Home Care In Diablo, CA

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.

Advocates 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 The plant also lacks safe long-term storage for nuclear waste, and uses an outdated cooling system that causes extensive and substantial harm to the marine environment.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 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.

While state and federal agencies continue to decide the fate of Diablo Canyon nuclear power plant, San Luis Obispo County wants to study another way the facility’s power-generating life might be extended.

That would be by adding new nuclear reactors.

On Tuesday, the San Luis Obispo County Board of Supervisors approved a $25,000 contract with Solestiss, a Maine-based nuclear energy consulting firm, to assess the economic impact of keeping Diablo Canyon open for another 20 years.

A $10,000 portion of the study will investigate the feasibility of developing a new advanced large-scale nuclear reactor and small modular reactors.

Small modular reactors — or SMRs — are reduced, theoretically easier-to-assemble reactors that can be more conveniently located near power-hungry areas than traditional plants, but this emerging technology does not yet exist in the United States beyond the design stage.

State law currently prevents new nuclear power from being built in California, but some SLO County supervisors hope the Solestiss study can help change that.

“California currently faces legislative obstacles to future nuclear development,” Supervisor Dawn Ortiz-Legg told The Tribune. “This study will examine those challenges and help identify pathways to responsibly expand nuclear technologies.”

One proposed state law, AB 305, seeks to exempt small modular reactors — or SMRs — from the nuclear plant building moratorium.

“The nuclear industry is rapidly evolving, and one reality is clear: the demand for clean, reliable and abundant energy will continue to grow,” Ortiz-Legg said.

However, others on the board see the study as a political effort through use of a pro-nuclear company to lobby in support of such legislation.

“Overall, it looks to me that the Solestiss contract is an attempt by a board majority to develop promotional materials for their position on extending operations at Diablo Canyon,” Supervisor Bruce Gibson told The Tribune.

The contract approval came just days before the California Coastal Commission’s decision to extend Diablo Canyon’s operations until 2030.

Solestiss CEO Brook Morrison told The Tribune the company cannot comment on contractual details, but she said her educational and professional background in environmental stewardship responsibilities for lands contaminated by the United States’ nuclear energy programs represents the values of Solestiss.

“I bring a deep passion for environmental stewardship to solving our nation’s unprecedented energy demand challenges today,” Morrison said.

What will the Solestiss study entail?

Over nine weeks, Solestiss will prepare a 20- to 30-page white paper assessing the economic impacts of approving Diablo Canyon for a 20-year term versus the current 5-year extension, according to the contract agreement.

The study will evaluate short-term — five-year — operational cost, jobs creation and revenues generated by taxes and exporting excess power. It will also include a short section comparing the economic contributions of nuclear power in countries with energy mixes similar to California’s, like the United Kingdom or Ontario, Canada.

Five to 10 pages of the paper will be dedicated to a high-level feasibility overview of the regulatory, technical, economic and logistical requirements for developing new reactors in SLO County, including an advanced, full-sized AP1000 pressurized water reactor and small modular reactors.

The contract did not specify if these technologies would be proposed as replacements or additions to the plant’s current pressurized water reactors.

The study will look at the state and federal regulatory pathways for these technologies, seismic and environmental land-use considerations, financing options, timelines, economics benefits and risks and integration with California’s energy grid and goals, according to the contract. It will not, however, provide detailed engineering designs for SMRs or advocate on behalf of the county.

The contract states the overview will be “forward-looking and non-binding” and draw from ongoing SMR projects, citing initiatives from SMR companies like NuScale Power and GE Vernova Hitachi Nuclear Energy as examples.

However, no SMR projects have broken ground in the United States.

There were in development worldwide as of Sept. 30, but only two were operating commercially: the KLT-40S in Russia and HTR-PM in China. Both projects had longer development timelines, higher costs and lower initial capacity factors than expected, according to a Stanford University fact sheet on SMRs.

