Will California Revive Nuclear Power to Feed AI Energy Demands?

If you’ve used ChatGPT to write a breakup text or figure out how to not burn the Christmas roast, you might’ve actually helped create jobs and profits in California, where the artificial intelligence tool was born.

Unfortunately, you’ve probably also contributed to climate change. Artificial intelligence is an energy hog, and every query to ChatGPT is like running a lightbulb for 20 minutes, a research scientist recently told NPR.

Artificial intelligence is so wasteful, in fact, that its rapid spread could endanger California’s goal of eliminating all carbon emissions by 2045 — even as AI companies may be flooding the state treasury with tax revenue.

The conundrum has legislators considering what was once unthinkable: Bringing back nuclear power as a driver of innovation and economic growth, sort of like it was the 1960s all over again.

Some lawmakers are pushing for exemptions to the state’s 49-year-old moratorium on the construction of new nuclear power plants; they’re also mulling a possible future for the once-left-for-dead Diablo Canyon on the Central Coast, the state’s last operational plant whose operator, Pacific Gas & Electric, said it is prepared for the possibility of the plant staying open longer.

Those are some of the signs of a subtle shift among state legislators and agencies, who just a few years ago seemed assured in their determination to close the book on nuclear power in California. They are being encouraged by a few outside influences: Sweating their own emissions goals, the state’s Big Tech companies have begun national efforts to rejuvenate the carbon-neutral energy source. And last summer, federal lawmakers overwhelmingly passed a bill, signed by President Biden, to accelerate the development of nuclear reactors and new technologies.

“There have been a couple times where there’s been momentum, where people use the word ‘renaissance’” around nuclear energy, said Maureen Zawalick, PG&E vice president of business and technical services. “But nothing like it is now, where there’s bipartisan support, a significant amount of federal funding, programs and incentives.”

Democratic State Sen. Henry Stern, a member of the Senate Energy Committee and an environmental attorney, was mentored by anti-nuclear advocates/environmentalists and has been a critic of Diablo Canyon and PG&E. But he, too, believes “there’s going to be broader and broader bipartisan support to just put this stuff on the table,” he said, referencing certain forms of nuclear energy in the state.

It’s possible artificial intelligence could grow more energy efficient, reducing the need for new power plants. Energy stocks recently sold off after a Chinese company, DeepSeek, unveiled a powerful AI model it said was produced with a fraction of the resources used by its American rivals. The accuracy of those claims and how DeepSeek might change industry practices are hotly debated.

Even assuming AI continues to stoke demand for electricity, nuclear power remains anathema to much of the statehouse, which in the last legislative session kept a measure to partially lift the moratorium bottled up in committee. Reactors are consistent sources of energy but also incredibly expensive to build and maintain, requiring stringent regulatory oversight, staffing, and upkeep. Disposing of radioactive waste is a time-intensive process with potential environmental harms, and there are always concerns of catastrophic outcomes at nuclear facilities: reactor meltdowns, cyberattacks, and other security threats. Building new facilities in the state means lifting the moratorium and clearing not only the federal Nuclear Regulatory Commission but also a thicket of California agencies like the Public Utilities Commission, Water Resources Control Board and, depending on site location, potentially the Coastal Commission and State Lands Commission.

These are among the reasons nuclear power skeptics are dubious of a comeback. Critics similarly question the merits of an emerging, allegedly safer form of nuclear power known as small modular reactors and whether tech companies are committed in their push for nuclear or if they’ll lose interest once they face the inevitable headwinds.

“Nuclear is desperate to seem relevant, new, and improved,” said Sharon Squassoni, a research professor at George Washington University who specializes in the risks posed by nuclear weapons and nuclear energy. Of the use of nuclear power to power AI she added that “it’s a marriage that looks good on paper.”

Big Tech ushers in a round of nuclear hype

Renewed interest in nuclear harkens back to earlier times. President Richard Nixon once called for the construction of 1,000 nuclear reactors in the United States by the year 2000. That moonshot missed by roughly 900 reactors, and there are approximately 90 commercial reactors today.

Tech companies have signaled that they’d like to boost those numbers — and they’ve already taken steps outside of California to harness nuclear power.

Citing the need to add “carbon-free electricity and capacity in the grids where we operate,” Microsoft signed a deal in late September to eventually get one of the reactors at Three Mile Island in southeastern Pennsylvania, site of a partial meltdown in 1979, back up and running. In mid-October, Amazon and Google separately announced agreements with energy companies—one of which, Kairos Power, is based in California—that are in the business of designing small modular reactors. “The grid needs new electricity sources to support AI technologies that are powering major scientific advances, improving services for businesses and customers, and driving national competitiveness and economic growth,” Google wrote in a statement about its deal with Kairos Power.

Meta announced in early December that it was seeking proposals from nuclear energy developers who could help in the pursuit of “AI innovation and sustainability objectives.”

