Functional Bounding Content Envelope for Type B Radioactive Material Transportation Packages

There is an increasing need within DOE/NNSA to transport radioactive material items that contain relatively unique mixtures of isotopes and/or impurities that are not currently approved for transportation in a Type B radioactive material transportation package. To reduce the need to develop new addenda to the Safety Basis [i.e., Safety Analysis Report for Packaging (SARP)] to include each additional new contents for a Type B packaging, it would be extremely useful and overall much more cost efficient, to identify and develop a broad bounding content envelope in the safety basis (i.e., SARP) that includes a large variety of isotopes, chemical forms, and impurities (including, light-element impurities). A recent report issued by the DOE presented a comprehensive set of shippable masses of various gamma emitters as well as neutron emitters with varying amounts of beryllium impurities to account for the neutron emissions from the (a, n) reaction in the Model 9977 packaging. This paper extends this set by presenting mass limits for the various actinides combined with varying amounts of light element impurities in the range of 0.1% through 90% by mass of the mixture. The light elements included are: beryllium, boron, lithium, fluorine, carbon, aluminum, magnesium, sodium, silicon, oxygen, and chlorine. In addition to complying with external radiation limits as prescribed by 10 CFR Part 71, the isotopic mass limits in this paper also account for design decay heat limits for bare sources as well as those in a polyethylene shielded container that has been approved for use in the Model 9977 packaging. A new set of mass limits for the gamma emitters that accounts for decay heat limits in an unshielded form or in the approved tungsten and lead shielded containers is also presented. These data will also serve as conservative limits of shippable masses in the Models 9975 and 9978 packagings.