Aslı Kurnaz

Radionuclides content in grape molasses soil samples from Central Black Sea region of Turkey

ABSTRACT The activity concentrations of radionuclides in grape molasses soil samples collected from Zile (Tokat) plain in the Central Black Sea region of Turkey were measured by using gamma spectrometer with a NaI(Tl) detector. Also, the concentrations of 222Rn in soil samples and air were estimated essentially taking the activity concentrations of 226Ra measured in soil samples. Grape molasses soil samples with calcium carbonate content are used for sedimentation for making molasses in this region. The average activity concentrations of 232Th, 226Ra, 40K, and 137Cs were found as 62 ± 2, 68 ± 3, 479 ± 35, and 8.0 ± 0.3 Bq kg−1, respectively. The average concentrations of 222Rn in soil samples and air were estimated to be 50 kBq m−3 and 144 Bq m−3. From the activity concentrations, absorbed gamma dose rate in outdoor air (D), annual effective dose from external exposure (EE), annual effective dose from inhalation of radon (EI), and excess lifetime cancer risk (ELCR) were estimated in order to assess radiological risks. The average values of D, EE, EI, and ELCR were found to be 90 nGy h−1, 110 μSv y−1, 1360 μSv y−1, and 4 × 10−4, respectively.

Environmental evaluation of natural radioactivity in soil near a lignite-burning power plant in Turkey

Natural radionuclides are released into the environment together with fly ash from the coal-burning power plant and cause an increase in the natural radioactivity in environmental samples. The study concerns to the evaluation the influence of Kangal lignite-burning power plant (LBPP) with a power of 457 MWe, which has been in operation since 1989, on natural radionuclide a concentration in surface soil samples around it. Activity concentrations of natural radionuclides (226Ra, 232Th, 40K and 222Rn) in the soil samples, and emanation coefficient (EC) and mass (ERM) and surface (ERS) exhalation rate of radon were determined by using a gamma-ray spectrometer with an HPGe detector. The average values of 226Ra, 232Th, 40K and 222Rn, EC, ERM and ERS were found as 37±5, 17±3, 222±30Bqkg-1 and 9±1kBqm-3, 12%, 12.1 µBq kg-1 s-1 and 7.1mBqm-2 s-1, respectively. Absorbed gamma dose rate in outdoor air and the corresponding effective dose rate from external exposure and excess lifetime cancer risk were estimated to evaluate radiological hazards for human population. The results revealed that the Kangal LBPP has caused a small increment in 226Ra concentration in the studied area. No influence was observed for 232Th and 40K.

Radiometric measurement of lignite coal and its by-products and assessment of the usability of fly ash as raw materials in Turkey

Abstract Lignite coal (LC) is a key energy source for electricity generation in Turkey. During lignite burning, huge amounts of fly ash (FA), bottom ash and slag are produced as by-products which contain radionuclides in the natural radioactive series of uranium and thorium, and radioactive potassium. These radionuclides may lead to radiological exposure of workers and the public and cause environmental problems. Therefore, finding diverse uses for the by-products in the construction sector and earthwork applications has considerable economic and environmental importance. In this study, the activity concentrations of 226Ra, 232Th and 40K in and radon emanating power (EP) and radon mass exhalation rate (EXRM) from LC, slag and FA obtained from the Kangal lignite-burning power plant with a power of 457 MWe were measured using gamma-ray spectroscopy. The major chemical components (SiO2, Al2O3, Fe2O3, CaO and MgO) of fly ash samples were analysed using an energy dispersive X-ray fluorescence spectrometer. The annual effective doses received by workers and members of the public were estimated using different scenarios specified in Radiation protection 122. The average activity concentrations of 226Ra, 232Th and 40K in LC, slag and FA samples were 187±21, 16±1 and 99±9 Bq kg−1, 620±18, 41±2 and 330±13 Bq kg−1, and 937±30, 38±2 and 272±17 Bq kg−1, respectively. The average values of EP and EXRM of the lignite, slag and FA samples were 8 %, 7 % and 10 %, and 0.1, 0.3 and 0.7 Bq kg−1 h−1, respectively. The highest average of the total annual effective dose is estimated at 153 μSv for members of the public and 74 μSv for workers, lower than the recommended annual limit of 1000 μSv.

