B210 Influence of Surface Solidification on Molten Material Jet and Coolant Interaction

For the safety design of the Fast Breeder Reactor (FBR), the Post Accident Heat Removal (PAHR) is required when a hypothetical Core Disruptive Accident (CDA) occurs. To clarify the interaction between molten material and coolant such as jet breakup behavior during the CDA for the FBR, the dominant mechanism of the jet breakup behavior is required. The objective of the present study is to clarify the dominant factor of the jet breakup length and size distribution of the fragments generated through the jet breakup behavior in the condition of surface solidification as simulation of phenomena in a real FBR system. A jet breakup behavior as interaction of simulated molten core material and coolant is observed with high-speed video camera. The solidified fragments are gathered and classified in size, and the each size is measured. The median diameter of the generated fragments is estimated from the mass distribution of the fragments. It is suggested that form of fragments is different by temperature conditions.