Atomic scale characterization of dissolution processes in simulant spent nuclear fuel
EMSL Project ID
47843
Abstract
This proposal aims to provide the underpinning atomistic understanding of the alteration of spent (used) nuclear fuel in contact with repository groundwaters using the unique combination of facilities available at the EMSL radiological annex. Key aspects will be the chemistry and morphology of the radiation damaged fuel surface and the growth rate of the hydrous uranium minerals that form on the surface. Simulated spent fuel (SIMfuel) consisting of depleted UO2 has been prepared and will be irradiated with highly energetic ions to produce the rim-like microstructures produced by radiation damage. These will be probed for surface chemistry with x-ray photo-electron spectroscopy to determine the uranium oxidation states. The detailed morphology will be examined by TEM and SEM and then the dissolution process will be followed. A second stage of the proposal involves the development of a method of determining uranium mineral growth rates with an AFM. Initially simple precipitation experiments onto polished UO2 surfaces will be undertaken, to provide proof of principle. Eventually the method will be adapted so that true dissolution-reprecipitation could be measured and the effect of redox chemistry of the repository groundwater could be simulated in in-situ or ex-situ experiments.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2013-10-01
End Date
2016-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Popel A, TW Wietsma, MH Engelhard, AS Lea, O Qafoku, C Grygiel, I Monnet, ES Ilton, ME Bowden, and IE Farnan. 2018. "The Effect of Ion Irradiation on the Dissolution of UO2 and UO2-based Simulant Fuel." Journal of Alloys and Compounds (735):1350-1356. doi:10.1016/j.jallcom.2017.11.216