Measurement of terrestrial gamma radiation dose-rate (TGRD) level in soil samples from the district of Rembau, Malaysia, using high-purity Germanium detectors

9th National Seminar on Medical Physics

物理学;医药卫生

Norbani, N.E.^1 ; Salim, N. A. Abdullah^2 ; Rahman, A. T. Abdul^1,3,4

Faculty of Applied Sciences, Universiti Teknologi MARA, Shah Alam

40450, Malaysia^1

Malaysian Nuclear Agency, Bangi

43000, Malaysia^2

Department of Physics, University of Surrey, Guildford

GU27XH, United Kingdom^3

Institute of Science, Universiti Teknologi MARA, Shah Alam

40450, Malaysia^4

关键词: Activity concentration;    Gamma radiation level;    Gamma ray detector;    High purity germanium detectors;    High-resolution gamma spectrometry;    Natural sources;    Naturally-occurring radionuclides;    Terrestrial gamma radiation;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/546/1/012016/pdf
DOI  :  10.1088/1742-6596/546/1/012016

学科分类：卫生学

来源: IOP

【 摘 要 】

This study assesses the gamma radiation levels and associated dose rates from the naturally occurring radionuclides232Th,238U and40K in soil samples collected from the district of Rembau, Malaysia using High-purity Germanium (HPGe) Detectors. A 105 measurement were performed on surface soil using NaI (Tl) gamma-ray detector with crystal size 1«x1», covering about 83% land of the Rembau district. The concentration of the naturally occurring radionuclides232Th,238U and40K in soil samples collected were determined by using HPGe detector based on high-resolution gamma spectrometry system at Malaysia Nuclear Agency. The range of natural gamma radiation measured was from 114±14 nGy h-1to 857±14 nGy h-1. The range of activity concentrations of U, Th and °K in soil from the studied areas varies from 151-401 Bq kg-1, 113-342 Bq kg-1and 674-1526 Bq kg-1with mean values of 245 Bq kg-1, 186 Bq kg-1and 1152 Bq kg1respectively. The mean values of terrestrial gamma radiation dose rate measured in Rembau district is 383±18 nGy h-1compared to the Malaysian average is 92 nGy h-1and world average is 59 nGy h-1(UNSCEAR, 2000). The average annual dose from such terrestrial gamma radiation dose rates to an individual in Rembau district, assuming a tropical rural setting is estimated to be 0.78 mSv per year, which is considered to be within the normal range for doses from natural sources. An isodose map for the Rembau district has been plotted.