The Department of Energy (DOE) Model 9975 Package is used to store plutonium bearing materials at the Savannah River Site (SRS). The plutonium is packaged in a 3013 container which consists of a convenience container, an inner welded container, and an outer welded container . All containers are made of stainless steel. A portion of the population of 3013 containers have plutonium oxide with alkaline earth chloride salts. Temperatures and temperature gradients within the 3013 container are useful to evaluate the transport of water vapor and potential corrosion in the inner container, particularly near the weld region. Thermal analyses of plutonium oxide packaged in 3013 containers which are stored in 9975 shipping packages were performed with emphasis on the temperatures and temperature gradients between the plutonium oxide and the inner container weld region. Thermal analyses investigated various plutonium oxide fill levels, heat generation, plutonium oxide thermal conductivity and 9975 package boundary conditions.
Not surprisingly, the results suggest the source heat is mostly dissipated radially outward as opposed to the vertical direction, and the 9975 package is insensitive to an adiabatic top and bottom surface boundary condition versus an adiabatic bottom surface assumption. The temperatures at locations of interest, such as the inner container weld region and the plutonium oxide centerline temperature may be correlated as a linear function of thermal loading and ambient temperature.