[en] KAERI has been carrying out the Korean VHTR (Very High Temperature modular gas cooled Reactor) project since 2004 and with the long-term aim to localize the TRISO fuel technology in Korea, KAERI has been endeavoring to research and develop the coated particle fuel technologies. The fundamental safety of a gas-cooled reactor largely relies on the mechanical integrity of the coated particle fuel. In this regard an irradiation test plan is being carried out by using surrogate coated particles to investigate thermo mechanical behavioral changes of coatings and coating combinations under irradiation. To eliminate the complicated influence of fissile material, the coatings were applied to dummy kernels composed of inert materials (zirconia). Test results will be useful in understanding and modeling of the thermo mechanical behavior of the PyC layer and can be used for validation purposes of High Temperature Reactor (HTR) fuel concepts. In this study, an attempt was made to predict the mechanical integrity of the test specimen by calculating the stress levels of the coating layer under the irradiation conditions. Used were an ABAQUS based finite element (FE) model which is being developed by KAERI to cover the linear and the non-linear behaviors of a coated particle fuel subject to creep, swelling, and pressures. This paper shows the stress calculation results of PyC coated surrogate fuel particles subject to an irradiation condition as assumed in the IAEA-CRP-6 benchmark case 6 to predict the mechanical integrity of the coating layers