Natural Ra-228, Ra-226, K-40, and artificial Cs-137 radionuclides distribution in soil in areas of lignite power plants of Western Macedonia

Radiometric determination of natural Ra-226, Ra-228, K-40 and artificial Cs-137 radionuclides distribution have been performed over the Kozani-Ptolemida-Amynteon basin (Western Macedonia). Here there are localized four lignite power plants, accounting for about 70% of the total production of Greece's electricity. Soil samples, 0 to 20 cm depths, from both uncultivated and cultivated soils have been investigated. No significant increase in soil specific activity due to natural radionuclides has been found in area of fly ash deposition. The numerical values of Ra-226, Ra-228, and K-40 specific activity i.e. 21 +/- 7.5; 24.5 +/- 9 and 341 +/- 147 Bq/kg are, within the limit of experimental errors, equal to those typical for Greek soils. Radiocesium has been presented in all samples at specific activities ranging between 1 and 395 Bq/kg, but never correlates with the other investigated natural radionuclides.