San Luis Obispo Mothers for Peace and the Environmental Defense Center advocated to shut down the plant due to seismic risks and significant harm to ocean life
Over fierce objections from San Luis Obispo Mothers for Peace, Senator John Laird,the Environmental Defense Center (EDC), and others, the California Coastal Commission today voted to approve PG&E’s coastal development permit and federal consistency certification, allowing continued operation of the Diablo Canyon Nuclear Power Plant through 2045. Read EDC’s comments written on behalf of Mothers for Peace.
Advocates for denial of the permits pointed out that one of the plant’s reactors is embrittled, creating the risk of a major accident on the coast in the event of an earthquake. The plant also lacks safe long-term storage for nuclear waste, and uses an outdated cooling system that causes extensive and substantial harm to the marine environment.
“This is a deeply disappointing day for California’s coast,” said Linda Seeley, spokesperson for Mothers for Peace. “The Commission had a chance to put safety and marine life above corporate convenience — and it failed. PG&E’s cooling system destroys marine ecosystems every single day, and its seismic data are decades old. Approving this permit unnecessarily places the Central Coast at great risk.”
The vote follows a staff recommendation urging conditional concurrence with PG&E’s proposal, despite the plant’s major inconsistencies with the Coastal Act, which requires protection of marine life. Commission staff concluded that PG&E’s once-through cooling system kills billions of marine organisms, resulting in the degradation of more than 14 square miles of nearshore waters annually – an area the size of the nearby city of San Luis Obispo.
Instead of addressing the ongoing destruction caused by the plant’s cooling system, PG&E proposed to offset marine damage by conserving thousands of acres of Diablo Canyon land. The Coastal Commission found that the plan – including easements, trails, and funding for access improvements — was inadequate to fully mitigate the significant harm to the ocean caused by the intake of ocean water and the heating of the marine environment near the plant.
Despite that determination, the Commission caved to PG&E and approved the project under the override provision of the Coastal Act, which allows a coastal-dependent industrial operation in the Coastal Zone if impacts are mitigated to the maximum extent feasible and the benefits of the project outweigh the adverse impacts.
Importantly, PG&E’s plan defers almost half of the proposed conservation area.
“Today’s decision undermines the Coastal Act and the very purpose of the Commission,” said Linda Krop, Chief Counsel for the Environmental Defense Center, which represents Mothers for Peace. “The Commission itself admitted that PG&E’s mitigation fails to offset the destruction of marine life, and the state’s own energy data shows that Diablo Canyon is not necessary to meet our needs. Advances in renewable energy, transmission improvement, and storage can more than make up for energy produced by the nuclear power plant, without any of the adverse impacts.”
Along with Mothers for Peace and EDC, state Senator John Laird pointed out that approving twenty years of operation exceeds the authorization passed by the state legislature in 2022.
“The Commission’s vote to approve twenty more years of operation at this aging plant goes well beyond the legislature’s authorization allowing operations for, at most, five years,” said Jane Swanson, spokesperson for Mothers for Peace, referring to the California legislature’s passage of SB 846. “The Commission’s action was not based on any evidence of need beyond 2030. In fact, the Commission could have limited its approval to a five-year permit. To add insult to injury, the Commission is putting millions of Californians in jeopardy should an earthquake occur. Diablo Canyon sits in one of the most seismically active coastal zones in the state, surrounded by multiple intersecting faults that could rupture together in a large, complex earthquake.”
The Commission’s staff report dismisses this risk, relying on outdated single-fault models and PG&E’s own limited studies to claim the plant is safe. Independent experts, including geophysicist Dr. Mark Legg, warn that this flawed analysis ignores the potential for many faults rupturing simultaneously, producing far stronger ground shaking than the plant was designed to withstand.