Evaluation of natural radioactivity in the soil surrounding Bhabha Atomic Research Centre, Visakhapatnam, Andhra Pradesh, India

Abstract

Abstract Activity concentrations of naturally occurring radionuclides in soil samples collected during 2013–2018 from different 53 locations around Bhabha Atomic Research Centre (BARC), Visakhapatnam, Andhra Pradesh, India, were determined using high-purity germanium gamma-ray spectrometry. An R and D center of BARC is upcoming at Visakhapatnam, North coastal Andhra Pradesh. The annual effective dose (AED) and the radiation indices from the soil activity were evaluated to generate the baseline data for this area. The average activity concentrations of the naturally occurring radionuclides 238U, 226Ra, 232Th, and 40K in the soil samples studied are 29 ± 8 Bq/kg, 31 ± 1 Bq/kg, 188 ± 2 Bq/kg, and 471 ± 10 Bq/kg, respectively. The concentration of 226Ra and 40K in the collected samples is comparable with the world average concentrations of 33 Bq/kg and 420 Bq/kg, however, 232Th is observed to be higher than the world average of 45 Bq/kg. AED due to external terrestrial radiation from the region studied is in the range the range 0.37 to 2.5 mSv/y with an average of 0.9 mSv/y. The mean radium equivalent activity values for around 70% of the studied samples are lower than the permitted levels of 370 Bq/kg. The mean external exposure index has been determined to be around the safe criterion limit of unity. The mean value of the representative level index Iϒ is 2.4. Higher values in some locations are due to thorium in monazite deposits. This report will be useful as preoperational study to evaluate the impact on the environment due to ongoing and future man-made developments.