In-situ, Time Resolved Monitoring of Uranium in BFS:OPC Grout. Part 1: Corrosion in Water Vapour

Uranium encapsulated in grout was exposed to water vapour for extended periods of time. Through synchrotron x-ray powder diffraction and tomography measurements, uranium dioxide was determined the dominant corrosion product over a 50-week time period. The oxide growth rate initiated rapidly, with rates comparable to the U + HO reaction. Over time, the reaction rate decreased and eventually plateaued to a rate similar to the U + HO + O reaction. This behaviour was not attributed to oxygen ingress, but instead the decreasing permeability of the grout, limiting oxidising species access to the metal surface.