Flow field analysis is a foundation to many thermal-dynamic phenomena in the nuclear containment. There are several ventilation systems under normal condition to assure the proper environment for staff and facilities, and the two main ventilation systems are the Reactor Pit Ventilation system (EVC) and the Containment Continuous Ventilation system (EVR). The fans of the ventilation systems recycle the air in the containment to various rooms, and cooling coils are cooled by the Nuclear Island Chilled Water system (DEG). In this paper, we simulated the 3D flow field in a Chinese traditional generation II+ PWR reactor containment under normal conditions with a commercial CFD software ANSYS FLUENT.
According the actual geometry data of the reactor plant, we built the geometry model, including the EVC and EVR system, and they were checked by plant experts to assure authenticity. Proper maximum mesh sizes were set for different parts at the ICEM CFD, and the grid number was about ten millions. We used the fan model in the ANSYS FLUENT to simulate fans in the ventilations. The calculated values of flow rate in ventilation systems were in good agreement with the design values.