PREDICTIONS OF REWETTING PROCESS FOR A NUCLEAR-FUEL ROD USING 1ST-PRINCIPLES EQUATIONS

The rewetting of a nuclear fuel rod is investigated numerically by a conjugated heat transfer model using first-principles equations. The two-phase flow in the coolant channel is treated by a turbulent, locally-homogenized model. The heat transfer coefficient, rewetting temperature and rewetting velocity are parts of the solution. The critical heat flux predicted by the model agrees with the experimental data available in other literature to a reasonable extent. The effect of gap resistance on the rewetting process is studied and the results show agreement with earlier analytical models. The predicted rewetting velocity agrees with experimental data within 15% discrepancy.