Nuclear Energy Research Articles

Flexible operation of nuclear hybrid energy systems for load following and water desalination

Nuclear hybrid energy systems (NHES) have the potential to provide dependable and emission-free electricity to the grid while also increasing the flexibility and reliability of the electrical grid. Molten salt reactor (MSR) technology can provide consistent, carbon-free electricity while also increasing efficiency, security, and sustainability and reducing nuclear waste. This study investigates the integration of Molten Salt Reactors (MSR) and conventional Pressurized Water Reactors (PWR) with desalination technologies: Direct Contact Membrane Distillation (DCMD), Multi-Stage Flash Distillation (MSFD), and Reverse Osmosis (RO). Dynamic first-principles models were developed and tested using real grid data from the New York Independent System Operator. The results demonstrate that nuclear power is capable of flexibly responding to changing grid demand while simultaneously producing clean water, particularly during periods of low electricity demand. The MSR-RO system was found to be the most efficient in electricity generation and water production, and all hybrid systems reduced CO2 emissions by 356,000 to 682,000 tons annually. Economic analysis reveals that nuclear desalination technologies are cost-competitive with conventional systems, especially when paired with RO. These findings confirm the technical feasibility and environmental benefits of nuclear hybrid systems for sustainable electricity and water production.

Development characteristics, problems and countermeasures of major scientific and technological infrastructures in the field of life sciences

The major science and technology infrastructure in the field of life science is an indispensable and important content in the large-science facility landscape. It encompasses cutting-edge, strategic, and fundamental aspects. This field differs from traditional facilities such as particle physics, astronomy and nuclear energy. Moreover, it represents a relatively underdeveloped area in China's facility landscape. Unique characteristics are observed in terms of capital investment, physical form, facility lifespan, digitization degree, organizational structure, project risk, and development effect when compared to traditional facilities. Despite its importance, challenges persist in project establishment, investment, management, and construction. Therefore, it is necessary to strengthen the condensing mechanism for addressing major scientific issues in the life science field, improve the strategic investment layout, facilitate the localization of technical equipment based on original scientific ideas, and strengthen the differentiated management capacity of life science facilities.

Karl George Emeléus and Physics in Belfast 1927–66

AbstractKarl George Emeléus (1901–1989) was educated at Cambridge and after a short period at King’s College, London, he spent the remainder of his career as lecturer (1929–33) and then professor (1933–66) of physics at Queen’s University, Belfast. At Queen’s, he set the direction of experimental research in gas discharge and plasmas for a generation and oversaw the growth of the department. He also acted as a spokesman for physics in Northern Ireland and was involved in public responses to concerns about the use of nuclear weapons and nuclear energy in the late 1940s and 50s. This paper summarises Emeléus’s life and work and sets it in the context of physics at Queen’s University in the mid-twentieth century.

Conjugated Porous Organic Polymers Featuring Both Soft-Hard Combined Coordination Sites and Photoelectrochemical Properties for Palladium Capture and Subsequent Photocatalysis.

Palladium (Pd) capture from high-level liquid waste for subsequent photocatalytic applications is desirable for the development of nuclear energy and the reutilization of valuable resources. Herein, we approach our design with a unique porous organic polymer containing thiazolo[5,4-d]thiazole units (denoted as TzPOP-OH). It possesses two potential soft-hard (N-O and S-O) combined coordination sites for Pd(II) coordination and features strong donor-acceptor repeating units and high planarity of linkage enforced by hydrogen bonds for subsequent photocatalysis. Accordingly, TzPOP-OH with three hydroxyl groups on the linkage exhibits a high Pd(II) capacity of 369 mg g-1 at 3 M HNO3, considerably surpassing those of the controlled polymer TzPOP without hydroxyl groups and most other reported materials. Additionally, TzPOP-OH boasts other merits, including outstanding acid tolerance, extraordinary radiation stability, good reusability, and remarkable selectivity. After palladium adsorption, Pd@TzPOP-OH demonstrates impressive photodegradation efficiency to reduce the concentration of rhodamine B in contaminated urban water from 10 to less than 0.1 ppm. This work provides a feasible approach to designing materials with both suitable coordination microenvironments and semiconductor properties for metal separation and photocatalysis.

