CFD Analysis of PWR Surge Line Subjected to Thermal Stratification

Thermal stratification effects have been a great concern in a pressurizer surge line of pressurized water reactor (PWR) since 1988. These effects may damage the structural integrity and contribute in reducing the operational life time of pressurizer surge line. Several nuclear power plants operators have so far reported such mechanical damages. To realistically assess the structural integrity of pressurizer surge line subjected to thermal stratification, it is necessary to analyze the transient temperature distribution. Several researchers and scholars have carried out considerable efforts to determine the temperature distributions in the pressurizer surge line. In this study, an effort has been made to simulate the behavior of thermally stratified flow and predict the transient temperature distributions in the pressurizer surge line realistically. To obtain realistic results for such complex geometry of pressurizer surge line 3D analysis is performed using CFX commercially available CFD software. The transient temperature distributions obtained are presented and discussed.