NuScale holds the only Nuclear Regulatory Commission certified SMR design in the country, but the company canceled the deployment of its first design, originally set to launch next year, due to timeline delays and cost overruns. Its updated design was approved in May, with an operational goal of 2030.

Meanwhile, GE Hitachi is building the first SMR in North America in Canada at the Darlington Nuclear Generating Station, with the first of up to four units aiming to be operational by 2028.

The Trump administration has made significant investments in nuclear power, overhauling the Nuclear Regulatory Commission and vowing to launch new nuclear technologies like SMRs within two and a half years, according to executive orders signed in May.

With this new boost, the Solestiss study may position Diablo Canyon to benefit from some of these federal subsidies and shortened regulatory timelines, if state legislation allows down the line.

The results of the Solestiss study will be presented at a future county board meeting when completed.

How long will Diablo Canyon stay open?

Solestiss’ study will evaluate the economic impacts of keeping Diablo Canyon open for another 20 years, but the plant currently only has state approval for a five year life-extension.

PG&E originally planned to shut down the plant’s two reactors in 2024 and 2025, before the state Legislature passed SB 846 in 2022 — directing PG&E to keep Diablo open to support California’s electrical grid until 2030.

Even with the state Legislature’s blessing, PG&E needs to secure multiple permits to keep the plant operating.

On Thursday, the California Coastal Commission gave PG&E a coastal development permit to continue operating the power plant until 2030.

Then, in February, PG&E must get a permit from the Central Coast Regional Water Quality Control Board to operate the once-through cooling system. Next year, the U.S. Nuclear Regulatory Commission will consider whether to award PG&E a 20-year license to operate the plant.

Even if the U.S. Nuclear Regulatory Commission approves a 20-year license, PG&E can only run the power plant for five years — as authorized by current state law. The state Legislature would need to pass another law to allow PG&E to operate the power plant past 2030.

PG&E is aware of the Solestiss study, but the company noted that small modular reactors are currently prohibited by state law.

“While we have studied extensive options for future activities at Diablo Canyon, that has not included SMR evaluation due to the state prohibition,” PG&E said in a statement.

PG&E has other priorities at the moment.

“At Diablo Canyon, we are focused on continuing to safely provide four million Californians with clean, reliable, affordable electricity through 2030, and possibly beyond should the state need Diablo Canyon longer to ensure grid reliability and a clean energy supply,” PG&E’s statement said.

SLO County supervisors support responsible nuclear power

The SLO County Board of Supervisors unanimously passed the Solestiss contract in Tuesday’s consent agenda, but only three of the five supervisors are all-in on extending Diablo Canyon’s operations another 20 years instead of five, Gibson said.

“I’m not necessarily opposed to it operating longer — it is indeed carbon-free electricity,” he said. “Any extension past 2030, however, would take new state legislation‚ and that legislation would certainly once again look at the need for and cost of Diablo power, as well as safety and reliability issues and its environmental impacts.”

Gibson said he is supportive of looking into new nuclear technology like SMRs, but doing so would require a thoughtful and objective approach, which he is unconvinced Solestiss can provide.

He said that, as an adviser to and advocate for nuclear power developers, Solestiss would likely provide an “enthusiastic endorsement” of extending the plant’s life by setting a low bar for the feasibility of SMRs and positing Diablo Canyon as a great place to host the budding technology.

“Solestiss is in the business of promoting and developing SMRs,” he said. “ ... I just don’t expect a particularly objective analysis to result from it.”

Ortiz-Legg, however, sees the study as a recognition of the county’s critical leadership in the field of nuclear energy as home to California’s last operating nuclear power plant.

“We also recognize the extensive regulatory processes required for any nuclear project, and we understand that progress will not happen overnight,” she said. “Our goal is simply to ensure that we are doing everything possible to voice our support for the industry, highlight the remarkable expertise and institutional knowledge at Diablo Canyon and promote our region as a leading center for nuclear energy.”

Gibson is less convinced.

“When Diablo was heading for decommissioning, we were well into envisioning a post-Diablo economy here is SLO County — we will adapt to its eventual closure, whenever that happens,” Gibson said.

