RADIOACTIVE WASTE DISPOSAL PROJECTS. IDAHO CHEMICAL PROCESSING PLANT TECHNICAL PROGRESS REPORT FOR JULY-SEPTEMBER 1959

The progress of extensive laboratory and pilot plant investigations on the fluidized bed process for the con version of radioactive liquid wastes to solids is reported. These studies are directed toward obtaining information on the dynamics of fluidized bed operation, the removal of volatile fission products and solids particles from gases, the development of equipment and operating techniques, and the various long term disposal aspects of all radioactive wastes. Laboratory studies on the removal of volatile ruthenium from a simulated calciner off-gas showed the removal efficiency of silica gel to decrease with successive wetting and drying cycles. Electrostatic precipitators were found to have a higher removal efficiency for solid particles (alumina) when a wetted wall rather than a dry wall type was used. Tests to determine the distribution of ruthenium in a pilot plant calciner were performed. Pilot plant data on particle growth in a fluidized bed were compared with theoretical equations. Operating experience with a NaK heat transfer system, and with liquid flow controllers is reported. The results of a series of qualitative tests to determine the likelihood of an explosive reaction should NaK leak into a fluidized bed calciner indicated that such a reaction is unlikely. A NaK leak that occurred at a welded junction was attributed to thermal overstressing of the metal and not due to corrosion. Calcium fluoride-impregnated Teflon was found to be a superior gasketing material, both chemically and mechanically, to pure Teflon. A literature survey on the chemistry of zirconium in a calcination process suggested the possibility of calcination in contact with silica and a laboratory unit is being installed to study the process. The hydraulics of a pulsed plate solids-liquid contactor and its associated equipment were determined. A preliminary investigation was started of the possibility of using metallizing techniques to surface coat solid particles and thereby reduce the leaching of fission products when contacted with ground water. Construction of a demonstrational fluidized bed calciner was approximately half completed; however, the national steel strike has slowed the construction schedule and the completion date cannot be estimated until the strike is settled. Process and equipment reviews of the facility and the results of thermal conductivity measurements on Idaho sands are reported. (auth