Thermal-Hydraulic Simulation of Cold Water Spray in a Nuclear Power Plant Containment

Sprays play an important role in cooling and decreasing pressure inside the containment of nuclear reactor in emergency situations and excessive pressure of containment. When temperature and pressure exceed 120 degrees C and 2 bars respectively, the sprays cool the inside of PWR containment. The containment spray system is designed to condense the steam to prevent the occurrence of high pressure and temperature, which could lead to disintegration of containment and the leakage of radioactive material to the environment. In this study a simulation of a concrete tank of the reactor (containment) with 250 sprays is accomplished using Ansys Fluent software (18.2). Multiphase mixture model and k-epsilon realizable turbulence model are used to model the reactor. Associated equations are solved using the finite volume method (SIMPLE algorithm with pressure and velocity coupling) in Ansys Fluent software. It is assumed that the flow regime is transient. Results of the thermal-hydraulic function of spraying, which has decreased pressure and temperature, are presented.