S0803-1-3 Study on Evaluation of Gas Entrainment in Nuclear Reactor Vessel using Numerical Simulation Method

Abstract

To evaluate the gas entrainment (GE) phenomenon in sodium-cooled fast reactors, two methods are proposed in this study. One is a CFD-based prediction method and the other is a high-precision numerical simulation method for interfacial flows. In the CFD-based prediction method, a theoretical flow model is applied to the CFD result obtained on a relatively coarse mesh to determine the indicators of the GE phenomenon, e. g. interfacial dent. This method was validated by evaluating the occurrence condition of the GE phenomenon in the full-scale testing of a fast reactor. On the other hand, several numerical algorithms were developed to achieve the high-precision numerical simulation of interfacial flows. In the development, physics-basis formulations were derived to improve the simulation accuracy on interface tracking. As a result, it was confirmed that the developed numerical simulation method can reproduce the GE phenomenon observed in a simple GE experiment.