Large-scale experiments on hydrogen distribution

The generation of hydrogen by radiolysis of water or metal-water reactions during an accident within an LWR and the resulting possibility of hydrogen explosions are an old concern in reactor safety research. This was substantiated by the accident at Three Mile Island during which the reactor core was degraded to a large extent, some hundred kg hydrogen were produced, and burnt in the reactor containment building resulting in a short-term pressure increase of 1.9 bar. As a consequence of this event, hydrogen research was intensified and some additional research programs were started in the USA and in Western Europe. The present paper is focussed on experimental investigations for hydrogen distribution within the containment