The durability of iodide sodalite

An iodide sodalite wasteform has been prepared by Hot Isostatic Pressing of powder produced by hydrothermal synthesis. The wasteform was free of leachable secondary phases which can mask leaching mechanisms. Leaching is by congruent dissolution and leach rates decrease as Si and Al accumulate in the leachate. Differential normalised leach rates are 0.005-0.01 g m−2 d−1 during the 7-14 day period. This indicates that sodalite dissolution in natural groundwater, already saturated in these elements, will be very low.