Evaluation of Hydrogen Distribution against THAI HM-2 Experiment using MELCOR and CFX

Abstract

Since the Fukushima Daiichi Accident, Filtered Containment Venting System (FCVS) has been introduced to the NPP in Korea. However, it is necessary for systematic understanding with detailed analysis of both local and global hydrogen behavior due to explosion possibility of hydrogen. Thus, our objective is to assess hydrogen risk in the FCVS using numerical code. However, preliminary evaluation for HM-2 experiment of OECD THAI project was decided in order to validate the methodology before the evaluation of FCVS. In this paper, therefore, numerical calculation of the HM-2 experiment was performed using MELCOR and CFX. Variables at diverse locations, which are pressure, hydrogen concentration from the calculation results, is compared with the experimental results. In addition, hydrogen behavior related to the stratification and erosion of the cloud by steam is visualized from both numerical results.