Objective of this session is to bring together scientists working on the different, but primarily mineralogical, aspects of the back end stage of the nuclear fuel cycles as well as radionuclides migration in the geosphere: novel nuclear waste disposal materials (confinement matrices), the corrosion of spent fuel and HAW glass dissolution of wasteforms, sorption of radionuclides onto minerals, mineralogical and geochemical aspects of disposal of nuclear waste, actinide solid state chemistry. Mineralogical aspects that impinge on the management of geological disposal of radioactive waste are also welcomed. This session provides a forum for wide interdisciplinary discussions aimed on the improvement of the safety case for the disposal of radioactive wastes.