Chemical and physical analysis of a select group of high level mixed waste storage tanks at Oak Ridge National Laboratory

The Gunite Tanks have been present at the Oak Ridge National Laboratory since the days of the original Manhattan Project. In the early 1970`s the Atomic Energy Commission removed the kettle-shaped tanks from service, but characterization of the tanks for cleanup has not been carried out in detail until recently. Analysis of the tank contents to determine feasibility for treatability has been successfully carried out on site at the Radioactive Materials Analytical Laboratory. In general, it has been found that the tanks contain an upper layer of liquid, or supernatant, and a lower layer of sludge sediment, in varying proportions with respect to each tank. With both the sludge and supernatant phases, specific analyses have been carried out to quantify important characteristics such as RCRA metals, radionuclides, and anions. Also, Plutonium and Uranium isotopes were determined to satisfy criticality concerns, as well as a modified K{sub D} determination to account for long term movement of radionuclides. In this presentation, four main aspects will be addressed: (1) the unique sampling methods used; (2) the performance of each analyses carried out; (3) a summary of the inorganic and physical data with respect to each tank. and (4) outline tentative plans for dealingmore » with these historic monuments.« less