[en] New pellet temperature calculation and thermal stress/strain analysis models were developed for dual cooled annular fuel. Temperature model was adopted a finite difference method to consider the local power generation and material property difference which are caused by steep temperature gradient. The developed models were verified by comparison with an analytical solution and a calculation results of finite element code ABAQUS. To evaluate the thermal stress/strain of annular pellets, 1-D hollow cylindrical model was developed. Under plane strain and free radial surface condition, the solution of detailed model can be derived analytically. By comparison with analytical solution which was calculated by ATHMATICA, the exactness of proposed model was verified. The newly developed models will be very helpful to understand the behavior of dual cooled annular fuel and design of it