Radon exhalation from uranium tailings - comparison of experimental and theoretical data

Two different experimental methods and a theoretical approach are used to c alculate Rn-222 fluxes in the soil-atmosphere inter face. As a common exper imental procedure, an open-faced 30 liters cylindrical container was invert ed and placed onto the tailing surface with the open face down. After a 24 h period, to balance any possible disturbance, the interior air was analyse d. One of the experimental methods is based on integrated Rn-222 measuremen ts of the accumulated air-gas mixture, using solid nuclear track detectors placed inside the container. The other method is based on spot air samples using scintillation cells, being the Rn-222 concentration measured in equil ibrium. The radon flux theoretical values are estimated from the Ra-226 con tent of the tailings material, determined by gamma spectrometry, and using the diffusion equation. The series of results obtained by the referred meth ods were compared.