Durability of an La2Zr2O7 waste form containing various amounts of simulated HLW elements

Phase evolution and chemical durability of co-doped Gd2Zr2O7 ceramics for nuclear waste forms

“…Obviously, the cubic lattice parameters display a gradual increase as the composition parameter x increases in the whole discussed range. Previous study shows that the lattice parameter generally exhibits an approximately linear increase when the smaller cation is replaced by the larger one [20]. However, when the larger cation is replaced by the smaller one it shows a gradual decrease [23].…”

“…Chemical durability in contact with an aqueous solution is one of the most important properties for a nuclear waste form. Since the released actinides can form dissolved or colloidal radionuclide complexes by contacting and reacting with water, and it might finally extend to the biosphere by transportation with underground water flow [20,21]. Furthermore, the prevention of water ingression to the nuclear waste is extremely difficult, which may form water soluble salt and increase the leachability of certain species [22].…”

Solubility of ThO2 in Gd2Zr2O7 pyrochlore: XRD, SEM and Raman spectroscopic studies

“…Gd 0. 8 ThO 2 can act as host lattices for GdO 1.5 but surprisingly, GdO 1.5 gets dissolved in zirconia only, not in thoria as seen by unchanged lattice parameter of thoria through out the compositions ( Table 1). The peak intensity of GSZ phase is higher in Gd 0.8 Th 1.2 Zr 2 O 7.6 compared to that in Gd 0.4 Th 1.6 Zr 2 O 7.8 which is obviously due to higher GSZ content in the former composition than the later one.…”

“…higher thermodynamic stability, lower leachability, higher chemical and radiation stability [4]. The thermal expansion coefficient should not be very high but the thermal conductivity should be high enough [1][2][3][4][5][6][7][8].…”

Synthesis and Rietveld structure refinement of americium pyrochlore Am2Zr2O7

“…In addition, due to their high ionic conductivity, they find a strong usefulness as electrolytes in solid oxide fuel cells [3]. They have also been envisioned in the 80 s as potential hosts for nuclear waste disposal as these compounds should provide both physical and chemical stabilities and exhibit low-leach rates in aqueous media [4]. Several studies have been published on that topic [5].…”