A passive cooling device and system for a floating spent fuel pool in a nuclear power plant

Abstract

The invention discloses a floating passive cooling device of a spent fuel pool in a nuclear power plant. The passive cooling device at least comprises a heat exchange tube assembly. The heat exchange tube assembly comprises a plurality of heat exchange tubes and a grillwork, wherein the heat exchange tubes are filled with a certain quantity of cooling working media, and certain negative pressure is kept inside each heat exchange tube; the heat exchange tubes are evenly arranged on the grillwork in an equidistant mode, and the grillwork can generate a certain amount of buoyancy in liquid of the spent fuel pool so that the heat exchange tube assembly can float on the liquid level of the spent fuel pool. The portion, placed under the liquid level of the spent fuel pool, of each heat exchange tube is a heat absorption end, and the portion, placed over the liquid level of the spent fuel pool, of each heat exchange tube is a heat release end. The cooling working media are low boiling point working media. The invention further discloses a floating passive cooling system of the spent fuel pool in the nuclear power plant. By implementing the floating passive cooling device and system of the spent fuel pool in the nuclear power plant, operating can be conducted in a completely passive mode, so that safety is improved; the heat radiating area is further increased, and the heat removal capacity is greatly improved; the heat transfer working media can be recycled, and the device and system are environmentally friendly and stable.

Description

technical field [0001] The invention relates to the field of nuclear power, in particular to a passive cooling device and system for a floating spent fuel pool of a nuclear power plant. Background technique [0002] After the fuel in the core of a nuclear power plant reaches burnup depth, it is removed from the reactor and moved to the spent fuel pool (SFP) for storage. There are two types of existing spent fuel pool storage, one is dry storage and the other is wet storage, and the latter is widely used at present. The anti-seismic structural design of SFP can ensure the integrity of the pool and fuel safety; the depth of the pool water covering the spent fuel provides sufficient radiation protection for the staff; the design of the fuel grid and soluble poison (boron) can ensure the subcritical safety of the spent fuel; The spent fuel pool cooling and purification system (SFS) provides sufficient cooling for the spent fuel pool water to remove decay heat. [0003] The cur...

AI Technical Summary

Problems solved by technology

[0005] 1. The cooling effectiveness of the spent fuel pool depends on the effectiveness of the AC power supply. If the power supply cannot be restored in time after an accident, the spent fuel will be exposed

In situations like the Fukushima nuclear accident, the safety of spent fuel cannot be guaranteed;

[0006] 2. In the passive cooling design of the spent fuel pool of the existing nuclear power plant (such as AP1000), the removal of the decay heat of the spent fuel pool relies on passive safe water supply, and the source of non-dynamic safe water supply is limited, so it implements passive cooling. The effective time of cooling is only up to 72 hours;

[0007] 3. In the passive cooling design of the spent fuel pool of the existing nuclear power plant (such as AP1000), the start-up and adjustment of the safety injection system depend on the 1E-level direct current and the actions of the operator. The failure of the 1E-level direct current will bring difficulties to it, and the operation On-site operations by personnel will result in an increase in individual doses;

[0008] 4 In the design of the existing wet spent fuel storage system (such as Chinese Invention Patent Publication No. CN103377737), the position of the heat exchange tube in the vertical direction is fixed. The length of the heat-absorbing section below the position is reduced, and the heat-absorbing area is reduced, so that the heat of the spent fuel pool cannot be effectively absorbed;

[0009] 5. In the existing design of a heat pipe cooling device for the spent fuel pool of a pressurized water reactor nuclear power plant (such as the Chinese invention patent publication number CN202855320), the heat pipe cooling components are placed horizontally, which is not conducive to the natural circulation of the working fluid in the heat pipe

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