Heat exchange type reactor core melt trapping device in U-shaped pipe

Abstract

The invention relates to a heat exchange type reactor core melt trapping device in a U-shaped pipe. The device includes a melt collecting and guiding device, a crucible holding container, a cooling tube bundle, a multi-wall cooling system, a cooling water injection system and a steam discharging system; the melt collecting and guiding device is arranged on the lower portion of a reactor pressure vessel; the crucible holding container is arranged on the lower portion of the guiding device; the cooling tube bundle is arranged in the crucible holding container, the multi-wall cooling system is arranged on the lower portion of the crucible holding container, the cooling water injection system is connected with the multi-wall cooling system, and the steam discharging system includes a reactor pit steam discharge hole and a safety valve. The device has the advantages that the effective cooling area is increased by a U-shaped tube bundle stretching into a melting pool, reactor core melt in asmall space can be cooled rapidly and efficiently, sacrificial materials filling the crucible holding container can be reacted with the melt, metal components in the melt can be oxidized, the meltingpoint of a mixture is reduced, and thermal load on the side wall of the crucible holding container is reduced.

Description

technical field [0001] The invention relates to the technical field of nuclear reactor severe accident prevention and mitigation, in particular to a reactor core melt collection device. Background technique [0002] At present, dozens of large-scale second-generation improved nuclear power plants are under construction and in operation in my country, but most of them have not been equipped with effective external melt retention systems. After the Fukushima accident in Japan, the safety issues of nuclear power plants, especially the prevention and mitigation of severe accidents, are more urgent. At present, under severe accidents, the cooling and retention strategies of the core melt can be mainly divided into two types: 1) The cooling and retention of the melt in the pressure vessel (IVR), this technology first appeared in the Loviisa VVER-440 power station in Finland , and have been applied in the design of AP600, AP1000, APR1400, CAP1400 (1400MWe pressurized water reactor...

AI Technical Summary

Problems solved by technology

Compared with the cooling time of at least 10 months for a VVER single crucible, the extended cooling concept proposed by EPR can greatly increase the contact area between the molten material and the cooling water, and the solidification cooling requirement can be achieved within a few days, but the disadvantage is that it needs about 170m 2 Left and right horizontal expansion space

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