Unravelling the Impact of Palladium on Ruthenium-Induced Corrosion of SiC Coating

This study investigates the corrosion behaviour of fission products (FPs) on SiC layers of tri-structural isotropic (TRISO) particles. Specifically, it explores the effects of Pd (strongly reactive FP) on Ru (weakly reactive FP)-induced corrosion. Ru silicides formed after Ru-SiC reactions at 1300/1500°C. In Pd-Ru/SiC systems, a Ru-Pd-Si liquid phase forms at high temperatures even with minimal Pd, accelerating corrosion along SiC grain boundaries. Comparing Pd’s role in Ru/SiC and Ag/SiC systems underscores the importance of liquid phases in FP migration. A novel approach is proposed for predicting the corrosion effects of multiple FPs on SiC through enthalpic interaction analysis.<br/