The Nuclear Comeback: How AI Turned the World's Most Unloved Power Source Into Its Most Wanted

For most of the last thirty years, nuclear power was the energy source nobody wanted to build. Plants closed early, projects were cancelled, and the industry's share of the world's electricity shrank year after year. Then the biggest technology companies on earth discovered they could not run artificial intelligence without a kind of power that is clean, enormous and never switches off. Nuclear is the one large source that fits that description nearly everywhere, and the money has started to move.

On October 6, Google signed a 20-year power purchase agreement with Constellation for 890 megawatts of new nuclear capacity, squeezed out of 11 existing reactors through upgrades that will cost Constellation $4.3 billion.¹ A month earlier, Google agreed to take up to half the output of Finland's Loviisa nuclear plant from 2030 through 2049.² Reactors that closed years ago in Iowa, Michigan and Pennsylvania are being brought back with federal loans. And by Independence Day, four brand-new reactor designs had reached criticality, the Energy Department said, beating the target set by the White House.³

This report explains how a technology written off for a generation became the center of a global scramble, who is paying for it, where the bottlenecks are, and what could still derail it. The short version: the demand is real, the contracts are signed, and the supply of fuel and reactors cannot be expanded quickly. That gap is where the money in this race is being made.

How Nuclear Lost Thirty Years

In 1996, nuclear plants supplied 17.5% of the world's electricity. By 2024, the latest full year in the World Nuclear Industry Status Report 2025, that share had fallen to 9%, the lowest in 40 years.⁴ The same report counts 243 reactors expected to be decommissioned by 2050, taking 203 gigawatts of capacity with them.⁴

The United States shows how it happened. Three Mile Island unit 1 in Pennsylvania closed in 2019.⁵ Duane Arnold in Iowa closed in 2020, even though its license ran until 2034.⁶ Palisades in Michigan stopped operating in May 2022 and was defueled the following month.⁷ These were working plants with valid licenses. They closed because, at the time, nobody was willing to pay what it cost to keep them running, and because nobody expected demand to change.

Then the demand changed.

The Customer That Changed Everything

The Energy Information Administration now expects U.S. electricity use to set records in both 2026 and 2027, reaching 4,288 billion kilowatt-hours this year and 4,356 billion next year, after a record 4,195 billion in 2025. Commercial demand, the category that includes data centers, is forecast at 1,549 billion kilowatt-hours, above last year's record of 1,493 billion, with AI and cryptocurrency data centers the main driver.⁸ McKinsey estimates data center capital spending will reach about $6.7 trillion through 2030, more than $4 trillion of it on computing hardware.⁹

A data center is a very particular kind of customer. It runs every hour of every day, it cannot tolerate interruptions, and the companies that build them have promised investors and regulators that the power will be clean. Wind and solar cannot deliver around the clock on their own. Gas can, but it is not clean. Nuclear is the one large source that is both and can be sited almost anywhere, which is why the richest companies in technology are now signing contracts that run into the 2040s.

The list of deals is long and getting longer. In January, Meta agreed to take 6.6 gigawatts of nuclear power from Vistra, TerraPower and Oklo on terms of up to 20 years, roughly the output of five or six large reactors. Amazon signed for 690 megawatts of nuclear power this year.¹⁰ Microsoft signed a 20-year power purchase agreement in 2024 for the output of the former Three Mile Island unit 1, now renamed the Crane Clean Energy Center.¹¹ Google's October deal with Constellation covers 3.6 gigawatts in total, with the nuclear portion coming from reactors in Illinois, Pennsylvania and New Jersey, and Bloomberg has reported that deliveries could begin as early as 2028.¹⁰

The Finnish agreement shows the race has crossed the Atlantic. On September 9, Google signed a long-term agreement with Fortum for up to 50% of the Loviisa plant's capacity, starting in 2028 at reduced volume and running at the full share from 2030 to 2049, alongside a deal to optimize a 94-megawatt battery at Google's Kajaani data center.² Big Tech is no longer buying nuclear power where it happens to be available. It is buying it wherever it can find it.

✓ Trusted partner One research team says it has identified where the money in this race for nuclear power is most likely to flow, and it is sharing its findings with readers →

Dead Plants Are Coming Back

The fastest way to add nuclear power is to restart a reactor that already exists, and the federal government is lending money to make that happen.

