Thermal treatment of Cs-exchanged chabazite by hot isostatic pressing to support decommissioning of Fukushima Daiichi Nuclear Power Plant

Ion exchange materials are used widely for the removal of radionuclides from contaminated water at nuclear licensed sites, during normal operating procedures, decommissioning and in accident clean-up, such as ongoing recovery operation Fukushima Daiichi power plant. Framework silicate inorganic ion materials, chabazite ((Na0.14K1.03Ca1.00Mg0.17)[Al3.36Si8.53O24]•9.7H2O), have shown particular selectivity towards 137Cs uptake, but their safe storage poses a number challenges requiring conditioning into passively waste packages minimal volume. We demonstrate transformation Cs-exchanged glass-ceramic wasteform by hot isostatic pressing to produce durable consolidated monolith. The application heat pressure resulted collapse framework, forming crystalline Cs-substituted leucite (Cs0.15(3)K0.57(4)Al0.90(4)Si2.24(5)O6) incorporated within K2O-CaO-MgO-Al2O3-SiO2 glass. Cs partitioned preferentially Cs/K-feldspar which ~77% Cs2O inventory. Analysis chemical durability revealed that release rates were comparable or lower than those reported vitrified high level intermediate wastes. Overall, was demonstrated be an effective processing technology spent yielding wasteforms.