California group demands Padilla respond to Trump administration’s rebuff of his urgent Diablo Canyon earthquake concerns 

In the wake of sobering tsunami warnings after a massive earthquake struck the east coast of Russia, the San Luis Obispo Mothers for Peace today issued an urgent letter to U.S. Senator Padilla, calling for immediate action in response to NRC decisions renouncing the agency’s commitment to fully evaluate earthquake risks at the Diablo Canyon nuclear plant before renewing the operating licenses held by Pacific Gas and Electric Company.

The Diablo Canyon nuclear reactors, built above a thrust fault, were designed (with NRC approval) to withstand a 7.5 earthquake, despite long-held concerns by seismologists that the fault region could experience a significantly stronger earthquake. An active thrust fault beneath the plant recently disclosed by PG&E, has not been assessed for its capacity to cause a significant earthquake.

According to the group, “decline in the quality of NRC regulation seems inevitable in light of recent reckless Trump administration behavior elevating speed over safety.  We urge you to resist these dangerous new policies by calling the NRC to account and demanding that it adhere to the commitments that it has made to the state of California and to you.”

The group contends that the damage done by NRC’s refusal to address serious seismic risks at Diablo Canyon is compounded by recent Trump orders elevate production of nuclear energy over safety, install DOGE overseers at the top of the agency to slash staffing levels, and require arbitrary reductions in regulations, including minimal standards for radiation exposure.

The administration has also fired the commission’s strongest safety advocate and forced the retirement of other experienced and safety-conscious senior staff.

In 2023, then-NRC Chairman Christopher Hanson committed before congress to a request by Padilla, to evaluate seismic risk to the Diablo Canyon nuclear plant as part of the license renewal process for the reactors.

Chairman Hansen was fired by Trump in June 2025, one month before the NRC refused to review a decision by NRC’s Petition Review Board denying a seismic enforcement petition against continued operation of Diablo Canyon.

The letter, signed by Jane Swanson, board president of San Luis Obispo Mothers for Peace, concludes, “We stress that the NRC made an explicit commitment to you and to your California constituents through the words of its chairman in the presence of the other commissioners and much of the senior staff. We trust that you too are offended by the NRC’s cavalier welching on that solemn commitment in a manner that would endanger much of California in the event of an earthquake comparable to Fukushima or to the one that just occurred in Russia.”

For detailed citations and documentation of the concerns highlighted in the letter, visit mothersforpeace.org/wp-content/uploads/2025/07/2025.07.31-SLOMFP-letter-to-Sen.-Padilla-re-DCPP-.pdf

San Luis Obispo Mothers for Peace
San Luis Obispo Mothers for Peace is a non-profit organization concerned with the dangers posed by Diablo Canyon and other nuclear reactors, nuclear weapons, and radioactive waste. Additionally, the organization works to promote peace, environmental and social justice, and renewable energy.