A study of the technologically modified sources of Rn-222 and its environmental impact in an Indian U mineralised belt

These investigations present qualitative and quantitative assessments of th e Rn-222 contributing potential of the technologically modified sources, e. g. mine exhausts and tailings piles, arising due to the mining and processi ng of uraniferous minerals at Jaduguda, India. The overall geometric mean o f the 222Rn flux from low-grade uranium (U) mill tailings being 1.19 Bq m(- 2) s(-1) requisite attenuation of 37.8% to the recommended limit of 0.74 Bq m(-2) s(-1) can be attained by a typical clay coverage of 20 cm. Theoretic ally, feasible options for selection of overburden materials for stabilisat ion of the tailings piles are examined. Extrapolation studies with a turbul ent diffusion model yield an atmospheric dispersion pattern of Rn-222 in re asonable correspondence with the prevailing concentrations, especially for locations beyond a 4 km radius. The overall 222Rn contribution of the U com plex to the ambient air is the same as that contributed by the adjoining la nd mass of 2.75 km radius in this mineralised terrain. (C) 2001 Elsevier Sc ience Ltd. All rights reserved.