Natural radioactivity in soil around Baoji coal-fired power plant

Based on systematic sampling of soil around the Baoji coal-fired power plant, the activity concentrations of the natural radionuclides 226Ra, 232Th and 40K were determined using γ-ray spectrometry. Each eight soil samples were collected within the range of 1 km of the plant, and at a distance of 1 and 3 km from the plant, respectively. Two layers of soil sample [0-25cm(layer A), 25cm-50cm(layer B)] were collected at each location. The concentrations of these radionuclides are different horizontally and vertically. The measured specific activity of 226Ra, 232Th and 40K were compared with the average activity of other cities in Shaanxi soil. The results show that 226Ra concentrations in layer A were higher than those in layer B and concentrations of 232Th and 40K in layer B were greater than those in layer A in soil samples collected at 1 km. (authors)