In November 2025, the Energy Department's Loan Programs Office closed a $1 billion loan to Constellation to restart the 837-megawatt Crane plant in Pennsylvania, with a target of 2027 after grid operator PJM approved an early interconnection request.⁵ At the end of March, Constellation's chief executive told investors the unit was still on schedule: "we continue to expect to start this unit in 2027."¹¹

On September 8, the Energy Department closed a loan of up to $1.9 billion to NextEra to restart the 615-megawatt Duane Arnold plant in Iowa, which is targeted to return by early 2029 and carries a 25-year power purchase agreement with Google.⁶ The Nuclear Regulatory Commission has issued a draft environmental assessment finding no significant impact from the restart, with the final version expected this fall.¹² NRC officials have said the full licensing bundle could be issued on or before January 29, 2028, if staff conclude the plant can run safely.¹³

Palisades in Michigan is the cautionary tale. Holtec, which owns the 800-megawatt plant, secured a $1.52 billion federal loan guarantee in September 2024 and had expected to be operating at the start of 2026.⁷ On August 30, as fuel loading began, a partially used fuel assembly shifted and was left tilted inside the reactor vessel; Holtec did not disclose the incident until late September and then delayed the restart indefinitely.⁷ Last Wednesday the company announced the assembly had been retrieved and that fuel loading can resume, but it has not given a new date, and its contract commits it to sell power by March 1, 2027.¹⁴

New designs are hitting milestones too. By Independence Day, four advanced reactors, from Aalo Atomics, Antares Nuclear, Valar Atomics and Deployable Energy, had reached criticality with Energy Department authorization, beating the goal of three that President Trump set in a May 2025 executive order. Energy Secretary Chris Wright put it this way: "we have surpassed that ask and delivered four!"³ Last week, X-energy, Amazon and American Electric Power announced a feasibility study for 12 Xe-100 small modular reactors totaling 960 megawatts on a former coal site in Sullivan County, Indiana, with Amazon funding the development work as part of a goal of more than 5 gigawatts of new nuclear capacity by 2039.¹⁵ Holtec plans two of its own small reactors at the Palisades site and says they should be producing power by 2031.¹⁶

Governments Are Racing Too

Companies are not the only ones in a hurry. At the Nuclear Energy Summit in Paris on March 10, China, Brazil, Italy and Belgium joined the Declaration to Triple Nuclear Energy by 2050, bringing the total to 38 countries, up from the 25 that launched it at the COP28 climate talks.¹⁷ When four more governments, including China and Brazil, sign the same pledge in the same year that Big Tech is signing 20-year nuclear contracts, the direction of policy is not in doubt.

In Washington, the push has come from the top. President Trump's May 2025 executive order set the criticality goal that four reactors beat.³ On August 27, the White House declared a national emergency over foreign-made equipment on the power grid and gave the Energy Department 120 days to write rules. Energy Secretary Wright had framed the stakes bluntly in May: "What's the most important source of energy for AI? Electricity."¹⁸

On October 21, the President went further on Truth Social, writing that "New and large, in some cases gigantic, Data Centers are mandated by me to make their own electricity" and telling the industry to "MAKE DEALS, and get them built!!!" It was a post, not an executive order, and it is unclear whether any formal action will follow.¹⁹ But the message to data center builders was plain: bring your own power. For a company trying to find clean, firm, dedicated supply, that means nuclear.

The next round of global climate talks, COP31, runs from November 9 to 20 in Antalya, Turkey.²⁰ Watch it for new signatories to the tripling pledge.

The Fuel Is the Chokepoint

Every reactor restart, uprate and new build runs into the same wall: fuel. Uranium has to be mined, converted, enriched and fabricated, and each of those steps is concentrated in a handful of companies and countries.

Prices show the strain. Cameco's month-end indicators put the uranium spot price at 89.63 on September 30 and the long-term price at 96.50, against 82.63 and 83.00 a year earlier.²¹ The long-term price, which is what utilities pay under multi-year contracts, has moved more than spot, which tells you buyers are locking in supply rather than waiting. In its second-quarter results, Cameco said it is "seeing durable demand growth" and that it has contracts for average annual deliveries of more than 28 million pounds of uranium over the next five years, with its average realized price up 18% from a year earlier.²² Its third-quarter results are due Friday, October 30.²²

✓ Trusted partner See the research behind this story →

Enrichment is the tightest link. The Prohibiting Russian Uranium Imports Act, signed in May 2024, barred imports of Russian enriched uranium from August 11 of that year through 2040, but allowed the Energy Department to grant waivers until January 1, 2028, capped at 464,183 kilograms this year and 459,083 kilograms next year.²³ After that date the waivers end, and whatever the United States cannot enrich at home it must buy from allies.

