Development of scenarios. Methodology and application. Report on the working package 8. Preliminary safety analysis Gorleben

The report describes methodology and application for the development of scenarios for the final repository Gorleben in the frame of the preliminary safety analysis. The concept includes site description and the geologic long-term prognosis, the final repository concept and the FEP (features, events, processes) catalogue. Based on the initial situation the reference scenarios are discussed for the two disposal variants (POLLUX/CASTOR casks or boreholes), including radionuclide mobilization, radionuclide transport and temporal development of processes. Alternative scenarios include climatic change and less probable occurrences like earthquakes, diapirism, subrosion, cryogenic fissure formation, cask failure, fluid pressure, volumetric alterations, safety gate movement, metal corrosion, thermochemical reactions, fluid infiltration.