Combined U-Pb isotopic signatures of U mill tailings from France and Gabon: A new potential tracer to assess their fingerprint on the environment.
J Hazard Mater
; 430: 128484, 2022 05 15.
Article
en En
| MEDLINE
| ID: mdl-35739667
ABSTRACT
Uranium milling activities have produced high volumes of long-lived radioactive processed wastes stored worldwide in near surface environment. The aim of this study is to highlight relevant tracers that can be used for environmental impact assessment studies involving U mill tailings. A multi-tracer study involving elemental content, 238U decay products disequilibria and stable Pb isotopes was performed in different types of U mill tailings (alkaline, acid, neutralized acid) collected from five Tailings Management Facilities in France (Le Bosc, L'Ecarpière, Le Bernardan, and Bellezane) and Gabon (Mounana). Our results showed that U and Pb concentrations range between 30 and 594 ppm and 66-805 ppm, respectively. These tailings have a strong disequilibrium of (234U/238U) and (230Th/238U) activity ratios (1.27-1.87 and 6-65, respectively), as well as higher 206Pb/207Pb (1.86-7.15) and lower 208Pb/207Pb (0.22-2.39) compared to geochemical background ((234U/238U) and (230Th/238U) equal to unity; 206Pb/207Pb = 1.20; 208Pb/207Pb = 2.47). In situ analyzes (SEM, SIMS) showed that Pb-bearing phases with high 206Pb/207Pb are related to remaining U-rich phases, S-rich phases and potentially clay minerals or oxyhydroxides. We suggest that the combination of the 206Pb/207Pb with the (234U/238U) ratio is a relevant tool for the fingerprinting of the impact of U milling activities on the environment.
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Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Contaminantes Radiactivos del Suelo
/
Residuos Radiactivos
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Uranio
País/Región como asunto:
Africa
Idioma:
En
Revista:
J Hazard Mater
Asunto de la revista:
SAUDE AMBIENTAL
Año:
2022
Tipo del documento:
Article
País de afiliación:
Francia