How Much Will It Cost You to Keep California's Last Nuclear Plant Running?

California regulators had slated Diablo Canyon Power Plant for closure in 2025, following decades of intense opposition to nuclear power and amid growing questions about its seismic safety.

But in 2022, worries about the stability of California’s electricity supply convinced state lawmakers to back peddle and pass legislation to keep the plant running until 2030.

Now, the estimated costs of doing so are in dispute.

Last year, PG&E, which runs the nuclear power plant, asked the California Public Utilities Commission in 2023 to approve a rate hike to cover $5.2 billion in operating costs. A few months later, the company revised that forecast to $8.1 billion, according to filings with the CPUC.

Now, environmental advocates allege PG&E is actually asking for $11.8 billion.

John Geesman, with the Alliance for Nuclear Responsibility, said Thursday he combed through PG&E’s request. The former California Energy commissioner found many hidden costs buried in the fine print.

“This is the salami approach to the utility business,” Geesman said. “Just show them a little piece at a time.”

“The cost increases are divided into small amounts,” Peter Bradford, the former U.S. Nuclear regulator, said. “The argument is always, ‘Yes, it’s unfortunate. We wish we’d known this at the outset, but it won’t cost that much more to go forward.’”

In a statement, PG&E called the $11.8 billion cost estimate “false” and wrote that the advocacy group’s analysis “incorrectly includes billions of dollars” of unrelated costs.

“This is a really bad idea to throw all this money into an aged, dangerous nuclear power plant,” said Linda Seeley with San Luis Obispo’s Mothers for Peace.

Activists called on the CPUC to reject PG&E’s rate hike proposal.

The state regulator–did not immediately return calls for comment.