OAKLAND — California Attorney General Rob Bonta joined a coalition of attorneys general in submitting a comment letter to the U.S. Nuclear Regulatory Commission (NRC) to oppose its proposed rule to fast-track licensing and deployment of small nuclear reactors that meet certain criteria. The proposed rule would create a new and expedited licensing process applicable to “microreactors” — a class of advanced nuclear reactors the NRC proposes to define by the level of radiological risk and amount of nuclear fuel stored on site. In the comment letter, Attorney General Bonta and the coalition argue that the illegal rulemaking violates the National Environmental Policy Act (NEPA) and the Administrative Procedure Act (APA), as it reduces safety and environmental protections across the country by skirting NEPA analysis.

“Formulating such a broad suite of licensing regulations on untested and experimental technologies is dangerous and puts public health and the environment at risk,” said Attorney General Bonta. "The NRC must not abandon the fundamental mandate Congress assigned it under the Atomic Energy Act: to provide reasonable assurance of adequate protection of the public health and safety, promote the common defense and security, and protect the environment. We can pursue innovation without sacrificing safety.”

On May 1, 2026, the NRC announced its proposal to expedite the licensing process and allow manufacturers to mass produce approved microreactor designs. Microreactors are typically defined as nuclear reactors under 20 MW, and, unlike traditional reactors, they are compact, highly transportable systems that are capable of being fabricated for repeat production and deployment. This rulemaking is intended to implement President Trump’s Executive Order 14300, which directed a wholesale revision of NRC regulations.

Nuclear energy may play a role in providing zero-emission, fossil-free energy that can power technological advances and help ensure reliability. However, microreactor designs to be licensed under this Rule — including unspecified, undefined reactors with “comparable risk profiles” that may also qualify — are largely untested and experimental. Therefore, States’ communities and environments will become the testing ground for these technologies. Among other things, before any Rule is finalized, the States urge the NRC to comply with NEPA by taking a hard look at the reasonably foreseeable environmental impacts from the fleets of microreactors the Rule contemplates.

California has one operating nuclear facility, PG&E’s Diablo Canyon Power Plant, which generates approximately 9% of California’s total in-state electricity generation and roughly 15% of the state’s carbon-free power supply. State law bans development of additional nuclear facilities in California. 

In the comment letter, Attorney General Bonta and the coalition assert that: 

• NRC failed to adequately consider potential environmental impacts of unproven risk models applied to novel, unproven technologies.
• The proposed rule’s licensing regulations would compromise States’ abilities to protect their residents and natural resources.
• The NRC must continue to uphold and apply the conservative design features and safety requirements that have been the hallmark of NRC licensing for decades
• The proposed rule is illegal as it violates the APA and NEPA. 

In sending the comment letter, Attorney General Bonta joins the attorneys general of Delaware, Illinois, Maryland, Massachusetts, New Mexico, Oregon, Vermont, Washington, and the District of Columbia.