Patent Number: 
Section: claims

1. A containment vessel of a nuclear power plant, comprising:an interior space;a condensing chamber disposed in said interior space, said condensing chamber being filled to a filling level with a cooling liquid;a pressure chamber disposed in said interior space, said pressure chamber having a top region;a condenser disposed in said interior space;a condensing pipe leading into said condensing chamber for enabling overflow of vapor into said condensing chamber from outside said condensing chamber; anda drain pipe for noncondensible gases, said drain pipe disposed in said interior space and fluidically connecting said top region of said pressure chamber to said condensing chamber, said drain pipe defining a direct connection to said condensing chamber, and said drain pipe not connected to said condenser, said drain pipe having an upper end disposed at a level above said condenser and a bottom end immersed into said cooling liquid;said condenser and said upper end of said drain pipe being disposed in said pressure chamber, and said upper end of said drain pipe being disposed to permit the noncondensible gases to be led off from atmosphere surrounding said condenser and thermally interacting with said condenser. 2. A containment vessel of a nuclear power plant, comprising:an interior space;a condensing chamber disposed in said interior space, said condensing chamber being filled to a filling level with a cooling liquid;a pressure chamber disposed in said interior space;a condenser disposed in said pressure chamber;a region around said condenser;a condensing pipe leading into said condensing chamber for enabling overflow of vapor into said condensing chamber from outside said condensing chamber; anda drain pipe for noncondensible gases, said drain pipe fluidically connecting said region around said condenser to said condensing chamber, and said drain pipe having a top end disposed above said condenser, and said drain pipe defining a direct connection to said condensing chamber, and said drain pipe not connected to said condenser, said drain pipe having an upper end disposed at a level above said condenser and a bottom end immersed into said cooling liquid;said condenser and said upper end of said drain pipe being disposed in said pressure chamber, and said upper end of said drain pipe being disposed to permit the noncondensible gases to be drawn off from atmosphere surrounding said condenser and thermally interacting with said condenser. 3. The containment vessel according to claim 1, wherein said drain pipe forms a permanently open flow path. 4. The containment vessel according to claim 2, wherein said drain pipe forms a permanently open flow path. 5. The containment vessel according to claim 1, wherein said condensing pipe ends below said bottom end of said drain pipe. 6. The containment vessel according to claim 2, wherein said condensing pipe ends below said bottom end of said drain pipe. 7. The containment vessel according to claim 1, including an external cooling basin, said condenser fluidically communicating with said external cooling basin. 8. The containment vessel according to claim 2, including an external cooling basin, said condenser fluidically communicating with said external cooling basin. 9. The containment vessel according to claim 1, wherein said drain pipe has a bottom end, and said condensing chamber contains a cooling liquid in which said bottom end of said drain pipe is immersed. 10. The containment vessel according to claim 2, wherein said drain pipe has a bottom end, and said condensing chamber contains a cooling liquid In which said bottom end of said drain pipe is immersed.