Overview of the clay-mineralogy studies presented at the ‘Clays in natural and engineered barriers for radioactive waste confinement' meeting, Brussels, March 2015

This special issue of Clay Minerals contains 13 full papers presented at the 6th conference on ‘Clays in natural and engineered barriers for radioactive waste confinement’ held in Brussels during 2015. The conference was organized by the Belgian Agency for Radioactive Waste and Enriched Fissile Materials (ONDRAF/NIRAS) together with partner organizations ANDRA (France), COVRA (The Netherlands), NAGRA (Switzerland), NWMO (Canada), POSIVA (Finland) and SKB (Sweden) and a broad international scientific committee. Since 2002, this conference has developed into the most important event for scientists from the world over, dealing with the disposal of highly and long-lived radioactive waste. After each of these conferences, a special issue of a journal was published which focused on clay radioactive waste (radwaste), research which has contributed in a significant way to the outstanding scientific level of the research in this field ( e.g . Landais & Aranyossy, 2011; Landais et al ., 2013; Norris et al ., 2014). Therefore, Clay Minerals - Journal of Fine Particle Science , is happy to be able to provide the present compilation of recent HLW-disposal research in clay mineralogy in an open access issue. Most of the 13 papers published in this special 2016 issue were taken from the session on alteration processes. Papers from this conference which focus on large-scale geological characterization, general strategies for clay-based disposal systems, geomechanics, or mass and gas transfer will be published in a ‘Special Publication’ of the Geological Society of London. Many countries have chosen to dispose of all or some of their radioactive waste in facilities constructed in stable geological formations. Geological disposal as a safe solution for the long-term management of radioactive waste is in line with international recommendations and practices. The development of a geological disposal facility at a specific site requires a systematic and integrated approach taking …