Main achievements and outstanding issues
The model development and initial modelling results of the 3D Bedrichov Tunnel Test Case illustrated the importance of understanding, handling and predicting the impact of uncertainties for the site characterisation and reliability of predictive modelling even for apparently ‘simple’ hydrogeological cases, which are in reality the corner stones of understanding and modelling the groundwater flow and solute transport processes for water resources and performance/safety assessments of repositories. The results from the initial modelling of the Bedrichov Tunnel Test case demonstrate that the subject of identification and management of uncertainties for site characterisation has not been understood in proper depth and investigated with adequate achievements and confidence. The research on the 2D BMT successfully investigated the interactions of stress, fluid flow and solute/particle transport in a complex fracture network, considering advective and matrix diffusion mechanisms, and served as a good demonstration of the importance of the stress effect on the flow and transport in fracture systems.
The major outstanding issues related to research for stress, flow and transport of fracture systems were identified through Task C, as the identification and management of the uncertainties in the input data concerning: fracture system geometry, fracture properties: hydraulic and mechanical as required, reliability of the in-situ measured data, development of a systematic approach for identification, quantification and monitoring of the sources and evolution of the uncertainties with the progress of modelling steps, and how to use the current numerical tools for investigating uncertainty issues.