[en] Andra (Agence Nationale pour la Gestion des Dechets Radioactifs - the French National Radioactive Waste Management Agency) has developed specific tools and processes to evaluate and understand the main transport mechanism for solute species. This paper focuses on three specific equipments already installed or planned for the determination of convection and diffusion parameters in a very low permeable environment. The first one is a specific well completion for head and permeability measurements using a wireless telemetry device. The second is an adaptation of a well known multi-packer equipment to study the evolution of the pressure at the limits of the host rock. The third one is a specific equipment design for studying migration and retention of radionuclides through a borehole drilled from the surface. (authors)

[en] Over the last years, Andra has collected an impressive amount of hydraulic data on the middle Jurassic, Callovo-Oxfordian argillite at a site located 300 km eastern from Paris. Preliminary analyses of the formation pressure (freshwater potential) and the hydraulic conductivity have been performed based on the hydraulic data of both the short term packer tests and the long term monitoring (EPG and Westbay). This was performed using numerical borehole simulators which enable taking into account the complete pressure history of the borehole, defining a suitable flow model and deriving best guess estimates and uncertainty ranges of the hydraulic parameters. For all measurement intervals investigated In-Situ, it was shown that the hydraulic conductivity was less than 2,10^-12 m/s. A comparison of the preliminary results of the packer tests and those of the long term pressure monitoring shows that the short term packer tests tend to highly over-estimate the formation pressure. The hydraulic conductivities obtained from the analysis of the packer tests are mostly higher than those obtained from the analysis of the EPG long term recovery. Further analyses are planned to check these preliminary analyses as well as the consistency between short term and long term measurements providing information on rock properties at different scales (different radius of visibility). (authors)

[en] This paper presents the application of so-called gas threshold pressure tests (GTPT) to assess the behavior and two-phase flow properties of clay-rich sedimentary rocks under investigation for disposal of high-level radioactive (HLW) and spent fuel. (authors)