预制裂隙下铀尾矿库土质覆盖层氡析出实验研究

Experimental study on the radon exhalation from the soil overburden of uranium tailing pond under prefabricated fractures

针对铀尾矿库滩面覆盖层裂隙氡析出问题,通过自制试验装置开展铀尾矿库滩面裂隙氡析出模拟实验,研究了不同裂隙参数(深度、数量和倾角)对覆盖层氡析出的影响。结果表明:氡的析出主要受孔隙-裂隙运移路径的影响,氡析出率与裂隙深度呈线性正相关;滩面裂隙倾角增大最短孔隙运移距离缩短,滩面氡析出增加,倾斜角60°较45°时的氡析出率增长0.164 Bq·m^(-2)·s^(-1);孔隙-裂隙路径对滩面氡析出存在影响边界,裂隙影响区域重叠后,氡析出增加量大幅减少;引入最短孔隙路径占比ζ,最短孔隙路径占比ζ与氡析出率J之间有良好的相关性。研究结果可为尾矿库滩面覆土的控氡治理提供理论参考依据。

Faced with the problem of radon exhalation from fractures in soil overburden layer of uranium tailing pond,a simulation experiment of radon exhalation from fractures in soil overburden layer of uranium tailing pond was carried out with a self-made test device,and the effects of different fracture parameters(depth,number and dip angle)on radon exhalation from overburden layer were studied.The results show that the radon exhalation is mainly affected by the pore-fracture migration path,and the radon exhalation rate has a positive linear correlation with the fracture depth.The shortest pore migration distance is shortened with the increase of fracture inclination angle,and the radon exhalation rate for slope angle of 60°increases by 0.164 Bq·m-2·s-1 than that of 45°.The pore-fracture path has an influence boundary on radon exhalation on tailing pond surface,and the increase of radon exhalation decreases greatly after the overlap of the fracture affected area.The shortest pore path proportionζis introduced,and there is a good correlation betweenζand radon precipitation J.The research results can provide a theoretical reference for radon control of tailing pond surface.