The Hydrodynamic behavior of molten core material falling in BWR complicated flow channel

Saito, Ryusuke*; Abe, Yutaka*; Kaneko, Akiko*; Suzuki, Takayuki; Yoshida, Hiroyuki  ; Nagase, Fumihisa 

It is important to estimate the behavior of molten core jet in RPV (Reactor Pressure Vessel) of BWR when severe accident occurred as can be seen from Fukushima Daiichi Nuclear Power Plant accident. Thus we are developing a simulation code to estimate the behavior of molten core falling in a lower plenum of BWR. Since there are many complicated structures in the plenum, it is expected that molten core would be injected in the complicated flow channel. The objective of the present study is to investigate the influence of complicated structures in a lower plenum on jet by experiment. To investigate it, we observe jet injection which simulated the molten core falling accident experimentally. We constructed a model of a lower plenum and a steady jet injection equipment. Results of experiment showed that jet behavior is affected by complicated flow structure.