The US Nuclear Regulatory Commission (NRC) has proposed revisions to 10 CFR Part 71 that would allow transportation package applicants to use risk-informed pathways for demonstrating compliance with required safety levels and provide a higher external radiation limit for certain transportation packages in exclusive-use shipments. The NRC aims to align 10 CFR Part 71 with the recently released 10 CFR Part 53 by allowing transportation of packages with an increased radiation level, specifically loaded microreactors pursuant to Section 53.620(d).
The proposed rule is not a wholesale revision of 10 CFR Part 71. The existing framework would remain available to applicants who are pursuing a Certificate of Compliance (CoC) for a transportation package with the NRC. Applicants who are choosing an alternative compliance method would need to submit the methodology for NRC review before filing a CoC application; the methodology must provide adequate safety during transport and be acceptable to the NRC.
Use of the higher radiation limit would trigger additional transportation and inspection requirements, subject to coordination with other relevant authorities. The NRC requested comments on the proposed rule by August 26, 2026.
Background
The NRC regulates the transportation of radioactive materials and spent nuclear fuel pursuant to 10 CFR Part 71. Under this framework, the NRC reviews applications for and issues CoCs for packages used to transport specified radioactive materials subject to maximum activity limits.
The NRC’s review of 10 CFR Part 71 CoC application focuses on the applicant’s demonstration of how the package meets required safety levels during prescribed normal and hypothetical accident conditions, including thermal, structural, and containment characteristics. The US Department of Transportation (DOT), as co-regulator, separately governs transportation operations, including preparation, labeling, notifications, routing, and operational controls.
The emergence of microreactor technologies may present transportation conditions not contemplated by the existing 10 CFR Part 71 framework. For example, a loaded microreactor may need to be transported without an extended cooling period, resulting in radiation levels that could require additional shielding and make the package too large or heavy for practical transportation.
In parallel with this proposed rule, the NRC has similarly accounted for new transportation conditions in Subpart I of the recently proposed 10 CFR Part 57, which includes provisions to allow the transport of fuel-loaded microreactors as a transportation package or as package contents in a 10 CFR Part 71 certified transportation package.
Proposed Updates
The proposed rule would preserve the existing 10 CFR Part 71 framework while adding the following voluntary alternatives and targeted administrative changes.
Risk-Informed or Performance-Based Approaches.
Proposed Section 71.41(e) would allow an applicant to use “another method of demonstration” in lieu of evaluating a package against the tests specified in Sections 71.71, 71.73, and 71.61. The applicant would need to submit the methodology for NRC review before filing the CoC application, demonstrate adequate safety during transport, and obtain NRC acceptance.
Applicants could reference a previously approved methodology or seek approval of a new one. For example, NRC has previously endorsed a risk-informed evaluation methodology for the Project Pele TRISO-based microreactor transportation package.
Alternative External Radiation Limit.
The current limit of 0.1 millisievert per hour (mSv/h) (10 millirem per hour (mrem/h)) at 2 meters from the vehicle would remain in place. The proposed Section 71.47(b)(3) would create an optional limit of 0.5 mSv/h (50 mrem/h) for certain exclusive-use shipments.
To use the higher limit, the package contents must meet DOT’s “highway route controlled quantity” definition in 49 CFR Section 173.403, and the licensee must coordinate in advance with appropriate federal, state, or local inspection authorities. The coordination must address the shipment’s radiological conditions, applicable controls, and appropriate dosimetry for inspection personnel.
International Lifting and Tie-Down Standards.
The proposed Section 71.45 would adopt internationally endorsed design-load values for package tie-down systems. This revision intends to align NRC requirements with International Atomic Energy Agency guidance to eliminate discrepancies and reduce burdens for applicants who are seeking certification or revalidation of foreign packages.
Reporting and Conforming Changes.
Proposed revisions to Sections 71.17 and 71.95 would facilitate electronic submissions for first-use registrations and required reports. The rule would also add a reference to applicable Federal Motor Carrier Safety Administration requirements in Section 71.5 and remove the unused definition of “spent nuclear fuel or spent fuel” from Section 71.4.
Implementation ConsiderationsThe proposed rule creates new regulatory pathways, which brings new considerations to 10 CFR Part 71 CoC applicants, and opportunities for NRC guidance and interagency coordination.
The proposed flexibility to use an alternative package evaluation methodology would require early planning. The NRC must review the alternative evaluation methodology and find it acceptable prior to use in a CoC application. This sequencing highlights the value of pre-application engagement through which the 10 CFR Part 71 applicant and NRC staff can outline the required steps in the alternative CoC review process for a specific application.
Implementation of the proposed higher radiation limit would also require increased interagency coordination between the NRC and DOT. Specifically, in cases where a package certified by the NRC at 0.5 mSv/h exceeds the corresponding DOT limit under 49 CFR Section 173.441, a shipper would need a DOT exception or special permit prior to transporting a package with the higher radiation limit approved by the NRC.
The CoC holder must confer with appropriate federal, state, or local inspection authorities, in advance of transporting a package with the higher radiation limit, to coordinate with required inspections. This interagency synchronization and the CoC holder engagement with various authorities present an opportunity for the NRC to outline the scope of interagency and CoC holder communications through guidance.
The NRC did not issue implementation guidance along with the proposed rule. Future guidance will be important in clarifying the content and reviewing criteria for alternative methodologies, determining the extent to which an approved methodology may be reused, and managing expectations for coordination with DOT and inspection authorities.
Comments
In addition to general comments, the NRC specifically requested input on:
- Criteria for allowing NRC-approved Type B packages that do not meet the highway route controlled quantity definition to use the optional higher radiation limit;
- Scenarios in which such packages could justify a higher limit, including safeguards needed to minimize public and occupational exposure and the supporting technical basis; and
- Whether the increased dose-rate provision should apply broadly to all radioactive-material shipments or instead be subject to specified criteria, limitations, or circumstances.
The NRC also sought comments on a proposed 30-day effective date, unintended consequences of the proposed changes, cost-and-benefit estimates, and disproportionate economic impact of the proposed changes.
How We Can Help
Our nuclear team stands ready to assist clients as they navigate ongoing updates to the NRC regulations. We continue to monitor the evolution of the NRC’s licensing and oversight frameworks and related opportunities to accelerate commercial nuclear deployment.