Paper on Anoxic Dissolution of UO2 Thin Films Published in ACS Applied Materials & Interfaces

Our paper exploring anoxic dissolution of UO2 thin films, led by Aleksej Popel, has just been published in ACS Applied Materials & Interfaces. We examine this behavior at unprecedented resolution using multimodal analytical STEM, revealing a complex film morphology and unique oxidative pathways.

From the abstract:

Our present understanding of surface dissolution of nuclear fuels such as uranium dioxide (UO2) is limited by the use of non-local characterization techniques. Here we discuss the use of state-of-the-art scanning transmission electron microscopy (STEM) to reveal atomic–scale changes occurring to a UO2 thin film subjected to anoxic dissolution in deionised water. No amorphisation of the UO2 film surface during dissolution is observed, and dissolution occurs preferentially at surface reactive sites that present as surface pits which increase in size as the dissolution proceeds. Using a combination of STEM imaging modes, energy-dispersive X-ray spectroscopy (STEM-EDS), and electron energy loss spectroscopy (STEM-EELS), we investigate structural defects and oxygen passivation of the surface that originates from the filling of the octahedral interstitial site in the centre of the unit cells and its associated lattice contraction. Taken together, our results reveal complex pathways for both the dissolution and infiltration of solutions into UO2 surfaces.

To view the manuscript, visit: https://doi.org/10.1021/acsami.0c09611

To download the manuscript directly, click here.