Environmental Rn levels around an Indian U complex

The ambient Rn behaviour in the environment around an Indian U complex at J aduguda is investigated using grab sampling as well as time-integrated moni toring techniques in 1990-1996. In this region with tropical-like climatic conditions, atmospheric Rn levels (i) range from 4.0 to 157 Bq m(-3) with a standard geometric mean of 22 Bq m(-3), (ii) attain minima in the afternoo n and about 1.5-5 times greater in the morning before sunrise, (iii) exhibi t a minimum level during the rainy season and about 4 times greater in wint er as a maximum, (iv) average at lower concentrations in days with cloudy s kies compared to clear skies. There is a negative linear correlation coeffi cient of -0.92 between monthly mean ambient temperature and Rn concentratio n. The radiological significance of Rn levels in air in the nearby areas an d the natural background is discussed. (C) 2000 Elsevier Science Ltd. All r ights reserved.