The Nuclear Regulatory Commission is proposing to remove a foundational radiation-safety principle that has helped limit radiation exposure in the United States for 50 years and has been adopted internationally.

Under current rules, facilities that use radioactive materials, including nuclear plants, hospitals and academic institutions, must keep radiation exposures “as low as reasonably achievable,” a standard known as the ALARA principle. The NRC proposal would abandon that approach while retaining a separate standard that sets maximum radiation-exposure limits.

The two standards have historically worked together in radiation protection. Dose limits establish the maximum amount of radiation that members of the public and radiation workers may receive, while ALARA requires facilities to keep exposures as low as practical beneath those limits. Research shows that radiation exposure increases a person’s risk of developing cancer, and that risk rises as the dose increases. Because ALARA governs decisions below the legal cap, the proposal centers on how much discretion regulators and operators should have when exposures are already within allowable limits.

The NRC is not proposing to change the dose limits. Instead, the agency, which regulates civilian nuclear energy technologies and radioactive materials, wants to replace ALARA with a “graded approach.” Under that framework, facilities would be required to take different actions depending on the potential radiation dose to workers. More rigorous radiation-protection measures would be required as exposures approach dose limits, in order to ensure those limits are not exceeded.

The proposal comes as President Donald Trump seeks to quadruple domestic nuclear energy production in response to rising electricity demand tied to the growth of data centers and artificial intelligence. Reforming the NRC is one way Trump is trying to accelerate nuclear reactor development. In an executive order last year, he directed the federal agency to “adopt science-based radiation limits.”

The Energy Department, which oversees national energy policy, has already stopped using ALARA. The NRC expects to finalize its radiation-protection regulations in the coming months.

NRC Chairman Ho Nieh said the commission is not reducing safety standards.

“We’re just removing the ambiguity,” Nieh said during a call with reporters. “But the standard for exposure to workers and the public, those are not changing. We’re just putting in place greater clarification.”

Nieh said he does not expect major changes for the nation’s existing fleet of large, traditional reactors. Companies designing and building new, smaller reactors, however, could move more quickly if they have a clearer understanding of radiation-protection requirements, he said. That makes the rulemaking important beyond today’s operating plants, because it could shape how radiation-protection obligations are interpreted for emerging reactor designs.

The NRC said radiation-exposure limits are set well below levels associated with health effects, and the agency expects remaining standards and industry practices to keep radiation doses far below those limits. Facilities also have practical incentives to do so: working in areas with higher radiation is more expensive and time-consuming because access must be restricted and additional surveys are required.

The nuclear industry’s trade association supports the NRC’s position.

“We will always continue to look at what can we do to reduce the dose to workers, and maintain our doses to the off-site public as low as possible,” said Doug True, chief nuclear officer at the Nuclear Energy Institute. “It’s not like we’re just going to throw open the doors and let everything run up to the limits.”

Justin Friedman, a nuclear energy consultant who previously spent three decades at the U.S. Department of State, said ALARA created a “moving target” for regulation. Eliminating the rule would allow NRC scientists to make more rational decisions about appropriate levels of manageable risk, he added.

Edwin Lyman, director of nuclear power safety at the Union of Concerned Scientists, warned that some parts of the NRC proposal could allow higher radiation doses in certain circumstances while still remaining below the cap. He specifically pointed to a proposed change in radionuclide emissions standards.

Radiation exposure for the general public is limited to 100 millirem per year. A typical chest X-ray delivers a radiation dose of about 10 millirem.

The NRC wants to raise its radionuclide emissions standard from a conservative dose of 10 millirem per year to 25 millirem per year. That figure is based on a hypothetical person living in a house at the property line of a nuclear plant.

The NRC says actual public doses would remain far lower because people generally live farther from nuclear sites and because radioactive material disperses through air and water.

Lyman said the NRC should improve ALARA rather than eliminate it, in order to protect the public and workers. He said ALARA has become a political target because some people mistakenly believe it requires radiation exposures to be as low as possible regardless of cost. In practice, he said, the principle allows tradeoffs.

Katy Huff, a former U.S. assistant secretary for nuclear energy, said the requirement may be difficult to regulate in some cases. Huff, now a professor and department chair at the University of Wisconsin-Madison, said additional clarity would improve the regulatory environment without harming the public.

However, Huff said she had expected the NRC to clarify what “reasonable” means within ALARA rather than discard the principle entirely. She said she is open to being convinced that the graded approach will be just as effective.

The National Council on Radiation Protection and Measurements, which was chartered by Congress to provide independent scientific guidance, has not formally weighed in on the proposal. Council president Kathryn Higley said she personally likes some elements of the 180-page document but considers others problematic.

Higley said the NRC should consider the full picture when managing risk. For example, if a worker at a nuclear power plant needs to enter an area where airborne radioactive materials are present, ALARA could lead that worker to wear full personal protective equipment, including a respirator, said Higley, professor emeritus at Oregon State University. That equipment can slow movement and potentially expose the worker to heat stress that may be more harmful than a low dose of radioactivity, she said.

One concern with the proposal, Higley said, is that it keeps the current occupational dose limit for adult radiation workers at 5 rem, or 5,000 millirem, per year. With ALARA in place, average worker doses have been well below that cap.

The International Commission on Radiological Protection recommends an occupational dose averaging 2 rem per year. The NRC previously concluded that matching that standard was not justified because workers were being exposed to less than that amount and because changing regulations is costly.

Higley said the United States may need to align with the international community if ALARA is eliminated.

This story was originally featured on Fortune.com: https://fortune.com/2026/07/26/nuclear-regulatory-commission-trump-safety-principal-radiation-exposure-as-low-as-reasonably-achievable/