Nuclear Analysis最新文献

The purpose of this study is to provide a new deterministic model for the SLOWPOKE-2 nuclear research reactor at École Polytechnique de Montréal (EPM) with LEU (Low Enriched Uranium) core. Using the latest release of the code system DRAGON5 and DONJON5 and the cross-section data library ENDFB.VII rel.1 evaluation, the developed model is applied to simulate the neutronic behavior of the SLOWPOKE-2 research reactor. We studied the separate temperature effects of the main components of the core (i.e., fuel, coolant/moderator, beryllium reflector, and water reflector). The contribution of different physical phenomena to the RTC was assessed. The temperature reactivity feedback calculated using the deterministic approach based on the DRAGON5 and DONJON5 code system using the ENDF/B-VII.1 evaluated nuclear data library produced in the WIMD-D4 format is in good agreement. Therefore, this work proves the capability of DRAGON5 and DONJON5 codes, normally used for power reactors, to reliably simulate a low-power research reactor.

Morocco's exploration of nuclear energy aligns with both climate goals and national energy ambitions, offering a promising low-carbon alternative to conventional fossil fuels. Despite the nation's significant strides in renewable energy, nuclear power remains understudied, revealing a critical literature gap. This research underscores the global imperative to transition to net-zero emissions and the pivotal role nuclear energy plays in addressing climate change. Within the context of Morocco's 2030 plan, which prioritizes renewable energy, nuclear energy stands as an underexplored aspect, lacking comprehensive research. To bridge this gap, the study employs a PESTLE analysis to examine the political, economic, societal, technological, legal, and environmental factors influencing Morocco's nuclear energy landscape. The integration of insights from various sources, including press releases, reports, and scientific publications, ensures a holistic and well-informed perspective on Morocco's nuclear industry. The paper concludes by providing an overview of nuclear energy use on different scales, accompanied by a detailed discussion of the PESTLE analysis outcomes. This approach seeks to contribute valuable insights for informed decision-making and strategic planning in the realm of nuclear energy development.

With the aim of removing ⁹⁹Mo from radioactive wastewater, a metal-organic framework Zr-MOF and its functionalized derivatives (Zr-MOF-SO₄ and Zr-MOF-C₂O₄) were prepared as adsorbents, and characterized by SEM, XPS and FI-IR. The results showed the –SO₄ and –C₂O₄ groups were successfully loaded onto the surface of the original Zr-MOF; the obtained Zr-MOF-SO₄ and Zr-MOF-C₂O₄ presented different morphologies as small pellets. Both exhibit high adsorption efficiency and fast adsorption rates due to their abundant –SO₄ and –C₂O₄ surface groups, that provide many adsorption sites for Mo(VI). The maximum adsorption capacities for Mo(VI) of Zr-MOF-SO₄ and Zr-MOF-C₂O₄ are 192.5 mg g⁻¹ and 432.3 mg g⁻¹, respectively, which is an improvement over other similar adsorbents. In addition, thermodynamic studies indicate a spontaneous exothermic mechanism for the adsorption process. These results demonstrate that anchoring of the functionalized groups is a good way to improve Mo(VI) adsorption capacity of MOF materials.

Traditionally, the determination of isotope ratios is analyzed by mass spectrometry (MS) method, which is usually destructive to sample (i.e., sample dissolution). Furthermore, the ⁵⁸Fe abundance (0.282%) is generally rather low relative to other Fe isotopes, therefore, ⁵⁸Fe/⁵⁴Fe results is not reported in the routine measurement for MS methods. Given the importance of investigating a possible genetic relationship between the stable isotope composition of the Moon and the Earth, here, we firstly report the isotope ratios of ⁵⁸Fe/⁵⁴Fe in the Chang’E-5 (CE-5) scooped bulk lunar sample. In this work, the ⁵⁸Fe/⁵⁴Fe ratios were analyzed by instrumental neutron activation analysis (INAA) which is essentially distinguished and a potentially complementary advantage for MS in the determination of stable isotope ratios. These data obtained for the CE-5 lunar sample were also compared with those of terrestrial sample GBW07105.

Low dose rate gamma irradiation blackening effect of organotin catalyzed silicone adhesive is presented. When the total dose accumulated to 350 kGy at low dose rate (0.03 Gy/s), there is a significant blackening of the color changing from transparent to black by the increasing of dose, which is simultaneously deepened by the decreasing of dose rate. That is, low dose rate and accumulated dose both affect the final color of silicone adhesive. The structure changes of silicone adhesive before and after blackening are characterized by UV–vis, FTIR, and SPME-GC-MS, and the mechanism of blackening is deduced to be related to the content of SnO.

Providing sufficient energy in emergency situations in nuclear power plants is of great importance due to their crucial role in improving power plant safety and eliminating disasters.

