BWR-type power plant

The present invention provides a BWR type reactor and a power plant in which a corrosion circumstance of primary coolants is moderated. Namely, the oxidative atmosphere of primary coolants is moderated by disposing a device of reducing a concentration of dissolved oxygen in a recycling channel of primary coolants. Although many kinds of oxidative ingredients are present in addition to oxygen in the primary coolants, the concentration of them is transferred rapidly to an equilibrium state under intense radiation rays. Accordingly, accumulation of all of the oxidative ingredients in the primary coolants can be suppressed by reducing the oxygen concentration as a main oxidative ingredient. As a result, a power plant in which corrosion circumstance of primary coolants is moderated can be constituted. As an example of calculation estimated relative to a BWR type reactor of 800MWe, when a device for reducing the dissolved oxygen concentration is disposed in recycling pipelines to reduce the dissolved oxygen concentration for the total amount of the reactor water to 30%, the dissolved oxygen concentration on the inner side of the shroud is reduced to 65% of that before disposing the device. (I.S.)