Activity: Examination types › Supervisor or co-supervisor of doctoral thesis
In Finland, as in many other countries, high-level radioactive waste is planned to be disposed of in deep-lying crystalline rock. There has been a tendency to play down the potential role of the geosphere as a safety barrier in repository performance assessment. Among other reasons current uncertainties in transport pathway definition and pore space characterisation of crystalline rock can be mentioned. Repository safety evaluation today requires going from laboratory and surface-based field work to the underground repository level. Little is known about the changes to rock transport properties during sampling and decompression. Recent investigations using resin impregnation of the rock matrix at the Grimsel Test Site imply that non-conservative errors in calculated transport properties derived from laboratory data may reach factors of 2/3. This may lead to over-conservative estimates of limited matrix diffusion depths, which may grossly underestimate geosphere radionuclide retardation.
Title of thesis: Matrix porosity in crystalline rock-PMMA method development in situ