Silicon and Zirconium Ceramics Radiolysis in the Presence of Water

Ceramic materials display several desirable characteristics for nuclear energy applications, and thus, understanding how they behave in a radiation field, particularly in accident scenarios, is necessary for their successful implementation. This work investigates the role of interfacial water on radiolytic processes occurring at the surface of silicon and zirconium carbides and nitrides. Modification of the surfaces and the effect of those surfaces on H2 production are investigated. All studied materials were found to have a layer of oxidation on the surface, and this oxidation layer affects H2 production. Radiolysis up to doses of 50 MGy was not found to affect the bulk material, and very few changes to the surface were observed. The amount of H2 produced during irradiation correlated with the amount of water adsorbed by the ceramics, and the importance of the ceramic surface decreased as the water fraction increased. The exact nature of the surface of these ceramics is therefore incredibly important when assessing the effects of radiation in accident scenarios.