[en] Sediment accumulation rates were estimated from the vertical distribution of excess ²¹⁰Pb in sediment cores collected at six stations in the Goekova Bay near the heavily industrialized Turkish Coastal zone of the Aegean Sea. Total ²¹⁰Pb was determined by measuring ²¹⁰Po activities. The sediment accumulation rates were calculated to vary from 0.32±0.01 cm yr^-1 (0.17±0.01 g cm^-2 yr^-1) to 1.92±0.20 cm yr^-1 (1.13±0.10 g cm^-2 yr^-1). The unsupported ²¹⁰Pb flux was calculated from the accumulated dry matter of the examined slices and their unsupported ²¹⁰Pb concentrations. The flux of unsupported ²¹⁰Pb varies between 62±5 and 105±8 Bq m^-2 yr^-1. The average depositional flux was found to be considerably higher for cores from the Mediterranean

[en] The growing demand of electric power and the large domestic deposits of lignite coal have made coal-fired plants grow in number in Aegean Region of Turkey. Some of this coals like Yatagan lignites are known to have high uranium concentration (315-405 Bq/kg for coal, 746-1076 Bq/kg for collected fly ash). The stockpiles of fly ash of these power plants are readily available for industrial uses as in the case of cement production. Therefore to assess the doses arising from building materials especially from cement in the cities of Aegean Region a project has been started beginning from Izmir. The traces of radium, potassium and thorium in 45 cement samples which are collected from building constructions in Izmir have been analysed by gamma spectrometry. The mean concentrations of Ra-226, Th-232 and K-40 were determined. The indoor radionuclide doses were calculated using the mean concentrations found in the measurements of this work. The results were compared with those given for other countries. (author)

[en] In this paper, fragment de-excitation in thermal neutron fission of 239-Pu and 241-Pu was studied using two different models for scission point configuration. The charge distribution of the secondary fragments as well as the neutron and the gamma emission were investigated using statistical and adiabatic models. Deviation of most probable charge from unchanged charge distribution for secondary fragments were also studied and compared with the experimental results. Adiabatic model was found to give better agreement with the experimental results. Monte-Carlo method was used for the calculations of neutron evaporation from the fragments

[en] Samples of marine surface sediments of different grain sizes collected in Goekova, a small bay on the Aegean Turkish Coast, have been examined to measure alpha- and gamma-radioactivity. The purpose of this research is to define a baseline study of man-made radionuclides on sediments along Goekova Bay, using a combination of direct gamma-spectrometry, radiochemical separation and alpha spectrometry. The analysis of these samples revealed measurable quantities of some artificial radionuclides namely: ^239+240Pu (from 0.13 ± 0.017 to 0.85 ± 0.15 Bq x kg^-1). ¹³⁷Cs, ²⁴¹Am and ²³⁸Pu were identified at a very low level. Concentration ratios of ²³⁸Pu to ^239+240Pu obtained seem to confirm that this artificial radioactivity is due mainly to Chernobyl accident. (author)

[en] Samples of marine surface sediments of different grain sizes collected in Goekova , a small bay on the Aegean Turkish Coast, have been examined to measure α- and γ- radioactivity. The purpose of this research is to define a baseline study of man-made radionuclides on sediments collected along Goekova Bay, using a combination of direct gamma spectrometry, radiochemical separation and a-spectrometry. As the artificial radionuclides, ''1''3''7Cs for all sediment cores samples were under detection limit. The activity concentrations of the ''2''3''9'',''2''4''0Pu were observed to be in the range of 0.13±0.017-0.85±0.15Bq.kg''-''1. ''2''4''1Am and ''2''3''8Pu were identified at a very low level

[en] Fly ash, bottom ash and coal samples from a power plant operating with uraniferous coal were analyzed for their ²¹⁰Pb and ²³⁸U contents by means of a technique developed in low energy scintillation γ-spectrometry. Results were compared with the ²²⁶Ra (eU) contents determined with high energy spectrometry. The measurements of ²³⁸U, ²³⁴Th and ²¹⁰Pb contents have shown significant departure from radioactive equilibrium indicating that the coal was mined from young deposits. The redistribution of radionuclides in the ash samples was also investigated and the enrichment factors were determined. (Author)

[en] Monitoring of ²¹⁰Pb in soil, water, sediment and biological materials has been increasing in several pollution studies in recent years. The ²¹⁰Pb in soils generated in situ by the decay of ²²⁶Ra is termed supported ²¹⁰Pb and is in equilibrium with ²²⁶Ra. ²¹⁰Pb activity in excess of the fraction which is derived from decay of the in situ ²²⁶Ra is called unsupported ²¹⁰Pb. The amount of unsupported or atmospherically derived ²¹⁰Pb in a soil can be calculated by measuring both the ²¹⁰Pb and ²²⁶Ra activities and subtracting the ²²⁶Ra supported ²¹⁰Pb component from the total ²¹⁰Pb in the sample. We have determined the deposition rates of ²¹⁰Pb from the atmosphere in Yatagan Region by measuring their inventories in core samples of cultivated and uncultivated soils.Yatagan is located in Western Turkey in a region where there are three CPPs operating with uraniferous coal. Energy production from coal is one of the major sources of increased natural radioactivity in the atmosphere. Soil samples were stored for a period of 2-3 half-lives (9 - 14 months) of ²¹⁰Po (t_1/2 =138 d) before analysis to allow build-up of ²¹⁰Pb from ²¹⁰Pb . The determination of the ²¹⁰Po activity by alpha-counting provided an indirect measurement of the ²¹⁰Pb activity. Measurements of ²¹⁰Po were made through its 5.30 MeV alpha particle emission, using ²⁰⁸Po (5.11 MeV alpha emission, t_1/2 = 2.9 yr) as the internal tracer. Measurements were made by silicon surface-barrier detector. The ²¹⁰Pb activity concentrations in cultivated and uncultivated bulk soil cores varied between 83 Bq kg^-1 - 22 Bq kg^-1 and 250 Bq kg^-1 - 55 Bq kg^-1, respectively. (authors)

[en] Short communication

[en] Effect of natural gas usage on indoor radon concentrations were investigated in dwellings in four counties of Izmir municipality using LR-115 Type II cellulose nitrate films. The dwellings were separated two groups: natural gas user and non-user. Indoor radon levels were found higher in natural gas using dwellings. Also, indoor radon levels were evaluated in terms of concentrations and annual effective dose. Indoor radon concentrations were found between 22.8 and 707.8 Bq m^-3 and highest concentrations were determined in kitchen in third floor of Bornova dwellings. Indoor radon concentrations in kitchens were found higher than the living rooms. On the other hand, opposite results obtained for annual effective dose, because of very short occupancy period of the kitchens. (author)

[en] ²¹⁰Po in environmental samples has been accumulated on various metals using the chemical electrodeposition technique. The ²¹⁰Po was deposited spontaneously on metal discs after decomposition of the sample in HCl acid and then measured using a ZnS(Ag)α-particle detector. Silver was observed to have the highest deposition efficiency when ²¹⁰Po deposition on different metals was studied. Copper discs were used in the application of activity assessment in cigarette smoke as this is more available and more economical although silver has a higher efficiency than that of other materials examined. The technique is applied for the analysis of ²¹⁰Po in tobacco, ash and butt for several brands of imported and domestic cigarettes smoked in Turkey. (Author)