| Popis: |
A two-dimensional finite element code, CRACK, simulates the effect of changes in surface air pressure on radon concentration in soil with parallel, partially penetrating cracks. A sensitivity analysis investigates the effect of changes in crack dimensions, soil characteristics, and surface air pressure on radon flux to the atmosphere from a dry, cracked soil. Radon flux is found to be most sensitive to changes in soil properties: the diffusion coefficient is most important, followed by permeability and porosity. Radon flux is also sensitive to changes in barometric pressure. Cracks have a more significant effect on radon flux from soils of low permeability. The effects of moisture should be considered in future studies, because of moisture's importance to the effective air-filled porosity, air permeability, and diffusion coefficient of soils. |
