The Diablo Canyon Power Plant, which accounts for about 9% of California’s in-state electricity generation, received federal approval on Thursday to extend operations for up to 20 more years.
The Nuclear Regulatory Commission said it will issue Pacific Gas & Electric — the investor-owned utility in Central and Northern California that operates Diablo — a license that stretches through 2045.
However, existing state law authorizes Unit 1 at Diablo Canyon to remain open through Oct. 31, 2029, and Unit 2 until Oct. 31, 2030. So it would require an act of the Legislature and the sitting governor of California to keep the only existing nuclear power plant in the Golden State up and running until 2045.
PG&E officials and Gov. Gavin Newsom celebrated the announcement from the NRC.
“Today, I welcome the Nuclear Regulatory Commission’s approval as we continue California’s clean energy transition, creating good-paying jobs, fighting climate change, and cementing the Golden State as a global powerhouse,” Newsom said in a news release.
The license extension of Units 1 and 2 “mean Diablo Canyon will continue to provide critical 24/7 carbon-free electricity as California navigates growing electricity demand and hotter summers, while continuing investments in grid reliability and additional clean energy resources,” the governor’s office said in the release.
The power plant’s two units provide 2,240 megawatts of electricity to the state’s grid.
Keeping Diablo Canyon open marked a significant change of course by Newsom.
When he was lieutenant governor, Newsom helped shape discussions that led to a 2016 agreement to close the plant in 2024 and 2025.
But in August 2020, California limped through two consecutive days of blackouts, with some parts of the state experiencing outages lasting as long as 2 1/2 hours. The following summer, the California Independent System Operator narrowly avoided a repeat when high temperatures blanketed nearly the entire state for days.
In 2022, Newsom spearheaded an effort in Sacramento to pass Senate Bill 846 to keep Diablo open to enhance grid reliability and reduce the risk of future outages. The bill, which included lending $1.4 billion to PG&E, zoomed through the Legislature and Newsom signed it into law.
“I am so excited my heart is just going to pop out of my chest,” PG&E senior vice president and chief nuclear officer Paula Gerfen said Thursday during a news conference, according to the San Luis Obispo Tribune.
Opponents of nuclear power denounced the NRC extension.
Linda Seeley, spokesperson for San Luis Obispo Mothers for Peace, questioned the long-term safety of the 41-year-old plant and the cost of keeping it running, among other issues.
“Diablo Canyon is not needed to meet our energy needs,” Seeley said, suggesting the money it takes to run the plant would be better spent on renewable energy and battery storage projects. “It’s a financial boondoggle.”
Edwin Lyman, director of nuclear power safety at the Union of Concerned Scientists, worries about potential earthquakes in and around Diablo Canyon.
“Given the substantial amount of public money for restoring this plant, which is essentially a subsidy, it’s not at all clear why some of that subsidy should not be going toward making seismic improvements and significantly reducing the seismic hazard” at Diablo, Lyman said.
Peter Jones, policy director at the Del Mar-based Samuel Lawrence Foundation, raised similar concerns, pointing out that the NRC last month granted an exemption and waived its Advisory Committee on Reactor Safeguards to review the license renewal application for Units 1 and 2.
“You just need to make sure that you have the right safeguards and that you follow the process that has been in place for decades,” Jones said, “and short-circuiting that is just irresponsible.”
At Thursday’s news conference, NRC representative Jeremy Groom said safety “remains the guiding principle of every action taken here … Diablo Canyon is a facility unlike any other.”
California has committed to derive 100% of its electricity from carbon-free energy sources by 2045, if not sooner.
Proponents of nuclear energy tout that its power plants do not emit greenhouse gases and that Diablo is California’s largest single source of carbon emissions-free energy. But critics say the nuclear waste left behind at commercial sites — and the federal government’s inability to find a permanent repository to send the spent fuel — undercuts the notion that nuclear fission can be described as a renewable energy source.
Unit 1 at Diablo has produced electricity since May 1985 and commercial operations at Unit 2 started in March 1987. The power plant covers about 12 acres near Avila Beach in San Luis Obispo County.