Study on the Flash Evaporation Characteristics of High-Temperature and High-Pressure Water Immersion Jet and the Behavioral Mechanism of Iodine in Liquid Pool

Abstract A pressurized water reactor nuclear power plant’s coolant may experience a dramatic phase shift near the rupture point in the case of a Steam Generator Tube Rupture (SGTR) accident. This might cause steam to enter the secondary side or inject radioactive materials into the secondary side using a high-temperature, high-pressure jet. There could be flashing at the rupture location. The process of iodine-containing high-temperature, high-pressure water in an immersed jet during a rupture event is the main subject of this work. In order to provide a theoretical foundation for the examination of SGTR accident source terms, it examines the primary parameters impacting iodine’s evaporation, deposition, and mass transfer during the jet flashing process. Through a series of studies, it was seen and determined that the temperature and pressure of saturated water cause the flashing fraction to grow, with the upward tendency eventually slowing down. When high-temperature, high-pressure water jets undergo a specific level of supercooling, there is an approximately linear correlation between the flashing fraction and the degree of supercooling. Research on iodine-containing high-temperature, high-pressure water jets shows that the flashing process is not significantly affected by the iodine’s presence. The retention behavior of iodine in the liquid phase provides information for the analysis of SGTR accident scenarios and is dependent on a number of variables in the solution, including iodine concentration, supercooling, hydrogen potential, and others.