Thermal stratification study for pressurizer surge line

In order to confirm the structural integrity of pressurizer surge line affected by thermal stratification, this paper theoretically analyzes the criterion of thermal stratified occurrence, establishes the thermal stratified transient by start-up of reactor, and studies the calculation method of thermal stratified stress. A complex 3-dimension problem is simplified into a combined one of 1-dimension and 2-dimension. Considering ANSYS code function, an engineering method is put forward for thermal stratified stress calculation of pressurizer surge line. (authors)