Numerical simulation on dynamic migration behaviour of radon of the exposed beach surface under non-isothermal conditions

Seasonal climate change profoundly affects radon release from uranium tailings beaches. This study evaluates radon migration in uranium tailings reservoirs by developing a non-isothermal radon migration model that incorporates freeze-thaw cycles. Using Computational Fluid Dynamics (CFD) numerical simulations combined with temperature and moisture control equations, the research analyzes the effects of atmospheric temperature variations on radon migration. The study examines the migration and exhalation patterns during typical heating and cooling stages. Findings reveal that both temperature and effective water saturation significantly influence radon migration parameters. Specifically, radon exhalation rates increase with tailings temperature, while freezing conditions notably restrict radon migration and release. This research provides a theoretical foundation for dynamically estimating radon exhalation rates and assessing radon pollution on uranium tailings surfaces in response to seasonal temperature fluctuations.