Abstract Heavy metal ions have increased wastewater production with the development of various nuclear activities. One of the most significant metal ions that harm the environment and living organisms, especially humans, is the uranyl ion. There are many methods to remove metal ions, and biological adsorption is the cheapest and most efficient method. In this research, the absorption of uranyl ions from aqueous solutions from tea waste has been studied. Due to the presence of various functional groups such as carboxyl, hydroxyl, amine, etc, tea wastes have good cations adsorption ability. The effective parameters in adsorption including pH, adsorbent dose, temperature, initial uranyl concentration, and contact time parameters were investigated. Response surface methodology (RSM) was used to conduct experiments and analyze the results. The optimum conditions for uranyl adsorption by tea waste adsorbent were pH = 3.9, temperature 25°C, adsorbent dose 0.275 g, initial concentration of uranyl 10 mg/L, and contact time 90 minutes. Using Freundlich's isothermal and pseudo-second-order models, we fitted the most accurate isothermal and kinetic models. Results showed that tea waste was a good bio adsorbent for uranyl adsorption from real wastewater with a 93.50% adsorption rate.

Abstract For the neutronic and thermal-hydraulic analysis of nuclear reactor cores, it is necessary to develop nuclear computing software to calculate neutronic and thermal-hydrodynamic parameters for their safe operation. In this paper, S4HC software was developed for steady-state thermal-hydraulic core calculations using a single heated channel method. To analyze the Bushehr reactor core, after calculating neutron parameters by the nodal expansion method, a thermal-hydraulic analysis of fuel assemblies was performed using S4HC software. After thermal-hydraulic calculations for the fuel assemblies, including the hot fuel assembly, it was concluded that all the coolant thermal-hydraulic parameters are within their allowed ranges and the reactor has sufficient saturation margins.

Abstract The product of the Molybdenum-99 purification process, obtained from Uranium-235 fission products, has a degree of purity of 90%-95%, which its present active and inactive impurities are destructive reducing the efficiency of 99mTc/99Mo generators. As an alternative to the common sublimation method, indirect sublimation could increase purity and reduce molybdenum loss. In this method, the molybdenum in the product will be absorbed by passing through the alumina column and then the dried absorbent will be sublimated. In the present study, the effective factors in molybdenum absorption such as the amount of adsorbent, and the volume and flow rate of the input solution and molybdenum were optimized. The final absorption efficiency reached 97-99%. This investigation is expected to be applied to molybdenum-99 production.

Abstract In this study, to produce and develop a new diagnostic radiopharmaceutical for the imaging of tumors with overexpressed somatostatin receptor, the [113mIn]In-DOTATATE chemical compound was prepared in optimal conditions using an in-house generator, and its preclinical studies were performed. The final product was obtained with a radiochemical purity of nearly 99% (RTLC and HPLC) and a specific activity of 26.2×1015 Bq/mol. The investigation of the stability of the labeled compound showed a radiochemical purity of more than 96% for at least three hours in PBS buffer and human blood serum. The results of the biodistribution and image assessment of the [113mIn]In-DOTATATE chemical compound in normal mice showed that the organs of the gastrointestinal tract such as the pancreas, stomach, and intestine, which have cells expressing the somatostatin receptor, have high uptake.

Abstract 60Co is used as a major industrial radioactive source in food and medical equipment sterilization. KCi sources can be used for laboratory research, however, few industrial centers utilize these sources for irradiating agricultural products. Hence, in this study, the potential of producing tens of kCi from 60Co sources in the Tehran research reactor has been investigated through the MCNPX code. Different assemblies including 59Co rods were modeled by a computational code. In addition, the loading of the 59Co rod assembly in different arrangements of the Tehran research reactor core was investigated. The 59Co production yield was calculated in each case. The results of this study show that by optimizing the 59Co rod assembly in a 27-fuel 1401-year core arrangement of the Tehran Research Reactor, it is possible to achieve about 40 kCi of 60Co product after 3 years of irradiation. The use of a beryllium reflector with optimized geometry can reduce the negative reactivity caused by the 59Co assembly loading. Also, loading the cobalt-59 assembly at the periphery of the equilibrium core of the Tehran research reactor can lead to the production of about 23 kCi of cobalt-60.

Abstract In this study, the Monte Carlo-based simulation code, Geant4, was applied to model the 2-inch NE-213 detector and Am-Be source available at Sharif University Faculty of Energy. The neutron and gamma spectrum for this source in the NE-213 detector could be achieved. Furthermore, a circuit based on the analog Constant Fraction Method (CFM) was used in the laboratory to get the neutron and gamma spectrum of the same source to be used for further comparisons. For the next step, three digital filters named Triangular, Trapezoidal, and Flat Top Cusp were scripted in MATLAB not only to see how each filter performs in the discrimination of these two spectrums but also to find the optimum values for the effective parameters in each of the filters by comparing the filter outputs with the results obtained from the constant fraction method in lab. As it turned out, in the triangular filter for k=11, the trapezoidal filter for k=10 and L=5, and in the flat top cusp filter for k=10 and L=20, the most accurate results were obtained. By comparing the results for these values in each filter, it was shown that the trapezoidal filter performed the most effectively in spectrum discrimination.

