FLOWSHEET DEVELOPMENT FOR THE DISSOLUTION OF ALUMINUM-CLAD RESEARCH REACTOR FUELS IN THE SAVANNAH RIVER SITE H-CANYON FACILITY

摘要

The U.S. Department of Energy has authorized thedissolution and recovery of U from High Flux IsotopeReactor (HFIR) and Material Test Reactor (MTR) fuelsby reprocessing at the Savannah River Site H-Canyonfacility. Mercury-catalyzed HNO_3 dissolution flowsheetswere demonstrated for the fuels using an Al-1100 alloywhich provided bounding values for H_2 generation. A Hgcatalyst concentration of 0.002 M was sufficient todissolve Al alloy coupons to a final concentration of≤ 2 M. The potential to generate flammableconcentrations of H2 in the offgas during HFIR and MTRfuel dissolutions was evaluated using experimental datafrom Al-1100 dissolutions. Measured H2 concentrationsin the offgas were scaled-up based on surface areas of thefuel assemblies and compared with 60% of the calculatedH2 LFL at the offgas temperature. Calculations showedthat five HFIR cores can be sequentially dissolved using0.002 M Hg to catalyze the dissolution. Initially, fourL-Bundles immersed to a depth of 1.37 m containing MTRfuel can be dissolved when the solution is allowed to boilfor 45 min prior to starting the Hg addition. The numberof allowable bundles which can be dissolved insubsequent charges was defined as a function of Alconcentration.