SMART (system-integrated modular advanced reactor), which is a 330 MWt advanced integral nuclear power plant, was developed by the Korea Atomic Energy Institute (KAERI) for generating electricity and desalinating seawater. To enhance its safety, various design concepts were adopted, such as containing most of the reactor coolant system (RCS) components and a passive residual heat removal system (PRHRS). A thermal hydraulic evaluation and analysis of SMART is performed by TASS/SMR-S (transient and setpoint simulation/system-integrated modular reactor safety). The TASS/SMR-S code has various models reflecting the design features for SMART such as the core models (core power and core heat transfer models), the component model,s and the condensation heat exchanger (CHX) model. In this paper, the validation of the CHX model in the TASS/SMR-S code was performed with the POSTECH (Pohang University of Science & Technology) CHX test to evaluate the conservative prediction capability of the heat transfer coefficient on CHX. According to the calculation results, the TASS/SMR-S code calculates higher fluid temperature on the CHX tube outlet than the test data in all the cases. In addition, the coolant temperature for the coolant pool outlet and the local heat transfer coefficients in the two phase region are underpredicted compared with the test results. Involving heat removal for the RCS, it is possible to conservatively predict the TASS/SMR-S code compared with the test results.