Abstract In this research, the effect of simultaneous application of plasma rotation and static external magnetic field in a plasma with a power law density function on the growth rate of Rayleigh-Taylor instability (RTI) has been studied analytically. Plasma is incompressible and enclosed between two planes z=0 and z=h. In a linear growth rate regime, the dispersion relation for the ideal MHD equations was first derived by applying the rotation effect and appropriate boundary conditions. The final dispersion relation represents the effect of the simultaneous combination of the axial magnetic field and the constant angular velocity of the plasma on the RTI growth rate. The results show that the growth rate of instability depends on the horizontal component of the magnetic field, the plasma rotation, and also on the dimensionless parameter λ*. The maximum instability occurs at *=-1.5 compared to the corresponding non-rotational case. Recent results show that the simultaneous combination of rotation and static external magnetic field improves the management of instability growth rate.

Abstract Saintpaulia ionantha is an attractive ornamental plant. To induce diversity by creating distinct genotypes of African violet in vitro Gamma rays were applied as physical and chemical mutagens. Explants were cultured in MS medium containing 2 mg L-1 BA, 1 mg L-1 NAA, 30g L-1 sucrose, and 7g L-1 agar. After two days they were treated with radiation (0, 20, and 40Gy). The dose of 40Gy reduced explant regeneration and the number of regenerated plantlets and leaves. This caused enhanced variation and morphological changes. The leaves' color, shape, and size were modified. Afterward, the genetic diversity of the mutant plants was investigated with an ISSR marker. Eight primer pairs in PCR amplified different fragments of genomic DNA. Overall, 71 bands were scored. The dendrogram of cluster analysis using the Jaccard coefficient and UPGMA algorithm showed high variability. The mutants were divided into 4 groups with a similarity of 0.51%. The genetic similarity coefficient varied between 0.45-0.98 and 6 mutants were introduced based on morphological and molecular variations. The results showed that in vitro mutagenesis of African violets by gamma radiation is a suitable strategy to increase diversity.

Abstract Cold atmospheric plasma technology has found wide applications in agriculture as a suitable alternative to traditional and environmentally friendly methods. In this research, the effect of RF plasma treatment on oilseed rape germination characteristics in response to drought stress has been investigated. This study was conducted as a factorial experiment based on a completely randomized design in 1401. The plasma factor in seven levels (P1, P2, P3, P4, P5, P6, and P7) and the drought stress factor in three levels were -0.3, -0.5, and -0.9 MPa. The results showed that drought stress levels of -0.5 and -0.9 MPa caused a significant decrease of 50.16 and 61.92% of root length, 8.42 and 71.57% of shoot length, 21.79 and 85.46% of root dry weight, 4.87% and 39.08% of stem dry weight, 16% and 24% of germination percentage compared to drought level -0.3 MPa. In this experiment, the longitudinal growth of the stem compared to the longitudinal growth of the root was more affected by severe drought. Therefore, it can be a suitable feature to evaluate drought tolerance. Exposure of canola seeds to plasma treatments of 200 W for nine minutes showed the most stimulating effect regarding the percentage of germination and seedling growth in canola.

Abstract Using Aliquat336 extractant, cobalt ions were extracted from a non-aqueous medium. The effect of different parameters on the non-aqueous extraction process including ethylene glycol concentration, extractant concentration, hydrochloric acid concentration, and cobalt ions concentration in aqueous solution was investigated using the experimental design approach. According to the desirability of one and the maximum extraction efficiency of cobalt ions, the optimal conditions include volume percentage of Aliquat336 (19.2%), cobalt concentration (899.4 ppm), volume percentage of ethylene glycol (65.3%) and hydrochloric acid concentration (7.81 M) were obtained. The validity of the data was observed with minimal error between the predicted data (94.82%) and the experimental data (99.36%).

Abstract Albumin particles are used in nuclear medicine as carriers of diagnostic and therapeutic radionuclides. Temperature was used to prepare these particles. After size determination, the particles were marked with gamma-irradiated radionuclide 99mTc in the presence of stannous chloride as a reducing agent. Chromatography methods analyzed radiochemical purity. For labeled particles, stability in normal saline and biodistribution in normal and glioma tumorized rats were investigated. The size of particles was determined below 50 nm. Radiochemical purity of more than 98% was obtained. Evaluation of labeled particle stability showed radiochemical purity of more than 90% during 6 hr in saline and human serum solutions. Biodistribution studies revealed liver and tumor uptake followed by high kidney washout. Gamma imaging scintigraphy in rats showed tumors and kidneys. The results confirmed the ability of marked particles as a tumor diagnostic radiopharmaceutical.

