抄録
In order to experimentally estimate the breakup behavior of the molten core material in coolant, in the present study, the molten jet that simulates the core material (U-alloy 78) is injected into the water. The visual data of the molten jet breakup behavior is observed by using the high-speed video camera. The jet front velocity is estimated by using the image processing from the visual data. It shows that the jet breakup behavior is influenced by the injection nozzle diameter, but isn't done by the jet penetration velocity. This result is close to the equation given by Epstein & Fauske when an entrapment coefficient E_0 is 0.066.
