Search Results (77)

Biflavonoids are a unique subclass of dietary polyphenolic compounds known for their diverse bioactivities. Despite these benefits, these biflavonoids remain largely underexplored due to their limited natural availability and harsh conditions required for their synthesis, which restricts broader research and application in functional foods and nutraceuticals. To address this gap, we synthesized a library of rare biflavonoids using a radical–nucleophile coupling reaction previously reported by our group. The food grade coupling reaction under weakly alkaline water at room temperature led to isolation of 28 heterocoupled biflavones from 11 monomers, namely 3′,4′-dihydroxyflavone, 5,3′,4′-trihydroxyflavone, 6,3′,4′-trihydroxyflavone, 7,3′,4′-trihydroxyflavone, diosmetin, chrysin, acacetin, genistein, biochanin A, and wogonin. The structures of the dimers are characterized by nuclear magnetic resonance spectroscopy (NMR) and high-resolution mass spectroscopy (HRMS). In addition, we evaluated the antioxidant potential of these biflavones using a DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay and the DPPH value ranges between 0.75 to 1.82 mM of Trolox/mM of sample across the 28 synthesized dimers. Additionally, a three-dimensional quantitative structure–activity relationship (3D-QSAR) analysis was conducted to identify structural features associated with enhanced antioxidant activity. The partial least squares (PLS) regression QSAR model showed acceptable r² = 0.936 and q² = 0.869. Additionally, the average local ionization energy (ALIE), electrostatic potential (ESP), Fukui index (F-), and electron density (ED) were determined to identify the key structural moiety that was capable of donating electrons to neutralize reactive oxygen species. Full article

The decommissioning of the Zion Nuclear Power Plant (NPP) provided a unique opportunity to harvest and study service-aged reactor pressure vessel (RPV) beltline materials. This work, conducted through the U.S. Department of Energy’s Light Water Reactor Sustainability (LWRS) Program, aims to improve the understanding of radiation-induced embrittlement to support extended nuclear plant operations. Material segments containing the Linde 80 flux, wire heat 72105 (WF-70) beltline weld and the A533B Heat B7835-1 base metal, obtained from the intermediate shell region with a peak fluence of 0.7 × 10¹⁹ n/cm² (E > 1.0 MeV), were extracted, cut into blocks, and machined into test specimens for mechanical and microstructural characterization. The segmentation process involved oxy-propane torch-cutting, followed by precision machining using wire saws and electrical discharge machining (EDM). A chemical composition analysis confirmed the expected variations in alloying elements, with copper levels being notably higher in the weld metal. The harvested specimens enable a detailed evaluation of through-wall embrittlement gradients, a comparison with the existing surveillance data, and the validation of predictive embrittlement models. This study provides critical data for assessing long-term reactor vessel integrity, informing aging-management strategies, and supporting regulatory decisions to extend the life of nuclear plants. This article is a revised and expanded version of a paper entitled, “Current Status of the Characterization of RPV Materials Harvested from the Decommissioned Zion Unit 1 Nuclear Power Plant”, PVP2017-65090, which was accepted and presented at the ASME 2017 Pressure Vessels and Piping Conference, Waikoloa, HI, USA, 16–20 July 2017. Full article

This paper analyses Poland’s participation in implementing European climate policy within the framework of the National Energy and Climate Plan (NECP), looking toward 2040. It assesses the feasibility of Poland’s commitments to the European Union’s decarbonisation targets, particularly with regard to transitioning from fossil fuels to renewable energy sources and nuclear power. The study highlights the challenges related to the speed of the energy transition, the security of electricity supply, and the competitiveness of the national economy. The study also assesses the energy mix scenarios proposed in the NECP, taking into account historical energy consumption data, economic and demographic projections, and expert analyses of energy security. It also critically examines the risks of delayed investment in nuclear and offshore wind, the potential shortfall in renewable energy infrastructure, and the need for transitional solutions, including coal and gas generation. An alternative scenario is proposed to mitigate potential energy supply shortfalls between 2035 and 2040, highlighting the role of energy storage, strategic reserves, and the maintenance of certain fossil fuel capacities. Poland’s energy policy should prioritize flexibility and synchronization with EU objectives, while ensuring economic stability and technological feasibility. The analysis underlines that the sustainable development of the national energy system requires not only alignment with European climate goals, but also a long-term balance between environmental responsibility, energy affordability, and security. Strengthening the sustainability dimension in energy policy decisions—by integrating resilience, renewability, and social acceptance—is essential to ensure a just and enduring energy transition. Full article

