Evaluation of Fracture Stress for the SiC Layer of TRISO‐Coated Fuel Particles Using a Modified Crush Test Method

Abstract

Fracture stress data for the chemical vapor deposition SiC coatings of tri‐isotropic carbon/silicon carbide‐coated fuel particles were obtained using a newly developed testing and evaluation method, and their relationship with microstructure was investigated. A crush testing technique using a blanket foil at load‐transferring contact has been developed for hemispherical shell SiC specimens based on finite element analysis results. The mean fracture stress varied with test material in the range of 330–650 MPa, and was linked to the combined characteristics of inner surface roughness and porosity.