Development of online radon and thoron monitoring systems for occupational and general environments

Online radon and thoron monitors have been developed using ZnS(Ag) detector for continuous monitoring of concentrations in occupational and general environments. Their performance has been tested successfully both in laboratory and field conditions. Special features of these monitors include low cost, high sensitivity and non-interference of humidity and trace gases. The capability of these radon monitors for networked radon monitoring in U mines and in the U-tailings pond has been demonstrated. The thoron monitor is designed for stack monitoring of thoron release in a thorium processing facility. Being highly sensitive, these monitors can also be used for radon/thoron monitoring in dwellings, radon exhalation measurements, radon concentration in water samples and thoron emission measurements from monazite sands in High Background Radiation Areas. (author)