Development of a 2D axisymmetric FDM structural analysis model for coated cladding

As a component of Accident-Tolerant Fuel (ATF) technology, coated cladding has attracted significant attention for its potential to improve the mechanical and thermal performance of nuclear fuel under elevated temperature and pressure conditions. However, the structural analysis of coated cladding remains challenging due to the complex multiphysics interactions introduced by the coating layers. Although finite element analysis (FEA) is widely employed for its capability to handle complex geometries and nonlinear material behavior, its high computational demand limits its utility for large-scale or long-term simulations. To address these limitations, this study proposes a two-dimensional axisymmetric structural analysis model based on the finite difference method (FDM), specifically designed to simulate the mechanical behavior of Cr-coated ATF cladding. The model accounts for elastic, plastic, and creep deformations in both the substrate and coating layers, achieving a favorable balance between computational efficiency and predictive capability under typical reactor operating conditions. It was successfully implemented into the GIFT nuclear fuel performance code, enabling integrated thermo-mechanical simulations. Validation against commercial FEA software confirmed strong agreement in stress and strain predictions. This work presents a practical and extensible modeling approach that supports the design and evaluation of advanced coated cladding systems within ATF development.