Radon exhalation studies for the remediation of uranium mill tailings ponds in Hungary

Abstract

After more than 35 years operation the uranium mining and milling facilities were shut down in Hungary in 1997. Concrete rings of 1 m diameter filled with test layers of different materials were used for in situ examination of radon exhalation. In total 11 columns were studied, including the uncovered pond as a reference point. Radon concentrations of the layers were measured by radon monitors, and radon flux was measured on the top of each column. On the basis of the evaluation, two covering options have been designed for detailed in-field studies on the tailings area covering about 2000 m2. Radon concentration in the layers and radon emanation from the surface of the cover were measured, and in situ gamma dose rate at 1 m height over the test cover was measured.