A major change to nuclear power regulation in the US is on track to take effect before the end of year: the removal of a requirement that nuclear operators keep radiation exposures as low as reasonably achievable, a concept often shortened to ALARA. The deregulatory move follows an executive order issued by President Donald J. Trump in May 2025 that seeks to quadruple the use of nuclear power in the US.
The US Nuclear Regulatory Commission (NRC) proposed in July that the ALARA principle be scrapped because it is inherently ambiguous, making it hard to either codify or enforce, and because it is based on a risk-assessment method called the linear no-threshold model, which the agency says is insufficiently supported by the scientific literature at low exposure levels. The NRC instead proposes to rely on a set of specific numerical radiation-exposure limits that includes different values for various types of nuclear workers and for the public.
A public comment period that ended Aug. 31 drew more than 2,000 responses, echoing the decades-long debate over ALARA as a regulatory foundation and public health tool.
Industry advocates often complain that the use of ALARA is a major contributor to the high price of nuclear power. Under ALARA, in theory, any technical advance that could reduce radiation exposure becomes a new regulatory requirement regardless of implementation and operating costs, even if the exposure it reduces is already below accepted safety limits.
Advocacy groups that focus on nuclear safety, such as the Union of Concerned Scientists, contend that ALARA is an essential safeguard against the for-profit nuclear industry taking shortcuts that put workers and the public at risk. The comments opposing the NRC’s change were mixed between urging the agency to stick with ALARA and contentions that the current regulatory regime is already too permissive.
Another cohort of comments complained about the fast pace of this rulemaking process and asked for extensions. The executive order set a deadline of Nov. 23 for the NRC to finalize this rule along with a slate of other regulatory changes.
Public opinion is divided
Arizona State University professor Majia Nadesan, who studies society-level risk logic and policy, says in her comment on the NRC proposal that ALARA and the linear no-threshold model are the best fit for the health outcome data from large-scale radiation incidents, including the accidents at the Chernobyl and Fukushima Daiichi nuclear power plants and the US’s use of atomic bombs against Japan. “Evidence concerning vulnerable populations, epigenetic mechanisms, chronic low-dose exposure, and ecosystem impacts suggests that existing risk models may underestimate rather than overestimate biological harm,” she says.
Several of the comments opposing the proposed changes say they fail to account for the disproportionate effects of radiation and radioisotope exposure on children and other medically sensitive populations. The nonprofit San Luis Obispo Mothers for Peace provided an analysis and bibliography that link childhood and prenatal exposure to iodine-137 and cesium-137, isotopes that have been historically released by nuclear weapon detonation and nuclear industry accidents, with thyroid cancer and malformation of the lungs, brain, and nervous systems. “When the consequences may be lifelong, the standard of protection must be guided by the best available science, the protection of the most vulnerable, and the precaution that uncertainty demands,” the group writes.
Other comments, however, support the move away from ALARA. “Because it asks licensees to reduce doses below already-conservative regulatory limits without a defined stopping point, it has produced years of inconsistent interpretation between licensees, regions, and even individual inspectors—driving compliance costs and delays that are not tied to any demonstrated reduction in health risk,” writes Mark L. Miller, a radiation safety expert retired from Sandia National Laboratories.
Dow, which has already begun site work to replace a gas-fired boiler at a plant in Texas with a quartet of small modular reactors, supports the abandonment of ALARA. “In practice, there has never been a viable regulatory definition of ‘reasonable,’ and the resulting ambiguity has consistently pushed licensees toward a zero-dose, zero-risk mindset rather than a defensible, risk-informed standard,” the firm writes in its comment. Along with many other proponents, Dow also encourages the NRC to further sideline the linear no-threshold model.
What’s next for ALARA
It will be interesting to see whether an industry consensus forms in support of or opposition to the move away from ALARA, says Michael C. Mims, a partner at the law firm Liskow & Lewis. Dow was one of the few corporations, along with the nuclear power firms Westinghouse Electric and Kairos Power, to participate in the comment period. All three support the change.
Some of the reticence from industry may come from institutional inertia, says Mims, who worked for the NRC on other facets of the agency’s implementation of the executive order but is not currently involved in the comment period proceedings. The NRC estimates that moving away from ALARA will save the industry about $9.5 million per year. But changing practices and retraining staff at already-operating nuclear power plants might be more expensive and risky than staying with their current approaches.
At the same time, the executive order driving the regulatory changes is explicitly intended to accelerate the deployment of new nuclear reactor designs, extend the lifetime of existing power plants, and raise the supply of nuclear energy on the US grid from 100 GW to 400 GW by 2050. “The debate is not simply nuclear advocates versus nuclear critics, but whether deregulation will produce a clearer, more durable safety system or discard a sound principle because it has sometimes been applied badly,” Mims says.
NRC staff will now analyze the comments and prepare a package of responses and recommendations for the NRC commissioners, explains Mims. “A final rule would likely draw litigation from public-interest organizations, labor groups, or states, most probably under the Administrative Procedure Act’s bar on ‘arbitrary’ or ‘capricious’ action,” Mims says. The administrative record is critical, he says, because a court will review the rule based on the evidence and reasoning borne out in that documentation.
