(153c) Estimation of Just Suspended Impeller Speed for Hanford Tank Waste Sludge

Several phases exist in the highly radioactive wastes stored in underground tanks at the Hanford Site from previous plutonium production. To transport the sludge from the tanks for processing, high enough velocities must be maintained to prevent the deposition of solid particles in piping. A relationship between impeller speed, impeller height, and particle suspension has been explored experimentally in small-scale (125 mL) and bench-scale (2500 mL) experiments. In this work, computational fluid dynamics models of the experiments are constructed and simulated. The velocity near the bottom of the tank is predicted for several impeller speeds and impeller heights. This velocity is compared with experimental data for the same impeller speed and height to identify the fluid velocity that leads to complete particle suspension.