Study On Rule Of Radon Exhalation In Radon Control Materials

In the process of underground mining of uranium mine,the radium material in the rock wall and broken ore heap will produce radon gas after a series of decay,and then it will be discharged to the surface with the ventilation process.But in the process of in-situ uranium mining,there are inevitably gaps in the facilities such as pipeline laying and building shielding.As an inert gas,radon has a strong ability of transmission and adhesion in the air,which is harmful to human health and environment.Therefore,in order to ensure the sustainable development of uranium mining in China,it is necessary to optimize the design of radon protection.Through reading a lot of academic literature,this paper summarizes the research status of domestic and overseas researchers on radon migration in media,and carries out the research on radon migration and exhalation from the aspects of radon migration theory and mathematical model in media.At the same time,a double-layer radon control material is designed.By measuring radon concentration and dynamic exhalation rate,the correctness of radon migration mathematical model is verified.The following conclusions are obtained:(1)Based on the research status of radon migration and exhalation in the medium at home and abroad,and from the physical and chemical properties of radon and the principle of radon control,the process of radon diffusion and seepage migration in the medium is systematically analyzed.(2)Based on the above theoretical research,the physical model and mathematical model of radon migration in the double-layer medium have been put forward.According to the model,several factors affecting the radon exhalation rate on the surface of the medium,including the diffusion coefficient,the thickness of the medium and the seepage velocity,are analyzed in detail.The diffusion coefficient of radon and the reality of the medium itself are compared Porosity is related.(3)Three kinds of commonly used building sealants are selected: two-component polyurethane,one component silicone and one component polysulfide building sealants to design double-layer radon control materials.The two-componentpolyurethane adhesive,as the bottom covering material of radon control material,plays the role of overall framework support.Single component polysulfide sealant and neutral silicone sealant,as the top layer covering material,can ensure the sealing of the material and prevent radon precipitation.(4)The radon control experiment was designed to measure the radon concentration and exhalation rate of radon through double-layer radon control materials under the condition of confined space and pure diffusion.(5)Under the laboratory condition,according to the value measured by the instrument,the calculation and analysis are carried out to verify the mathematical model of radon migration.