Domestic capacity is being built, but slowly. On June 2, Urenco USA announced plans to add 2.1 million separative work units of capacity at its plant in Eunice, New Mexico, on top of an existing 4.3 million, with the first new cascades starting production in 2032 and a separate 700,000-unit expansion due in 2027.²⁴ As reported in early July, Centrus signed a contract with the Energy Department to finalize a $900 million task order to expand production of high-assay low-enriched uranium, the fuel most advanced reactors need, at its Piketon, Ohio plant, with options bringing the total to $1.07 billion. The first new commercial capacity is expected by 2029, with an initial 12 metric tons a year of the advanced fuel and enough conventional capacity to work through a $2.4 billion backlog.²⁵

Put the dates side by side. Russian waivers end at the start of 2028. Crane targets 2027, Duane Arnold 2029, the Indiana reactors sometime after a feasibility study, and new enrichment arrives in 2027, 2029 and 2032, most of it after the waivers end. Demand is arriving faster than supply, and in a commodity market that is the condition under which prices rise and the owners of existing supply get paid.

Where the Money Tends to Flow

This is not a story about one company. It is a story about a supply chain that was starved for thirty years and is now being asked to double. The money tends to flow to five kinds of businesses.

First, fuel: miners with pounds in the ground and contracts already signed, converters, and the few Western enrichers adding capacity. Cameco's five-year book of more than 28 million pounds a year is what a contracted fuel business looks like.²² Second, uprates. Squeezing 890 megawatts out of 11 reactors that already exist, as Constellation is doing for Google, is faster than building new, and the customer signs for 20 years.¹ Third, restarts. A closed plant with a valid license, a federal loan and a 20- or 25-year buyer is a rare combination, and there are only so many of them.⁶

Fourth, the small reactor supply chain: the designers that have already reached criticality, the fuel makers that can supply them, and the engineering firms that build the sites. Four designs went critical this year with government sign-off, and a 12-unit project in Indiana has one of the world's largest companies paying for its development.^3, 15 Fifth, utilities and generators that already own reactors on grids where data centers are landing. The Google agreements and the Microsoft deal for Crane went to a company that owned the plants before the AI boom began.

Note what is not on the list: the data centers themselves. They are the customers. In every contract described in this report, the technology company is the one paying, often for decades, and the energy company is the one collecting.

In every contract described in this report, the technology company is the one paying, often for decades, and the energy company is the one collecting.

What Could Go Wrong, and What to Watch

The honest case against this story is that nuclear has disappointed before, and this year offered fresh examples. Palisades was supposed to be running at the start of 2026 and is now delayed indefinitely after a fuel-handling incident the owner took weeks to disclose.⁷ A Reuters report citing a PJM analysis suggested Crane might not reconnect to the grid until 2031; Constellation's chief executive has said the restart will not face a delay of several years.¹¹ The Duane Arnold licensing bundle is not due until January 2028 and the plant itself not until 2029.^13, 6 Even Google's uprates may not deliver power until 2028.¹⁰

Cost and scale are the other risks. The World Nuclear Industry Status Report projects that small modular reactors will supply no more than 5% of nuclear generation by 2050.⁴ A proposed six-reactor campus in Kentucky is estimated to need at least $60 billion and its developer has already dropped a stock offering planned for this year.¹⁵ Regulators move at their own pace, neighbors object to restarts and retrieval plans, and every one of these projects depends on a technology industry that keeps spending at a record rate. If AI capital spending slows, so does the demand that underpins every contract in this report.

Here is the calendar. Cameco reports third-quarter results on Friday, October 30.²² COP31 opens in Antalya on November 9.²⁰ The NRC's final environmental assessment for Duane Arnold is expected by the end of the year.¹³ Palisades must finish fuel loading, complete testing and obtain NRC approvals before it can run, and its contract clock runs out on March 1, 2027.¹⁴ Crane is targeted for 2027, the Russian waivers expire on January 1, 2028, and the Duane Arnold licensing decision is due by January 29, 2028.^{5, 23, 13}

Thirty years ago the world decided it did not need more nuclear power. The companies building the future of computing have decided otherwise, and they are backing that decision with contracts that run past 2040, federal loans in the billions, and a fuel supply chain that cannot keep up. The question for investors is no longer whether the comeback is real. It is which parts of the chain get paid first.