Modeling of fission product adsorption in zeolite packed column for molten salt treatment

Metallic alloy fuels from fast reactors are reprocessed by a non-aqueous electrochemical technique known as electrorefining. This results in the accumulation of heat generating fission products especially Cs-137 in the eutectic salt. These fission products need to be removed from the salt so as to reduce the decay heat load and contamination. Numerical studies have been conducted in COMSOL 6.0 to simulate Cs⁺ adsorption in a zeolite column. The developed model is validated by comparing the predictions for breakthrough curves with experimental data available in literature. The numerical model could predict the breakthrough behavior and concentration profile in the mass transfer zone for cesium adsorption in zeolite at a superficial velocity of 0.5 cm/min better as compared to that at 3.3 cm/min. The numerically predicted breakthrough time for Cs uptake in Zeolite-4A at superficial velocities of 3.3 cm/min and 0.5 cm/min had deviations of 0.94 % and 2.3 % respectively from the experimental data available in literature. Considering axial dispersion, the model is extended to other fission products like Sr²⁺, Ba²⁺, and Nd³⁺, showing improved predictions compared to previous model available in literature.