Demonstrating the safety of disposal facilities for mining and minerals processing waste

Mining and minerals processing waste is characterized by large volumes and long half-lives. In this respect, it differs from the operational and institutional radioactive waste which is normally disposed of in near surface repositories. Technical and economical constraints usually limit management options to near or above surface disposal. Consequently, reliance has to be placed, to a large extent, on engineered barriers. Since these cannot be expected to last for long periods of time, it is not possible to achieve a 'walk away' solution. Long term, essentially perpetual, maintenance and care will therefore be required and safety assessments cannot be based on the assumption that active and passive institutional control will cease after a period of, for example, 300 years as is usually assumed for near surface disposal facilities. The implications of these particular boundary conditions are discussed with emphasis on regulatory aspects, radiological criteria and approaches to safety assessment. (author)