I am a doctoral student in geological science at Stockholm University, supported within MetTrans by the Swedish Nuclear Fuel and Waste Management Co. (SKB) and the Swedish Museum of Natural History. In general, I am interested in the geological aspects of the sustainable implementation of nuclear energy, including the world’s U and Th resource and the geologic disposal of spent nuclear fuel (SNF). In Sweden, SNF is predominantly comprised of UO2+x. Currently, I am conducting a field investigation into redox history and mobility of natural U within the fractured crystalline bedrock at Forsmark, Sweden. This is of local relevance because the site currently hosts a repository for low- and intermediate-level waste and has been proposed to host a deep geological repository for SNF. Within the investigation, U minerals and U/Th series isotopes are applied as tracers of water-U mineral interaction. In-situ methods of U mineral characterization include optical petrography, SEM-EDS, and EMPA, in addition to SIMS and LA-ICP-MS. Groundwater investigations include the application of U-series disequilibrium, notably through the measurement and modelling of Ra-isotopes. Combined with hydrochemical modelling, it is expected that this multi-stage study will contribute to an understanding of the local mobility of natural U and its radiogenic daughters on a range of time-scales relevant to that of a radioactive waste repository.
Krall L., Sandström B., Tullborg E-L, & Evins L.Z. Natural uranium in Forsmark, Sweden: The solid phase. Applied Geochemistry, 59 (2015), pp 178-188.