INVESTIGATION OF THE ACTIVITY LEVEL AND RADIOLOGICAL IMPACTS OF NATURALLY OCCURRING RADIONUCLIDES IN BLAST FURNACE SLAG

122. The mean activity concentrations of the 226 Ra, 232 Th and 40 K in BFS samples were found to be 152.4, 54.9 and 183.1 Bq kg 21 , respectively. These values are compared with typical values measured in BFS samples from the European Union countries, which are 270, 70 and 240 Bq kg 21 for 226 Ra, 232 Th and 40 K, respectively. The values of radium equivalent activity index calculated for BFS samples were within the recommended safety limits. The highest total annual effective doses evaluated as 0.9 and 0.4 mSv y 21 for members of the public and workers, respectively, were lower than the annual limit of 1 mSv y 21 .