Oxygen generation suppression method by using radiolysis in BWR type reactor and device therefor

An organic compound (for example, trymethylamine) or an inorganic compound (for example, CO and CO2) having an effect of reacting with OH radicals generated by radiolysis of water to annihilate the OH radicals is injected instead of injecting hydrogen to reactor water. With such procedures, a same effect can be obtained by using hydrogen in an amount about 1/10 of required amount in the prior art. Further, since injection is conducted in the form of liquid, a volume type pump can be used, to facilitate recognition of the injection amount. Further, leakage can be detected easily, to further improve reactor safety. (T.M.)