Abstract In this research, the effects of high-energy proton bombardment produced by the plasma focus device on the surface morphology and structural parameters of tungsten and molybdenum were investigated. Tungsten and molybdenum samples, placed 6 cm from the anode head, were irradiated with hydrogen ions for 20 discharges. The samples were examined before and after irradiation using a scanning electron microscope (SEM). The SEM results revealed blisters, cracks, and surface melting on both tungsten and molybdenum samples due to high-energy proton irradiation. To characterize the ion beam of the plasma focus device, Lee's code was employed. Lee's code indicated approximately 7.9 × 1014 ions are emitted from the plasma column in each discharge. Additionally, the SRIM code was used to calculate damage caused by tungsten and molybdenum. In addition, it calculated the hydrogen density at various depths within the materials. According to the SRIM code results, the maximum value of displacements per atom (dpa) per shot for tungsten and molybdenum samples irradiated with hydrogen ions was estimated to be 0.025 and 0.014, respectively, at depths of 150 nm and 250 nm. Moreover, the maximum concentration of hydrogen ions in the irradiated samples of tungsten and molybdenum at depths of 150 nm and 250 nm was 0.4% and 0.035%, respectively.

Abstract A factorial experiment was conducted to determine the effects of different doses of gamma irradiation on postharvest life and quality of bulbs of four Iranian onion cultivars (White-Ghom, White-Neyshabour, Red-Ridge-Lump, Red-Ray-Corrugated) during 120 days storage at 10-15 °C and 70% relative humidity. Interactive effects of cultivar and irradiation dose significantly affected sprouting, weight loss, firmness, soluble solids content (TSS), and contents of reducing sugars and pyruvic acid (PA) of the bulbs after 120 days of storage. Sprouting of the bulbs ranged between 10-100%. The untreated bulbs showed the highest sprouting and weight loss. Gamma irradiation (30-150 Gy) significantly restricted the sprouting percentage and decreased bulb weight loss. Firmness of the irradiated bulbs (90-150 Gy) was higher than the control bulbs. Weight loss of the bulbs was positively correlated with sprouting and negatively correlated with bulb firmness. The irradiation treatments increased the TSS (30-150 Gy) and a reduction in the sugar content of the bulbs (60-150 Gy). The untreated bulbs had the lowest PA content at the end of the experiment. Exposure to 90-150 Gy irradiation doses resulted in the highest PA content in the bulbs. In summary, the application of 90 to 120 Gy of gamma radiation for improving post-harvest shelf life and quality of onions can be considered as a general guideline.

Abstract Nowadays, due to the need of all countries to provide sustainable energy, nuclear energy plays a significant role in the energy portfolio of developed countries and developng countries. For this reason, it is very critical to choose the appropriate nuclear fuel cycles for the optimal use of nuclear energy. In addition, it is important to draw the road map of the country's nuclear industry. ; which itself is a function of several parameters (the level of nuclear knowledge, sources and reserves of nuclear materials economic factors, etc.). These factors play a significant role in determining the appropriate cycle). In this research, four main scenarios have been proposed by comparing uranium, plutonium, and thorium fuel cycles. In addition, four scenarios have been examined by examining nuclear material capacity. Suitable and cautious fuel cycles have been introduced for each required nuclear fuel scenario and consumption amount. Among the proposed scenarios, the scenario of "accessing sufficient uranium resources and opening up the enrichment and reprocessing" was introduced as the most likely scenario and based on the suggested axes, the most suitable closed uranium fuel cycles, with a fast sodium reactor and uranium TRU and FP fuel cycle” were selected" with a minimum of 2320 and a maximum of 5296 GW of energy production and total costs of approximately $117 million per GW of energy.

Abstract Xenon radioisotopes are one of the products of uranium nuclear fission. These radioisotopes are released in the form of gas in the process of dissolving the uranium target to extract 99Mo. This research aims to measure the activity of released xenon radioisotopes. For this, radioxenon is separated from other fission products using activated charcoal and purified after passing through a carbon molecular sieve. Pure radioxenon is directed into the measurement chamber and determined by an HPGe detector. Calibration of the detector efficiency has been performed via experimental and simulation (using MCNPX27e code) and the difference was less than 22%. In this way, the average activity of 100 cc of radioxenon gas at the moment after irradiation was equal to 54225 ±2272 Bq.

