Containment filtered venting system used for nuclear power plant

Abstract

The present invention relates to a containment filtered venting system used for a nuclear power plant, the system comprising: a containment filtered venting container for storing a composition of the containment filtered venting system; an entrance pipe connected to the containment filtered venting container and a nuclear reactor building; a combined nozzle connected from the entrance pipe and immersed in a filtering solution filled in a part of the container; a cyclone separator for removing most of droplets and aerosols having large sizes, which have escaped from the combined nozzle and then been mixed with the filtering solution, and guiding the filtering solution to a metal filter; the metal filter which is connected to an upper end of the cyclone separator and filters out the remaining droplets and aerosols; a molecular sieve for removing organic iodine from exhaust gas filtered through the metal filter; and an exit pipe interconnecting the containment filtered venting container and a stack.

Description

technical field [0001] The invention relates to a filter exhaust system for use in nuclear power plants. Background technique [0002] The present invention relates to a containment filter discharge system, which refers to preventing the risk of damage to the containment caused by overpressure in the containment in advance when a major accident occurs in a nuclear power plant. Functions as a system for draining material from a nuclear reactor building. When implementing this discharge process, since the nuclear reactor building contains a large amount of radioactive aerosols and radioactive gases, it needs to be accompanied by proper filtration of radioactive materials, and this nuclear reactor building filter discharge system has been adopted by AREVA (AREVA) The company, Westinghouse (WH, Westinghouse) company, IMI company and many other existing equipment development companies have developed and applied to power stations. [0003] In the case of Areva Corporation (forme...

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Problems solved by technology

[0006] But in the case of Areva's CFVS, the droplets passing through the nozzle will be physically adsorbed in the pretreatment filter and then recirculated to the scrubber solution by gravity. When the filter flows in, there is a possibility of obstructing the flow of the flow or causing problems such as clogging due to inflow to the metal fiber filter (Metal fiber filter) at the rear end

Moreover, since the number of nozzles is relatively small, when individual nozzles are damaged, the impact on other nozzles is relatively large

[0007] On the other hand, IMI's CFVS uses a chemical substance called Aliquat336 added to the scrubber solution in order to remove organic iodine. However, it has been pointed out that there is a risk of explosion and a forming phenomenon in the normal temperature environment. Possibility, and the performance verification of the above substances is still in the initial stage, so the effectiveness in the high temperature environment, which is the actual operating condition of CFVS, has not yet been demonstrated

Also, due to the use of hundreds of Impact nozzles, there are difficulties in making machine settings

[0008] On the other hand, Westinghouse supplies two types of CFVS such as DFM and FILTRA-MVSS, and in the case of DFM, there is a possibility of hot spot (Hotspot) caused by clogging and waste heat, and the iodine filter ( In the case of zeolite filled with iodine filter), since the filtration efficiency is higher at high temperature than normal temperature, there is no additional pre-heating at the beginning of CFVS operation, except for the scrubber solution Besides, there is no additional unit for the removal of organic iodine, therefore, the removal efficiency of the same substance is reduced, and there are difficulties in fabrication and installation due to hundreds of long Venturi nozzles

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