Radioactive iodine concentration control system for primary loop of pressurized water reactor and control method thereof

Abstract

The invention belongs to the technical field of primary loop radioactive source item control of nuclear power plants, and particularly relates to a radioactive iodine concentration control system fora primary loop of a pressurized water reactor and a control method thereof. The method comprises the following steps: 1, rapidly changing a large amount of water in the primary loop by using clean boron water in a boron water storage tank A; 2, using clean boron water in a boron water storage tank B to intermittently change the water in the primary loop; and 3, using the clean boron water in the boron water storage tank B to rapidly change a large amount of water in the primary loop. According to the method, the concentration of radioactive iodine in the primary loop can be reduced to below the control level by performing water exchange and purification operations on a primary loop coolant and the boron water storage tanks, hardware reconstruction cost is not required, and during the period of postponing the lifting of a reactor top cover to continue purification, a main pump and a steam generator can normally carry out subsequent maintenance work by installing of a sealing blocking plate, and the influence on the overhaul process of the unit is reduced.

Description

technical field [0001] The invention belongs to the technical field of controlling radioactive source items in a primary circuit of a nuclear power plant, and in particular relates to a radioactive iodine concentration control system and a control method for a primary circuit of a pressurized water reactor. Background technique [0002] During the operation of PWR nuclear power units, the fuel cladding is damaged from time to time; during the overhaul shutdown to reduce the temperature and pressure, gaseous fission products such as radioactive iodine in the fuel quickly enter the primary circuit coolant in large quantities through cladding defects, resulting in spikes (according to According to the research and statistics of the NRC of the US Nuclear Regulatory Commission, the peak effect of the shutdown process can cause the concentration of radioactive iodine in the primary circuit to increase by 1000 times); after the primary circuit system equipment is opened, the radioac...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a pressurized water reactor primary circuit radioactive iodine concentration control system and its control method for the above-mentioned deficiencies in the prior art, which is used to solve the technology in the prior art that needs to rely on the operation of the main pump to control the iodine concentration of the primary circuit question

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