Comparative overview of dangers, protective measures and risks for the final disposal of radioactive wastes

The purpose of this report is to present an overview of the anticipated risks of geological disposal of radioactive wastes and to compare these to 'conventional' risks, which voluntarily or involuntarily are associated with human activities and have accompanied mankind for long times. Radioactive wastes which result from the generation of electricity by commercial nuclear reactors as well as those originating from research, industrial and medical applications necessitate prolonged isolation from the biosphere to their long-lived, although decaying, toxicity. Chapter 2 of this report contains a survey of the nature and extent of the potential hazard of radioactive waste, drawing attention to the fact that the toxicity of radionuclides is comparable to that of nonradioactive chemical compounds. The possibility of adverse effects on the public cannot be ruled out for either kind of waste. Current plans aim at the safe and effective disposal of radioactive wastes in deep and stable geological formations which should serve as hosts for engineered final repositories. For a final repository to be suitable, the site chosen should be free from circulating groundwater or the free movement of the groundwater must be strongly restricted. In order to prevent radioactive substances migrating away from the final repository in which they have been placed, it is planned to utilise natural and man-made barriers which function largely independently from each other. Thorough knowledge of the properties of man-made barriers, is as important as knowledge of the natural barriers, which are determined by the geology and hydrogeology of the site of the final repository. This principle of protection is known as a 'multiple-barrier concept' and is considered capable of providing safe disposal of radioactive wastes