Radiation Applications
Reza Pourimani; Saeed Ghahani; Parisa Nobakht; Iman Mirzae Moghadam
Abstract
Today, with the development of nuclear technology and radiation therapy equipment, radiation protection is important. This study aimed to design heavy concrete with high compressive strength and effective protection against neutron and gamma rays. In this study, 11 types of concrete with different mixing ...
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Today, with the development of nuclear technology and radiation therapy equipment, radiation protection is important. This study aimed to design heavy concrete with high compressive strength and effective protection against neutron and gamma rays. In this study, 11 types of concrete with different mixing designs including 88 samples were made. In these samples, iron ore aggregates galena, limonite, hematite, polypropylene fibers, nanoparticles, micro-particles of silicon, and B4C powder have been used. Concrete quality coefficient, compressive strength, gamma, and neutron attenuation coefficients were measured for all samples. Also, the neutron attenuation coefficient for all samples was calculated using the Monte Carlo simulation (MCNPX) code and compared with the experimental values. The density, neutron attenuation coefficient, and compressive strength of concrete samples varied from 2.37 to 3.17 g.cm-3, from 0.0162 to 0.0306 cm2.g-1, and from 48.0 to 81.3 MPa respectively. The linear gamma attenuation coefficient and gamma-ray tenth value layer (TVL) were obtained from 0.148 to 0.398 cm-1 and 15.74 to 5.85 cm respectively. These results showed that the highest neutron and gamma attenuation coefficients were obtained for concrete containing 70% galena iron ore and 20% boron carbide and the highest compressive strength belonged to sample G15 containing 15% galena iron ore and 1.8% boron carbide. G70 was the best concrete regarding the quality factor, defined as the product of multiplying the compressive strength and linear attenuation coefficients of neutron and gamma.
Reza Pourimani; Mohammad Reza Zare; Mehrdad Aghamohammadi
Abstract
In this work, the concentration of tritium in D2O of various degrees of purity was measured. Samples were taken from the Arak heavy water plant and tritium concentrations were determined using a liquid scintillation detector (LSC) based on tritium decay. In this work, instead of simple distillation, ...
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In this work, the concentration of tritium in D2O of various degrees of purity was measured. Samples were taken from the Arak heavy water plant and tritium concentrations were determined using a liquid scintillation detector (LSC) based on tritium decay. In this work, instead of simple distillation, is used the azeotropic distillation method. Absorption and fluorescence spectra were recorded using a Shimadzu UV-2100 spectrometer and an LS50B fluorescence spectrometer. The tritium concentration in the samples varied from 1.75 ± 0.80 to 6.16 ± 1.01 Bq.L-1 in D2O enrichment from 0.35% to 77.50%. The correlation coefficient between tritium concentration and D2O purity in heavy water was obtained as R2 = 0.853. Deviation for 99.8% D2O enriched in heavy water. This was observed from a straight line, leading to a drop in R2. The results of this measurement showed that the tritium concentration did not exceed the value set by the Nuclear Regulatory Commission (NRC).
Reza Pourimani; Mobin Bajelan; Monire Mohebian
Abstract
The specific activity of radionuclides in the soil of the Borujerd region using high purity Germanium detector (HPGe) was measured and the associated radiological hazards were calculated. The mean specific activity of radionuclides of Ra-226, Th-232, K-40, and Cs-137 in soil was obtained at 10.99±5.11, ...
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The specific activity of radionuclides in the soil of the Borujerd region using high purity Germanium detector (HPGe) was measured and the associated radiological hazards were calculated. The mean specific activity of radionuclides of Ra-226, Th-232, K-40, and Cs-137 in soil was obtained at 10.99±5.11, 35.36±4.44, 324.20±10.24, and 2.93±0.60 Bq.kg-1. These values were below the global average. Also, the value of basic radiological risk parameters, such as Raeq, AEDout, AEDint, Hex, Hin, and Iγ, ranged from 52.02 to 139.54 in Bq.kg-1, from 24.98 to 68.27 and from 42.90 to 117.22 in mSv.y-1, 122.57 to 334.93, 0.14 to 0.37, 0.16 to 0.40, and 0.27 to 1.04, respectively. The range of excess lifetime cancer risk (ELCR) value for the surrounding soil samples varied from 0.15×10-3 to 0.41×10-3, in which samples S4, S14, S24, S27, S28, S29, and S30 exceeded the global average of 0.29×10-3. A radiological map of the city of Borujerd was prepared using the GIS program. The study showed that the level of radioactivity in the Borujerd area did not exceed the critical value and is in line with the global results.
Vahidreza Babaei; Peiman Rezaeian; Sedigheh Kashian; Reza Pourimani; Azam Akhavan
Abstract
In this paper, the spectrophotometric properties of a colored Nickel-based solution complex (Nickel nitrate hexahydrate and Methyl Orange (MO)) were investigated as a stable chemical dosimeter for using in radiation processing of agricultural products. Its simple synthesis method as well as low cost ...
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In this paper, the spectrophotometric properties of a colored Nickel-based solution complex (Nickel nitrate hexahydrate and Methyl Orange (MO)) were investigated as a stable chemical dosimeter for using in radiation processing of agricultural products. Its simple synthesis method as well as low cost made it a suitable dosimeter for use in radiation processing. The variation of absorbed dose was applied to measure the absorbed dose. The maximum absorbance for the solution was observed at 460 nm. This solution was irradiated at three different concentrations of Ni(No3)2.6H2O and MO by Co-60 gamma-ray. Also the variation of the absorbance as a function of PH of the solution was investigated. The results showed the solution absorbance decreases with an increase in doses, and this solution can be used as a routine dosimeter and has a linear response in the 50 to 1500 Gy range with acceptable stability in environmental conditions up to 40 days before and after irradiation.
Reza Pourimani; Monire Mohebian; Mobina Abdi
Abstract
Nuclear radiations are harmful to the human body. The main sources of nuclear radiation are the decay chains of U-238, U-235, and Th-232 and also some radionuclides as K-40, which are present in small amounts in the materials of the earth's crust, including plants, rocks, soil and water. Radioactive ...
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Nuclear radiations are harmful to the human body. The main sources of nuclear radiation are the decay chains of U-238, U-235, and Th-232 and also some radionuclides as K-40, which are present in small amounts in the materials of the earth's crust, including plants, rocks, soil and water. Radioactive substances are transferred to the human body in a variety of ways, including plant and animal products. Therefore, it is very important to determine the amount of radioactive substances in food products. In this research, seven samples of pistachios with different types were collected from Tehran markets in Iran. In this project, ultra-pure germanium spectroscopy system model GCD30195 was used. The specific activities of Ra-226, Th-232 and K-40 varied from <1.96 to 9.86, from 1.21 to 1.95, and from 317.22 to 382.80 Bq.kg-1. The artificial radionuclide of Cs-137 in all samples was lower than minimum detectable value (MDA). Calculations of the radiological impact showed that consumption of pistachios would endanger human health. The results of this study also showed that the amount of natural radionuclides in pistachio cores is higher than pistachio shells.
