Study on application of CHF models on reactor pressure vessel lower head for severe accident condition

According to the in-vessel retention (IVR) mitigation and the heat transfer characteristics, two theoretical models for predicting the critical heat flux (CHF), the interfacial lift-off theoretical model and the theoretical model considering the hydrodynamic behavior of the vapor-liquid interface of a bubble, are modified, respectively, and a general CHF model is developed to analyze the lower head CHF. The results indicate that the CHF model could well predict the experimental data on large scale curved surface.