Abstract The flow passed chemical traps is a mixture of light gas, hydrogen fluoride and uranium hexafluoride. It is necessary to take samples from the chemical traps output flow, to assure the accurate operation, non-saturation of adsorbent, proper loading and to control the output concentration of hydrogen fluoride and uranium hexafluoride. The routine approach for sampling is impossible because of the process of continuity and vacuum conditions. A procedure for the chemical traps output sampling is introduced in this paper under the assumption of the lack of uranium hexafluoride at the output of the chemical trap, and its effective parameter was optimized. As a result, the sampling time and pressure which are considered as the most important parameter were evaluated and their optimized values were estimated.

Abstract In the present study the rotary reactor used for producing UO₂ from AUC is modeled. For this purpose, the governing equations, including mass and energy balance equations for the existing species and phases are derived based on the conservation laws and then they were solved numerically. All other required parameters for solving the governing equations, including the geometrical characteristics of the solid bed, hydrodynamic conditions of the bed and reactor, thermo-physical properties of gaseous and solid species and existing reactions were obtained from the literature and were used. Individual reaction kinetics, presented in the literature for the reactions which are taking place in this reactor, shows many shortages for condition in which all the reactions are taking into account simultaneously. Thus, for the first time, a new kinetics model is proposed and is applied successfuly. The results of using the model are in good agreement with the logical and expected behavior which can be obtained based on the principles of chemical engineering science. 

Abstract Recent advances in radiation therapy have made obvious the need for dosimeters that can measure three-dimensional (3-D) dose distributions. Currently, radiosensitive gel dosimeters have provided 3-D dose measurements using the MRI technique. However, this method has some limitations. Recently, a novel transparent polymer dosimeter, PRESAGE, has been introduced which exhibits a radiochromic response when exposed to ionizing radiation. This dosimetry technique has some advantages compared with other gel dosimeters. In this study, the dose response, linearity, sensitivity, and stability of this type of dosimeter were investigated for different levels of the activator, and leuco dye concentration. In this regard, the PRESAGE dosimeters were made with different formulations and were irradiated by gamma-rays of Cobalt-60 in the dose range of 0-50 Gy. Then, the optical absorption changes of the dosimeters were measured by a spectrophotometer over a period of 14 days after the irradiation. The results indicated that increasing the activator concentration leads to the increase of the sensitivity, but decreases the stability of the dosimeter response. Furthermore, it was noted that the dosimeter shows a linear response to the radiation dose with a high level of correlation (R²>0.99).  

Abstract In this study two Polyacrylonitril-Ti(IV) tungstophosphate organo-inorganic ion exchangers with different molar ratios have been synthesized. These ion exchangers have been characterized by FT-IR, X- ray diffraction, TG, SEM and CHNSO techniques and their cation exchange capacity has been measured by continuous method. Distribution coefficients (K_d) for metal ions and radionuclides were determined by batch method andwith these ion exchangers, separation of metal ions was achieved on a glass column.

Abstract Pain palliation of bone metastases is one of the perspectives of medical science. Among the different modalities, the use of radionuclides is a well-established approach. One of these radionuclides is Yttrium-90 (⁹⁰Y) associated with chemical component EDTMP. One method for production of ⁹⁰Y is neutron activation of ⁸⁹Y. This radionuclide is a pure beta emitter with a high energy and appropriate half life and has been considered for medical usages in nuclear medicine. In this research ⁹⁰Y has been produced by irradiation of Y­­­­­_2­­O­­­₃ powder and by the addition of EDTMP ligand, the ⁹⁰Y-EDTMP complex has been achieved at ambient temperature. Radiochemical purity was investigated by ITLC method and radionuclidic purity by liquid scintillation counting. The radiopharmaceutical biodistributions were performed in different rat organs. 

Abstract The aim of this study was the application of irradiation process to decrease bacterial contamination of the penaeus monodon. The shrimp samples were obtained from Hormozgan and were sent to the microbiological laboratory. Bacterial contamination of shrimp were determined by counting the aerobic mesophil bacteria, Staphylococcus areus, Choliforms, Vibrio parahemolyticus and Salmonella. The shrimp samples were irradiated at different doses of gamma ray. Finally, the optimum dose of the gamma ray for bacterial decontamination of shrimp, especially of Vibrio Parahemolyticus, was obtained to be 2kGy. Also, the chemical factors of irradiated and non-irradiated samples such as Protein, Fat, total volatile Nitrogen (TVN), Non Protein Nitrogen (NPN), Peroxide Value (PV) and Amino Acids were measured. There were not any important difference among them. Also, there were not any significant difference between TVN and Peroxide Value (P>0.05) for the irradiated and
non-irradiated shrimp samples. Study of bacterial contaminations of the irradiated and non irradiated samples after 12 months showed that irradiation by 2kGy can control the microbial contaminations. Four types of films for packaging: Pet.pe, Pp.pe, Bopp, and Pe.20 were used for storage of the irradiated and non irradiated shrimp samples in-18°C during 12 months. All of the packages were studied on the aspects of color, odor, tissue and taste of shrimp samples and elasticity and pressing of packages. For the irradiated and non irradiated shrimp Pet.pe and Pp.pe were preferred, respectively.