The technological transformation of the Russian energy sector forced by carbon regulation

RELEVANCE of the study lies in the assessment of the impact that various carbon regulation instruments stimulating the achievement of national climate goals have on the development scale of different electricity and heat production technologies in Russia.THE PURPOSE. To consider the change in the optimal technological structure of the electric power industry and district heating in Russia by 2050 assuming the introduction of various carbon regulation instruments in 2030.METHODS. We used the developed at ERI RAS system technological model EPOS for the optimization of the energy technology structure in the Russian energy sector according to the criterion of the minimum total discounted costs for energy supply to the economy until 2050.RESULTS. The article provides an analysis of the scale of changes in installed capacity and electricity production of various types of power plants in the UES of Russia, as well as changes in heat production of different heat supply sources by 2050 for 16 carbon regulation options and business-as-usual scenario. Also it describes the optimal technological structure in the electric power industry and district heating under the conditions of certain administrative, fiscal and economic instruments of climate policy. Carbon regulation options based on the corresponding increases in the installed capacity of power plants in the UES of Russia by 2050 are compared.CONCLUSION. Decarbonization of the electric power industry in Russia will mainly occur by expansion of nuclear energy, heat production – by deployment of electric boilers, taking into account current forecasts of scientific and technological progress. At the same time, for carbon regulation options leading to a greenhouse gas emissions reduction by 30% relative to 2019 level, nuclear power plants could become the new dominant technology in the structure of electricity production instead of gas thermal power plants. The total increase in installed capacity of power plants in the UES of Russia by 2050 may differ by almost seven times for various carbon regulation options. Among the climate policy options considered, emission quotation and carbon taxes have the strongest impact on the technological structure of the electric power industry and district heating in Russia.

Monte Carlo Workflow Unification for Nuclear Reactor Analysis with Metamodel-Driven Modeling

Monte Carlo (MC) transport codes are a cornerstone of nuclear reactor analysis frameworks, providing reference solutions and multigroup cross sections, and even as core components in multiphysics couplings. These applications can be seen in toolkits from the Nuclear Energy Advanced Modeling and Simulation program and the U.S. Nuclear Regulatory Commission’s BlueCRAB (Comprehensive Reactor Analysis Bundle). Contrary to their ubiquitousness in reactor physics modeling and simulation, popular MC codes, such as MCNP, Serpent, and KENO, are still reliant on antiquated textual input formats. These input languages use a plethora of keywords with terse syntax to specify all facets of a model, including its geometry, materials, physics settings, and tally options. This poses a steep learning curve and a poor user experience. Being tied to unique text-based input formats also significantly complicates programmatic input generation or modification that may be desired and/or required within a multiphysics framework. This work demonstrates how the development of programmatic interfaces for MC codes can support model unification and translation activities. Building on the Python application program interface (API) development of MCNPy, similar capabilities are being implemented for Serpent that are able to support model translation. In future work, the Serpent API capabilities will be made more robust and the work will be further expanded to include translations with KENO.

Insights into irradiation-affected structural evolution and mechanical behavior of amorphous carbon

The distinctive hybridization structure of amorphous carbon (a-C) imparts remarkable mechanical and tribological characteristics, making it highly relevant for lubrication applications, particularly in critical sectors such as nuclear energy. In this work, we employed molecular dynamics simulations to examine the effects of irradiation on the structural evolution and mechanical behavior of a-C. The findings indicate that with increasing irradiation doses, the short-range order within the a-C is disrupted, leading to a substantial increase in sp2 hybridization. Then, nanoindentation simulations revealed a reduction in both hardness and elastic modulus as a consequence of irradiation damage, associated with the transition in hybridization from sp3 to sp2 and the associated creation of free volume. Furthermore, nanoscratch mechanical testing showed a slight increase in the friction, primarily attributed to the weakened load-bearing ability of a-C after irradiation. Interestingly, a metastable transition from sp2 to sp3 hybridization was observed on the scratched surface, which was concurrently validated by experiments as Raman spectroscopy and TEM-EELS. This study provides a detailed atomic-level mechanism for the irradiation-induced damage on the structural bonding and mechanical properties of a-C, offering guidance for its performance in nuclear reactors and the aerospace industry.

