The U.S. Nuclear Regulatory Commission (NRC) is proposing to eliminate a foundational radiation safety principle that has been in place for 50 years and adopted globally. The change comes as the Trump administration seeks to accelerate the development of nuclear energy to meet surging demand.
Currently, facilities using radioactive materials, including nuclear power plants, hospitals, and academic institutions, are required to keep radiation exposures "as low as reasonably achievable" (ALARA). This principle has worked in tandem with dose limits, which set the maximum permissible radiation exposure for the public and workers. The ALARA principle ensured that exposures were kept as low as practical within those limits.
The NRC's proposed replacement is a "graded approach." This would require facilities to take specific actions based on the potential radiation dose to workers, with more stringent measures implemented as exposures approach the established limits. The NRC maintains that the maximum dose limits themselves will not change and that the new approach will provide greater clarity without lowering safety standards.
NRC Chairman Ho Nieh stated that the commission is "just removing the ambiguity" and that the standard for public and worker exposure remains the same. He suggested that while the change may not significantly impact existing large reactors, it could expedite the development of new, smaller reactor designs by providing clearer regulatory requirements.
Research indicates that radiation exposure increases cancer risk, with the risk escalating as the dose increases. The NRC asserts that existing dose limits are set well below levels associated with health effects, and other standards and industry practices are expected to keep actual doses significantly lower. The agency also noted that working in higher radiation areas is more costly and time-consuming due to restricted access and increased survey requirements.
The nuclear industry's trade association, the Nuclear Energy Institute, supports the NRC's proposal. Doug True, the institute's chief nuclear officer, stated that the industry will continue to seek ways to reduce worker doses and keep public doses as low as possible, emphasizing that they would not simply allow exposures to rise to the maximum limits.
Some experts believe eliminating ALARA could lead to more rational decision-making regarding manageable risk. Justin Friedman, a nuclear energy consultant, suggested that ALARA's requirement for a "moving target" could be replaced by a system allowing for more scientifically based risk assessments.
However, concerns have been raised about specific aspects of the proposal. Edwin Lyman, director of nuclear power safety at the Union of Concerned Scientists, cautioned that certain revisions could potentially increase permissible radiation doses in specific situations, even if they remain below the caps. Notably, the NRC is proposing to increase its radionuclide emissions standards from 10 millirem per year to 25 millirem per year, based on a hypothetical scenario of a person living at a nuclear plant's property line. The NRC contends that actual public doses would remain much lower due to distance from sites and natural dispersion.
Lyman argued that the NRC should enhance, not eliminate, ALARA to better protect the public and workers, suggesting it has become a political target due to misunderstandings about its practical application, which allows for tradeoffs between cost and exposure reduction.
Katy Huff, a former U.S. assistant secretary for nuclear energy, acknowledged that ALARA can be challenging to regulate but expressed that she had expected the NRC to clarify its meaning rather than discard it. While open to being convinced of the graded approach's effectiveness, she believes increased clarity in the regulatory environment could be beneficial without compromising public safety.
Kathryn Higley, president of the National Council on Radiation Protection and Measurements, indicated that the council has not yet formally commented but finds aspects of the proposal both favorable and problematic. She suggested a holistic approach to risk management, citing an example where strict adherence to ALARA might lead a worker to use protective equipment that causes heat stress, potentially posing a greater risk than a low dose of radiation.
Higley also noted that the proposal maintains the occupational dose limit for adult workers at 5 rem (5,000 millirem) per year. Under ALARA, average worker doses have remained well below this limit. The International Commission on Radiological Protection recommends an average occupational dose of 2 rem per year. Higley suggested that the U.S. might need to align with international standards if ALARA is abandoned.
The U.S. Department of Energy has already ceased using the ALARA principle in its operations. The NRC anticipates finalizing its revised regulations in the coming months.