Effects of compartmentalized hydraulic conditions on geological disposal systems

Investigation programs for and construction of radioactive waste repositories are carried out worldwide to dispose the accumulated wastes. The existing guides for developing the disposal system include the consideration of site-specific conditions. As most sites can be characterized by having similar geological conditions, the ones with special features require unique solutions. One of these sites is the Bátaapáti site in Hungary which is characterized by its compartmentalized hydraulic conditions. The hydraulic compartmentalization of the site provides favorable conditions for the disposal of radioactive wastes but may also require the development of new disposal concepts and investigation methods. Hydrogeological and total system performance assessment models were used to investigate the possible evolution of the disposal system based on whether or not the hydraulically compartmentalized conditions prevail after the final closure of the repository. The results demonstrate the high sensitivity of the total system performance on a single feature, namely the efficiency of the bulkheads to be constructed in the access tunnels where they had penetrated the compartment boundaries. Based on our investigations we propose to consider hydraulically compartmentalized systems as a favorable alternative for radioactive waste disposal.