Three-component melt jet breakup model for FCI analysis

A new molten core jet breakup model was developed to for JASMINE-pre, the premixing module of the steam explosion simulation code developed at JAERI. The new model was designed emphasizing two aspects: separation of the melt model from the multiphase solver, and giving finer spatial resolution for the melt. The model consists of 3 components: jet, pool and particles, and it is designed to be combined with a two-phase flow code to handle the coolant flow field (ACE-3D). The melt jet is solved by 1-D CIP, which is known as a high resolution method, while the pool and particles are handled by 1-D FDM and Lagrangian particle method, respectively. In a simulation of a melt jet breakup experiment in non-boiling conditions (ALPHA-MJB16), the present model qualitatively reproduced the experimental results. (author)