Abstract
Silicon carbide (SiC) fiber–reinforced SiC matrix (SiC/SiC) composites are promising materials intended for use as a fuel cladding for light water reactors and advanced fission reactors. The design and performance analysis of SiC/SiC composites for nuclear applications requires nondestructive, noncontact techniques and models based on microstructural information that can assess the complex microstructures of this type of material. Multiple types of SiC/SiC architectures can be tailored to enhance the lifetime and properties of these SiC/SiC composites. Manufacturing defects, preexisting pores, and defects created by the exposure of the material to a nuclear reactor environment can reduce the thermal conductivity of SiC/SiC composites. A reduction of thermal conductivity in SiC/SiC composites can lead to their deterioration or cracking. In this report the authors propose the use of novel image-based modeling methodologies, a combination of x-ray computed tomography and finite element analysis, to nondestructively assess the thermal properties of SiC/SiC composite cladding. The proposed microstructural heat transfer models help to identify which pores or defects are more detrimental to the performance of the SiC/SiC composites. In addition, the proposed method is useful to evaluate the anisotropy of the thermal properties, which cannot be determined by conventional experiments.
