Quantifying Diffusion Rates through Crystalline Rock Matrices

Projekti: Tutkimusprojekti

Projektin yksityiskohdat

Kuvaus (abstrakti)

Quantifying Diffusion Rates through Crystalline Rock Matrices (GeoChem)
A methodology has been developed for investigating uranium phases that occupy inter- and intra-granular porosity within crystalline rock matrices. Surveying beta/gamma autoradiography and alpha radiography using polycarbonate films is employed to characterise localised zones of uranium enrichment and to select locations for subsequent microscopic investigations. Autoradiography of 14C-PMMA-impregnated samples allows correlation of the uranium mineralization with the conductive pore network of the matrix, and its relationship to larger trans-missive features. Furthermore electron microscopy and energy dispersive X-ray analyses (FESEM/EDAX) are used for detailed analyses down to the micrometric scale. These techniques are used in the project which has the specific objectives to investigate the mechanism and quantify the rate of uranium migration through micro fissures in crystalline rock, to simulate the effect of spent fuel oxidation in situ (defective canister scenario) in microcosm experiments under ambient (opera-tional) and over-pressure (post-closure) conditions and to provide quantitative data for model calibration and verification within the Finnish national programme (KYT2010). The work is done in collaboration with Helsinki University of Technology/Geoenvironmental laboratory, University of Reading School of Human & Environmental Sciences and Geological Survey of Finland.
Todellinen alku/loppupvm01/01/200331/12/2008