Diablo Canyon Redux: Joint Letter to CA Governor Misfires

A letter to Governor Newsom signed by prominent academics and others is urging further extension of the Diablo Canyon nuclear power plant’s operating life, shortly after Stanford and MIT researchers released a report (reviewed here) with the same recommendation. Both assume inaccurately that running Diablo Canyon after its operating license expires in 2025 would cost much less than zero-carbon alternatives. Both include other significant errors and omissions, reflecting in part the authors’ failure to consult with any of the numerous parties – including the plant’s owner, workers, host communities, NRDC, and other environmental groups -- who spent years developing and negotiating a long-term plan to retire and replace Diablo Canyon with zero-emission resources.

Diablo Canyon Nuclear Power Plant

The letter’s supposedly “new” arguments for life extension were considered and rejected repeatedly in public proceedings before both state and federal decision-makers between 2016 and 2021. The signers likely don’t know that and haven’t reviewed the replacement plan, and NRDC hopes they will join us and others in supporting much more affordable and practicable approaches to decarbonizing California’s economy. We all share that crucial objective, and this disagreement involves only one of numerous potential solutions.   

The letter to Governor Newsom is premised on the false notion that Diablo Canyon is being “prematurely shut down;” in fact, the Diablo plant is expected to operate through August of 2025, which marks the end of its 40-year federal license. The letter concedes that California law requires that Diablo Canyon be replaced without triggering any increases in emissions of greenhouse gases or other pollutants.  The letter acknowledges further that the California Public Utilities Commission (CPUC) has recently issued a comprehensive procurement order establishing a detailed implementation plan to ensure compliance with the state mandate. A diverse portfolio of zero-emission resources will replace Diablo Canyon at significantly lower cost than refurbishing it to run longer.  

The letter also mistakenly equates the San Onofre and Diablo nuclear plant retirements, arguing that because San Onofre’s closure in 2013 triggered additional fossil fuel generation, Diablo Canyon’s retirement will have the same result. But San Onofre closed suddenly and unexpectedly following massive equipment failures, with no opportunity to plan for long-term zero-carbon replacements. By contrast, the 2016 Diablo Canyon agreement left nine years for remedial action, which is now underway, overseen by the Public Utilities Commission.

Most of the claims in the letter to the governor have been litigated unsuccessfully before both the CPUC, the California Court of Appeal, and most recently the Federal Energy Regulatory Commission. The FERC decision came just this past March. Diablo Canyon’s owner, Pacific Gas & Electric Company, has withdrawn and will not renew its application to the federal Nuclear Regulatory Commission to extend the plant’s 40-year federal operating license. Diablo Canyon will retire in 2025. Governor Newsom, who as a member of the State Lands Commission cast a key vote in favor of the retirement plan back in 2016, has no legal authority to extend that deadline.

Shortly before Mr. Newsom cast that vote, the New York Times editorialized strongly in favor of the Diablo Canyon retirement proposal, calling it “a positive example for other states and nations that may in time need to replace aging nuclear plants.” It was indeed, and always will be.  

About the Authors

Ralph Cavanagh

Energy Co-Director, Climate & Clean Energy Program

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