Thermal Soil Radon Mitigation

Abstract

In this work, consideration is given to the possibility for thermal soil radon mitigation. It is known that the diffusion coefficients of radon through minerals and rocks are characterized by Arrhenius linear plots and then increasing as the temperature increases. For the case of rocks, for example, it was observed that a mild heating, less than 100 °C, translates into a radon release, which can be enhanced by 100–1000 times than the normal release at standard temperature and pressure. Therefore, it is reasonable to think that if soil is deliberately heated and then creating a thermal gradient, it could be possible to pump radon from soil because the radon atoms will escape preferentially from cold regions (low diffusion coefficient) toward hot regions (high diffusion coefficients) where a radon sink is located. Utilizing a simplified two-group thermal one-dimensional model, an expression was derived, which allows a first assessment on this possible mitigation technique.