System for mitigating consequences of loss of coolant accident at nuclear power station

A system for mitigating the consequences of a loss of coolant accident at a nuclear power station, comprising:

• a first room confined within a hermetically sealed envelope and having walls and a floor;
• a second room confined within a hermetically sealed envelope having walls and a floor;
• said first room accomodating therein a reactor plant liable to an accidental loss of coolant and an active-type sprinkler means intended to condense the steam released by the boiling coolant after an accident;
• said second room, accomodating a basin-type condenser to condense steam;
• an intermediate chamber positioned between the said first room and the said second room within the said hermetically sealed envelope;
• holes provided in said walls of said first room in immediate proximity to said floor of said first room and spaced at a maximum distance from one another along the perimeter of said walls;
• said intermediate chamber communicating with said first room through said holes so that most of the air contained in said first room is forced therefrom as a result of the rising pressure following an accident;
• a plurality of vertical channels located within said envelope on the exterior of said intermediate chamber having inlets and outlets and communicating through their inlets with the upper edge of said intermediate chamber wherefrom air is forced through said inlets into said channels and through their outlets to said basin-type condenser, so that steam released as a result of an accident is condensed and air forced through said outlets of said channels is discharged into said second room;
• the length of said channels being selected so as to form a water lock to prevent the backflow of air from the second room to the first and thus produce rarefaction in said first room.