Why California is shutting down its last nuclear plant

California is not keeping up with the energy demands of its residents.

In August 2020, hundreds of thousands of California residents experienced rolling electricity blackouts during a heat wave that maxed out the state’s energy grid.

The California Independent System Operator issues flex alerts asking consumers to cut back on electricity usage and move electricity usage to off-peak hours, typically after 9 p.m. There were 5 flex alerts issued in 2020 and there have been 8 in 2021, according to CAISO records.

On Friday, Sept. 10, the U.S. Department of Energy granted the state an emergency order to allow natural gas power plants to operate without pollution restrictions so that California can meet its energy obligations. The order is in effect until Nov. 9.

At the same time, the Diablo Canyon nuclear power plant, owned by Pacific Gas and Electric and located near Avila Beach in San Luis Obispo County, is in the middle of a decade-long decommissioning process that will take the state’s last nuclear power plant offline. The regulatory licenses for reactor Unit 1 and Unit 2, which commenced operation in 1984 and 1985 will expire in November 2024 and August 2025, respectively.

Diablo Canyon is the state’s only operating nuclear power plant; three others are in various stages of being decommissioned. The plant provides about 9% of California’s power, according to the California Energy Commission, compared with 37% from natural gas, 33% from renewables, 13.5% from hydropower, and 3% from coal.

Nuclear power is clean energy, meaning that the generation of power does not emit any greenhouse gas emissions, which cause global warming and climate change. Constructing a new power plant does result in carbon emissions, but operating a plant that is already built does not.

California is a strong advocate of clean energy. In 2018, the state passed a law requiring the state to operate with 100% zero-carbon electricity by 2045.

The picture is confusing: California is closing its last operating nuclear power plant, which is a source of clean power, as it faces an energy emergency and a mandate to eliminate carbon emissions.


The explanations vary depending on which of the stakeholders you ask. But underlying the statewide diplomatic chess is a deeply held anti-nuclear agenda in the state.

“The politics against nuclear power in California are more powerful and organized than the politics in favor of a climate policy,” David Victor, professor of innovation and public policy at the School of Global Policy and Strategy at UC San Diego, told CNBC.

Earthquake country
Diablo is located near several fault lines, cracks in the earth’s crust that are potential locations for earthquakes.

Concerns about nuclear plants and earthquakes grew after the 2011 disaster at the Fukushima Dai-ichi nuclear power plant in Japan. On March 11, 2011, a 9.0-magnitude earthquake struck Japan, causing a 45-foot-high tsunami. Cooling systems failed and the plant released radioactive material in the area.

In July 2013, the then on-site Nuclear Regulatory Commission inspector for Diablo Canyon, Michael Peck, issued a report questioning whether the nuclear power plant should be shuttered while further investigation was done on fault lines near the plant. The confidential report was obtained and published by the Associated Press, and resulted in an extensive review process.

The Hosgri fault line, located about 3 miles away from Diablo Canyon, was discovered in the 1970s when construction was in early stages and the NRC was able to make changes to the research and construction plans. Peck’s filing brought attention to another collection of nearby fault lines — the Shoreline, Los Osos and San Luis Bay.

All of these discussions of safety are set against a backdrop of shifting sentiment about nuclear energy in the United States.

“Since Three Mile Island and then Chernobyl there has been a political swing against nuclear—since the late 1970s,” Victor told CNBC. “Analysts call this ‘dread risk’ — a risk that some people assign to a technology merely because it exists. When people have a ‘dread’ mental model of risk it doesn’t really matter what kind of objective analysis shows safety level. People fear it.”

For citizens who live nearby, the fear is tangible.

“I’ve basically grown up here. I’ve been here all my adult life,” Heidi Harmon, the most recent mayor of San Luis Obispo, told CNBC.

“I have adult kids now, but especially after 9/11, my daughter, who was quite young then, was terrified of Diablo Canyon and became essentially obsessed and very anxious knowing that there was this potential security threat right here,” Harmon told CNBC.

In San Luis Obispo County, a network of loud sirens called the Early Warning System Sirens is in place to warn nearby residents if something bad is happening at the nuclear power plant. Those sirens are tested regularly, and hearing them is unsettling.

“That is a very clear reminder that we are living in the midst of a potentially incredibly dangerous nuclear power plant in which we will bear the burden of that nuclear waste for the rest of our lives,” Harmon says.

Also, Harmon doesn’t trust PG&E, the owner of Diablo Canyon, which has a spotted history. In 2019, the utility reached a $13.5 billion settlement to resolve legal claims that its equipment had caused various fires around the state, and in August 2020 it pleaded guilty to 84 counts of involuntary manslaughter stemming from a fire caused by a power line it had failed to repair.

“I know that PG&E does its level best to create safety at that plant,” Harmon told CNBC. “But we also see across the state, the lack of responsibility, and that has led to people’s deaths in other areas, especially with lines and fires,” she said.

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