Crushing strengths of SiC-Triso and ZrC-Triso coated fuel particles

The whole-particle and third-layer crushing strengths of SiC-Triso and ZrC-Triso coated fuel particles were measured. The third-layer crushing strengths did not differ for the two types of Triso-coated particles if their particle diameters and third-layer thicknesses were not different. The third-layer failure stresses calculated with the model by Delle et al. were found still dependent on the particle radius. The failure stress divided by the particle radius was about constant for a given third-layer material. The whole-particle crushing strength of SiC-Triso particle was larger than that of ZrC-Triso particle in the as-coated condition, but the contrary was the case when those particles were annealed at 2073 K for 1 h. By the annealing the whole-particle strength of SiC-Triso particle decreased but that of ZrC-Triso particle increased. Both of these changes could not be ascribed to the corresponding changes in the third-layer strength. (orig.)