Study on the Dosimetry and Assessment of Terrestrial Radiation Exposure
Jun, Jae-Shik;Oh, Hi-Peel;Ha, Chung-Woo;
ABSTRACT
For the quantitative evaluation and assessment of radiation exposure from terrestrial component of natural environmental radiation, successive thermoluminescence dosimetry and periodical in-situ gamma ray spectrometry were carried out for a period of 24 months. LiF PTFE dise TLDs and $3&{phi}{times}3'$cylindrical NaI(Tl)scintill ation detector in association of portable multichannel analyzer (4096 ch) were used in this study. The doses measured were evaluated and assessed in terms of effective dose equivalent. As a concomitant output, the dose equivalent due to ionizing component of cosmic ray was able to be evaluated. According to the results obtained in terms of variance weighted mean, the annual effective dose equivalents of terrestrial gamma ray and cosmic ray ionizing component in Taejeon area came out to be $564{pm}4;{mu}Sv(64.8{pm}0.5nSv{cdot}h^{-1}$ and $300{pm}2;{mu}Sv(34.3{pm}0.2nSv{cdot}h^{-1}$, respectively, which are reasonable comparably with that appeared in UNSCEAR Report[28]as per caput annual effective dose equivalent in 'areas of normal background radiation'.