Abstract The low grade mineral needs pre-treatment operation prior to concluding processing. This is especially proper for uranium and gold mineral naturally forming low grade into crest of the earth. This paper surveyes the enhancement of uranium ore grade in Saghand by using gravity separations methods. The mineral deposits grade is low and refractory within this realm. The study of mineralization demonstrated that uranium ore type is Davidite and the average content of the uranium specified by X-ray diffraction analysis was 300ppm. Also, the amount of other minerals were 57.39% (SiO₂), 1.29% (TiO₂), 5.64% (Fe₂O₃) and the contented value of rare earth elements, as well. The initial step of processing operation is to release the elements, particularly uranium. Therefore, the ore sample is crushed by jaw and roll crusher and then ground by rod milling to gain access to suitable degree of liberation. The milling output size was classified by the laboratory screens and divided into six sections. Each section of the screened product was washed by water and separated by shaking table. The results confirmed an increase in the grade of uranium and other minerals up to 4463ppm.

Abstract In this work, the possibilities of molybdenum content reduction in uranium leach liquor was investigated by adsorption techniques. Several activated charcoals were used as adsorbents. Under the optimized condition, 83.59% of molybdenum was adsorbed with “Norit PK 0.25-1” activated charcoal. Since the low uranium adsorption is the aim of this work, by performing the optimization conditions, the uranium adsorption with activated charcoal was determined to be 2.74%.

Abstract Dose rate is one of the most important factors that should be considered in handling, stacking and transportation of nuclear materials for the occupational radiation protection and for the people who are exposing to. Uranium hexafluoride is one of the radioactive compounds of uranium which is used in the enrichment industry. UF₆ is kept and transferred in special carbon steel containers. In this study, the absorbed dose of radiations emitted from 30B cylinder containing fully-aged natural UF₆ is simulated by MCNP4C code and results are compared with the actual data. The absorbed dose rate depends on some factors such as cylinder contents, storage time before and after discharge, radiation energy, geometry, the enrichment percent, etc. The satisfactory consistency between the calculations and measurements confirms that the simulation model can contribute to the dose mapping data around the UF₆ cylinder and can be used for determination of the allowable exposure time and to control absorbed dose rate. This study is performed experimentally at the KALA ELECTRIC Company.

Abstract In this work, the effective factors on the preparation of ⁶⁷Ga-oxinate complex for white blood cell labeling were determined. Gallium-67 was produced at AMIRS 30MeV cyclotron via ⁶⁸Zn(p,2n)⁶⁷Ga reaction in the from of ⁶⁷GaCl₃, and was used for radiolabeling of oxinate complex at optimized conditions. A mixture of ⁶⁷GaCl₃ (3uL, 200uCi) and ethanolic oxine solution (1mg/ml, 100μl) was evaporated and reacted at 25^ºC for 1 h in the presence of NaOAc solution (pH. 5.5). ITLC was performed using a mixture of ammonium actetae and methanol solution (1:1) followed by recording the activity using radio thin layer chromatography scanner. The radiochemical purity of %95.18 at these conditions was obtained (specific activity of 1432 GBq/mmol). Freshly prepared white blood cells were separated from human volunteers and used for labeling by the above mentioned complex at 37^ºC. ⁶⁷Ga-oxinate complex due to it’s lipophilicity and suitable gamma rays is a suitable cell labeling agent and available for blood stem cell and microorganism studies. 

Abstract O-Tyrosine is proposed as a marker for identification of irradiated protein-rich foods. In this study, HPLC/ Fluorescence method that allows accurate quantification of 0.1ng of o-tyrosine has been used. The method involves freeze-drying of sample, acid hydrolysis and fractionation by HPLC. By using Spherisorb ODS2 column, the base-line separation of o-tyrosine from impurities was performed. The yield of o-tyrosine in the irradiated chicken meat was proportional to the irradiation dose. Since the variable levels of o-tyrosine were found in unirradiated chicken meat (0.15-0.42 µg/g per wet weight), this method is able to identify the irradiated chicken meat at 4kGy or higher. Because the dose response curve can be extended over 50kGy, the method is suitable for detecting the overdosed samples.

Abstract The variation of thermal and structural properties of 2-{[4-(2-hydroxybenzylideneamino) phenylimino]methyl}phenol (PAM)Schiff base were studied using differential scanning calorimetry (DSC) and powder X-ray diffraction techniques before and after fast neutron (1.050 and 1.740kGy), beta (11.01Gy) and gamma (453.0Gy) irradiations. Under fast neutron irradiation, the melting and decomposition enthalpies and temperatures were changed with increasing the irradiation time. The kinetic parameters were calculated using both model free isoconversional and Kissinger analysis methods. Gamma irradiation showed similar effectonstructural and thermal properties.