Crystallographic Evaluation of Sodium Zirconium Phosphate as a Host Structure for Immobilization of Cesium and Strontium

Sodium zirconium phosphate (NZP) is a potential material for immobilization of nuclear effluents. It was observed up to ~7.16 wt% (~2.67 mol%) of strontium and ~14.46 wt% (~3.56 mol%) of cesium could be simultaneously loaded into NZP formulations without significant changes in the three-dimensional framework structure. The crystal chemistry of Na1−x(Cs1.33Sr1)xZr2P3O12 (x = 0.1–1.0) has been investigated using General Structure Analysis System programming. The CsSrNZP phases crystallize in the space group R-3c and Z = 6. Powder diffraction data have been subjected to Rietveld refinement to arrive at a satisfactory structural convergence of R-factors.