This study proposes a decision-making model based on the economic assessment of phased decommissioning of energy facilities, specifically focusing on a nuclear power plant (NPP). The objective of the research is to develop and validate an economic assessment methodology for comparing immediate and deferred dismantling strategies for a 1000 MW NPP unit. For economic justification, a comparison of the economic expenses is proposed based on the accumulation of radioactive waste, safety activities, and labour costs for the two options. The methods employed include a multifactorial analysis based on expert assessments, considering economic expenses related to radioactive waste accumulation, safety activities, and labour costs. Criteria with differences exceeding 10% for quantitative indicators and fundamental differences for qualitative indicators were deemed significant; each criterion’s acceptability was weighted accordingly. The key results show that deferred dismantling is economically preferable; the total score for deferred dismantling exceeds that of immediate dismantling by approximately 10% (14.16 points vs. 15.86 points). A comparison of block schedules for decommissioning, dynamics of labour costs, and annual volumes of reprocessed radioactive waste for the baseline and optimised deferred dismantling options shows that both options meet the continuity condition of the ‘active’ stages. At the same time, the optimised option demonstrates significant advantages in the uniformity of labour costs and workload of radioactive waste treatment plants during dismantling. The activities at the stage of power unit decommissioning are proposed to be carried out within the licence framework for its operation by the organisational and technical solutions to ensure safety during operation. The deterministic consequences and risks will align with the safety assessment, which will be determined based on the latest analysis results, taking into account sustainable operation. Full article

Our objective is to test the published models of partonic energy loss, particularly those describing the energy loss mechanisms of quarks traversing nuclear matter, within the framework of semi-inclusive deep inelastic scattering. Our methodological approach focuses on quantifying the quark energy loss in cold matter by analyzing the positive pions (${\pi }^{+}$) produced in various nuclear targets, including deuterium, carbon, iron and lead, while our first approach only includes deuterium and carbon. Before normalizing the pions’ energy distribution to unity to perform a shape analysis, acceptance corrections were performed to account for the detector’s efficiency and ensure accurate comparisons of the spectra. By normalizing the energy spectra of ${\pi }^{+}$ produced from these distinct targets and based on the Baier–Dokshitzer–Mueller–Peigné–Schiff theory, which posits that quark energy loss depends only on nuclear size, it is assumed that the energy distributions of the targets will exhibit similar behavior. For this normalization, an energy shift between these distributions, corresponding to the quark energy loss, is identified. To ensure accuracy, statistical techniques such as the Kolmogorov–Smirnov test are used. The data used to test and explore the analysis technique and method were from the CLAS6 EG2 dataset collected using Jefferson Lab’s CLAS detector. Full article

Boron neutron capture therapy (BNCT) is a specialized cancer treatment that leverages the high absorption cross-section of boron for thermal neutrons. When boron captures neutrons, it undergoes a nuclear reaction that produces alpha particles and lithium ions, which have high linear energy transfer (LET) and can effectively damage nearby cancer cells while minimizing harm to surrounding healthy tissues. This targeted approach makes BNCT particularly advantageous for treating tumors situated in sensitive areas where traditional radiation therapies may pose risks to critical structures. In this study, the deuterium–deuterium (DD) neutron generator, specifically the DD-110 model (neutron yield Y = 1 × 10¹⁰ n/s), served as the neutron source for BNCT. The fast neutrons produced by this generator were thermalized to the epithermal energy range using a beam-shaping assembly (BSA). The BSA was designed with a moderator composed of 32 cm of MgF₂, a reflector made of 76 cm of Pb, and filters including 3 cm of Pb and 1.52 cm of Bi. A collimator, featuring a 10 cm high Pb cone frustum with a 12 cm aperture diameter, was also employed to optimize beam characteristics. The entire system’s performance was modeled and simulated using the MCNPX code, focusing on parameters both in-air and in-phantom to evaluate its efficacy. The findings indicated that the BSA configuration yielded an optimal thermal-to-epithermal flux ratio (${\phi }_{ther}$/${\phi }_{epth}$) of 0.19, a current-to-flux ratio of 0.87, and a gamma dose-to-epithermal flux ratio of 1.71 × 10⁻¹³ Gy/cm², all aligning with IAEA recommendations. The simulated system showed acceptable ratios for ${\phi }_{ther}$/${\phi }_{epth}$, gamma dose to epithermal flux, and beam collimation. Notably, the advantage depth was recorded at 5.5 cm, with an advantage ratio of 2.29 and an advantage depth dose rate of 4.1 × 10⁻⁴ Gy.Eq/min. The epithermal neutron flux of D110 exceeded D109, but D110’s fast neutron contamination increased ~6.6 times. On the other hand, D110’s gamma contamination decreased by 30%. Based on these findings, optimizing neutron source characteristics is crucial for BNCT efficacy. Future research should focus on developing advanced neutron generators that balance these factors, aiming to produce optimal neutron yields for enhanced treatment outcomes and broader applicability. Full article

