STUDY ON THE INFLUENCE OF DRY DENSITY AND PARTICLE SIZE FRACTAL DISTRIBUTION ON THE RADON CONTROL PERFORMANCE OF OVERLYING SOIL IN URANIUM TAILINGS POND.

In order to explore the influence of dry density and particle size fractal distribution on the radon control performance of overlying soil in uranium tailings pond, overlying soil samples with different particle size fractal dimension and dry density were prepared for radon exhalation experiments. According to the principle of radon generation and diffusion, a set of radon measuring device was designed independently. In addition, the radon concentration on the surface of different overlying soil layers was measured by local static method, and the radon exhalation rate was further calculated. The relationship between radon exhalation law, dry density and fractal dimension of overlying soil was studied by correlation analysis method. Furthermore, a piecewise linear function between radon exhalation rate, dry density and fractal dimension was constructed. Then, the average value of the experimental data was compared with the calculated results. Results show that: at the same dry density and different fractal dimension, the radon exhalation rate decreased with the increase of fractal dimension. When the fractal dimension increased to a certain value, the radon exhalation rate tended to be stable. At the same fractal dimension and different dry density, the radon exhalation rate decreased with the increase of dry density. The calculated results of piecewise linear function were relatively close to the experimental data, which verified the practicability of the formula.