Repositories in crystalline host rock: An overview of site selection procedures, data aquisition and modelling (BGR), December 1, 2023
According to § 1 of the Site Selection Act (StandAG), in addition to rock salt and clay rock, crystalline rock is also considered as host rock for the final disposal of high-level radioactive waste in Germany. For the implementation of the StandAG, detailed information on the structural geology and the barrier properties of potentially suitable crystalline host rocks in Germany is therefore required. The current report of the BGR's DaFNe Research and Development project describes the basics of a workflow for a systematic survey of the distribution, formation and properties of fractures and fault zones, and for transferring these datasets into a geostatistical model. This will allow numerical analyses as are required within the context of safety cases. For this purpose, site selection procedures and development stages in identified countries are provided where repositories in crystalline host rock are planned or implemented and fundamentals of the formation and interpretation of fractures are outlined. This report presents the individual steps from the acquisition of raw data to the creation of a representative Discrete Fracture Network (DFN) or continuum model. It provides compilations of possible survey methods for geometric data collection of fractures in outcrops, and of the input parameters required for modelling. Furthermore, the key equations required for modelling groundwater flow in fractured porous media material in the subsurface are outlined. |