Exfoliated layered nanosheets of orthorhombic SnS, subjected to 90 MeV carbon ion irradiation

Derived through liquid phase exfoliation, the irradiation response of nanoscale, exfoliated tin sulfide (SnS) systems are being reported in this work. The SnS nanosheets were exposed to 90[Formula: see text]MeV [Formula: see text] ion beams across fluences ranging from [Formula: see text] to [Formula: see text][Formula: see text]ions/cm2. With an electronic energy loss ([Formula: see text]) of [Formula: see text]56[Formula: see text]eV/Å, dominating over the nuclear energy loss ([Formula: see text]), the average crystallite size of the irradiated samples displayed an augment when compared to its pristine counterpart. Exhibiting an orthorhombic crystal structure, structural analyses of both pristine and irradiated samples were conducted via X-ray diffraction (XRD) technique. Raman analysis has manifested some modifications in the SnS nanosystem upon radiation exposure, particularly with higher fluences causing local structural disorder and amorphization of the material. Moreover, morphological changes in the irradiated SnS samples were examined using field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM), with AFM images revealing an increase in the root mean square (RMS) roughness corresponding to ion fluence. Furthermore, swift heavy ion (SHI) irradiation prompted a non-rectifying Ohmic [Formula: see text] characteristics and altered the electrical conductivity of the SnS nanosheets.

Non-invasive ultrasonic sensing of internal conditions on a partial full-scale spent nuclear fuel canister mock-up

The safe storage of spent nuclear fuel (SNF) in dry cask storage systems (DCSSs) is critical to the nuclear fuel cycle and the future of nuclear energy. A critical component of DCSSs is the SNF canister. The canister is a sealed stainless-steel structure, which is first vacuum dried and then backfilled with helium. The structural deterioration within a canister can be monitored through its internal gas properties. This monitoring serves as the driving force behind the non-invasive ultrasonic sensing approach in this paper. A major challenge in collecting gas-borne signals using ultrasonic sensing is the impedance mismatch between the stainless-steel canister and the helium gas inside. Only a small fraction of the ultrasonic signal makes its way from the transmitter to the receiver through the gas medium. In this paper, experimental studies on a partial full-scale canister mock-up were carried out to capture the gas-borne signals. Damping materials were applied on the outside, and blocking and unblocking tests were conducted to identify the gas-borne signal. The research results showed that the excitation frequency played an important role in maximizing the gas-borne signals. The gas-borne signal was successfully detected at around the theoretical time-of-flight (TOF) at 225 kHz. A high signal-to-noise ratio (SNR) was achieved in the measurements. Next, acoustic impedance matching (AIM) layers were added, and it was found that the gas signal energy was improved by 160.4% compared with that of no AIM layers. Subsequently, the relative humidity (RH) level and temperature of the gas were varied to simulate abnormal internal conditions of the canister. The non-invasive testing system demonstrated reliability and sensitivity in detecting gas temperature and RH variations. Theoretical calculations demonstrated the potential for detecting low-level xenon and air within an actual SNF canister filled with helium. Last, an active noise cancellation (ANC) method, previously developed by the authors, was verified on the canister mock-up for the first time. The results showed that the SNR of the gas signal was improved by 213.6% compared with that of no ANC.

A Demonstration of the Risk-Informed NEI 18-04 Design Evaluation Model for the Modular High-Temperature Gas Reactor

Several advanced reactor designs are now under active development in the United States and elsewhere, promising sustainable solutions to the growing world energy needs. The designs currently being considered are quite diverse and different from the more established light water reactor technology that has dominated the operating commercial nuclear landscape. While advanced reactor concepts were first explored in the dawn of the nuclear age, they are now being reconsidered under the light of modern needs, and specifically, for their flexible operating conditions and inherent safety characteristics. In response, the U.S. Nuclear Regulatory Commission staff is moving forward with development of 10 CFR Part 53 rulemaking, which is a more risk-informed, technology-agnostic framework for licensing and regulating such new designs. The nuclear industry response to this regulatory initiative resulted in the technical report by the Nuclear Energy Institute, NEI 18-04 Revision 1, which provides an implementation roadmap of the risk-informed approach when defining the safety case for a new plant design. The implementation of this safety case may be a nontrivial exercise for an actual reactor design. This paper provides a demonstration of performing such an analysis for a representative advanced reactor. Public information from the General Atomics high-temperature gas reactor design was considered in this demonstration. The analysis workflow was facilitated with the FPoliSolutions’ proprietary Risk-Informed System Engineering (RISE) digital platform, a product that was presented in previous publications. RISE is one application of FPoli’s enterprise digital platform, which was created to facilitate orchestration of complex workflows leveraging recent technologies developed at national laboratories, such as Idaho National Laboratory’s RAVEN and EMRALD frameworks. The analysis described in the paper includes the selection and classifications of events, the integration of probabilistic risk analysis artifacts, and event modeling simulations for consequence evaluations. The results are then used for system, structures, and components safety classification and a synthesis of the safety case for the design in line with the frequency-consequence targets presented in NEI 18-04. The purpose of the analysis, as framed in RISE, is to readily produce outputs and views that can aid users and regulators in making risk-informed decisions to demonstrate their plant safety case.

