Investigation of Anomalous Hydrogen Production from Water Adsorbed on Metal Oxide Surfaces

UoM administered thesis: Phd

  • Authors:
  • Jamie Southworth

Abstract

The production of H2 from the radiolysis of water in contact with spent nuclear fuel presents significant safety and engineering challenges. Anomalous gas production from adsorbed water radiolysis has the potential to generate flammable atmospheres in PuO2 storage containers residing in interim storage. Due to the nature of working with PuO2, a non-active analogue must be sought so the anomalous effects it has can be probed without the limitations associated with working with plutonium. The search for a metal oxide with a similar effect on radiolytic yields of H2 to PuO2 was undertaken by investigating the radiolysis of water adsorbed on or aqueous suspensions of ZnO. Samples were prepared humidity control it was found that the presence of ZnO enhances radiolytic H2 production, contrary to indications from literature. During the same experiments, O2 was observed in comparable quantities. Remarkably, O2 was also observed during the radiolysis of dry ZnO, previously unseen in similar experiments with other oxides. The 5.5 MeV He2+ ion beam radiolysis of aqueous ZnO suspensions was also undertaken and the results compared to the 􏰀-ray radiolysis results. In conjunction with this, the development of a novel method by which the radiolysis of water can be evaluated is discussed. The vacuum line method was developed primarily to give much greater control over the amount of water introduced for a metal oxide sample surface for irradiation and aimed to reduce the sources of unquantifiable errors in the experiment. The method was then used to investigate the radiolysis of water adsorbed on ZrO2 with a particular focus on low water loading.

Details

Original languageEnglish
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Award date31 Dec 2019