This study addresses the urgent need for transitioning to clean energy systems to achieve net-zero emissions and mitigate climate change. It introduces an algebraic modeling framework inspired by the nuclear fission six-factor formula to optimize the construction rates of clean power plants, with a focus on Small Modular Reactors (SMRs). The framework integrates four key factors affecting SMR deployment: Public Acceptance (PA), Supply Chain Readiness (SC), Human Resource (HR) Availability, and Land Availability (LA), including their associated sub-factors. The proposed algebraic formula optimizes projections from the existing Dynamic Integrated Climate-Economy (DICE) model. By capturing socio-economic and environmental constraints, the model enhances the accuracy of clean energy transition scenarios. In the case of Ontario’s pathway to achieving net-zero emissions, the results indicate that incorporating the algebraic formula reduces the SMR construction rate projected by the DICE model from 5.2 to 3.7 units per year by 2050 and from 2.7 to 1.9 units per year by 2100. This reduction highlights the need for accelerated readiness in key deployment factors to avoid delays in reaching net zero targets, reinforcing the importance of strategic investments in PA, SC, HR, and LA. Validation against historical nuclear deployment data from the U.S., Japan, and Canada confirms the model’s ability to reflect real-world trends, with PA and SC emerging as the most influential factors. In addition to informing SMR planning, this approach offers a structured tool for prioritizing policy actions and can be adapted to other clean technologies, enhancing strategic decision making in support of net-zero goals. Full article

Uranium–niobium (U-Nb) alloys, used in a variety of industrial and energy applications that require high density, ductility, and good corrosion resistance, comprise a highly complex, multiphasic system with a phase diagram well established through decades of extensive experimental and theoretical research. They are also one of the best candidates for a metallic fuel alloy with high-temperature strength sufficient to support the core, acceptable nuclear properties, good fabricability, and compatibility with usable coolant media. The key factor determining the performance and safety of a metallic fuel such as U-Nb is its operational limits in the application environment, which are closely related to material’s structure and thermodynamic stability. They are in turn closely related to the ambient (zero-pressure) melting point $\left(T_m\right);$ thus, $T_m$ is an important engineering parameter. However, the current knowledge of $T_m$ of the U-Nb system is limited, as the only experimental study of its Nb-rich portion dates back to 1958. In addition, it has not yet been adequately modeled based on general thermodynamics principles or using an equation-of-state approach. In this study, we present a theoretical model for the melting curve (liquidus) of a mixture, and apply it to U-Nb, which is considered as a mixture of pure U and pure Nb. The model uses the known melting curves of pure constituents as an input and predicts the melting curve of their mixture. It has only one free parameter, which must be determined independently. The ambient liquidus of U-Nb predicted by the model appears to be in good agreement with the available experimental data. We calculate the melting curve (the pressure dependence of $T_m$) of pure U using ab initio quantum molecular dynamics (QMD), the knowledge of which is required for obtaining the model parameters for U. We also generalize the new model to nonzero pressure and consider the melting curve of U-6 wt.% Nb (U-6Nb) alloy as an example. The melting curve of U-6Nb alloy predicted by the model appears to be in good agreement with the ab initio melting curve obtained from our QMD simulations. We suggest that the U-18Nb alloy can be considered as a proxy for protactinium (Pa) and demonstrate that the melting curves of U-18Nb and Pa are in good agreement with each other. Full article