Big tech’s ambitions for new plants are especially focused on small modular reactors. The idea behind the reactors is that they’d function as mini-reactors, producing up to roughly one-third of the energy as a conventional facility, but with factory-designed components that could be shipped to a predetermined location. This would, in theory, cut down on costs, allow for more flexible siting, and reduce the lengthy construction period typical for larger nuclear reactors. The International Atomic Energy Agency characterized proposed designs as simpler and safer than already-running reactors, and more recently, the Department of Energy accepted applications to help fund the design and development of these smaller reactors.

The problem is that small reactors exist more in the abstract than in reality. “They’re totally unproven. They exist basically on a computer,” said Allison Macfarlane, former chair of the Nuclear Regulatory Commission under the Obama administration. “Nuclear reactors aren’t like software or social media products. They’re not fungible in the same way. … You can’t apply the tech bro mentality to these nuclear facilities, but that is what is happening.”

Squassoni released a study in April 2024 (PDF) noting that, “Although they are marketed as new and advanced, small modular reactors so far feature few true innovations among the scores of designs. Quite a few are old wine in new bottles.”

Other than Microsoft’s Three Mile Island investment, and a Bill Gates-backed venture in Wyoming, it’s hard to say which other states could someday house the tech industry’s hypothetical nuclear facilities — small reactors or otherwise. California is currently one of the only states that isn’t an option.

In 1976, a California law placed a moratorium on the development of additional nuclear facility sites in the state until the federal government could come up with a permanent nuclear waste disposal plan. The moratorium was largely in response to environmentalist and anti-nuclear groups in California. Almost five decades later, the federal government still has not figured out a permanent disposal method. Nowadays, spent fuel often ends up in dry casks, which are generally considered a solid, but interim, solution for storing radioactive waste. California remains one of nine states with a nuclear energy moratorium, according to the Department of Energy. Four states have repealed their moratoriums since 2016, and Illinois recently carved out an exemption for the construction of small modular reactors.

In 2013, Southern California Edison announced it would shutter reactors at the San Onofre Nuclear Generating Station in San Diego County due to defects in new steam generators. That reduced California’s nuclear energy arsenal to just the two reactors at Diablo Canyon.

The issues at San Onofre, in addition to the 2011 Fukushima Daiichi nuclear power plant disaster in Japan, further limited California lawmakers’ appetite for nuclear energy. Diablo Canyon was scheduled to shut down beginning in 2024, but those plans have been postponed a half-decade. The site’s two remaining reactors are a vital part of California’s power grid, even more so because of environmental concerns brought about by climate change, as well as the state’s growing energy needs.

The legislators trying to spark a chain reaction in the Capitol

The world’s largest tech companies are racing to train and develop AI tools, which require immense amounts of electricity. The exact metrics, as far as total AI energy consumption is concerned, remain murky, largely because the tech industry has been murky on the subject. It’s clear, though, that tech companies are reliant on big, windowless data centers to power AI, and that these data centers are extremely energy-intensive — and prevalent in California. The Los Angeles Times reported in August that the state has at least 270 data centers, many clustered, perhaps unsurprisingly, in Silicon Valley. Tech companies have eyed dozens more data centers up and down the state, the Times reported.

Those sorts of statistics are a major concern for California lawmakers. “Tech is a new part of the equation because of data centers, AI, and all these things,” said Republican Assemblymember Josh Hoover, a proponent of nuclear energy from the Sacramento suburbs. “The reality is that even before all of that, our grid was not nearly prepared for the energy demands of a clean energy future. And so I am a big believer that nuclear energy needs to be part of that conversation.”

Hoover is referring to California’s power grid and the state’s mandatory transition to 100% carbon-free energy by 2045, under a 2018 measure. California has made significant strides toward the target but scores a low D- rating for its resilience to extreme weather events and other disruptive threats, according to measurements by the nonprofit Grid Clue. Despite an ongoing shift to renewables, California is still heavily reliant on fossil fuels, and its grid is increasingly under peril because of wildfires, heat waves, and other weather events linked to climate change.

Diablo Canyon provides roughly 9% of the state’s electricity, which is partly why Gov. Gavin Newsom supported extending the use of its reactors to 2029 and 2030. “That struck me as a courageous decision and the right decision, and I would hope that that’s reflective of his belief to look at all different energy sources,” said Republican Assemblymember Diane Dixon, who represents Newport Beach.

Representatives for PG&E, which owns and operates Diablo Canyon, have typically adopted a defensive posture when asked about their nuclear facility and the cost overruns it routinely incurs. But the utility company has been singing a different tune lately.

Zawalick, the PG&E vice president, demurred when asked if she thinks Diablo Canyon will ultimately stay open past the station’s latest deadline. “We have to be asked by the state legislators to go longer than 2030,” she said. “But we will be ready, is what I say. And we’re planning to be.” She told CalMatters she hasn’t had any “formal” conversations with tech companies about Diablo Canyon’s future.

Stern described Diablo Canyon as a “cost-suck” and “old,” adding, “If you were building new nuclear, you would not build it like Diablo Canyon.” But Stern conceded that San Onofre’s shutdown strained the state’s energy grid (it also led to more greenhouse gas production), and he’s come to accept Diablo Canyon’s role, at least for now.

