ABSTRACTResearch has been carried out to optimize the consolidation stage for the immobilization of pyrochemical wastes with a sodium aluminophosphate glass. The alternative techniques of hot pressing and hot isostatic pressing of the calcined wastes with the glass have been investigated. This has been performed on simulant waste material and the products investigated by scanning electron microscopy and X‑ray diffraction. The consolidation techniques were compared to each other and to the original process for suitability as a waste-form.