Assessment of the U.S. regulations for fissile exemptions and fissile material general licenses

The paragraphs for general licenses for fissile material and exemptions (often termed exceptions in the intemational community) for fissile material have long been a part of the U.S. Code of Federal Regulations (CFR)-10 CFR Part 71, Packaging and Transportation of Radioactive Material. Although Part 71 has been revised to provide consistency with the 1985 Edition of the IAEA Regulations for the Safe Transport of Radioactive Material (IAEA 1985), general licenses that provide for transport of fissile material in nonapproved packages or controlled shipments remain a part of Part 71. More recently, the Nuclear Regulatory Commission (NRC) issued a final rule on Part 71 via emergency rule-making procedures (Federal Register 1997) in order to address an identified deficiency related to one of the fissile exemptions. To address the specified deficiency in a general fashion, the emergency rule adopted the approach of the 1996 Edition of the IAEA: Regulations for the Safe Transport of Radioactive Material (IAEA 1996), which places restrictions on certain moderating materials and limits the quantity of fissile material in a consignment. The public comments received by the NRC indicated general agreement with the need for restrictions on certain moderators (beryllium, deuterium, and graphite). The comments indicated concern relative to both the degree of restriction imposed (not more than 0.1% of fissile material mass) and the need to limit the fissile material mass of the consignment, particularly in light of the subsequent NRC staff position that the true intent (consistent with draft IAEA advisory information) was to provide control for limiting the fissile mass of the conveyance. Even though the NRC emergency rule remains in place, staff at Oak Ridge National Laboratory (ORNL) are working with the NRC staff to perform a coherent review and documentation of the technical and licensing bases for the general licenses for fissile material and the fissile material exemptions. The purpose of the review is to identify potential deficiencies that might be adverse to maintaining adequate subcriticality under normal conditions of transport (NCT) and hypothetical accident conditions (HAC). In addition, ORNL has been asked to identify changes that would address any identified safety issues, enable inherently safe packages to continue to be unencumbered in transport, and seek to minimize the impact on current safe practices. This paper will examine the complex issues that must be addressed in the assessment and will discuss potential recommendations under consideration.