Deep geological repository

There is now a global consensus that the only safe way to store high-level waste is in a deep geological repository. Only then can it be kept away from humans and their environment for long enough. In Switzerland, the KEG, the Nuclear Energy Act, stipulates that all radioactive waste must be disposed of in deep geological repositories.

Measured in human terms, the processes and material cycles that occur in deep and stable geological formations are extremely slow; they are measured in geological time, i.e. millions of years.

A deep geological repository has several different technical and natural barriers. These barriers are designed to manage the containment and retention of radioactive waste and must operate passively, i.e. without the need for monitoring or maintenance, although monitoring is required during the construction/operation/observation phases. In addition, monitoring may be required even after the repository has been sealed. A deep geological repository is designed so that most of the radioactive waste decays in the repository and is rendered harmless. It is neither possible nor necessary to contain all waste indefinitely. However, the storage system, including the technical and natural barriers must prevent radionuclides and other pollutants escaping into the human environment in harmful quantities. Reliable evidence of this is required in the form of a safety analysis, including an assessment of any potential effect on the storage system in the future.