Sharif Digital Repository

Uranium recovery from wastes produced in every stage of nuclear fuel cycle is very important from both the economic and environmental points of view. Zircon, zirconium-containing ore that is the input feed to Zirconium sponge production factories, contains considerable amounts of uranium compounds. The majority of this uranium will enter to the different waste streams of the plant. In this study, by analyzing the waste streams of the Zirconium Production Plant (ZPP) located at Isfahan, Iran, total mass balance of uranium in waste streams was identified. It was concluded that bottom residuals at furnaces of the chlorination unit is the primary uranium-containing waste stream. The preliminary... 

Nuclear energy is one of the most important sources of energy from the economical point of view and also in terms of cleanliness and safety. Hence, strategically, uranium is one of the most basic elements of the earth and nowadays, the importance of this element is more marked due to the nuclear industry developement. Therefore, uranium recovery from the wastes generated during nuclear fuel production in Isfahan’s uranium conversion plant- in which yellow cake is converted to uranium hexafluoride- is quite pivotal. In this experimental research, we have to remove Fluoride from waste after dissolution by several methods like precipitation. After that uranium is extracted from the sludge of... 

The Atomic Energy Organization of Iran (AEOI) has launched a program of low level waste management. This program also includes waste produced at Uranium Conversion Facility (UCF) of Esfahan. The liquid waste, which was generated during the operation of plant and concentrated in lagoon, was characterized for the development of the treatment process. The aim of this study was to recovery of uranium content of liquid waste in the lagoon. The recovery of uranium has the advantage of saving this valuable metal and the avoidance of unacceptable discarding solution to the environment. Uranium may be recovered from an aqueous solution by precipitation, solvent extraction and ion exchange.... 

Fog computing environment consists of several devices which distribute across an arbitrary topology. Each of these devices is capable of carrying out a designated computation simultaneously with other devices. One of the common ways of describing a computation is through the usage of workflows. Workflow is a flexible and formal way of modeling tasks and their requirements for execution. A workflow is essentially a DAG. Therefore, it can model the data dependency between tasks quite accurately. The complex structure of a workflow in conjunction with the homogenous nature of devices in a fog environment makes it difficult to find a resource management algorithm to minimize execution time, used... 

This project focuses on the design of fuel drop tanks for airplanes that add minimal drag and positive lift to the flying object. This will obviously effect the stability and dynamic performance of the airplane. To reduce adverse dynamic effects the tank was divided to several segment with a special emptying sequence. The add-on tank has to have no interference with the object existing systems and require minimum structural changes in the object. Several designs were proposed and the one gaining highest marks was selected. The flow field and the dynamic behavior of combined vehicle and drop tanks were studied using FE simulations. The result shows that adding a drop tank with optimized... 

In order to identify the representative radioactive waste streams at Bushehr Nuclear Power Plant (BNPP) for use in Scaling Factor Determination Program for BNPP, all the relevant technical documents of BNPP including the Final Safety Assessment Report (FSAR) and Operation Manuals (OM) were carefully studied. In addition, the waste stream lines were closely examined by frequently visiting the plant and consulting with the responsible technical staff of BNPP.
As a result, twelve distinct waste streams (2 streams of concentrated waste, 3 streams of sludge, 1 stream of spent resin of TC31B001 tank, 1 stream of spent resin of UZ20B001 tank, 1 stream of selective sorbent TR41B001, 1 stream of... 

In this thesis, a Segmented Gama Scanning System for measuring total activity of the low/intermediate level radioactive waste drums is designed and a prototype 3-segmented commercial system is manufactured by using NaI detectors. The optimum distance of detector from drum surface and the optimum number of detectors on reconstruction of the radioactivity of the waste drum were studied by MCNP simulations. In addition, the effects of inhomogeneous distribution of radioactivity, the addition of lead filters to detectors, the change in collimator length and the asymmetrical placement of a drum on the rotary plate were also examined by the MCNP calculations. In the absence of a real radioactive... 

At a unit in zirconium production plant under the supervision of Soure Co. nuclear grade zirconium is produced. In the process it is required that hafnium get separated from Zirconium. Zirconium and hafnium separation are performed by nitric acid (4N) and hydrochloric acid (4N). This isolation environment is considerably corrosive and damaging for the equipment. Powder coating is one of the solutions to deal with the corrosion. To do so, electrostatic powder coating method was used for ECTFE polymer. After the coating, according to spark test, roughness analysis, thickness, elasticity and adhesion; temperature and time of the spraying and the spraying of top coating was determined. In... 

The raw and conditioned operational waste streams of Bushehr Nuclear Power Plant (BNPP) was determined by reviewing numerous plant’s documents (such as FSAR and operational documents) as well as by interviewing with persons in charge of BNPP waste management office. It was found that low/intermediate (type І and ІІ) level operational waste streams generated in BNPP is divided into eight independent streams. By using gamma emitting radionuclides as virtual DTM nuclides and determination of scaling factors for these nuclides, it was concluded that all the 8 waste streams can be grouped into one, that is, a universal scaling factor can be applied for all the 8 waste streams. In addition the... 

