Reactor protection system

Object: To permit output power of a BWR type reactor to be rapidly reduced the level of water when the reactor pressure or the level of water becomes abnormally high, thus permitting quick recovery from the abnormal state. Structure: Signals from a reactor pressure detector and a level detector of water are treated in a back-up protection system. When an abnormally high reactor pressure and abnormally high level are detected, the output power of the reactor is quickly reduced through combination of quick pressure reduction by opening a reactor escape valve and reduction of core flow by tripping of a recirculation pump, thereby protecting the reactor. (Moriyama, K.)