Experimental study on hydrogen behavior at a subcompartment in the containment building

Hydrogen control in the case of severe accidents has been required by nuclear regulations to ensure the integrity of the nuclear containment building after Three Miles Island (TMI) accidents. Up to now, many experiments have been conducted to estimate the distribution of hydrogen during accidents in nuclear power plants. In this study, local hydrogen behavior has been experimentally investigated in a cylindrical multi-subcompartment mixing chamber of the SNU (Seoul National University) hydrogen mixing facility, measuring the local concentration in various conditions and mixture injection locations. Hydrogen is simulated by helium in the experiments. Results showed remarkably different local behavior of helium in experiments of several conditions, and the local analysis for hydrogen concentration rather than the lumped compartment analysis, used widely in most plants, would be important to ensure the equipment survivability or to determine the positions of ignitors.