Abstract: The RELAP5/MOD3.3 code was modified by adding a module calculating the effect of rolling motion and introducing new flow and heat transfer models. The thermal hydraulic code in rolling motion was developed. The experimental data were used to validate the theoretical models and calculation results. It is shown that the new flow and heat transfer models can correctly calculate the frictional resistance and heat transfer coefficients in rolling motion. The developed thermal hydraulic code can be used to simulate the thermal hydraulic system in rolling motion.