The effects of oxygen, carbon dioxide and water vapor on reprocessing silicon carbide inert matrix fuels by corrosion in molten potassium carbonate

The molten salt reaction/dissolution method for reprocessing silicon carbide based inert matrix fuels (IMF) is further developed in this paper through comparison of the corrosion rate in multiple gases and gas mixtures. Water vapor was firstly introduced in the SiC/K2CO3 corrosion system. The SiC corrosion rate in the H2O atmosphere was dramatically enhanced 3–4-fold compared to the rate under an O2 atmosphere. The corrosion rates in different atmospheres of O2, CO2, O2/CO2, H2O, O2/H2O and CO2/H2O with various partial pressures were compared in order to determine the optimal reaction atmosphere and to better understand the reaction mechanism. The SiC pellets with 5 wt.% of CeO2, a surrogate for PuO2 were fabricated. CeO2 was successfully separated from the SiC matrix by using the molten salt reaction/dissolution strategy.