REGULATORY CHALLENGES RELATED TO SHIELDING SAFETY ANALYSES FOR NON-FISSILE RADIOACTIVE MATERIAL TYPE-B TRANSPORTATION PACKAGES

U.S. Nuclear Regulatory Commission (NRC) regulations and NRC staff review guidance for Type B radioactive material transportation package design require that Certificate of Compliance (CoC) applicants demonstrate that the package design meets the regulatory requirements with dose rate measurements as a final check for each shipment. However, for historic reasons, some legacy Type B non-fissile material transportation packages were reviewed and approved based on pre-shipment dose rate measurements. Since that time, NRC experience, regulations and staff review guidance has evolved significantly. Pre-shipment dose rate measurements are no longer considered adequate for this purpose. The NRC staff faced challenges in performing some reviews for Type B transportation packages. Some of the applications for certificate amendments for new contents do not include shielding evaluations that bound the maximum content specifications and if loaded with the maximum allowed contents, packages would not meet regulatory dose rates. In addition, recent experiences also show that a package without appropriate consideration for dose rates during design approval can lead to operational issues. To help address these challenges, the NRC has issued a regulatory issue summary (RIS) that clarifies its use of staff review guidance for the review of content specifications and shielding evaluations included in the CoC and safety analysis reports (SARs) for Type B transportation packages. This paper discusses the staff’s considerations for sufficient demonstration for compliance with the regulation in its review and approval of the legacy packages as well as new Type B package designs in light of the RIS.