[en] The validity of the operational licences of the existing Swiss nuclear power plants (NPP) Beznau I and II, Muehleberg, Goesgen and Leibstadt after 31st. December 1985 is, because of official requirements, dependent on the demonstration of permanent, safe management and final disposal of radioactive waste. For this purpose, the NPP companies have to prepare a so-called guarantee project and present this to the Bundesrat for review. The appropriate investigations and research have been carried out by Nagra (National Cooperative for the Storage of Radioactive Waste). The 1985 Project Gewaehr (Guarantee) is described in an eight volume report NGB 85-01 to 85-08 and individual research projects are reported on in separate NTB-series reference reports. The present volume NGB 85-01 takes the form of a self-contained project overview in which the concepts for nuclear waste management are described, the contents of the remaining volumes NGB 85-02 to 85-08 are summarized and Project conclusions are drawn from Project Gewaehr 1985. Project Gewaehr 1985 covers two repository types: Type C repository for high-level and certain alpha-containing intermediate-level waste, and Type B repository for all remaining intermediate- and low-level waste. The Project shows in detail that technical feasibility of final disposal can be assumed given presently available methods, that the technical safety barriers show a high level of efficiency and that suitable geological options are available to ensure long-term safety in Switzerland as the concept is defined by official requirements. The Project safety analyses show that the chosen disposal concepts assure the protection of mankind and the environment under all realistically anticipated conditions