The deep underground location of the repository in a setting that is not at risk of disruptive geological events and processes and with all access routes sealed ensures that the radioactive waste is safely enclosed for a very long time. Careful selection of a favourable repository site at a suitable depth contributes to the safety functions of isolation of radioactive waste from humans and the environment, immobilisation, retention and slow release of radionuclides and long-term stability of the repository system regarding the long-term geological and climatic evolution, encompassing erosion, neotectonics, and glaciations. The favourable overall geological setting of the repository guaranties stable conditions over geological time periods.