Determination of radon exhalation rates and effective radium contents in soil samples around Orhaneli, Keleş and Osmangazi districts of Bursa

In this thesis, it was aimed to determine radon exhalation rates and effective radium contents of the soil samples collected from Orhaneli, Keleş and Osmangazi districts of Bursa by using "Sealed Can Technique" and solid state track detectors (LR-115). The radon concentration added to the indoor radon activity via radon exhalation from the soil was also determined and the annual effective doses due to radon in indoor environments were calculated. Determination of radiological risks with radioactivity measurements is very important for all living creatures and humans. This study, which is carried out around the thermal power plants planned to be established in Keleş and Osmangazi, will be a comparison study for the radiological studies to be performed after the power plants are installed and operated for a term. Mass and surface exhalation rates obtained in soil samples vary from 27.32±2.61 to1132.7111±16.83 mBqkg-1h-1 with an average value of of 316.22±8.89 mBqkg-1h-1 and 0.65±0.40 to 24.25±2.46 Bqm-2h-1 with an average value of 7.15±1.34 Bqm-2h-1, respectively. The effective radium content was found to vary in the range 0.34±0.29 to14.231.89 Bqkg-1 with an average value of 7.15±1.34 Bqm-2h-1. The indoor radon concentration contributed by surface radon exhalation from soil varies from 2.61 to 97.88 Bqm-3 with an average value of 28.59 Bqm-3. The average surface radon exhalation rate determined in the study is lower than the annual average value (118.8 Bqm-2h-1) reported by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR, 2000). The estimated annual effective dose values in the study area vary between 0.07 and 2.72 mSvy-1 (with an average of 0.80 mSvy-1) and are below the recommended action values (3-10 mSvy-1, UNSCEAR, 2000). When the results obtained in this study are compared with the limit values proposed by national and international organizations, it is understood that most of the soils in the studied area do not pose any radiological danger.