Small-Scale Ion Exchange Removal of Cesium and Technetium from Hanford Tank 241-AN-103

The pretreatment process for BNFL, Inc.'s Hanford River Protection Project is to provide decontaminated low activity waste and concentrated eluate streams for vitrification into low activity and high level waste glass, respectively. The pretreatment includes sludge washing, filtration, precipitation, and ion exchange processes to remove entrained solids, cesium, transuranics, technetium, and strontium. The ion exchange removal of cesium (Cs) and technetium (Tc) ions is accomplished by using SuperLig 644, and 639 resins from IBC Advanced Technologies, American Fork, Utah. The resins were shown to selectively remove cesium and technetium (as pertechnetate), from alkaline salt solutions. The efficiency of ion exchange column loading and elution is a complex function involving feed compositions, equilibrium and kinetic behavior of ion exchange resins, diffusion, and the ionic strength and pH of the aqueous solution. A previous experimental program completed at the Savannah River Technology Center demonstrated the conceptualized flow sheet parameters with a similar Hanford tank sample (241-AW-101). Those experiments included determination of Cs and Tc batch distribution coefficients by SuperLig 644 and 639 resins and demonstration of small-scale column breakthrough and elution. The experimental findings were used in support of preliminary design bases and pretreatment flow sheet development by BNFL, Inc