Quench model for lower temperature than thermohydrodynamic maximum liquid superheat

This report presents a new quench model applicable to the low temperature quench phenomena which occurs at the lower temperature than the thermohydrodynamic maximum liquid superheat. In the reflood phase of PWR-LOCA, the low temperature quench usually appears at the lower portion of the core. For development of this model, some literatures were reviewed and the hydrodynamic maximum liquid superheat was adopted as the second rewetting temperature. And the probability function determining the thermodynamic on hydrodynamic maximum liquid superheat as a rewetting temperature or a given quench temperature was derived from the data of the JAERI small scale reflood experiments. Sakurai's correlation for hydrodynamic maximum liquid superheat which is built in the new model was well predicted the instantaneous quench temperature measured in the reflood test. (author)