Study on the Interaction of Molten Metal and a Coolant

In a core disruptive accident (CDA) of a fast breeder reactor, the post accident heat removal (PAHR) is crucial for the accident mitigation. The molten core material should be cooled by the inventory of the coolant in the lower plenum of the reactor vessel. It is still unknown whether two phase cooling can be expected during molten core material and coolant interaction. The purpose of the present study is to experimentally clarify the cooling capability of the coolant for the molten material including two phase boiling. In the experiment, simulated molten metal jet is injected into water to experimentally obtain the visualized information of the fragmentation and boiling phenomena during PAHR in CDA. (authors)