Chemical Engineering Division waste management programs. Quarterly report, January--March 1975

Development work on the study of consolidation techniques for Zircaloy fuel-cladding hulls included scouting tests on volatility schemes for separating the zirconium as the volatile tetrachloride and ignition tests on several Zircaloy materials to further characterize the pyrophoric behavior of Zircaloy. All tests were with nonirradiated metal pending acquisition of irradiated samples. Installation is nearly complete of a glovebox facility for studies on the salvage of alpha-contaminated metals by pyrochemical methods. Disposal of a major portion of fission product tritium formed in light water reactor fuels by deep- well injection of the low-level aqueous waste from plants reprocessing such fuels is being evaluated. The question of siting is a very important factor in determining the feasibility of this particular disposal option. A review is given of the status of information for U. S. sedimentary basins, the areas most likely to be generally suitable for siting of waste wells. Work on the reliability of high-level-waste canisters included an examination of creep, shot- peening, and subcooling of the filler canister below storage temperatures, as methods of relieving stresses induced in canisters due to differential contraction of canister and glass during cooling. A method was investigated for relieving stresses in calcine-filled canisters. Properties of fission product oxides were examined to elucidate possible adverse corrosive effects at the canister-waste interface. (LK