Indian Journal of Science and Technology

Abstract

Objectives: The present study has been carried out to assess the activities concentration of some terrestrial gamma emitting radionuclides and to evaluate the radiation radiological hazard. Methods/Statistical Analysis: In-situ gamma ray spectrometer with a large high-density Bismuth Germanate crystal detector was used for field measurement. Under assumption of secular equilibrium of 238Th and 238U activity concentration and associated radiological hazard indices such as Radium equivalent activity (Raeq) and External Radiation hazards (Hex) and gamma dose rate were estimated. Findings: The following means (±standard error) of concentration (BqKg-1) were obtained: 260.57±31.17 for 40K, 12.82±0.75 for 232Th and 17.04±2.21 for 238U. The Raeq values ranging from 26.10 BqKg-1 to 117.61 BqKg-1 ; the Hex ranged 0.07 Bqkg1 to 0.31 BqKg-1; the total effective dose rates varied from 12.55 nGy.h-1 56.15 nGy.h-1 while the indoor and the outdoor maximum value was 0.27 mSv and 0.07 mSv, respectively. This study is the first evaluation of reference background levels of terrestrial gamma emitting radionuclides in this area. Application/Improvements: Measured primordial radionuclides are essential data for radiological assessment and radioprotection studies as well as for nuclear safety regulatory bodies.

Keywords: Gamma Dose Rate, Naturally Occurring Radionuclides, Radiological Hazard