The Nuclear Regulatory Commission should establish a clear floor below which further radiation dose reduction is no longer required, according to a new comment from the Breakthrough Institute submitted as part of the NRC's ongoing overhaul of its radiation protection standards. The institute recommends a de minimis threshold of 1 millisievert (100 millirem) per source per year as the preferred long-term level, though it acknowledges that adopting this standard would require broader coordination with federal agencies. The comment supports the NRC's proposed shift away from the decades-old "as low as reasonably achievable" standard but argues the agency's plan doesn't solve the core problem: the absence of a definitive stopping point for dose reduction efforts.
The NRC is currently revising its radiation protection framework in response to Executive Order 14300, which directed the agency to reconsider both the ALARA standard and the linear no-threshold model that has guided radiation regulation for decades. The proposed rule would replace ALARA with a graded approach that links protection requirements more directly to specific dose thresholds. However, the Breakthrough Institute notes that many of these thresholds primarily trigger administrative measures like instruction, monitoring, and reporting rather than establishing a firm regulatory boundary. If the NRC isn't prepared to adopt the 1 mSv threshold in this rulemaking, the institute recommends either 0.1 mSv (10 mrem) per source as the strongest immediate option within existing federal frameworks, or elevating the currently proposed 0.25 mSv (25 mrem) cost limitation to a full de minimis threshold.
The report emphasizes that a de minimis criterion would differ fundamentally from claiming radiation below a certain dose has no biological effect. The Breakthrough Institute argues the NRC shouldn't require proof of a biological threshold before setting a regulatory boundary, since scientific evidence becomes increasingly unable to resolve effects as doses decline. Instead, the agency should make an explicit regulatory judgment about when additional control is no longer justified. The institute stresses that such a threshold would only end the obligation to pursue further dose reduction—monitoring, reporting, recordkeeping, security, safeguards, and other independent requirements would remain in place. The recommended doses are described as trivial compared to the larger background radiation exposures every person receives annually.
The comment warns that the NRC can't complete this reform in isolation. The Environmental Protection Agency previously withdrew separate radionuclide emission standards for NRC-licensed facilities after determining under Clean Air Act Section 112(d)(9) that the NRC's regulatory program provided an ample margin of safety. That determination relied partly on features of the NRC framework this rule would change, including ALARA terminology, reactor effluent controls, and the numerical envelope the EPA had evaluated. The Breakthrough Institute therefore recommends substantive joint work between the two agencies to establish a renewed and more durable basis for that determination, grounded in the concrete requirements of the revised framework rather than continued reliance on ALARA terminology. With a clear floor, a defined purpose, and a genuine interagency path, the graded approach could ground radiation protection standards in actual risk rather than perpetual dose reduction.