The advent of small modular reactors (SMRs) represents a transformative leap in nuclear technology. With their smaller size, modular construction, and safety features, SMRs address challenges faced by traditional reactors. However, these technological advancements pose significant regulatory challenges that must be addressed to ensure their safe and effective integration into the energy grid. This paper presents robust regulatory strategies essential for the deployment of SMRs. We also perform economic and sensitivity analysis on a notional SMR project to assess its feasibility, profitability, and long-term viability, pinpointing areas for cost optimization and determining the project’s resilience to market trends and technological changes. Key findings highlight market demand as the most influential factor, with public acceptance, regulatory clarity, economic viability, and government support playing critical roles. The sensitivity analysis shows that SMRs could account for 3% to 9% of the energy market by 2050, with a base case of 4.5%, emphasizing the need for coordinated efforts among policymakers, industry stakeholders, and regulatory bodies. Technological maturity suggests current designs are viable, with future R&D focusing on market appeal and safety. By synthesizing these insights, the paper aims to guide regulatory authorities in facilitating informed decision-making, policy formulation, and the adoption of SMRs. Full article

This paper introduces a holistic framework to assist less industrialized countries in adopting nuclear energy (NE) for peaceful purposes considering the challenges and opportunities this entails. It underscores the pressing need for sustainable and secure energy solutions, proposing NE as a viable option. The study aims to delve into the technical, social, economic, regulatory, and policy aspects of NE’s development and its broader applications beyond conventional power generation, such as industrial processes, medical applications, agricultural advancements, and mining activities, explicitly targeting less industrialized regions. Employing a systematic review of existing practices, the paper identifies and examines barriers to NE adoption alongside strategies to mitigate these issues. Findings suggest that NE can play a pivotal role in fostering economic growth and scientific progress, potentially sparking the emergence of new industries within these countries. However, significant obstacles—namely governance, public acceptance, safety, security, development of expertise, and securing financing—pose considerable challenges. The paper concludes that a strategic and well-coordinated deployment of NE is essential for driving socio-economic growth and environmental sustainability in less industrialized countries. It emphasizes the necessity for comprehensive planning and international collaboration to fully unlock NE’s potential, advocating for a multifaceted approach to overcome the identified hurdles. Full article

Nuclear power technology has rapidly advanced with the growing global demand for clean energy. As one of the core components of nuclear power plants (NPPs), the design and lifespan evaluation of reactor pressure vessels (RPVs) are critically important. However, while fatigue analysis methods for RPVs in land-based NPPs are relatively well established, the application of these methods to floating nuclear power plants (FNPPs) faces great challenges. Existing analysis methods are difficult to directly apply, and no widely accepted fatigue analysis approach currently exists for this context due to the complex working conditions in marine environments. A time-domain design stress (TDDS) method is developed in this study for the fatigue analysis of RPVs in FNPPs. This method systematically analyzes the impacts of wave loads, internal pressure, and thermal effects on the fatigue life of RPVs by simplifying the wave environment into a time-domain model of roll and pitch motions and adopting the regular wave superposition techniques. This method further adjusts the initial phases of regular waves considering the uncertainty of various load combinations, and superimposes the stress components caused by regular waves with different initial phases, thermal loads, and pressure loads. Subsequently, stress history curves are analyzed using the rainflow counting method, and combined with the damage accumulation theory, the upper and lower limits of fatigue damage are obtained. The results demonstrate that compared to traditional methods in time-domain analysis, the proposed TDDS method provides greater accuracy in evaluating the fatigue life of RPVs in FNPPs, with the average error in fatigue damage values being only 0.033%. Furthermore, the TDDS method reduces analysis time by approximately 70%, which significantly improves computational performance. These findings underscore the reliability and effectiveness of this method in practical applications. Full article

This study examines the effects of transitioning to hydrogen production in the National Capital Region (NCR) and Palawan Province, Philippines, focusing on technology, environment, and stakeholder impact. This research, conducted through a July 2022 survey, aimed to assess public awareness, knowledge, risk perception, and acceptance of hydrogen and its environmentally friendly variant, green hydrogen, infrastructure. Disparities were found between urban NCR and rural Palawan, with lower awareness in Palawan. Safety concerns were highlighted, with NCR respondents generally considering hydrogen production safe, while Palawan respondents had mixed feelings, particularly regarding nuclear-based hydrogen generation. This report emphasizes the potential ecological advantages of hydrogen technology but highlights potential issues concerning water usage and land impacts. It suggests targeted public awareness campaigns, robust safety assurance programs, regional pilot projects, and integrated environmental plans to facilitate the seamless integration of hydrogen technology into the Philippines’ energy portfolio. This collective effort aims to help the country meet climate action obligations, foster sustainable development, and enhance energy resilience. Full article

