The U.S. Nuclear Regulatory Commission (NRC) has approved another 20-year operating license for California’s lone nuclear power plant. The April 2 decision by the NRC means the Diablo Canyon Power Plant, once slated for closure this decade, can operate into the 2040s, though operator Pacific Gas and Electric Co. (PG&E) on Thursday said extending operations past 2030 would require action from state lawmakers.
The NRC’s decision comes after a three-year license renewal process that also included approvals from state and regional agencies including the California Public Utilities Commission, the State Lands Commission, the California Coastal Commission, and the Central Coast Regional Water Quality Control Board. Diablo Canyon, which came online in 1985, supplies about 9% of the state’s total electricity, and about 20% of California’s emissions-free energy, according to PG&E.
“The NRC’s approval of Diablo Canyon’s license renewal application marks an important milestone for California’s energy future,” said Pacific Gas and Electric Company CEO Sumeet Singh. “Diablo Canyon is the state’s largest source of clean energy and a cornerstone of reliability. Every day, we maintain an unwavering focus on operating a safe, reliable, affordable and clean energy system that can meet growing demand in a changing climate. The NRC’s thorough and thoughtful review underscores the strength of our commitment, and we are proud of Diablo Canyon’s continued role in supporting California’s focus on net-zero energy.”
‘Stabilizing Force’ for State Grid
Jeremy Groom, acting director of the NRC’s Office of Nuclear Reactor Regulation, during a license renewal signing ceremony on Thursday, said the two-unit, 2.3-GW Diablo Canyon station continues to be a stabilizing force for California’s electric grid.
“Today’s milestone reminds us that when discipline, science, responsibility and vision all come together, we can build an energy future that is both sustainable and secure,” said Groom. “Diablo Canyon’s procedures and oversight have evolved throughout the years and through rigorous review, continuous inspection and technical refinement. This license renewal reflects that strength of commitment and confidence earned through a thorough and transparent NRC review.” Groom also noted the operating license renewal a milestone for the NRC, as it marks the 100th renewal license issued by the agency. The NRC began operating in January 1975 as a successor to the U.S. Atomic Energy Commission.
Thursday’s approval means Diablo Canyon’s two four-loop Westinghouse pressurized water reactors can operate until November 2, 2044, and August 26, 2045, respectively, if state legislators agree. A 2022 state law requires the California Legislature to approve any extension of operations at Diablo Canyon that goes beyond 2030.
PG&E in 2016, as part of a decision reached along with labor and environmental groups, had said it would retire Diablo Canyon’s Unit 1 in November 2024, with Unit 2 going offline in August 2025. A series of power outages during a 2020 heat wave, and new projections about increased power demand in the state, led lawmakers in 2022 to pass Senate Bill 846. That legislation, signed by Gov. Gavin Newsom, directed Diablo Canyon to run through 2030 for its grid reliability and clean energy supply. PG&E in 2023 submitted its license renewal application to 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 statement Thursday.
“Throughout the license renewal process and our more than 40-year history, we’ve demonstrated our constant commitment to operating Diablo Canyon with safety at the forefront,” said PG&E Senior Vice President and Chief Nuclear Officer Paula Gerfen. “It’s a privilege to continue powering California’s clean energy future, and we realize we must earn the right to do so every day by operating at the highest levels of safety, performance and reliability.”
A 2025 report from the California Energy Commission found that “[electric] system reliability is expected to continue to significantly improve due to [several factors that include] the near-term retention of Diablo Canyon Power.” The commission has said it expects peak electricity demand in California will grow by more than 20 GW by 2045. PG&E also noted that extending Diablo Canyon operations through 2030 will bring annual financial benefits of $450 million due to avoided greenhouse gas emissions.
The Diablo Canyon plant employs about 1,300 workers. It is one of the largest private employers in San Luis Obispo County, located in California’s Central Coast region.
—Darrell Proctor is a senior editor for POWER.
