Preliminary analysis of Loca with explosion accident in Korean demonstration fusion reactor using Melcor

Abstract

To secure high efficiency and temperature margin of nuclear power plant system, most of nuclear reactors use pressurized water system. To use this well-developed engineering technique, nuclear fusion demonstration reactor in Korea will use this pressurized water as primary and secondary cooling system. Because the pressurized water cooling system is not fully engineered in the fusion reactor, the safety concern is main subject in designing cooling system. Loss of coolant accident (LOCA) is important accident in fission reactor. Most of accidents in the nuclear power plant are about leakage of coolant from the cooling system. Also, hydrogen explosion is important phenomena in both nuclear fusion and fission reactor. In this paper, one of beyond design basis accidents, hydrogen and dust explosion accident with LOCA in ITER, is applied to the preliminary design of nuclear fusion demonstration reactor to conduct preliminary safety analysis. The reason of this accident selection is that it is important to keep the pressure inside containment building under the atmospheric pressure to protect public from radioactive exposure, and this LOCA and explosion accident is representative accident of system pressurization. MELCOR is used to simulate this accident and parametric analysis about effect of safety systems and break size. The effect of LOCA accident to the aerosol leakage is studied. As a result, aerosol distribution of each control volume and amount of leakage is calculated.