The Iranian Nuclear waste management Company is responsible for the safe disposal of the low-level radioactive waste resulting from the various processes of the nuclear fuel cycle and other radioactive-related activities. The safety assessment of waste disposal requires the measurement of transport parameters of radioactive nuclides in the soil around the disposal site.In this project, concentration profiles within a column which filled with Anarak Radioactive Waste Disposal Site soil were obtained using collimated gamma scanning method. Concentration profiles were measured at two different times (69 and 138 hours after injection). Then, using STANDMOD software, the equilibrium... 

The Iranian Nuclear waste management Company is responsible for the safe disposal of the low-level radioactive waste resulting from the various processes of nuclear fuel cycle and other radioactive-related activities. The safety assessment of waste disposal requires the measurement of transport parameters of radioactive nuclides in the soil around the disposal site. In this project, the transport parameters of cobalt nucleus in the Naeein disposal soil were measured using two static (batch) and dynamic (column experiment) methods. In the static method, the distribution coefficient was determined by performing batch adsorption experiments, and then the retardation factor for the soil disposal... 

Safety assessment of the final disposal of radioactive waste is crucial to ensure the waste isolation from the biosphere for long periods of time. There are various scenarios for the radionuclide transport from the disposal site to the environment, among which the ground water scenario is considered as the main scenario of the radionuclides migration. In this scenario, the transport parameters of the radionuclides are very important in the safety assessment of the final disposal of radioactive wastes. These parameters are determined using either dynamic or static methods, which usually the dynamic method leads to more realistic results. In the dynamic method, one of the two approaches of... 

Cancer can be defined as a stochastic phenomenon. Thus, the tumor growth can be defined as a stochastic process. A Cancer tumor can be analyzed by its geometric shape. Furthermore, computing fractal dimension of shapes is a useful technique to analyze chaosity and complexity of shapes. This approach can be used to compare results from laboratory with simulated results of a mathematical model. A stochastic model of tumor growth will be presented. And some geometrical properties will be analyzed through computer simulation of the model  

The effects of combined task demands on the way muscles are recruited to balance external loads during posture and movement is of great importance in quantitative analysis of upper arm function. Pain and disability of shoulder joint is becoming more important as population spends more often interacting with computers in seated position and carrying repetitive tasks using upper extremities. Shoulder joint that is more dependent on the muscles for its normal function than other joints such as hip due to its small articular surface and large range motion has been used here to study its coordination during isometric exertions. Since, the numbers of tasks that could be performed are enormous. In... 

Spent fuel assemblies are kept in spent fuel maintenance pools, designed at the vicinity of the reactor, after consuming. As capacity of these pools are limited, fuel assemblies should be transported to outside of the reactor building for maintenance. Transportation cask is used for this reason which is Russian type, named TUK-13, at Bushehr Nuclear Power Plant. The aim of this project is to ensure proper removal of heat from the transportation cask(TUK-13). For this purpose, numerical computational fluid dynamics method is used. The software used in this study is the Comsol. The temperature range suitable for any part of the chamber is different; but the most sensitive and the most... 

In Iran, the Iranian Nuclear Waste Management Company (INWMC) is responsible for safe disposal of low-level radioactive waste which results from different processes of nuclear fuel cycle and other radioactive-related activities. The safety assessment program is essential to ensure safe isolation of radioactive waste from the biosphere for long periods of time. Usually, the ground water scenario is considered as the main scenario of radionuclides migration from repository to the biological environment. Thus, it is required to measure the transport parameters of radionuclides in the porous media (soil) around the disposal site. In this research, laboratory scale columns, filled with Nain... 

In the present study, the axisymmetric liquid gas/air diffusion flame in the presence of fuel concentration oscillations and velocity perturbations has been investigated experimentally. Several industrial combustions take a place by diffusion mechanism which necessitate scientists to make far better understanding of diffusion flames. In order to study diffusion flames, the instrument with two separated lines of fuel and air has been developed. Nitrogen is used for fuel dilution oscillatory with pulse of 1, 2, and 4 Hz frequencies. The pulse duration effects on flame structure are also studied. The flame shape has been captured by high speed camera and the results are processed by image... 

The purpose of this study was to create a three-cationic electro phosphate coating of zinc-nickel-manganese by cathodic method and to investigate the effect of operating variables on the properties of zinc-nickel-manganese tri-cationic electro phosphate coating. Hence, the effects of variables such as coating acidity, coating thickness, coating temperature, coating time and concentration of manganese were studied in the bath on the properties such as coating morphology, corrosion resistance, coating thickness. Coating morphology was characterized by scanning electron microscopy and corrosion resistance by polarization test. The pH values of 1.4, 1.8, 2 and 2.2 were selected, and the results...