The deformed relativistic Hartree–Bogoliubov theory in continuum (DRHBc) has garnered significant attention for its ability to describe the properties of nuclei across the entire nuclear chart, from light to heavy nuclei, including both stable and exotic ones. As part of ongoing efforts to construct a mass table using the DRHBc theory, determining the ground states of nuclei is a crucial task in the systematic studies of deformed nuclei. In this work, a strategy for identifying the ground state in the superheavy nuclei region is proposed and evaluated, by taking $Z=134$ and 135 isotopes as examples. First, we examine how the step size of the initial quadrupole deformation parameter, $\Delta {\beta }_2$, affects the pattern of the potential energy curves (PECs) and the determination of the ground state. Our findings indicate that $\Delta {\beta }_2=0.05$ producing smooth and well-defined PECs while maintaining an acceptable numerical cost. Next, we explore the convergence of PECs with respect to the angular momentum cutoff, $J_{\max }$. Based on the results, we recommend using $J_{\max }=31/2\hslash$, especially for nuclei with competing oblate and prolate minima. Finally, we conclude that the accurate identification of the ground state can be achieved by performing unconstrained calculations around the minima of the PECs. Full article

In response to the urgent threat of climate change and the drivers of high greenhouse gas emissions, countries worldwide are adopting policies to reduce their carbon emissions, with net-zero emissions targets. These targets vary by region, with Canada aiming to achieve net-zero emissions by 2050. In response to the Independent Electricity System Operator’s (IESO’s) “Pathways to Decarbonization” report, which evaluates a proposed moratorium on new natural gas generating stations, this study presents a methodology to support energy transitions in Ontario by using a modified Dynamic Integrated Climate-Economy (DICE) model, which focuses on replacing fossil fuel power plants (FFPPs) with clean energy sources, including nuclear, solar, wind, and hydro. This research expands on our prior work that used the DICE model to evaluate the potential for replacing FFPPs with Small Modular Reactors (SMRs) on a global scale. This study includes solar, wind, hydro, and SMRs to provide a diversified clean energy portfolio and integrates fuzzy logic to optimize construction rates and address uncertainties. The study uses Ontario as a case study, aligning with IESO’s objectives for Ontario’s energy transition. The IESO’s projections for net zero by 2050 are applied. The study is extended to 2100 to assess the longer-term implications of sustained energy transition efforts beyond the immediate goals set by the IESO. This approach is scalable to other regions and countries with similar energy transition challenges. The study results indicate that to meet Ontario’s 2050 net-zero target, approximately 183 SMR units, 1527 solar units, 289 wind units, and 449 hydro units need to be constructed. For the 2100 target, the required number of units is slightly higher due to the longer time frame, reflecting a gradual ramp-up in construction. The optimization of construction rates using fuzzy logic shows that the pace of deployment is influenced by critical factors such as resource availability, policy support, and public acceptance. This underscores the need for accelerated clean energy deployment to meet long-term emissions reduction goals. The findings highlight the complexities of transitioning to a low-carbon energy system and the importance of addressing uncertainties in planning. Policymakers are urged to integrate these insights into strategic energy planning to ensure the successful deployment of clean energy technologies. This study provides valuable recommendations for optimizing energy transitions through a robust, flexible framework that accounts for both technological and socio-economic challenges. Full article

This bibliometric review of global nuclear energy strategies reveals a renewed interest in this technology as a fundamental part of the energy transition and the fight against climate change. The findings highlight an emerging leadership of China and other Asian countries in scientific production, although the United States and European countries maintain a greater impact in their research. There is an evolution from a purely technical focus to a greater focus on security, energy policy, climate change, and sustainability, reflecting a more holistic understanding of the role of nuclear energy. The 21st century has seen a resurgence of interest in nuclear energy, driven by concerns about climate change, although these topics are still relatively underrepresented in specialized literature. New areas of research are identified, such as integration with renewable energy and advanced applications. Research on public perception and social acceptance has gained sophistication. Surprisingly, an apparent lack of scientific interest in international collaboration is detected, despite its recognized importance in addressing global challenges and promoting the peaceful use of nuclear energy. This analysis provides a comprehensive overview of the current status and future trends in nuclear energy research and strategies. Full article