CFD SIMULATION OF BOILING AND CONDENSATION AROUND NUCLEAR FUEL ROD

Abstract

There is a growing need for alternative energy resources due to limited fossil fuels, environmental pollution and increasing cost of conventional fuels. In this context one of the potential alternatives can be nuclear energy. During the operation of light water nuclear reactor the nuclear scientist faces a number of risks like Loss of Coolant Accident (LOCA). During LOCA accidents, large amount of steam are injected to the pressure suppression system resulting in increase in temperature of the pool and thereby increasing the pressure. The analysis of the jrocess of the blowdown of the steam by numerical methods or experiments has got great importance in the area of nuclear safety. The present work discuss about the Computational Fluid Dynamics (CFD) simulation of steam injected to the wet well of BWR through the blowdow n pipes and there by investigating the hydrodvnamic and thermal characteristics of the system. And also to understand the role of different parameters on the hvdrodvnamic and thermal characteristics of the pool. The numerical simulations were performed with ANSYS FLU EN I' 15.0 using multiphase 3D Volume of Fluid (VOF) model and k—s model was adopted for modelling turbulence flow. The condensation of steam from the blowdown pipe at the steam water interphase is successfully simulated qualitatively by varying the pool parameters.