Tracing U Mobility in Deep Groundwater Using Ra Isotopes

Autor: Eva-Lena Tullborg, Per Andersson, Lindsay Krall, Don Porcelli, Juhani Suksi, Giada Trezzi, Jordi Garcia-Orellana, Luis F. Auqué
Rok vydání: 2017
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Zdroj: Zaguán. Repositorio Digital de la Universidad de Zaragoza
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ISSN: 1878-5220
DOI: 10.1016/j.proeps.2016.12.122
Popis: The mobility of natural U is compared among four boreholes in a fractured granite using Ra isotopes and geochemical modelling. Rn-222/Ra-226 activity ratios (ARs) spanning an order of magnitude underline differences in reactive surface area. (Ra-224/Ra-228)(ARs) up to 9 indicate recent changes in hydrogeochemistry, and (Ra-226/Ra-228)(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)(3)(0).
Databáze: OpenAIRE