not only taken a sledgehammer to the basic principles that underlie effective nuclear regulation, but it has also done so in the shadows, keeping the public in the dark,” said Edwin Lyman, UCS director of nuclear power safety, in a statement. “These longstanding principles were developed over the course of many decades and considered lessons learned from painful events such as the Chernobyl and Fukushima disasters.”

Despite the fears, Oklo, Antares Nuclear, Natura Resources, and other startups in the reactor pilot program are pressing forward, contending their projects are much smaller and safer than the past disasters that unfolded in the former Soviet Union and Japan.

The Energy Department just granted Antares preliminary safety approval for its Mark-0 demonstration reactor to come online this summer in Idaho.

In February, Natura reached a deal to develop a 100-megawatt reactor project to help power oil and gas and water treatment facilities in West Texas’ Permian Basin. Natura also has a DOE reactor project in the works at Abilene Christian University in Texas.

Elsewhere, Kairos Power is building a DOE demonstration reactor in Oak Ridge, Tennessee, but Kairos also has a bigger deal to deal to develop 500 megawatts of SMR power to Google by 2035 for Tennessee, Alabama, and other sites. And Amazon backs x-Energy planning to build 5 gigawatts of SMR power by 2039, including about 1 gigawatt in Washington state.

But this potential nuclear renaissance isn’t just about varying SMR technologies. With the Trump administration’s support, traditional nuclear developer Westinghouse is building 10, pre-licensed AP1000 reactors—the same kind as Vogtle—by 2030, each with 1.1 gigawatts of power.

Even DeWitte acknowledges the need for both large and small reactors.

“I’m not a fan of the small versus large debate,” he said. “Large plays an important role in certain areas. It faces a really difficult capital allocation challenge. Smaller reactors need fewer dollars, so they’re easier to find the capital, and then you build faster because they’re smaller. They can iterate more quickly, both on cost and time. That’s important because the learning cycles matter, and they compound.”