California environmental regulators on Thursday struck a landmark deal with Pacific Gas & Electric to extend the life of the state’s last remaining nuclear power plant in exchange for thousands of acres of new land conservation in San Luis Obispo County.

PG&E’s agreement with the California Coastal Commission is a key hurdle for the Diablo Canyon nuclear plant to remain online until at least 2030. The plant was slated to close this year, largely due to concerns over seismic safety, but state officials pushed to delay it — saying the plant remains essential for the reliable operation of California’s electrical grid. Diablo Canyon provides nearly 9% of the electricity generated in the state, making it the state’s single largest source.

The Coastal Commission voted 9 to 3 to approve the plan, settling the fate of some 12,000 acres that surround the power plant as a means of compensation for environmental harm caused by its continued operation.

Nuclear power does not emit greenhouse gases. But Diablo Canyon uses an estimated 2.5 billion gallons of ocean water each day to absorb heat in a process known as “once-through cooling,” which kills an estimated 2 billion or more marine organisms each year.

Some stakeholders in the region celebrated the conservation deal, while others were disappointed by the decision to trade land for marine impacts — including a Native tribe that had hoped the land would be returned to them. Diablo Canyon sits along one of the most rugged and ecologically rich stretches of the California coast.

Under the agreement, PG&E will immediately transfer a 4,500-acre parcel on the north side of the property known as the “North Ranch” into a conservation easement and pursue transfer of its ownership to a public agency such as the California Department of Parks and Recreation, a nonprofit land conservation organization or tribe. A purchase by State Parks would result in a more than 50% expansion of the existing Montaña de Oro State Park.

PG&E will also offer a 2,200-acre parcel on the southern part of the property known as “Wild Cherry Canyon” for purchase by a government agency, nonprofit land conservation organization or tribe. In addition, the utility will provide $10 million to plan and manage roughly 25 miles of new public access trails across the entire property.

“It’s going to be something that changes lives on the Central Coast in perpetuity,” Commissioner Christopher Lopez said at the meeting. “This matters to generations that have yet to exist on this planet ... this is going to be a place that so many people mark in their minds as a place that transforms their lives as they visit and recreate and love it in a way most of us can’t even imagine today.”

Critically, the plan could see Diablo Canyon remain operational much longer than the five years dictated by Thursday’s agreement. While the state Legislature only authorized the plant to operate through 2030, PG&E’s federal license renewal would cover 20 years of operations, potentially keeping it online until 2045.

Should that happen, the utility would need to make additional land concessions, including expanding an existing conservation area on the southern part of the property known as the “South Ranch” to 2,500 acres. The plan also includes rights of first refusal for a government agency or a land conservation group to purchase the entirety of the South Ranch, 5,000 acres, along with Wild Cherry Canyon — after 2030.

Many stakeholders were frustrated by the carve-out for the South Ranch, but still saw the agreement as an overall victory for Californians.

“It is a once in a lifetime opportunity,” Sen. John Laird (D-Santa Cruz) said in a phone call ahead of Thursday’s vote. “I have not been out there where it has not been breathtakingly beautiful, where it is not this incredible, unique location, where you’re not seeing, for much of it, a human structure anywhere. It is just one of those last unique opportunities to protect very special land near the California coast.”

Others, however, described the deal as disappointing and inadequate.

That includes many of the region’s Native Americans who said they felt sidelined by the agreement. The deal does not preclude tribal groups from purchasing the land in the future, but it doesn’t guarantee that or give them priority.

The yak tit?u tit?u yak ti?hini Northern Chumash Tribe of San Luis Obispo County and Region, which met with the Coastal Commission several times in the lead-up to Thursday’s vote, had hoped to see the land returned to them.

Scott Lathrop is a member of the tribe’s board and has worked on the issue for several years.

“The sad part is our group is not being recognized as the ultimate conservationist,” he told The Times. “Any normal person, if you ask the question, would you rather have a tribal group that is totally connected to earth and wind and water, or would you like to have some state agency or gigantic NGO manage this land, I think the answer would be, ‘Hey, you probably should give it back to the tribe.’”

