Patent Number: 058898301
Section: claims

1. In a nuclear power plant having a reactor core and a containment chamber for receiving core melt of the reactor core, a cooling system for cooling the containment chamber, comprising: a flooding container to be filled with coolant fluid;  a cooling pipe leading from said flooding container to the containment chamber; and  a passively opening closure element closing said cooling pipe in said flooding container, thus interrupting a flow of the coolant fluid from said flooding container to the containment chamber and opening as a function of a level of the coolant fluid.  a flooding container to be filled with coolant fluid;  a cooling pipe leading from said flooding container to the containment chamber; and  a passively opening float closing off said cooling pipe in said flooding container and opening as a function of a level of the coolant fluid. 2. In a nuclear power plant having a reactor core and a containment chamber for receiving core melt of the reactor core, a cooling system for cooling the containment chamber, comprising: 3. The cooling system according to claim 2, wherein said float has an interior to be filled with the coolant fluid, and a filler pipe extends into said interior and has an inlet opening for receiving a flow of the coolant fluid if the coolant fluid reaches a flooding level rising above an operative level. 4. The cooling system according to claim 2, wherein said float has a condensed water suction removal device. 5. The cooling system according to claim 1, including a return for the coolant fluid extending geodetically above said cooling pipe and connecting the containment chamber to said flooding container, and a further closure element closing said return in said flooding container and opening as a function of the coolant fluid level. 6. The cooling system according to claim 5, wherein said further closure element has a ball valve. 7. The cooling system according to claim 1, wherein said cooling pipe is a flood pipe discharging into the containment chamber. 8. The cooling system according to claim 7, including a closure element closing said flood pipe in the containment chamber and opening as a function of temperature. 9. The cooling system according to claim 8, wherein said closure element opening as a function of temperature is a bale closure with a tightening screw melting above 900.degree. C. 10. The cooling system according to claim 8, wherein said closure element opening as a function of temperature is a closure cap soldered with silver. 11. The cooling system according to claim 1, wherein the containment chamber has a floor element and a wall element, and including an external cooling device for cooling at least one of said elements with the coolant fluid, said cooling pipe connecting said external cooling device to said flooding container as a supply line. 12. The cooling system according to claim 1, wherein the containment chamber is a crucible-like catch basin disposed below the reactor core. 13. The cooling system according to claim 12, wherein said cooling pipe has a compensator outside the catch basin for compensating for thermal expansions of the catch basin. 14. The cooling system according to claim 1, wherein the containment chamber is a propagation chamber disposed laterally below the reactor core .