Tracing U mobility in deep groundwater using Ra isotopes

L. Krall, L. Auque, E. L. Tullborg, J. Suksi, G. Trezzi, J. Garcia-Orellana, P. Andersson, D. Porcelli

Research output: Chapter in BookChapterResearchpeer-review


The mobility of natural U is compared among four boreholes in a fractured granite using Ra isotopes and geochemical modelling. 222Rn/226Ra activity ratios (ARs) spanning an order of magnitude underline differences in reactive surface area. (224Ra/228Ra)ARs up to 9 indicate recent changes in hydrogeochemistry, and (226Ra/228Ra)ARs 0.6-30 indicate variable deposition of U. Dissolved U is related to dissolution of a solid U(VI) phase by groundwater with HCO3− >20 mg·L-1. U reduction is hindered by Ca2UO2(CO3)30.
Original languageEnglish
Title of host publication15th Water-Rock Interaction International Symposium, Wri-15
Publication statusPublished - 2017

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