Natural Circulation Flow with Inclined Downward Facing Heating Channel

Natural circulation flows are adapted in various engineering cooling channels in nuclear power plants such as IVR-ERVC(In-vessel retention through external reactor vessel cooling) and ex-vessel molten corium cooling system. And also the natural circulation flow loops usually have inclined downward facing heating channels. Under the IVE-ERVC condition, the boiling induced natural circulation flow is generated in a coolant path between a hot hemispherical vessel wall and cold coolant reservoir. The engineered corium cooling system of an ex-vessel core catcher under consideration is a passive system consisting of an inclined engineered cooling channel made of a single channel between the body of the core catcher and the inside wall of the reactor cavity. Under severe accident conditions, water is supplied to the engineered cooling channel. The water in the inclined channel absorbs the decay heat transferred from the corium through the carbon steel structure of the core catcher body and boils off as steam. In this paper, a small-scaled natural circulation flow experiments with the inclined heating channels are investigated