| About this Abstract |
| Meeting |
MS&T21: Materials Science & Technology
|
| Symposium
|
Thermodynamics of Materials in Extreme Environments
|
| Presentation Title |
Dissolution of Uranium Based Dioxide in Nitric Acid: Impact of Fission Products and Microstructure |
| Author(s) |
Nicolas Dacheux, Thomas Barral, Thibault Kaczmarek, Malvina Massonnet, Laurent Claparede, Nicolas Clavier, Stephanie Szenknect, Renaud Podor |
| On-Site Speaker (Planned) |
Nicolas Dacheux |
| Abstract Scope |
SNF dissolution appears as a key step for its reprocessing although complex chemical, structural and microstructural properties complicate the global understanding of its chemical durability. In this field, sintered samples of UO2 doped with FP (mainly lanthanides such as Ce, Nd and Gd or PGM’s) were prepared by wet chemistry routes, sintered then submitted to dissolution tests in various nitric acid solutions to mimic reprocessing conditions. Using a macroscopic approach, the impact of each FP was analysed through the elemental releases in solution. Either lanthanide and PGM elements induced significant modification of the dissolution rates of the ceramics. This macroscopic description was connected to operando monitoring of the evolving solid/solution interface during the dissolution. Preferential dissolution zones (pores, grain boundaries, …) as well as different evolution depending on the crystal orientation in the grains were observed by ESEM, suggesting various progresses of the dissolution reaction at the solid/solution interface. |