Abstract One of the key steps in the nuclear fuel cycle is uranium enrichment. It is essential to control processes using continuous measurement on the way to uranium with the desired enrichment of the facility. On the other hand, due to being in an environment with high external radiation and also suitable for internal exposure of the operator, especially when working with uranium powder, it is necessary to use accurate instruments with the ability to monitor online and continuously, which is a special place in nuclear instrumentation. In this work, we worked on a conceptual design of the enrichment and weight measurement system for uranium tetrafluoride powder in loading and handling tanks. This is in the nuclear industry. To reduce costs while eliminating maximum counting errors, only gamma rays emitted from powder or with radioactive lateral sources were considered. The design was based on geometric location optimization of scintillating detector/detectors around the tank containing uranium tetrafluoride powder to have maximum measurement accuracy. The simulation results in Monte Carlo software show that for different enrichment percentages and different heights of uranium powder inside the cylindrical tank, we can have the greatest accuracy in measuring two parameters, enrichment percentage and powder weight at specific angles.

Abstract In this research, ultraviolet (UV) photodetectors based on aligned ZnO nanorods thin films with controllable responsivity were fabricated. Aligned nanorods were grown on seeded glass substrates by the chemical bath method. Then, they were characterized using a Scanning Electron Microscope (SEM), X-ray diffraction (XRD), photoluminescence (PL), and Energy Dispersive X-ray Analysis (EDAX). The effect of perimeter and area variation of interdigitated electrodes on the responsivity of UV ZnO nanorods-based photodetector was investigated. With a decreasing electrode perimeter and maintaining the same area, the responsivity decreases. By keeping the perimeter constant at the maximum value, it is observed that the response of the photodetector is increased with increasing the gap between the fingers of the electrode so that the gap of 160 µm reaches the maximum as high as 105 AW-1 at 2 V bias voltage. The dominant mechanism for change of responsivity with electrode geometry is variation in the area of depletion regions resulting from Schottky barriers between ZnO and Au and the formed barriers between ZnO nanorods due to adsorption and desorption of oxygen species. This research demonstrates a simple way of optimizing photodetector devices' responsivity for practical applications.

Abstract By applying two relativistic high-intensity laser beams under different conditions to low-density plasma, the effects of the beams' corresponding distance and angle on their filamentation were investigated and studied. The results of the simulations using the particle in cell (SMILEI) two-dimensional code show that when the distance and the corresponding angle between the pulses are zero, the results are the same as a powerful pulse with intensity equals four times a single pulse. Meanwhile, it was clear that the impact of relative beam angles on pulse filamentation is more significant and sensible than the effect of distance variation. So, it is shown that by increasing the distance, separate plasma channels are formed, and more filaments are observed. Moreover, the effect of relative beam angle variation reveals that, unexpectedly, two distinct channels formed and traveled through plasma. By increasing the angle to
θ = 2^°, the channels merged and formed a single wide channel. Further, for a constant beams distance, the maximum filaments are observed at the middle angles θ = 4^°, 6^°. It should be noted that studying laser beam filamentation in plasma is so critical for stable pulse propagation through the plasma. Our simulations indicate that in some relative angles, we will not have stable and efficient pulse propagation. This could be distractive in some experiments such as inertial confinement fusion.

Abstract We are studying the experimental behavior of non-refractory and refractory wires in the 1 kJ pulsed electrical system. This article discusses the experimental study of non-refractory (copper-nickel) and refractory (tungsten) explosive wires in pulsed electric discharge systems. The system energy is 1 kJ, the wire length is 4 cm, and its diameter is 200 μm. To study the behavior of the wires, the electrical parameters of current and voltage of electric discharge and shock waves have been investigated. In non-refractory wires, the current is periodic and has two peaks. In refractory wires, two current peaks are formed at a longer time interval. This shows that the energy level of 1 kJ was not enough to change the state and create plasma in this sample of wires. Finally, under the current test conditions and comparison of the experimental results, it can be seen that the non-refractory wires create a more substantial shock wave than the refractory samples. This pressure is 8.5 MPa in non-refractory wire (copper-nickel) and 6 MPa in refractory wire (tungsten). Also, we compared the electrical discharge current for three copper-nickel wires with diameters of 100, 200, and 300 micrometers and experimentally observed that the electrical discharge current is higher in the wire with a thicker diameter.

Abstract One of the most frequently observed random processes in nuclear experiments is the Poisson process. Due to the dead time effect of detection systems, the experimental process is different from the Poisson process. In this work, based on stochastic methods, a nuclear detection system is identified. The BF3 detector is a typical pulse mode detector. In this research, a typical BF3 detector is selected to implement the above method. Observed pulses at the detector output in the time domain were measured and analyzed using stochastic fluctuations analysis. In experiments such as measurements related to zero-power reactor noise theory, the transfer function of the detection system itself also affects the obtained results. Therefore, knowledge of the transfer function of the detection system used in these experiments is of particular importance. Also, in measurements where it is necessary to correct the detection system dead time, the specificity of the transfer function can provide valuable information about the effects of dead time. This study investigates the transfer function of a typical neutron detection system based on BF3.