Using students’ critical aspects to deepen understanding of nuclear physics concepts

Identifying students’ understanding provides a pathway to develop focused teaching to facilitate conceptual understanding. This study aims to gain more insight into undergraduate students’ conceptual understanding of two nuclear physics concepts: nuclear binding energy (NBE) and nuclear force; as the literature has shown that students face difficulties in learning and understanding such concepts. Phenomenography was used to provide a special qualitative research approach to exploring students’ in-depth understanding which was not addressed in previous studies. Data was collected from purposively selected students (N = 30) through semi-structured interviews. Phenomenography was used to reveal the different ways in which students understand these concepts and serves as indicators of potential conceptual difficulties. Based on these, the relevant and irrelevant critical aspects discerned by students are identified using the variation theory of learning. These critical aspects illustrate how the students understand each concept. For instance, NBE is the energy that must be added to a nucleus to separate it into its constituents and relates to a relevant critical aspect. However, NBE is also the energy that binds nucleons and this relates to an irrelevant critical aspect. These critical aspects can provide crucial information that can assist physics instructors in developing focused teaching and learning strategies. Thus, the responses to the interview can be used as a basis for teaching and learning nuclear physics concepts.

Plastic deformation mechanism of γ phase Fe–Cr alloy revealed by molecular dynamics simulations

Abstract Due to their outstanding mechanical properties, anti-corrosion properties, and anti-irradiation swelling properties, Fe–Cr alloys have been fully improved and developed for nuclear energy applications as structural materials. To ensure the performance stability of γ-phase Fe–Cr alloys, the present study adopted molecular dynamics (MD) simulations to explore the plastic deformation mechanism of these alloys. The slip model was constructed, and the generalised stacking fault energy (GSFE) and Peierls–Nabarro (P–N) equations were solved, revealing that {110}<111> is the preferentially activated slip system. The twinning model was constructed and the generalised plane fault energy was solved, demonstrating that twinning is preferred over slipping in the {112}<111> system. The above findings are also verified through MD simulations in which Fe–Cr specimens are stretched along the [100] direction. In addition, in the 15 at.%–25 at.% Cr range, an increase in the Cr content has a negative effect on slip but a positive effect on twin formation.

Total electricity generation dynamics analysis and renewable energy impacts in South Africa

AbstractThis research explores the dynamics of total electricity generation (TEG) in South Africa through an analysis of data from the International Energy Agency database from 1990 to 2020. A comprehensive examination of various energy sources, including coal, oil, biofuels, nuclear, hydro, solar photovoltaic (PV), solar thermal, and wind, is conducted to ascertain their respective contributions to TEG. Employing the R software environment, the study employs a methodical analytical framework encompassing meticulous data preparation, statistical analysis, and model formulation. The data preparation phase involves intricate processes such as structuring, cleansing, and visualization aimed at eliminating stochastic variables and outliers. Missing data are addressed through the application of the Piecewise Cubic Hermite Interpolating Polynomial method. Subsequent statistical analyses are informed by tests for normality and homogeneity of variance, revealing deviations from normality and disparate variances across energy source groups. Consequently, non‐parametric methodologies such as the Kruskal–Wallis test are adopted. Findings underscore the significant role of nuclear energy in TEG despite facing challenges. Model development entails the construction of multiple linear regression models with varying predictor sizes, with Model m06 emerging as the optimal choice, incorporating key predictors such as coal, nuclear, and solar PV. Rigorous diagnostic assessments confirm the robustness of Model m06 and its suitability for TEG prediction. Comparative analysis against actual data validates its superior performance, characterized by minimal errors and high predictive accuracy. The efficacy of Model m06 in capturing TEG dynamics underscores its utility for informing energy planning initiatives. Recommendations derived from the study advocate for prioritizing renewable energy integration, infrastructure investment, research endeavors, monitoring mechanisms, and public awareness campaigns to advance sustainable energy development goals in South Africa.