Determination of tritium activity concentration in natural water samples

ABSTRACT This study aims to measure tritium activity concentrations in tap, well, and spring water samples from Mersin province in Turkey using a liquid scintillation counting (LSC) system and to evaluate the corresponding radiological hazards due to the ingestion of water samples. The tritium activity concentrations measured in the water samples varied from < 1.9 (detection limit) to 14.1 ± 1.0 Bq L−1 (119.5 ± 8.5 TU) with an average of 6.2 ± 0.6 Bq L−1 (52.5 ± 5.4 TU). The tritium activities in the water samples were significantly lower than the limit of 100 Bq L−1 for water intended for human consumption. The annual effective doses estimated for different age groups of the members of the public due to the intake of the tritium varied from 0.009 to 0.185 μSv y−1.

Radiological impact assessment of nuclear weapon depots in Valley Rwagh, Libya

ABSTRACT Activity levels of the natural (238U, 232Th, 226Ra, and 40K) and artificial (137Cs) radionuclides in surface soil samples collected from different areas of Libya, especially the southern and central provinces, including Valley Rwagh, which is in a mountainous region in Al-Jufra Oasis amid the Libyan desert, 600 km southeast of Tripoli, and in which there are stores of various weapons, were determined using a gamma-ray spectrometer with a HPGe detector. The average activity concentrations of 238U, 232Th, 226Ra, and 40K were measured as 87 ± 11, 202 ± 36, 121 ± 19, and 73 ± 3 Bq kg–1, respectively. The activity levels of artificial radionuclide 137Cs measured in soil samples were below the detection limit. The average concentrations of radon in soil and air were estimated as 103 kBq m–3 and 327 Bq m–3, respectively. The average values of outdoor absorbed gamma dose rate and the corresponding annual effective dose rate from external exposure, annual effective dose rate from inhalation of radon, and lifetime cancer risk estimated for assessing the radiological impacts caused by ionizing radiation emitted from these radionuclides on the population in the region were found to be 165 nGy h–1, 203 μSv y–1, 3096 μSv y–1, and 7 × 10–4, respectively.

Reference levels of background radioactivity for beach sands and soils in İnebolu/Kastamonu-Turkey

This paper presents the measurement results of environmental radioactivity levels for Inebolu district (tourist area), Kastamonu-Turkey. The radioactivity concentrations of 238U, 232Th, 40K and the fission product 137Cs in soil samples collected from 13 region surroundings of study area and in 12 beach sand samples collected from along the coast of Inebolu were determined. To evaluate the radiological hazard of the natural radioactivity, based on the measured concentrations of these radionuclides, the mean absorbed gamma dose and the annual effective dose were evaluated separately, and found to be 112.90 nGy h-1 and 138.46 µSv y-1 for soil samples and 75.19 nGy h-1 and 92.22 µSv y-1 for beach sand samples, respectively. The results show that Inebolu does not have high background.

Distribution of natural radionuclides in soils and beach sands of Abana-Çatalzeytin (Kastamonu)

A gamma spectrometric study of distribution of natural radionuclides in soil and beach sand samples collected from the terrestrial and coastal environment of Abana and Catalzeytin counties of Kastamonu Province in Turkey was performed with the aim of estimating the radiation hazard of the tourist area and the concentrations of 238U, 232Th and 40K were determined. The activity concentrations of 238U, 232Th and 40K were determined in the ranges 14.95–56.0, 46.5–99.4 and 357.5–871.3 Bqkg−1 for soil samples and the mean concentrations were ascertained as 42.34, 71.24 and 624.18 Bqkg−1, respectively. In sand samples, 238U, 232Th and 40K contents were varied in the ranges of 13.35-41.6, 30.9-53.4 and 275.5-601.3 Bqkg−1 and the mean concentrations were ascertained as 20.57, 45.05 and 411.71 Bqkg−1, respectively. The mean annual effective doses were calculated as 113.08 and 69.16 µSvy−1 for the soil and sand samples, respectively.