Interaction of Hydrogen with Actinide Dioxide (011) Surfaces
semanticscholar(2019)
The hydrogen catalysed oxidation of nuclear materials has led to containment vessel failure. The interaction of hydrogen with actinide dioxide (AnO2, An = U, Np, Pu) (011) surfaces has been completed by DFT+U; where, spin-orbit interactions and noncollinear 3k antiferromagnetic behaviour have been included. The energy of atomic hydrogen adsorption for UO2 (0.44 eV), NpO2 (-0.47 eV), and PuO2 (-1.71 eV) has been calculated, where the subsequent formation of an OH group is shown to distort the surface structure. The dissociation of hydrogen on the PuO2 (011) surfaces has been found; however, UO2 (011) and NpO2 (011) surfaces are relatively inert. The recombination of hydrogen ions on the UO2 (011) and NpO2 (011) surfaces is highly-probable; whereas, hydroxide formation on the PuO2 (011) surface has been shown. The results have consequences for fuel storage management.