Pilot characterisation of the rock mass for the verification of the methodology for the creation of 3D site models
This section consists of the geological characterisation of the rock mass in the underground areas and on the surface. The data obtained from the underground and surface areas is gradually being amalgamated and subjected to detailed evaluation. The basic output will consist of a data set that will serve for the construction of 3D geological and mechanical models of the site. Furthermore, specialised methodologies are being developed for the detailed description of rock masses.
Testing of long-term monitoring methods concerning processes underway in the DGR
The contribution of the monitoring of the geological environment at deep geological repository depth will consist of the estimation of a range of important rock environment parameters and their development, a detailed knowledge of which is essential for the description of potential sites for the construction of the future deep geological repository and the assessment of their stability. Hydrogeological monitoring will provide the data essential for an understanding of groundwater behaviour trends as potentially the most important transport medium within the deep repository.
Moreover, in order to evaluate the stability of the various characteristics of the sites, it is necessary to perform seismic monitoring and to compile a description of the activity of fragile structures. Finally, it will also be necessary to acquire data on the microbiological colonisation of the rock environment over the long term so as to be able to determine the degradation of the various materials employed in the future repository.
Testing of models of groundwater flow and radionuclide transport
The aim of this research section will consist of the testing and verification of mathematical models of radionuclide migration in the natural environment. Testing will focus on a description of both the rock environment and transport processes with concern to the relevant elements in fractured environments and intact matrices. The transport of the various types of radionuclides as a result of water flow depends on a wide range of processes such as precipitation, dissolution, diffusion into the matrix, sorption and dilution due to their mixing with uncontaminated water.
Testing of the influence of the rock environment at repository depth on changes in the properties of the planned engineered barriers
The experimental programme will consist of the monitoring of the influence of the real conditions of the rock mass on the materials which will make up the various engineered barriers which isolate disposed of waste from the rock environment. Complex experiments will be conducted which will allow for the monitoring of several phenomena at the same time (corrosion of the disposal container materials, changes in the clay sealing material, i.e. bentonite, and the influence of microbial activity). Materials (steel, concrete, cement, bentonite) will be examined which, up to now, have only been studied under laboratory conditions.
Testing of the creation and development of disturbed zones around underground openings
The requirement for a detailed description of the character of the zone impacted by the construction of the underground facility results from the necessity to define those zones with increased permeability that might be created during the construction of underground spaces. This part of the research will involve the application of both geophysical methods for indirect rock mass characterisation purposes and direct measurement and analysis.
Research of the influence of the rock mass on the construction of individual underground workings
During the construction of the deep geological repository, it will be necessary to apply certain technological procedures which require special methodology which is not normally employed with respect to standard commercial excavation work, i.e. specialised excavation and drilling procedures. The main aim will be to first define and then to optimise the relevant methodology concerning such work in terms of the time of application, efficiency and financial considerations as well as the long-term monitoring of the stability and behaviour of the workings.
The necessity for the conducting of demonstration experiments results from the complexity of the various interactions between the individual components of the planned disposal system. Demonstration experiments serve to verify the ability of the supply chain to cooperate in the context of complex workflows from the project preparation stage of the various components through production and installation in-situ to eventual stabilisation in the underground environment.