Migration de l'uranium, en condition d'altération météorique, dans les verses à stériles granitiques

Abstract : In a time span of 50 years uranium mining in France generated 163 Mt of waste rocks. These form waste rocks piles which are subjected to enhanced weathering compared to natural granitic outcrops. Therefore, as part of the French radioactive waste and material management plan (PNGMDR), waste rocks are studied in order to assess their potential environmental impact. This study specifically focuses on the internal structure of waste rock piles complemented by geochemistry and mineralogical data, in order to develop a model that assesses the waste rock pile’s weathering state and uranium’s stability. Results show uranium (U) is mainly associated to phosphates, either in primary accessory minerals, such as monazites, or crystallized in secondary uranyl-phosphates. When U is associated to amorphous iron oxyhydroxides, phosphorous is also associated. The importance of iron oxyhydroxides and phosphorous in uranium trapping is clearly demonstrated. Both iron oxyhydroxides as well as uranyl-phosphates form efficient and stable U traps, limiting U dissolution as long as pH, redox and temperature parameters remain stable. In case of variable conditions, smectite identified in the waste rock pile might also play a role in preventing further uranium diffusion.
Complete list of metadatas

Cited literature [212 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-02288732
Contributor : Abes Star <>
Submitted on : Monday, September 16, 2019 - 2:15:28 AM
Last modification on : Wednesday, September 18, 2019 - 9:32:53 AM

File

2017PA066629.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-02288732, version 2

Citation

Aisha Kanzari. Migration de l'uranium, en condition d'altération météorique, dans les verses à stériles granitiques. Géologie appliquée. Université Pierre et Marie Curie - Paris VI, 2017. Français. ⟨NNT : 2017PA066629⟩. ⟨tel-02288732v2⟩

Share

Metrics

Record views

111

Files downloads

25