Environmental Orgs Sound Alarm on Extending Diablo Canyon’s Operations into 2045

Aside from the earthquake dangers and potentially brittle structures at Diablo Canyon nuclear power plant, it costs more to run the plant than it makes back in electricity bills. And, Diablo hogs the transmission lines, leaving no space for wind and solar at times. These were among the contentions voiced by a panel convened by a group of environmental organizations, among them the San Luis Obispo Mothers for Peace. About 25 staffers for Sacramento legislators were listening in on August 14, as was the press.

Sacramento will be deciding the long-term fate of Diablo Canyon, after Governor Gavin Newsom punted earlier this month on the question of extending the power plant’s license to 2045, which would match the extension given by the Nuclear Regulatory Commission (NRC).

Newsom started the extension ball rolling in 2022, after owner Pacific Gas & Electric (PG&E) had decided in 2016 to start decommissioning the plant once its licenses expired in 2024 and 2025. But heatwaves hit in summer 2021 and 2022 with the potential to cause brownouts. In addition to pleading with the public to cut power usage, Newsom offered to loan PG&E $1.4 billion to remain in operation through 2030. PG&E, having chosen to shut Diablo down, had been reducing its future repairs and replacements, which the no-interest, forgivable loan was now to help cover. The feds kicked in as well: President Joe Biden authorized $1.1 billion to repay the loan, and last Friday, President Donald Trump gave PG&E $271 million toward the loan from the Civil Nuclear Credit Program.

“PG&E is a financial predator, and in 2022, SB846 invited an unsupervised fox into a hen house where taxpayers and ratepayers were left unprotected” were attorney John Geesman’s opening words during Friday’s forum. A former member of the state Energy Commission and Independent System Operator board, Geesman said a “chasm” existed between PG&E’s costs at Diablo Canyon and the revenue it earned. For example, PG&E was forecasting a $595 million deficit in Diablo Canyon’s operations for 2027. Cumulatively, since November 2024, the power plant showed a $1.7 billion shortfall. PG&E was correct to determine in 2016 that the 40-year-old plant should be shut down, Geesman said.

When it came to the reduction of greenhouse gases through nuclear-generated electricity, Geesman argued that each metric ton saved was costing $71, or twice the price on the carbon credit market. In Senate Bill 846, which authorized the loan and license extension to 2030, 34.5 million metric tons of emissions were projected to be eliminated through 2030. Geesman explained his $71 came from a calculation based on PG&E’s forecasted net costs, plus the state and federal subsidies, or more than $2.5 billion through 2030.

Finance was also on the mind of Peter Bradford, a former NRC commissioner, especially since PG&E’s costs related to Diablo Canyon are being paid by all Californians, not just PG&E customers. For California to continue the exceptions given to PG&E would be imprudent, or unnecessarily risky, he said, risk being an important consideration for both legislators and the Public Utilities Commission. Bradford has been on the utility commissions for Maine and New York, and he said that with increases in electricity costs in California outstripping inflation, other states have found that alternative sources are more economical than an aging reactor. California should take the time to do the same energy procurement analyses, he advised, especially if it was going to consider propping up Diablo Canyon for 15 more years.

For Ed Lyman, who directs Nuclear Power Safety at the Union of Concerned Scientists, the NRC has always been a troubling agency. But after Executive Order 14300 to reform the NRC, the agency’s independence is in greater question, he said. Safety inspections are decreased by half and that the rules, say in response to terrorism, were being rewritten to eliminate security onsite and instead transfer that burden to local law enforcement without concomitant funding.

Beyond safety and finances is the actual function of Diablo Canyon, which is producing electricity. That, too, is an issue. Because of Diablo, almost 30 percent of the solar and wind energy produced in California goes to waste, said Mark Jacobson, a civil and environmental engineering professor at Stanford University. Because a nuclear reactor has no dimmer switch, Diablo Canyon runs full tilt 24/7, but transmission lines carry only a finite amount of energy.

“Wind and solar actually shut down … especially during spring [when] clean renewable energy meets over 100 percent of the demand in California for up to 10 hours a day,” Jacobson said. The consequence was an estimated 29 percent of wasted wind and solar energy in 2026, which is slowing California’s transition to alternative energy sources while raising costs. In other states and worldwide, power produced by wind, water, and solar led to lower electricity prices, Jacobson said, while nuclear and fossil fuels increased prices on the grid.

“The other argument that, well, if we shut Diablo Canyon, we’ll use gas. That’s not true,” Jacobson noted. In California, energy produced by fossil gas has fallen 55 percent since 2023, he said. Solar, wind, and batteries, “That’s what’s going to replace Diablo Canyon.”

Request to PG&E for responses or comment were not returned.