2019 Volume 68 Issue 9 Pages 621-630
Soil samples were collected around the uranium deposit of Kitongo to determine activity concentrations of 238U, 232Th and 40K using a NaI(Tl) detector. Ambient dose equivalent rates were measured using a survey meter. 222Rn-220Rn discriminative measurements were performed using passive type monitors. The activity concentrations of 238U, 232Th and 40K ranged from 20±5 to 337±78 Bq kg−1, 14±4 to 53±13 Bq kg−1 and from 21±4 to 897±190 Bq kg−1 respectively, with the average values of 99±24, 27±4 and 592±125 Bq kg−1, respectively. Ambient dose equivalent rates ranged from 0.05 µSv h−1 to 6.20 µSv h−1. Higher values were recorded inside the two galleries of the uranium deposit. The maximum dose to prospective miners was calculated to be 15.2 mSv y−1. In case of the miner staying permanently inside the galleries, the external dose received would vary from 32 to 54 mSv y−1 with an average of 43 mSv y−1. Radon concentrations ranged from 416±13 to 523±14 Bq m−3 with the average value of 486±14 Bq m−3. Occupational inhalation dose ranged from 2.8 to 3.5 mSv y−1 with an average value of 3.2 mSv y−1.