Study on radon dispersion modes from the U-mine disposal sites at Žirovski Vrh (Slovenia)

¹ Slovenian Nuclear Safety Administration, 1000 Ljubljana, Slovenia
² Federal Office for Radiation Protection, 85764 Oberschleissheim, Germany
³ Žirovski Vrh Mine, 4224 Gorenja vas, Slovenia

Abstract

Long-term averages of outdoor radon levels give no information on time and spatial behaviour of dispersed radon that exhales from U-mine disposal sites. A comprehensive network of automatic stations for continuous measurements of short-lived radon decay products was installed in the early nineties at the Žirovski Vrh uranium mine. The instruments were positioned at key locations, on-site and off-site uranium mining area, and recorded EEC levels, alpha spectra, and local temperatures, all at least on hourly basis. Analyses of simultaneous records of EEC time series from several locations and analyses of corresponding alpha spectra gave more detailed information on characteristic patterns of radon behaviour and its dispersion from the sites under study. The identified modes of radon dispersion, depending on the presence and type of temperature inversion and the related major findings on the radon impact to the environment are shortly presented.