Retrieval process development and enhancements FY96 pulsed-air mixer testing and deployment study

Millions of gallons of radioactive wastes resides in underground tanks at US Department of Energy sites. The waste was generated primarily by the processing of nuclear fuel elements to remove fissile radionuclides for use in atomic weapons. Plans call for the waste to be removed from the tanks and processed to create immobile waste forms, which will be stored to prevent release to the environment. The consistency of the waste ranges from liquid, to slurry, to sticky sludge, to hard saltcake. a variety of waste- retrieval and processing methods are being evaluated and implemented. One such method is pulsed-air mixing, which is the subject of this report. Pulsed-air mixing equipment has been successfully applied to a number of difficult mixing applications in various chemical-process industries. Most previous applications involved the mixing of particle-free viscous fluids. The study described in this report was preformed to improve the understanding of how pulsed-air mixing applies to slurries. This document describes work conducted to evaluate the potential application of pulsed-air mixers to the slurry- mixing needs of the US Department of Energy's waste-retrieval programs