Abstract:
The HPGe detector was used to calculate the specific activity of natural radionuclides 238U, 232Th, and 40K in rock samples obtained from the Um-Bogma area. Um-Bogma is divided into four regions : Abu Zarab (AZ), Sad Elbanat (SB), TaletSelim (TS), and Allouga (AG). The dose rate and hazards parameters have been calculated. Concentration of 222Rn emanated (226Ra decaying) has been calculated using empirical formulae and compared with that measured using Solid State Nuclear Track Detector CR-39 (SSNTD). The average specific activity in Bqkg-1(dry weight) for 238U, 226Ra 232Th and 40K were 396.3±3.3, 405.04±3.4, 61.45±1.3 & 377.2±5.8 respectively for Abu Zarab area, 1216.6±5.4, 1475.4±6.7, 61.8±1.3 & 359.2±6.1 Bqkg-1 respectively for Talet Seleim area, 467.8±4.2, 408.41±3.5, 29.60±0.9 & 259.2±2.9 Bqkg-1 respectively for Allouga area and 557.05±4.1, 491.78±3.9, 63.45±1.4 & 420.55±3.6 Bqkg-1 respectively for Sad AlBanat area. The measured radon concentrations for the four regions were 4.95, 10.4, 4.6 and 3.9 Bq/m3. From the data obtained , it is found that the geological structure considered the main factor for the increase of radon concentration.