抄録
For severe accident analysis in a fast breeder reactor and accelerator driven system, it is predicted that gas-liquid two-phase flow with large density ratio may be formed. We are proposing to develop applicable models for safety analysis. Experiments were performed to measure radial profiles of void fraction and bubble frequency using four-sensor probe method for nitrogen gas-molten lead-bismuth two-phase flow. The experimental results show that the measured void fraction profile changes from wall-peak to core-peak distribution with increasing gas velocity j_g, at j_f=20〜60cm/s and that the bubble breakup is dominant along the flow direction in the present experimental conditions.