Solar power is capable of providing a secure energy source which could be used for emergency power loads. The main goal of this study is application of solar energy for providing emergency loads of the Tehran research reactor. A 100 kW solar power plant connected to the grid and 400 kWh battery pack which is capable of providing 50 kw loads for 8 h is designed. As the first priority, the plant charges the battery pack and discharges excess energy to the power grid. Therefore, the proposed scheme, in addition to increasing safety, also has economic benefits. Design procedure of the power plant was carried out using PVsyst which is international well known software for designing solar power plants and results were investigated. Economic evaluation of the project is carried out using RETSCREEN software and different schemes are evaluated. Due to the critical nature of the power loads and their sensitivity, application of this scheme for providing emergency energy loads of the Tehran research reactor is suggested. Considering the expansion of nuclear safety and the protection of the environment and humanity, we request the respected editors and reviewers of the journal to have positive opinions about the publication of the article.

In order to describe the behavior of finite fission chains in a fission system initiated by a δ neutron source, we present the conception of the finite fission chains group (FFCG). The group is the collectivity of the fission chains initiated by plenty of neutrons at the same time. Based on the result of the solving generating function, we deduced the lifetime distribution formula of FFCG based on the point kinetics model. Finally, the formula is validated by the experiment with a single pulse neutron source in CFBR-Ⅱ.

The concentration distribution in blend of polyethylene oxide (PEO)/polycaprolactone (PCL) and subsequent crystallization were investigated with differential scanning calorimetry, in-situ small angle X-ray scattering and wide angle X-ray scattering. By using PEOs with a molecular weight of 1 × 10⁶ g/mol (PEO1M) and 1 × 10⁵ g/mol (PEO100k), respectively, it is revealed that in initial blend the concentration of PEO1M in PEO-rich region is higher than that determined by miscibility. This non-equilibrium distribution induced by crystallization is maintained after melting, since slow relaxation of PEO1M hinders the redistribution process. Crystallization behavior of blend with 25 % of PEO1M at different melting temperatures was further investigated. The crystallinity shows no dependence on melting temperature, while the long period of PEO1M decreases continuously when melting temperature exceeds 140 °C. This decrease indicates more PCL chains diffuse into PEO-rich regions with increasing temperature and molten PCL chains reduce the entanglement number of PEO1M as solvent. Moreover, the periodicity of PEO1M lamellae becomes worse when crystallization proceeds faster, which is related to slower exclusion of PCL chains.

Although nuclear power plants produce about 20% of India's power, the risk posed by radioactive leakage is considerable. Radiation leakage detection devices must be installed in all nuclear power plants to ensure that avoidable catastrophes never occur again and that the loss of human life is prevented. A safe atmosphere for inhabitants and workers may be ensured by keeping a consistent radiation level in all applications that use radioactive material. Complementary Metal-Oxide Semiconductor technology, or CMOS, uses complementary and symmetrical MOSFETS for logic-based functions in various applications, such as analog circuits (CMOS sensors). The Internet of Things (IoT) extends the power of the Internet beyond computing devices to a multitude of other things, processes, and environments. The main objective of this paper is to find a better and more creative solution for radioactive leakage detection techniques over present-day techniques. In this paper, the Authors aim to integrate CMOS and IOT applications for radioactive leakage detection methods on an industrial level. Within this paper, we have given brief descriptions of CMOS and IoT with their types, functions, methodology, and applications. CMOS is considered to be the most sophisticated and precise technology that can be employed to measure radiation leaks of all types (alpha rays, beta rays, gamma rays, and neutrons). With the help of IOT, massive disasters can be averted using complex alert systems. A well-coordinated combination of the two technologies has the potential to vastly increase leak detection potential and consistency. The study's major goal is to develop new and improved technology for detecting released radiation in the industry in order to obtain real-time information about the material leaked, as well as the location of the leak and the quantity of leakage that occurred, in order to reduce the danger of a natural catastrophe.

The thermodynamic parameters of the complexes of Th with N-methylethylenediamine-N,Nʹ,Nʹ-triacetic acid (MEDTA; denoted as H₃L with three dissociable protons) were studied. Potentiometry and microcalorimetry were used to determine formation constants and enthalpies, respectively. Thermodynamic analysis revealed two successively formed complexes, namely, ThL⁺ and ThL₂²⁻ (L³⁻ denotes the totally deprotonated MEDTA). Results indicated that both complexation reactions were exothermic and driven by entropic force. The first stepwise reaction (Th⁴⁺ ​+ ​L³⁻ = ThL⁺) was mainly driven by entropy with minimal effect on enthalpy change. The second stepwise reaction (ThL⁺ ​+ ​L³⁻ = ThL₂²⁻) was more exothermic and showed less entropic change than the first stepwise reaction. The strong chelation of MEDTA would inhibit the hydrolysis of Th⁴⁺ and increase solubility.