A cross-disciplinary team from the University of Illinois Urbana-Champaign has submitted a public comment to the U.S. Nuclear Regulatory Commission on a far-reaching proposed rule that would revise reactor licensing, safety oversight, and siting practices across several parts of the NRC's regulations.
Read the full public comment: NRC public rulemaking docket
The comment addresses the NRC's proposed rule, Modernizing Reactor Licensing, Safety Oversight, and Siting Practices, published at 91 Federal Register 44,560 under Docket No. NRC-2025-0975. The proposal includes changes affecting reactor siting, fuel enrichment, quality assurance, license renewal, construction, and the use of risk information in regulatory decisions.
The effort was led jointly by NPRE Professor Zahra Mohaghegh, director of the Socio-Technical Risk Analysis (SoTeRiA) Research Laboratory, and Professor Arden Rowell, associate dean for research in the College of Law. The team also included George Joslin, an NPRE Ph.D. student and SoTeRiA graduate research assistant, and Dr. Seyed Reihani, an NPRE senior research scientist affiliated with the SoTeRiA Laboratory.
Combining expertise in nuclear engineering, risk analysis, and administrative law, the team evaluated whether the proposed rule provides a sufficient technical and legal basis for satisfying the NRC's statutory obligations. The analysis focuses especially on the relationship between the agency's longstanding responsibility to provide reasonable assurance of adequate protection and the ADVANCE Act's newer mandate to regulate efficiently without unnecessarily limiting the civilian use of nuclear energy or its benefits to society.
Key concerns
- Safety evaluation methods, thresholds, and probabilistic risk analysis: The researchers argue that the NRC did not adequately justify how consequence-focused deterministic methods and criteria, including the proposed 25-rem unmitigated-consequence threshold for Tier 1 siting, support a finding of reasonable assurance of adequate protection. Because these methods do not characterize accident likelihood, they are also insufficient by themselves to estimate expected safety risk for cost-benefit analysis. The comment explains that probabilistic risk analysis is necessary to estimate expected safety risk and support cost-benefit analysis under the efficiency mandate, while deterministic and probabilistic risk methods should work together to support adequate protection and regulatory efficiency.
- Comprehensive regulatory analysis: The researchers conclude that the regulatory analysis supporting the proposed rule is not yet comprehensive. Although the NRC quantified some industry and agency implementation costs and selected operating benefits, significant provisions were not separately evaluated for their costs, benefits, or safety effects. These include changes involving fuel enrichment, quality assurance, alternative acceptance criteria, construction, license renewal, and siting in areas of greater population density.
- Balanced treatment of costs and benefits: According to the comment, uneven treatment of quantified and unquantified effects may bias the analysis toward a finding of net benefits. The researchers recommend a more comprehensive assessment of reasonably foreseeable costs, benefits, alternatives, uncertainty, environmental and public health effects, and nonmonetized impacts.
Recommendations
The public comment supports modernization of the NRC's regulatory framework while calling for a stronger evidentiary foundation. As the authors state, "These comments are not intended to oppose the modernization of the NRC's licensing framework." Instead, the submission asks the NRC to demonstrate more clearly how the proposed framework can advance efficient licensing while continuing to protect public health and safety.
The team recommends that the NRC conduct an additional legal and technical review, strengthen the bases for its safety determinations, revise the regulatory analysis, and issue a supplemental notice of proposed rulemaking with another opportunity for public comment before taking final action.
About the project
This submission continues an interdisciplinary collaboration between the SoTeRiA Research Laboratory and the University of Illinois College of Law. The work is supported by the U.S. Nuclear Regulatory Commission through the project Context-Based Analysis of a Risk-Informed, Performance-Based Regulatory Approach for Advanced Nuclear Reactors (Grant No. 31310024M0018). Earlier this year, the researchers submitted interdisciplinary comments on the NRC’s proposed Part 57 rule for advanced reactor licensing, combining engineering analysis with legal scholarship to address emerging regulatory challenges. The research project also includes the team’s public comment on the NRC’s proposed changes to ALARA and related work on modernizing ALARA. Together, these efforts propose a risk-informed framework for integrating adequate protection, regulatory efficiency, uncertainty, and societal benefits in radiation-protection decisions.
The views expressed in the public comment represent the professional judgment of the research team and do not necessarily reflect the views of the University of Illinois Urbana-Champaign or the NRC.