Monte Carlo method for determining radon diffusion coefficients in porous media

Radon diffusivity is a key parameter for estimating radon emanation from porous media. We have developed a Monte Carlo method for determining radon diffusion coefficients in porous media. In the proposed method, the probability model for pore diameter derived from fractal theory is used to describe the microscopic pore structure of porous media. The Monte Carlo technique is utilized to search for the pore size that satisfies the probability model for porous media. The convergence rate of the proposed is fast (similar to 3 min). Radon diffusion coefficients measured by the closed chamber method are used to validate the accuracy of the proposed method.