This paper develops a new two-dimensional model to estimate the radon exhalation rate of fractured porous media. The fractal discrete fracture network is used to characterize the fracture structure in the model. The finite element method solves the governing equations of radon migrations in fractures and porous matrix. Well-equipped laboratory tests validate the model with reasonable accuracy. The comparison of the model with the traditional radon migration model indicates that the model can simulate radon migration in fractured porous media more effectively than the traditional model. The effects of fracture intensity (P21), seepage velocity, and fracture connectivity on radon migration in fractured porous media are analyzed using the model. The radon exhalation rate increases with the fracture intensity and seepage velocity. There is an exponential relationship between fracture connectivity and radon concentration. The model provides a reliable method to analyze radon migration in fractured porous media and is helpful for radon pollution prevention and control.
Keywords: Finite element method; Fractal discrete fracture network; Fractured porous media; Radon migration.
© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.