Synchrotron X-rays have been used to study the oxidation of uranium and uranium hydride
when encapsulated in grout and stored in de-ionised water for 10 months. Periodic synchrotron
X-ray tomography and X-ray powder diffraction have allowed measurement and identification
of the arising corrosion products and the rates of corrosion. The oxidation rates of
the uranium metal and uranium hydride were slower than empirically derived rates previously
reported for each reactant in an anoxic water system, but without encapsulation in
grout. This was attributed to the grout acting as a physical barrier limiting the access of oxidising
species to the uranium surface. Uranium hydride was observed to persist throughout
the 10 month storage period and industrial consequences of this observed persistence are
discussed.