Numerical simulation of two-phase flow in 44 simulated fuel bundle

Ono, Ayako ; Yamashita, Susumu   ; Suzuki, Takayuki*; Yoshida, Hiroyuki  

An evaluation methodology of critical heat fluxes (CHFs) based on a mechanism for fuel assemblies in light water reactors (LWRs) is needed in order to design and evaluate the safety for the fuel assemblies in LWRs. JAEA is embarking on the establishment of methodology to simulate the two-phase flow in the fuel bundles which applies to prediction CHF. In this study, the numerical simulation of two-phase flow in 44 bundle was implemented by using JUPITER in order to establish the evaluation method of the size and velocity of bubbles by the numerical simulation, which is the multi-physics simulation code and enable to track the gas-liquid surface. It was confirmed that the JUPITER enables to simulate the two-phase flow in the 44 simulated fuel bundle which is large calculation domain over 3 m.