Elaboration of groundwater models for deep geological repository sites

The Sectoral Plan Deep Geological Repositories (“Sachplan geologischer Tiefenlager –SGT”, developed by the Swiss Federal Office of Energy SFOE) is the Swiss road map to establish repositories for radioactive waste. SGT Stage 1 with focus on the selection of geologically suitable regions led to the proposal of six geological siting regions for the L/ILW (low- and intermediate-level radioactive waste) repository (Südranden, Zürich Nordost, Nördlich Lägern, Jura Ost, Jura-Südfuss, Wellenberg) and three geological siting regions for the HLW (high-level radioactive waste) repository (Zürich Nordost, Nördlich Lägern, Jura Ost). As a quantitative decision basis for the site selection process, provisional safety analyses studies are to be performed for all relevant repository configurations. One of important tasks is to evaluate the local groundwater flow conditions in the different potential siting regions, considering present and future conditions for relevant long-term evolution scenarios.