The Evaluation of Radon-Protective Characteristics in Engineered and Existing Buildings with the Radon Diffusive Entry from the Soil

Abstract

Abstract A human receives more than half of the annual individual radiation dose from the radon and its progeny contained in indoor air. Therefore, in order to limit domestic exposure of the population in the Russian Federation the national radon control levels have been established. The excess of these levels is not allowed in buildings with a long people’s residence. Radon entry into the building through horizontal underground walling from the soil base and therefore, the restricting of the soil radon flux in the ground floor rooms indoor air is possible only with construction technologies and means. The effectiveness of radon-protective technologies directly depends on the understanding of the laws of radon transport in porous media, since this transport may occur through diffusion and/or convection (filtration). Each of these mechanisms may be dominant under the certain conditions and requires its own radon-protective measures. This article compares the density of diffusive and convective radon fluxes in the entire range of soils permeabilities. The range of underground walling and soils permeability was determined, in which the prediction of radon conditions in a building can be built exclusively on the patterns of diffusive radon transport in porous media. The approach to the underground walling design on the basis of the one-dimensional model of stationary diffusive radon transport in porous media is proposed.