ACID LEACHING OF PRODUCTS FRCM THE FLUIDIZED-BED COMBUSTION OF GRAPHITE-BASE REACTOR FUELS AND THE HF-O2 DISINTEGRATION OF STAINLESS STEEL- AND ZIRCONIUM-CLAD OXIDE FUELS

摘要

Combustion of graphite-base reactor fuels and oxidative disintegration of stainless steel- and zirconium-clad oxide fuels in fluidized beds of alumina are being studied as head-end processing methods. Aqueous leaching of the products can provide solutions that are suitable as feeds for conventional solvent extraction purification and recovery processes. This report is a summary of laboratory-scale leaching studies conducted with typical products from unirradiated fuel samples.nGraphite-base fuels containing carbon-coated Th-U carbide or oxide fuel particles are easily burned in oxygen at 700 to 750°C in a fluidized bed of alumina. The product beds are dispersions of Th-U oxides in alumina. Leaching for 3 to 6 hr of typical product beds with boiling 4 to 13 M HKO3 solutions that were also 0.05 M in-HF resulted in thorium ana uranium recoveries of 99-7% or higher. Less than 2% of the alumina (Norton RR) was dissolved.