Radiolysis of Nitrogen, Oxygen and Water on Stored PuO2

Radiolysis of over gases and water adsorbed on the surface of PuO2 can lead to pressurisation of the containers used for interim storage. This phenomenon has only been observed for a very small number of containers, while others show no pressure increase. One possible reason for this erratic behaviour is the radiation-induced back-reaction of H2 and O2 to (re)form water, potentially catalysed by the presence of the metal oxide surface (PuO2). This project will use a synergistic experiment and modelling approach to study influence of oxide surfaces on the gas phase radiolytic recombination of H2 and O2, as well as the chemistry of N2 / O2 mixtures to form NOx compounds and eventually HNO3. It will utilise the unique experimental capabilities of the DCF and the NNL Central Laboratory, running in parallel to two PDRA projects on PuO2 storage funded by the EPSRC DISTINCTIVE consortium.