Abstract
Pressurized thermal shock (PTS) is a key issue of the vessel integrity for pressurized water reactor (PWR) during a transient accident. It would lead to loss of coolant and subsequent rescue problems when the pressure vessel damaged due to PTS condition. The CFD (computational Fluid Dynamics) is selected in this project to simulate and calculate the detail of flow behavior in the part of downcomer of Maanshan nuclear power plant (NPP) in order to improve the flow analysis error of RETRAN and RELAP5 in the past. The analysis process and validation is based on the data from ROCOM facility test to ensure the accuracy of model establishment of Maanshan power plant. After one year operation, the validation of analytical techniques and establishment of Maanshan power plant analytical model are successfully completed. The analysis of temperature distribution in the pressure vessel is also calculated with the information of MSLB accident. It shows that the geometry of neutron shielding plate and hot and cold loops inside the downcomer would lead to higher cooling rate in some parts of pressure vessel wall in the results. The data for upper project of analyzing fracture mechanics is compiled in this study in addition to analysis and discussion. This research is not only to improve current model but to investigate the selected case of accident in the future in order to assist the upper project completing the PTS of Maanshan power plant analysis program.