The US Nuclear Regulatory Commission (NRC) has approved Pacific Gas and Electric Company’s (PG&E’s) 20-year licence renewal application for extended operations of Diablo Canyon Power Plant. The approval follows a public process through which NRC determined that Diablo Canyon is safe and environmentally sound to operate for another 20 years. Unit 1’s operating licence will now expire on 2 November 2044, and unit 2’s will expire on 26 August 2045.
NRC’s review of the licence renewal application addressed safety and environmental matters. Both a safety evaluation and a final supplemental environmental impact statement were issued in June 2025. The NRC issued the renewed licenses after receiving documentation from PG&E of the required federal certifications under the Coastal Zone Management Act and the Clean Water Act.
The three-year licence renewal process 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.
However, extending operations beyond 2030 for the plant’s two 1,100 MWe Westinghouse-designed 4-loop pressurised water reactors will require action from the California Legislature. PG&E had agreed with environmental and labour groups in 2016 to retire Diablo Canyon’s unit 1 in November 2024 and unit 2 in August 2025.
Then, in 2022, after statewide rotating power outages during a heat wave in 2020 and new energy demand projections, California lawmakers passed and Governor. Gavin Newsom signed Senate Bill 846, directing Diablo Canyon to operate until 2030 for its grid reliability and clean energy supply. In 2023, at the California State Legislature’s direction, PG&E submitted its licence renewal application to the NRC.
“The NRC’s approval of Diablo Canyon’s licence renewal application marks an important milestone for California’s energy future,” said PG&E 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.”
Acting Director of the NRC’s Office of Nuclear Reactor Regulation Jeremy Groom noted: “Diablo Canyon’s procedures and oversight have evolved throughout the years and through rigorous review, continuous inspection and technical refinement. This licence renewal reflects that strength of commitment and confidence earned through a thorough and transparent NRC review.” He added that Diablo Canyon’s licence renewal marked the NRC’s 100th renewed operating licence for a US power plant.
“Throughout the licence 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.”
The NRC approval marks the end of PG&E’s multiyear journey to gather the necessary state and federal permits to keep its facility online. In December 2025, PG&E received a key permit from the California Coastal Commission by agreeing to give up 12,000 acres of nearby land for conservation in exchange for the loss of marine life caused by the plant’s operations. In February, the Central Coast Regional Water Board approved waste discharge permits for the plant and granted a certification under the Clean Water Act, the last step required before NRC could issue its final approval.
A 2025 report from the California Energy Commission (CEC) 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.” CEC expects peak electricity demand to grow by more than 20 GWe by 2045. Diablo Canyon’s extended operations through 2030 include financial benefits of $450m a year due to avoided greenhouse gas emissions. The plant employs nearly 1,300 employees.
Groups that oppose the plant are taking steps to prevent the plant’s continued operation. The California Coastkeeper Alliance has filed a petition asking the State Water Resources Control Board to cancel the facility’s water discharge permit. The group alleged that the Central Coast Regional Water Board illegally allowed the facility to continue operating without technology required under the federal Clean Water Act to protect marine life. Other groups have petitioned the board to limit Diablo Canyon’s Clean Water Act certificate to 2030, rather than 2045.
