title: Combined diffusive and advective transport of radon in a homogeneous column of dry sand.
abstract: To validate a model for radon transport in soil, measurements of combined advective and diffusive radon transport under well-defined and controlled conditions have been made in a homogeneous column of dry sand with and without an air-filled volume on top. This volume simulates a crawl space. The measurements concern steady-state as well as time-dependent combined advective and diffusive transport and are performed in the framework of a systematic validation study which will also cover more complex situations (e.g., presence of pore-water). The experimental data were compared with results of a two-dimensional numerical model based on the finite-difference approach of the differential equation describing radon transport. Validations of the numerical model with analytical solutions were carried out for one-dimensional steady-state combined diffusive and advective transport, and for two-dimensional time-dependent diffusive transport. The results of the measurements with combined advective and diffusive transport are in good agreement with (numerical) model calculations with maximum deviations <10%.
authors.affiliation: Environmental Radioactivity Research and Consultancy Group, Kernfysisch Versneller Instituut, Rijkuniversiteit Groningen, The Netherlands.
authors.forename: W H
authors.initials: WH
authors.lastname: van der Spoel
authors.forename: E R
authors.initials: ER
authors.lastname: van der Graaf
authors.forename: R J
authors.initials: RJ
authors.lastname: de Meijer
mesh_terms: D004058:Diffusion; D008962:Models, Theoretical; D011886:Radon; D012822:Silicon Dioxide; D012987:Soil
chemical_list: D012987:Soil; D012822:Silicon Dioxide; D011886:Radon