Effect of Weibull parameters and crack distribution on the failure probability of multi-layered SiC cladding

In this paper, an improved Weibull failure probability model which considers initial cracks distributed in the cladding has been proposed. Considering the coupling of force, heat and irradiation acting on the multi-layered SiC cladding, failure probabilities of the cladding under different conditions have been obtained. The results indicate that compared to linear heat rate, the cladding is more sensitive to changes in inner pressure of fuel elements. The cladding can be optimized by adjusting the proportion of different layers. Further investigations indicate that effect of different Weibull parameters of CVD SiC on the failure probability is small and can be ignored in real fuel elements. Meanwhile, cracks in SiC composite layer and crack length have little effect on the failure probability. However, the initial inclination angle can affect the failure probability greatly. Results indicate that the most dangerous inclination angle in the cladding is about 73 degrees. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

An improved Weibull failure probability model taking into account initial cracks distributed in the cladding has been proposed in this paper. The study focuses on the failure probabilities of multi-layered SiC cladding under different conditions, showing that the cladding is more sensitive to changes in the inner pressure of fuel elements and can be optimized by adjusting the proportion of different layers. The effects of different Weibull parameters of CVD SiC on failure probability are small and negligible in real fuel elements.