The impact of national policies on Europe-wide power system transition towards net-zero 2050

This research aims to investigate the potential impact of national policies on the attainment of Europe's goal of achieving net-zero greenhouse gas emissions by 2050. Specifically, it analyses the effects of policies on the power sector, by evaluating capacity expansion portfolios, import reliance, and costs by 2050. A linear programming model, the IESA-EUPS, is utilized to optimize the expansion and operation of the power system, considering 28 nodes and hourly temporal resolution. The study includes five scenarios from 2020 to 2050, with varying levels of biomass and nuclear penetration based on existing member state policies. Results show that by 2050, changes mainly occur in the interplay between firm capacities and cross-border transmission levels. Limiting biomass can significantly increase nuclear energy generation, while enforcing all policies leads to a 40 % rise in cross-border transmission by 2050, due to imbalances between countries. Some member states, such as Spain and Finland, are less affected, whereas others are heavily reliant on firm nuclear capacities. Western European countries with strict biomass and nuclear restrictions may see a boost in nuclear installations in countries allowing it. Member states without both nuclear and biomass may rely more on variable renewables, resulting in surplus electricity and increased LCOE.

Potential applications of microbial genomics in nuclear non-proliferation.

As nuclear technology evolves in response to increased demand for diversification and decarbonization of the energy sector, new and innovative approaches are needed to effectively identify and deter the proliferation of nuclear arms, while ensuring safe development of global nuclear energy resources. Preventing the use of nuclear material and technology for unsanctioned development of nuclear weapons has been a long-standing challenge for the International Atomic Energy Agency and signatories of the Treaty on the Non-Proliferation of Nuclear Weapons. Environmental swipe sampling has proven to be an effective technique for characterizing clandestine proliferation activities within and around known locations of nuclear facilities and sites. However, limited tools and techniques exist for detecting nuclear proliferation in unknown locations beyond the boundaries of declared nuclear fuel cycle facilities, representing a critical gap in non-proliferation safeguards. Microbiomes, defined as "characteristic communities of microorganisms" found in specific habitats with distinct physical and chemical properties, can provide valuable information about the conditions and activities occurring in the surrounding environment. Microorganisms are known to inhabit radionuclide-contaminated sites, spent nuclear fuel storage pools, and cooling systems of water-cooled nuclear reactors, where they can cause radionuclide migration and corrosion of critical structures. Microbial transformation of radionuclides is a well-established process that has been documented in numerous field and laboratory studies. These studies helped to identify key bacterial taxa and microbially-mediated processes that directly and indirectly control the transformation, mobility, and fate of radionuclides in the environment. Expanding on this work, other studies have used microbial genomics integrated with machine learning models to successfully monitor and predict the occurrence of heavy metals, radionuclides, and other process wastes in the environment, indicating the potential role of nuclear activities in shaping microbial community structure and function. Results of this previous body of work suggest fundamental geochemical-microbial interactions occurring at nuclear fuel cycle facilities could give rise to microbiomes that are characteristic of nuclear activities. These microbiomes could provide valuable information for monitoring nuclear fuel cycle facilities, planning environmental sampling campaigns, and developing biosensor technology for the detection of undisclosed fuel cycle activities and proliferation concerns.

