Beyond Nuclear, Inc. v. U.S. Nuclear Regulatory Commission

The D.C. Circuit Court of Appeals denied a petition for review challenging the Nuclear Regulatory Commission’s (NRC’s) 2024 revision of the Generic Environmental Impact Statement (GEIS) for nuclear power plant operating license renewals. The court rejected Beyond Nuclear and Sierra Club’s argument that in determining that the environmental impacts of “severe accidents” during extended operation was “small,” the GEIS did not adequately consider how aging components and climate change affect the risk of accidents involving reactor-core damage. Noting that its review of the GEIS was required to be “substantially deferential,” the D.C. Circuit found that the NRC reasonably addressed the risks of aging and of climate change effects such as storms and flooding. The court stated that “[t]wo high-level considerations frame our analysis.” First, “neither the effects of aging on components nor the effects of climate change on external hazards are themselves environmental impacts that [the National Environmental Policy Act (NEPA)] required the [NRC] to address”; instead these issues were “upstream factors that may increase the likelihood of severe accidents.” Second, the NRC reasoned that its risk estimate would have to increase by more than 10,000% to alter the determination that the environmental impacts of severe accidents were small. Regarding climate change, the court found that the NRC had acknowledged climate-related events but had declined to conduct additional modeling of the future effects of climate change on severe storms because (1) the NRC concluded that such risks were “minimal compared to other risks” such as seismic events and fires, (2) “its overall analysis already included a large buffer that could account for these types of uncertainties,” and (3) “regulatory mechanisms exist to address the issue should circumstances change.” The court further noted that no party had identified “any estimate—or even speculation—suggesting that the impact of climate change on storm severity could put a meaningful dent in the greater-than-10,000 percent buffer for uncertainties in the [NRC’s] analysis.” The D.C. Circuit also rejected the petitioners’ related challenge to the NRC’s decision not to require plant-specific severe-accident mitigation alternatives because that decision also rested on the premise that the GEIS’s consideration of aging and climate change was insufficient.