Closure of the Diablo Canyon Power Plant

Tatiana Balabanis
March 14, 2019

Submitted as coursework for PH241, Stanford University, Winter 2018


Fig. 1: Photo of the Diablo Canyon Nuclear Power Plant on the coast of San Louis Obispo. (Source: Wikimedia Commons

The Diablo Canyon Nuclear Power Plant in San Luis Obispo, California has been the only active nuclear power plant in the state for quite some time. But the era of nuclear energy in California is coming to an end. In January 2018, the California Public Utilities Commossion announced its approval of Pacific Gas and Electric's request to close the plant. The plant will be fully closed by the time its permits expire in 2025 with a full settlement of $85 million. [1]

Plant's History

Construction on Diablo Canyon first commenced in 1968. The plant became fully operational in 1985. [2] The plant faced a lot of dissent and protest from the San Luis Obispo community, starting from the beginning of construction through 1984. It was intended to be a source of cleaner energy for the state of California. It has been that. Diablo Canyon does not emit greenhouse gases, even though it provides approximately 10% of the state's electric energy. Yet people still protested the construction of this nuclear plant because of the negligence that went into the architectural design of the actual plant. Claims were made that the plant would not be able to withstand an earthquake of the highest possible magnitude given its proximity to the Hosgri fault. Additionally, residents of San Luis Obispo County were quite outraged by the $5.52 billion cost to complete the project.

What's Next

There are a lot of factors that PG&E needs to take into account with the closing of this plant, especially the considerable impact this will have on the community. The plant's closure is anticipated to have a sizable effect on San Luis Obispos school district, causing a few schools to be shut down in the next few years. Luckily, the county has 9 years to prepare for the closure, which a lot more notice than other communities have had when nuclear plants have closed in the past. PG&E has reserved over $210 million to retain its workers until 2025 and has included in its budget over $10 million to retrain workers for whatever the new energy plant may look like. [3] In the short term, customers who receive their electricity from this power plant will see an increase in their monthly bills, but in the long run the closure will not have a significant impact on electricity prices.


The closure of the Diablo Canyon Nuclear Power Plant marks the end of nuclear energy usage in California while also paving the way for new sources of renewable and efficient energy. [4] While nuclear energy has provided a better alternative to fossil fuels, there are still more strides to be made towards renewable energy sources. California will continue to progress towards these kinds of energy sources that are better and better for the environment without compromising the amount of electricity needed to properly and adequately supply the state.

© Tatiana Balabanis. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.


[1] K. Leslie, "Diablo Canyon Will Close in 2025 Without SLO County's $85 Million Settlement," San Luis Obispo Tribune, 11 Jan 18.

[2] L. Koenen, "The Diablo Canyon Nuclear Power Plant, a 48-Year Odyssey," KCET, 25 Mar 11.

[3] R. Nikolewski, "Nuclear Power Receives its Death Sentence in California: Regulators Vote to Shut Down Diablo Canyon," San Diego Union Tribune, 11 Jan 18

[4] I. Penn and S. Masunaga, "PG&E to Close Diablo Canyon, California's Last Nuclear Power Plant," Los Angeles Times, 21 Jun 16.