Tribe chair Mona Tucker said she fears that free public access to the land could end up harming it instead of helping it, as the Coastal Commission intends.

“In my mind, I’m not understanding how taking the land ... is mitigation for marine life,” Tucker said. “It doesn’t change anything as far as impacts to the water. It changes a lot as far as impacts to the land.”

The deal has been complicated by jurisdictional questions, including who can determine what happens to the land. While PG&E owns the North Ranch parcel that could be transferred to State Parks, the South Ranch and Wild Cherry Canyon are owned by its subsidiary, Eureka Energy Company.

What’s more, the California Public Utilities Commission, which regulates utilities such as PG&E, has a Tribal Land Transfer Policy that calls for investor-owned power companies to transfer land they no longer want to Native American tribes.

In the case of Diablo Canyon, the Coastal Commission became the decision maker because it has the job of compensating for environmental harm from the facility’s continued operation. Since the commission determined Diablo’s use of ocean water can’t be avoided, it looked at land conservation as the next best method.

This “out-of-kind” trade-off is a rare, but not unheard of way of making up for the loss of marine life. It’s an approach that is “feasible and more likely to succeed” than several other methods considered, according to the commission’s staff report.

“This plan supports the continued operation of a major source of reliable electricity for California, and is in alignment with our state’s clean energy goals and focus on coastal protection,” Paula Gerfen, Diablo Canyon’s senior vice president and chief nuclear officer, said in a statement.

But Assemblymember Dawn Addis (D-Morro Bay) said the deal was “not the best we can do” — particularly because the fate of the South Ranch now depends on the plant staying in operation beyond 2030.

“I believe the time really is now for the immediate full conservation of the 12,000 [acres], and to bring accountability and trust back for the voters of San Luis Obispo County,” Addis said during the meeting.

There are also concerns about the safety of continuing to operate a nuclear plant in California, with its radioactive waste stored in concrete casks on the site. Diablo Canyon is subject to ground shaking and earthquake hazards, including from the nearby Hosgri Fault and the Shorline Fault, about 2.5 miles and 1 mile from the facility, respectively.

PG&E says the plant has been built to withstand hazards. It completed a seismic hazard assessment in 2024, and determined Diablo Canyon is safe to continue operation through 2030. The Coastal Commission, however, found if the plant operates longer, it would warrant further seismic study.

A key development for continuing Diablo Canyon’s operation came in 2022 with Senate Bill 846, which delayed closure by up to five additional years. At the time, California was plagued by rolling blackouts driven extreme heat waves, and state officials were growing wary about taking such a major source of power offline.

But California has made great gains in the last several years — including massive investments in solar energy and battery storage — and some questioned whether the facility is still needed at all.

Others said conserving thousands of acres of land still won’t make up for the harms to the ocean.

“It is unmitigatable,” said David Weisman, executive director of the nonprofit Alliance for Nuclear Responsibility. He noted that the Coastal Commission’s staff report says it would take about 99 years to balance the loss of marine life with the benefits provided by 4,500 acres of land conservation. Twenty more years of operation would take about 305 years to strike that same balance.

But some pointed out that neither the commission nor fisheries data find Diablo’s operations cause declines in marine life. Ocean harm may be overestimated, said Seaver Wang, an oceanographer and the climate and energy director at the Breakthrough Institute, a Berkeley-based research center.

In California’s push to transition to clean energy, every option comes with downsides, Wang said. In the case of nuclear power — which produces no greenhouse gas emissions — it’s all part of the trade off, he said.

“There’s no such thing as impacts-free energy,” he said.

The Coastal Commission’s vote is one of the last remaining obstacles to keeping the plant online. PG&E will also need a final nod from the Regional Water Quality Control Board, which decides on a pollution discharge permit in February.

The federal Nuclear Regulatory Commission will also have to sign off on Diablo’s extension.