Nuclear materials are transported between mines, mills, enrichment facilities, fuel fabrication facilities, power plants, medical facilities, and interim storage facilities.
Transportation Package Contents
Uranium for fuel enriched to 5 weight percent U-235 or less is currently transported from the enrichment facility as uranium hexafluoride (UF6) in 30-inch-diameter cylinders. These cylinders hold approximately 5,000 pounds of UF6 and are placed in a protective transport overpack. The NRC’s regulations currently require applicants for packages containing UF6 enriched above 5 weight percent U-235 to perform an additional criticality evaluation beyond those performed for packages containing UF6 enriched up to 5 weight percent. Applicants will need to either provide that evaluation or request an exemption, which the NRC staff would review.
Under NRC regulations, applicants must evaluate whether HALEU-containing fuel will maintain subcriticality during transportation. This presents a technical challenge because there are a limited number of critical experiments in the HALEU enrichment range. Among other methods, applicants for package approval could potentially address this challenge by performing new critical experiments in the HALEU enrichment range; performing sensitivity or uncertainty analysis to validate existing critical experiments; adding appropriate margin, or some combination of the preceding options.
Applicants for certificates of compliance for transportation packages for irradiated HALEU-containing fuel designed for light water reactors will likely evaluate the packages using similar approaches to those currently used for non-HALEU certificates of compliance. Further, the NRC staff will likely review these packages using similar approaches to those it uses when reviewing applications for packages to transport non-HALEU. At this time, the NRC staff has not received information on the final fuel form for the HALEU-containing fuel and associated technical issues related to irradiation. The NRC does however have experience in evaluating irradiated TRISO fuel and irradiated metal fuel. The NRC staff will use this experience, to the extent possible, when it evaluates non-light water HALEU-containing fuel.
Page Last Reviewed/Updated Friday, July 07, 2023