The Nuclear Regulatory Commission proposed changes to its transportation regulations in preparation for the development of microreactor technologies.
The proposed rulemaking, announced on July 22, would modify Title 10 Code of Federal Regulations Part 71 – or 10 CFR Part 71 – and update package approval requirements suitable for microreactors and new fuel types.
“America’s next generation of nuclear technologies requires a transportation framework designed for today’s challenges,” NRC Chair Ho Nieh said in a press release. “Enabling regulation protects people without slowing down innovation.”
Smaller than traditional large reactors and even small modular reactors (SMRs), many microreactors are designed to be compact enough to be hauled by trucks. This advanced reactor technology could conceivably be transported to remote locations and potential military installations.
The rule will also revise the package certification process to use a more adaptable, “risk-informed” approach and provide an “alternative radiation standard for approval of Type B packages for certain exclusive use shipments,” according to the rulemaking.
A Type B package is a heavily shielded container, built to withstand severe accidents, which holds highly radioactive material, such as spent nuclear fuel.
The alternative radiation standard would likely apply to conditions of transportation of an irradiated microreactor, NRC said. When a licensee cosigns an irradiated microreactor to a carrier to be transported, NRC said that the licensee is required to coordinate with the relevant federal, state or local authorities to ensure they are informed of the higher radiation level limit.
The licensee is also required to ensure that the package materials “meet the definition of highway route-controlled quantity specified in 49 CFR 173.403,” according to the rulemaking.
The proposed rule comes as a part of a series of rulemakings triggered by Executive Order 14300. The executive action, which was issued in May 2025, called for an overhaul of the NRC, including a wholesale revision of its rules and regulations.