ESTIMATION OF RADIOLOGICAL EXPOSURE LEVELS IN A MINING AREA BASED ON 238U, 226Ra, 232Th and 40K ACTIVITY MEASUREMENTS: A CASE STUDY FOR BEYLIKOVA-SIVRIHISAR COMPLEX ORE SITE IN TURKEY

The study estimated the radiological exposure levels in a mining area for miners in the Beylikova-Sivrihisar (Turkey) complex ore site containing 238U, 226Ra and 232Th. Sixty samples were collected from the study area based on a geologic map. The radionuclide activities were measured using a 78.5% efficient n-type HPGe detector. The measured mean activities were 1871 ± 38 Bq kg−1 for 238U, 1749 ± 5 Bq kg−1 for 226Ra, 3467 ± 9 Bq kg−1 for 232Th and 309 ± 2 Bq kg−1 for 40K. From the measured results, the external effective dose was calculated to be max. 3.80 ± 0.03 mSv y−1 (mean: 2.04 ± 0.03 mSv y−1) for inside gallery and max. 7.59 ± 0.05 mSv y−1 (mean: 4.08 ± 0.05 mSv y−1) for outdoor. Additionally, the external exposure index was calculated to be Hex = 33.5 ± 0.2(mean: 18.2 ± 0.3) and internal exposure index to be Hin = 45.9 ± 0.3 (mean: 22.9 ± 0.4). The results indicate that additional radiation protection measures should be taken during the mining process if an opencast mining is implemented in Beylikova complex ore deposit.