Engineered barrier systems and the safety of deep geological repositories

Repositories for the disposal of radioactive waste generally rely on a multi-barrier system to isolate the waste from the biosphere. This multi-barrier system typically comprises the natural geological barrier provided by the repository host rock and an engineered barrier system (EBS). The EBS project being conducted by the NEA Integration Group for the Safety Case (IGSC) seeks to clarify the role that an EBS can play in the overall safety case for a deep geological repository. It is in this context that the European Commission and the NEA have prepared the present report, which describes the state of the art for engineered barrier systems and provides a common basis of understanding from which to plan future programmes. It is based on answers to a questionnaire received from 13 countries and 17 organisations. (author)