Emergency reactor core cooling device

The device of the present invention improves reactor safety by suppressing lowering of water level in a shroud which surrounds a reactor core, even upon occurrence of rupture of pipelines in an emergency reactor core cooling system in a recycling pump-incorporated type reactor. Namely, an opening of each of cooling systems which forms the emergency reactor core cooling device in a reactor pressure vessel is disposed above the upper end of the reactor core. Further, it also comprises an independent high pressure water injection system, gravitational dropping type water injection system and an automatic depressurization system. With such a constitution, even if rupture of pipelines in the system should be assumed, coolants never flow directly from the shroud which surrounds the reactor core. In addition, there are no pipelines to be ruptured below the upper end of the reactor core with respect to the structure. Accordingly, a great amount of water can be stored in the reactor core upon occurrence of accidents. Further, since the number of high pressure type emergency reactor core cooling systems is increased from existent one to three systems, durability against rupture of medium diameter pipes can be increased. (I.S.)