Evolution of noncrystalline uranium in lake sediments over 3,300 years

Pierre Lefebvre (1) , Arnaud Mangeret (2) , Alkiviadis Gourgiotis (2) , Jean-Pierre Sabatier (3) , Pierre Le Pape (1) , Olivier Diez (2) , Pascale Louvat (4) , Pauline Merrot (1) , Camille Baya (1) , Mathilde Zebracki (2) , Pascale Blanchart (5) , Emmanuel Malet (3) , Didier Jezequel (4) , Jean Louis Reyss (3) , John R Bargar (6) , Jerome Gaillardet (4) , Charlotte Cazala (2) , Guillaume Morin (1)

1 IMPMC - Institut de minéralogie, de physique des matériaux et de cosmochimie
2 IRSN/PSE-ENV/SEDRE/LELI - Laboratoire de recherche sur le devenir des pollutions de sites radioactifs
3 EDYTEM - Environnements, Dynamiques et Territoires de la Montagne
4 IPGP (UMR_7154) - Institut de Physique du Globe de Paris
5 IRSN/PSE-ENV/SEDRE/USDR - Unité d'expertise des sites et des déchets radioactifs
6 SSRL SLAC - Stanford Synchrotron Radiation Lightsource

The long-term behavior of U in contaminated soils and sediments downstream former U-mines is a widespread environmental challenge. Although reducing subsurface environments are generally considered as favorable for U immobilization, it has been shown that U is often present in the form of potentially labile non-crystalline U(IV) species in contaminated anoxic sediments [e.g. 1-3] and soils [e.g. 4-6]. The fate of such mononuclear or polymeric U(IV) species and their ability to eventually transform into less soluble minerals at the century or millennial scale remains poorly documented, which thus deserves further research to better constrain contaminated sites management.

Domaines: Sciences de l'environnement

Pierre Lefebvre, Arnaud Mangeret, Alkiviadis Gourgiotis, Jean-Pierre Sabatier, Pierre Le Pape, et al.. Evolution of noncrystalline uranium in lake sediments over 3,300 years. GOLDSCHMIDT 2021, Jul 2021, Lyon, France. ⟨irsn-03523229⟩