| About this Abstract |
| Meeting |
MS&T21: Materials Science & Technology
|
| Symposium
|
Thermodynamics of Materials in Extreme Environments
|
| Presentation Title |
Incorporation of Thorium and Uranium in the Monazite Structure by Wet Chemistry Route: Synthesis, Sintering and Long-term Behavior |
| Author(s) |
Nicolas Dacheux, Danwen Qin, Alison Roche, Adel Mesbah, Nicolas Clavier, Stephanie Szenknect, Renaud Podor |
| On-Site Speaker (Planned) |
Nicolas Dacheux |
| Abstract Scope |
From long, several phosphate-based ceramics, including monazites, have been considered to manage the specific conditioning of actinides or plutonium. In this field, monazite ceramics were reported as promising candidates based on their easy way of elaboration, structural flexibility, sintering capability and good resistance to radiation damage and to weathering conditions.New recent advances allowed preparing, by wet chemistry routes, some single phase and homogeneous samples containing tetravalent thorium or uranium. Optimized sintering conditions were fixed with the help of sintering maps to prepare well densified pellets, which were submitted to multiparametric leaching tests. From a kinetic point of view, the high chemical durability of the ceramics was confirmed. Moreover, several low-soluble neoformed phases formed rapidly at the solid/solution interface when saturation conditions were reached in the solution. Associated thermodynamic data, including solubility constants confirmed the very good properties of monazites in terms of long-term behavior. |