Maximum Inner Container Dose Rate That Will Ensure Meeting Regulatory Limit at Package Surface - 19206

Often, the shipper of radioactive material does not know the exact radioactive isotopic composition of the materials that need to be shipped. This is especially important for legacy materials that need to be removed from a site that is in the process of being decommissioned. A method of determining the acceptability of such material for shipment before it is placed in into the shipping package will allow more flexibility in planning for decommissioning activities. A series of Monte-Carlo calculations were performed to calculate the dose rate at the surface of a convenience container or a shielding pig separately and then at the surface of a new shipping package being designed by the Savannah River National Laboratory (SRNL). The purpose of these calculations is to determine the maximum dose rate at the surface of the convenience container or the shielded pig that will ensure the dose rate at the outer surface the shipping package is less that the regulatory limit of 2 mSv/h. The calculations also considered the effect of shape of the radioactive material and its possible movement inside the convenience container along with movement of the convenience container inside the confinement vessel of the shipping package. (authors)