Freudenbergite: A Possible Synroc Phase for Sodium‐Bearing High‐level Waste

Abstract

Earlier studies have shown that the presence of excess sodium in high‐level nuclear waste can give rise to increased leachability when the waste is incorporated in Synroc‐type titanate ceramics. Freudenbergite (Na 2 Al 2 Ti 6 O 16 ) can incorporate sodium and it exhibits satisfactory leaching resistance in water and reasonable resistance to radiation. From X‐ray diffraction studies, freudenbergite is compatible with the other phases in Synroc. Thus, Synroc containing freudenbergite as an additional phase offers potential for immobilizing sodium accompanying high‐level nuclear fuel reprocessing waste.