Hydrogen removing system

The system of the present invention comprises a catalytic hydrogen removing device which passes a gas containing hydrogen and oxygen into an LWR type reactor to recombine the hydrogen and oxygen and a blower for sending an atmospheric gas in the reactor container to the catalytic hydrogen removing device. The catalytic hydrogen removing device is disposed so that a gas to be processed is entered from the lower portion and passed to the upper portion thereof. The inlet for the gas to be processed is connected with a blowing port of the blower so that both of them are integrated. The blower is operated using, as an operation source, a hydraulic pressure of coolants in container cooling spray pipelines which are automatically pressurized when such an event should occur that coolants in the reactor pressure vessel is reduced. Pipelines on the side of a gas outlet of the catalytic hydrogen removing device may be opened to an upper portion of a dry well or opened into a pressure suppression pool. (I.N.)