Device for controlling combustible gas concentration in reactor container

Purpose: In a reactor container, to simplify the structure without affecting its safety and to control the combustible gas concentration. Constitution: When accidents such as loss of coolant occurs, a large amount of hydrogen gas is generated. In this case the concentration of hydrogen alone increases, and since the concentration of oxygen is still low, it does not immediately reach the critical combustion limit. However, quantity of hydrogen and oxygen continues to increase due to radioactive decomposition and if this situation is left unattended the mixture reaches the critical combustion limit affecting the safety of the container. Therefore, the gases are combusted safely while its concentration still low, using igniters installed in the container. As the container is inert, the combustion takes place quite smoothly. Even if combustible gas is generated due to radioactive decomposition of coolant, combustion of the gas assures safety of the container. (Kawakami, Y.)