Device for limiting accidental pressure overloads in a nuclear reactor confinement structure

A device for limiting accidental pressure overloads in a confinement structure of a nuclear reactor, comprising a first thin-walled enclosure which contains the reactor, a refrigerant circuit for cooling the reactor core in said first enclosure, said first enclosure being surrounded by a second high-strength enclosure having thick walls, an intermediate space defined between said enclosure partly filled with a volume of refrigerant in the liquid state, an air cushion above said volume in said space, means for communication between said enclosures including bubbling ducts opening at one end of the wall of said first enclosure above the level of the volume of refrigerant in the liquid state within said intermediate space and opening at the other end beneath said liquid level, each of said ducts having an internal partition system at the lower part of said other end extending in a direction parallel to the axis of the duct to separate the flow of gas within said duct and to break-up bubbles produced within the volume of refrigerant, said partition system of each of said ducts extending to a greater depth of immersion in said volume than that of said duct itself and defining a plurality of parallel channels distributed over the cross-section of said duct, the depth of immersion in said volume of the extremities of said channels being of progressively decreasing value from the center to the periphery of said cross-section.