The Department of Energy says advanced nuclear reactor designs – many of which have so far existed mainly at the experimental, testing, or demonstration stage – generally pose limited environmental risk and can qualify for a streamlined environmental review for future projects.
The DoE announced the “categorical exclusion” for advanced nuclear reactors (ANRs) in a Federal Register filing on Monday, establishing a pathway that can allow ANR projects to proceed without a full environmental assessment or environmental impact statement under the National Environmental Policy Act (NEPA), provided specific conditions are met. The move follows Trump’s executive orders directing agencies to streamline environmental reviews for nuclear reactors in order to accelerate their deployment.
A categorical exclusion means that a covered category of actions “normally does not significantly affect the quality of the human environment and therefore does not require preparation of an environmental assessment or environmental impact statement,” the filing says. In this case, that’s referring to ANRs, which include Generation III+ reactors, small modular reactors, microreactors, and stationary and mobile reactors.
Authorization, siting, construction, operation, reauthorization, and decommissioning of ANRs are all included in the categorical exclusion.
The DoE justified its decision in a written record of support, arguing that safety features of next-generation reactor designs generally limit their potential environmental impact.
“Advanced nuclear reactors have key attributes such as safety features, fuel type, and fission product inventory that limit adverse consequences from releases of radioactive or hazardous material from construction, operation, and decommissioning,” the DoE said in the record of support, while conceding that most advanced reactor designs have yet to move beyond experiments and demonstrations.
“Although past advanced reactor projects have been for solely experimental, testing, and demonstration purposes … these reactors indicate that reactors in this category developed for additional purposes, such as power production and industrial applications, are also appropriate for this categorical exclusion,” the document explained.
The DoE’s move isn’t entirely surprising given Trump’s executive orders cited in the Federal Register publication specifically ask the DoE to establish categorical exclusions for ANRs. Additionally, the DoE reportedly quietly rewrote other nuclear safety documents to streamline reactor projects recently, eliminating hundreds of pages of requirements, loosening groundwater protections, and increasing radiation exposure limits for personnel, among other changes.
Nonetheless, the DoE’s Office of Nuclear Energy told The Register that, contrary to the definition of a categorical exclusion stated in the Federal Register publication, nuclear reactors would still undergo an environmental review under NEPA.
“The U.S. Department of Energy is establishing the potential option to obtain a streamlined approach for advanced nuclear reactors as part of the environmental review performed under NEPA,” a Nuclear Energy spokesperson told us in an email.
“The analysis on each reactor being considered will be informed by previously completed environmental reviews for similar advanced nuclear technologies,” the spokesperson continued. “This methodology is a win for bipartisan supported NEPA reform and will accelerate licensing of advanced reactors while upholding the highest standards of safety and security.”
The Union of Concerned Scientists’ nuclear power safety director, Edwin Lyman, disagrees, telling us the DoE’s move cuts corners that will create a public health and environmental safety risk.
“The test reactor designs currently under construction have primarily existed on paper. This lack of real-world experience with the reactors means that they should be subject to more rigorous safety and environmental reviews before they’re built, not less,” Lyman told us. “Any nuclear reactor, no matter how small, no matter how safe it looks on paper, is potentially subject to severe accidents.”
As Lyman noted, most of the ANR designs that the DoE wants to exempt are still in the development phase. Only a single pair of Generation III+ nuclear reactors has been constructed in the US, and those came online in 2023 and 2024, respectively, at the Vogtle nuclear power facility in Georgia.
Small modular reactors, microreactors, and other fantasy generators are still the stuff of dreams. Just one SMR design has cleared US regulatory approval, and none has yet been built and operated, with at least one project already abandoned. Nonetheless, Energy Secretary Chris Wright claims the US will have at least one SMR up and running before the 4th of July in 2026.
Given how far behind the nuclear industry is in deploying reactor designs that are still the stuff of dreams, it’s going to need as many regulatory rewrites as possible. ®