Numerical investigation on the influence of ventilation shaft on gaseous radionuclide diffusion of uranic exhaust in atmosphere

Abstract

Understanding the distribution of radionuclides from uranium mine tail gas into the surface atmosphere is one way of dealing with radioactive pollution, but the factors affecting the concentration distribution are considered insufficiently studied. This article looks into the structural characteristics of the exhaust shaft of a uranium mine and studied the effect of the cross-sectional shape (square or round) on radionuclide concentrations. We used numerical simulation to verify the significance and clarity of the impact. The results show that, without considering the terrain, the radionuclide concentration distribution is not sensitive to wind direction at different heights, regardless of exhaust shaft shape. There are 2–5 times more radionuclides discharged from the round exhaust shaft as the square shaft, and the difference increases with height. The concentration exceeds the maximum dose requirement until approximately 500 m downwind when the square exhaust shaft is used, while it is at least 1000 m with the round exhaust shaft. These conclusions imply that the structural features of the exhaust shafts, especially the cross-sectional shape, should be given high priority during construction, and the structure of the exhaust shafts should not be neglected or oversimplified in the study of similar problems.