Abstract: An emergency cooling device for a pressurized water nuclear reactor, through the injection of cooling liquid into the primary circuit of the reactor, comprising at least one double injection circuit equipped with two pumps arranged outside the safety enclosure of the reactor and a set of accumulators containing a certain amount of cooling liquid under pressure arranged inside the enclosure. The accumulators are distributed in a first set at a pressure P1 less than the pressure of the primary circuit of the reactor and a second set at the pressure P2 less than the pressure P1. The injection of cooling liquid through one and other set is caused by the automatic opening of valves when the pressure of the primary circuit drops below P1 and below P2, respectively, in the event of a leakage in this circuit. The invention is useful for pressurized water nuclear reactors having any number of primary loops.