Investigation of rock samples using x-ray-microscomputer-tomography before and after mercuryintrusion porosimetry

摘要

A new method for the physical characterization of rock matrices for use in site investigations of nuclear waste repositories has been developed. The method can provide information beeded in the assessment of the performance of the geosphere working as a natural barrier retarding the migration of radionuclides by diffusion into the rock matrix. Most conventional methods for the physical characterization of rocks giveonly bulk information. The combination of mercury porosimetry and computer tomography can give 3-D data on mineral-specific porosity distributions with additional pore size information. Additionally, limits for mineral-specific internal surface areas can be estimated, which is essential for the assessment of water-rock interaction and reactive interaction with radionuclides (sorption). Results of measuremdents on granitic rock (granodiorite) from the Baltic shield are discussed and integrated with results by complementary methods.