In a significant environmental and energy milestone, federal officials on Thursday renewed the license for Diablo Canyon, guaranteeing that California’s last remaining nuclear power plant will remain open after years of debate about safety, the stability of the state’s power grid, and the role that nuclear energy should play in reducing climate change.
The hulking plant on the San Luis Obispo County coast, 200 miles south of San Jose, provides 9% of California’s electricity, enough for roughly 4 million people.
Built in the 1960s, it had been scheduled to close in 2025. But after a series of heat waves in 2020 and 2021 strained the state’s power grid and caused two brief blackouts, Gov. Gavin Newsom and state lawmakers, on recommendations of state energy planners and dozens of scientists at Stanford, UC Berkeley, MIT, Yale, and other universities, pushed to keep the plant open while the state continues to expand solar, wind, and other renewable energy sources.
Newsom signed a law in 2022 that directed PG&E, the plant’s owner, to take action to extend the plant’s operating license, rather than letting it expire in 2025. The law also provided a $1.4 billion state loan to PG&E to cover plant upgrades and relicensing costs, which was backed by guarantees from the Biden administration.
On Thursday, the Nuclear Regulatory Commission granted Diablo Canyon a 20-year lease renewal, until 2045.
“As California advances its clean energy and reliability goals, Diablo Canyon remains a stabilizing force on a dynamic grid,” said Jeremy Groom, acting director of the nuclear reactor regulation at the Nuclear Regulatory Commission, at a ceremony at the plant with hundreds of cheering PG&E employees. “It provides a steady source of carbon-free power during a period of rapid transition, supporting climate objectives while ensuring that the lights stay on at homes and businesses across the state.”
Newsom praised the decision.
“Tackling extreme weather and supporting a reliable grid are essential to building a safe, affordable, and resilient future for our state,” Newsom said. “Today, I welcome the Nuclear Regulatory Commission’s approval as we continue California’s clean energy transition.”
To operate beyond 2030, PG&E will need further approval from the state legislature.
Some anti-nuclear groups — concerned about earthquake risk and the effect of the plant using more than 2 billion gallons of ocean water a day for cooling — have vowed to fight that.
“We’re disappointed and concerned,” said Haakon Williams, executive director of the Committee to Bridge the Gap, an anti-nuclear group. “The Nuclear Regulatory Commission was always more beholden to industry than it should be. This shouldn’t be received as an assurance of the plant’s safety.”
Operators train in a simulator at the Diablo Canyon Power Plant on Monday, February. 9, 2026, in San Luis Obispo, Calif. (Aric Crabb/Bay Area News Group)
Williams said that because California has built dozens of new battery storage plants since 2020 to store solar and wind power at night, the risk of blackouts and power shortages is much lower than it was only a few years ago.
Conversely, the leader of one of Northern California’s leading business groups, the Bay Area Council, said Thursday that his organization will make it a priority to urge state lawmakers to keep the plant running for at least another 20 years.
“At a time when California is trying to grow its economy, bring down costs and lead on climate, we cannot afford to lose power that is clean, stable and always available,” said John Grubb, interim president and CEO of the Bay Area Council, whose membership includes more than 350 large companies.
“This facility does something incredibly important,” he added. “It keeps the lights on when demand is high, when renewables aren’t enough and when reliability matters most. That’s not theoretical. That’s essential infrastructure.”
In the 1960s and early 1970s, PG&E proposed building numerous nuclear power plants along the California coast, including at Bodega Bay in Sonoma County and Davenport in Santa Cruz County. Due to local opposition, most were never built.
Turbine unit at the Diablo Canyon Power Plant on Monday, February. 9, 2026, in San Luis Obispo, Calif. (Aric Crabb/Bay Area News Group)
The Sierra Club supported the construction of Diablo Canyon. At the time, leaders said nuclear power would be less harmful than coal-fired power or new hydroelectric dams, particularly after PG&E agreed to move the plant from the environmentally sensitive Nipomo Dunes area near the Santa Barbara-San Luis Obispo County line to its location north of Avila Beach. That debate split the Sierra Club, leading to the resignation of its leader, David Brower.
After construction began on the plant in 1968, several previously unknown earthquake faults were discovered. Lawsuits, protests involving celebrities like singer Jackson Browne, studies and redesign work delayed its opening until 1985, when the first of its two massive reactors was finally turned on.
Since then, Diablo Canyon has never had a significant accident.
“Diablo Canyon meets the highest standards of nuclear safety and environmental protection,” said Paula Gerfen, PG&E’s senior vice president and chief nuclear officer, on Thursday, adding, in reference to federal and state authorities approving the license extension: “They are saying we are safe and we are environmentally sound and it doesn’t get any better than that.”
Blackouts and power shortages in 2020 and 2021 posed a major political risk to Newsom and Democrats pushing for the state to achieve 100% carbon-free electricity to combat climate change. Not only was former Gov. Gray Davis recalled from office in 2003 amid energy shortages, but Republicans were attacking California for its lack of reliability five years ago.
“Our leaders were worried about blackouts,” said Severin Borenstein, an energy economist at UC Berkeley. “It was a real concern that this could set back the movement to decarbonize the grid. That opened a lot of people up who had once said ‘we have to get rid of nuclear power’ to the idea we have to continue with Diablo Canyon.”
He noted that although battery storage plants have improved the situation dramatically, most only store 4 hours of electricity.
“Would we make the same decision now to keep Diablo Canyon open that we made a few years ago? I don’t know,” Borenstein said. “We hadn’t had the massive rollout of batteries. But there are still things Diablo Canyon can do that batteries can’t.”
Diablo Canyon Power Plant on Monday, February. 9, 2026, in San Luis Obispo, Calif. (Aric Crabb/Bay Area News Group)
California once had four nuclear power plants. Humboldt Bay near Eureka closed in 1976. Rancho Seco near Sacramento closed in 1989. San Onofre in San Diego County closed in 2013.
No new ones can be built under existing state law. Former Gov. Jerry Brown signed legislation in 1976 that prohibited the construction of new nuclear power plants in California until a permanent repository for spent nuclear waste is established by the federal government.
A plan to build a national nuclear waste storage site in the remote desert at Yucca Mountain, Nevada, stalled in the 1990s over opposition from environmentalists and Las Vegas casino owners. As a result, spent nuclear fuel rods that will remain radioactive for thousands of years continue to be stored on site at many of America’s 54 nuclear power plants, including Diablo Canyon.