Development of a transient thermal-hydraulic analysis code for China advanced research reactor

A transient analysis code was developed to calculate the thermal-hydraulic behaviors of China advanced research reactor (CARR). The detailed structure of CARR and the fluid flow direction inverse during the process of natural circulation establishment were considered. Moreover, the flow patterns and heat transfer conditions were taking into account. In addition, Gear method and Adams predictor-corrector method were adopted separately for a better solution to the stiff differential equations. Some important parameters such as pressure, flow rate and temperature for the mean channel and hot channel were obtained. Our research result show that the used of emergency cooling system obviously reduced the peak operational temperature to ensure the safe operation of CARR more effectively.