Democratic Assemblymember Joaquin Arambula, who represents Fresno and has co-sponsored nuclear energy legislation, also worries “about what would occur if a member of our energy portfolio was taken offline, how that would increase rates for the rest of us.” Hoover echoed Arambula’s view and said he wants Diablo Canyon to stay open indefinitely.

An opening for small modular reactors

Diablo Canyon is one (complicated) piece of the nuclear puzzle. Then there’s the separate conundrum of whether to roll back all, or some, of the state’s nuclear energy moratorium. As it stands, Republican lawmakers are the political faction that has pushed to change the moratorium. Last year, Dixon was a cosponsor of Assembly Bill 2092, which would’ve asked the California Public Utilities Commission to conduct a feasibility studies about the possible benefits and effects of small modular reactors by the beginning of 2027. The bill never got a vote on the Assembly floor.

“It’s good to have stretch goals,” Dixon said of the state’s zero emissions target. “But we have to be mindful of the impact on the local economy, on jobs, and driving businesses out of California. I want to at least start the process to study this important possible new alternative.”

Another recent proposal, Assembly Bill 65, would’ve created a moratorium exemption for the development of small modular reactors. Hoover and Arambula were co-sponsors on AB 65, and Arambula said he hopes to introduce a similar measure in the 2025–26 legislative session.

In April 2023, the last time lawmakers debated the bill to allow small modular reactors, Arambula was one of few Democratic politicians to publicly back pro-nuclear legislation. Los Angeles Democratic Assemblymember Rick Zbur, for instance, told his colleagues he couldn’t support the measure because, while he “used to be someone who believed that nuclear was part of the solution to a carbon-free future,” he changed his views after the 2011 nuclear power plant disaster in Japan. “I don’t think that the California public supports this,” he continued. “I don’t think that we need this to get to a carbon-free future.” (Zbur confirmed to CalMatters that his stance hasn’t changed of late.)

Other prominent Democratic politicians are beginning to sound more bullish on nuclear energy sources. Democratic state Sen. Scott Wiener of San Francisco told CalMatters that he’s noticed “a gradual increased openness among Democrats to nuclear,” and that he thinks nuclear “should certainly be part of the conversation.” Stern, the Senate environment committee member, said he’s interested in giving consideration to some nuclear power bills.

Stern previously authored a law that required the California Energy Commission, in consultation with other state agencies, to write an assessment of commercially feasible energy sources. That assessment, which was released in August 2024, suggested more research and development into small modular reactors and recommended that the legislature pass a law to exempt such reactors from the state’s nuclear moratorium.

In a statement, Newsom’s office left the door open to the possibility of small modular reactors and a nuclear moratorium exemption in California. “The Governor has always maintained an interest in new, promising technologies, including advancements in emerging nuclear power technologies, that follow strong safety, cost, and environmental considerations,” Newsom’s Deputy Director of Communications Daniel Villaseñor wrote to CalMatters.

State Sen. Josh Becker, the new chair of the Senate Energy Committee, also left the door open to nuclear technologies in California: “Climate change is an urgent crisis demanding a comprehensive and proactive response,” the Silicon Valley Democrat wrote in a statement. “To address it effectively, we must consider every viable solution.”

What happens next?

The 2025–26 legislative session will be instructive in showing state lawmakers’ willingness to embrace nuclear energy. Any policy changes in California — followed by a hypothetical nuclear site selection process — would proceed at a slow, methodical pace, the exact opposite of how tech companies prefer to operate.

In addition to needing to get a carve-out from the state’s nuclear moratorium and approvals from various state and federal entities, nuclear plant builders could well face lawsuits and other pushback from anti-nuclear groups.

With all those factors in mind, the legislative session will also reveal whether tech companies feel emboldened to push for nuclear energy sites in California, or if they’re satisfied pursuing their energy needs in other states.

After all, just because many key AI companies are based in California doesn’t mean their data centers have to be. The recent failed bills to permit some kind of nuclear power in California were proposed shortly before tech’s fast and furious incursion into the nuclear energy space and thus weren’t part of the industry’s 2023–24 legislative lobbying efforts. Public support and lobbying for the two bills came from a handful of relatively small pro-nuclear advocacy groups, as well as a handful of labor groups, and the Nuclear Energy Institute, a pro-nuclear trade association.

“It’s too soon to tell how serious these tech firms are about promoting nuclear energy to power their electricity needs,” Squassoni said. “It could be a fad — it could be that once they get a real whiff of the costs and time it takes to build new plants, they may back off a little bit.”

Lawmakers who spoke to CalMatters said they aren’t against tech companies joining in on broader policy debates around California’s energy grid. Hoover said tech’s nascent nuclear interest may “allow for new conversations to happen,” while Wiener characterized the industry’s involvement as a “positive thing,” so long as companies participate in expanded clean energy initiatives that aren’t exclusively nuclear.

Stern, for his part, posited that tech’s interest “certainly doesn’t hurt the zeitgeist around nuclear being a less toxic and scary thing.” He added: “There’s some other incredible tech that, in a lot of cases, beats nuclear from a cost perspective. But it doesn’t quite make sense to me anymore that we don’t let nuclear compete in that contest.”