The Effect of CANLUB Graphite and Siloxane Coatings on UO2/Zircaloy-4 Interactions

Abstract

Experiments have been performed to measure the rate of interaction between UO₂ and Zircaloy with no interfacial coating and with CANLUB graphite and SILOXANE lubricant coatings over the range 1423 to 2023 K. The results with no coating agree well with other published data. With a 5-μm CANLUB graphite coating, the interaction was completely suppressed for temperatures below 1773 K. Above this temperature the reaction rates with and without the graphite coating were identical. A 5-μm SILOXANE coating was found to have essentially no impact on the UO₂/Zircaloy interaction. These results are discussed in terms of the chemistry of the lubricants and the UO₂/Zircaloy interaction.