Destruction of organics in Hanford tank wastes using high temperature aqueous systems

High temperature hydrothermal processing has been recognized as a possible technology for organic component destruction in Hanford tank wastes. This technology involves the thermal oxidation of organic matter at temperatures of 350 degrees C to 470 degrees C, using nitrate and nitrite already present in the waste as an oxidant for the organic matter. Reactions are studied at pressures near 1 kbar, which are required to keep 3:1 diluted tank waste simulants as single phase solutions. Organic destruction results are presented for both bench-scale (5-15 g/min) and small pilot-scale (50-100 g/min) reactors. Simple kinetic models are presented for a variety of simulant subsets. Gas production rates and product selectivities are also discussed. Issues concerning the applicability of high temperature hydrothermal processing are identified