Containment protection with hydrogen recombiners

Core meltdown and concrete - melt interactions cause free hydrogen to be produced. Devices protecting against concrete - melt interactions can largely help to avoid hydrogen releases outside the containment. In the hydrogen -steam - air system, the hydrogen concentration should not exceed the limits of deflagration; on no account must it reach the detonation level. Minimum steam fractions can be maintained by means of hydrogen recombiners. The devices should be designed so that the limits of hydrogen concentration can be observed. In the process of catalytic recombination, hydrogen is oxidized at an early stage without producing any flames and before reaching the level of ignitability. (orig.)