Patent Number: 
Section: claims

1. A containment cooling apparatus, comprising:a cooling water tank disposed above a containment and containing cooling water therein;a spray header connected to the cooling water tank via a first communicating pipe, wherein the spray header is disposed on an outside of the containment for spraying the cooling water to an outer wall of the containment;a bell shaped shield covering the containment, wherein the cooling water tank is disposed on a top portion of the shield;a space formed between an inner wall of the shield and the outer wall of the containment, wherein the spray header is disposed in the space;an exhaust hole disposed on the top portion of the shield;a water separator disposed in the exhaust hole and/or the space; anda gas tank disposed in the containment, wherein the gas tank is connected to an upper portion of the cooling water tank via a second communicating pipe, and the cooling water tank is a closed container. 2. The containment cooling apparatus according to claim 1, wherein the cooling water tank is annular, and an axis of the cooling water tank is collinear with an axis of the shield. 3. The containment cooling apparatus according to claim 1, wherein a cooling water outlet is disposed on a bottom portion of the shield. 4. The containment cooling apparatus according to claim 1, wherein the spray header is axisymmetrically disposed above the containment. 5. The containment cooling apparatus according to claim 1, further comprising a rupture disk disposed in the gas tank and/or the second communicating pipe, wherein the rupture disk is ruptured during an increase of pressure in the gas tank, and the rupture disk in an intact state is capable of isolating a space on both sides thereof.