Abstract
Fuel debris which is removed from the Fukushima Dai-ichi Nuclear Power Plant is packed to radioactive waste long-term storage containers. When the fuel debris includes water, hydrogen and oxygen are generated by radiolysis of water. Since hydrogen is flammable gas, it has a high risk of combustion and explosion. Therefore, it is important to reduce the hydrogen concentration in the radioactive waste long-term storage container. An experimental study on the effectiveness of hydrogen concentration reduction have been conducted using the geopolymer-based catalyst, which is one of the passive autocatalytic recombiner (PAR). However, it was found that the geopolymer-based catalyst has a problem in durability. Then, the alumina-based catalyst was used to the present experiment using a sealed container. It is also one of PAR and can expect high durability and integrity in comparison with the geopolymerbased catalyst. This paper describes the experimental results on the hydrogen concentration reduction by the alumina-based catalyst. Moreover, numerical analyses were performed to clarify the performance of the catalyst affecting the reduction of hydrogen concentration in the container.