Examination of the Peaceful Uses of Nuclear Energy in Turkish Legislation

Population growth, industrialization and technological advances increase the demand for energy. Due to problems such as global warming, environmental pollution and destruction, the trend towards alternative energy sources continues on a global scale. For this reason, the use of nuclear energy, one of the secondary energy sources, has tended to increase in recent years. Reasons such as the geographically uneven geographical distribution of resources that are raw materials for energy among countries and their exhaustibility, fluctuations in energy prices and the economical production of nuclear energy are among the reasons why countries in the world turn to nuclear energy. A number of accidents at nuclear power plants have had a negative impact on the perception of nuclear power plants, but for different reasons, nuclear energy is gaining popularity again. Nuclear power plants are the first thing that comes to mind when it comes to nuclear power, but it is also used effectively in medical treatments and applications of various branches of science as well as energy production. In global energy production; the fact that it aims to reduce carbon emissions by providing more energy production within the scope of sustainability, the continuous and uninterrupted continuation of electricity production using nuclear, the production of electricity at more affordable costs in nuclear power plants compared to other power plants (thermal, renewable, etc.), the fact that greenhouse gas emissions are almost negligible, and the use of nuclear technology in many fields such as physics, medicine, transportation, agriculture as well as energy production have made nuclear energy back on the agenda of countries in recent years. In nuclear energy, nuclear waste and their storage processes continue to be discussed as a problem in this process. For these reasons, the possibility of peaceful use of nuclear power has been questioned in academic platforms and various criteria have been determined This article examines Turkey's compliance with the criteria for the peaceful use of nuclear energy and clarifies the development process in this regard. Turkey's legislation on nuclear energy, international conventions, nuclear safety, radiation control criteria and compliance with national legislation will be examined.

Strong Electron-Electron-Nuclei Correlations in Two-Photon Double Ionization of H_{2}.

Two-photon double ionization is a paradigmatic example of how electron correlation manifests. In molecular targets, its coupling with the slower nuclear motion introduces an additional complication and induces electron-electron-nuclei correlations. Experimentally, momentum-coincident measurements can provide a complete kinematical image of the molecular full Coulomb breakup. Previous theoretical studies have described this process by ignoring nuclear motion and the subsequent Coulomb explosion of the dication. Here we show, by means of a full-dimensional treatment of two-photon double ionization of the H_{2} molecule, that nuclear motion plays a decisive role even for pulses as short as 1.5fs, a time during which the nuclei are not expected to move significantly. We find strong correlations between nuclear and electronic degrees of freedom, giving access to different electronic processes as a function of nuclear kinetic energy. In particular, we observe unexpectedly strong back-to-back asymmetry in the photoelectron angular distributions, as well as novel interferences resulting from the coherent contributions from two-photon sequential absorption paths via different molecular cationic states.

How Does Nuclear Energy Affect Environmental Pollution? Evidence from the United States

Research Originality: Nuclear power plant installation activities, which have gained momentum since the 1970s, have made the use of nuclear energy widespread, and especially the US ranks first in the world in the nuclear energy use. This article contributes to the existing literature on environmental economics by incorporating environmental technologies and globalization into the investigation of the impact of nuclear energy on environmental pollution. Research Objectives: The aim of this study is to analyze the effects of nuclear energy consumption, environmental technologies and globalization on environmental pollution in the US.Research Methods: The paper use ARDL approach with the data of 1970-2018 period. Empirical Results: According to the findings, nuclear energy consumption negatively affects environmental quality in the US both in the short and long run. On the contrary, while environment-related technologies contribute positively to environmental quality with a reducing effect on carbon footprint in the long run. Also, globalization has an insignificant effect on environment in both short and long run.Implications: It is thought that environmental quality will improve as a result of supporting environmental technologies and exchanging nuclear energy with renewable energy sources in the US.JEL Classification: Q43, C32How to Cite:Atay Polat, M., Savranlar, B., Arslan, F. (2024). How Does Nuclear Energy Affect Environmental Pollution? Evidence from US. Etikonomi, 23(2), 511 – 526. https://doi.org/10.15408/etk.v23i2.37692.

A review on recent progress of refractory high entropy alloys: From fundamental research to engineering applications

Refractory high-entropy alloys (RHEAs) have emerged as frontier materials for high-temperature structural applications due to their exceptional mechanical properties and thermal stability. This review aims to provide a comprehensive and in-depth summary of the latest research progress in the field of RHEAs. By systematically analyzing 253 publications since 2022, this review presents a panoramic overview of the current research status in the field of RHEAs, covering aspects from alloy design, microstructure, processing techniques, mechanical behavior, to physicochemical properties. Key strengthening and toughening mechanisms, such as solid solution strengthening, precipitation strengthening, and grain boundary strengthening, are extensively analyzed. The high-temperature mechanical performance, oxidation resistance, and adaptability of RHEAs in extreme environments including corrosion and irradiation, are critically reviewed, and the potential application value of these research findings in aerospace, nuclear energy, biomedical, and other fields is discussed. Simultaneously, the multidisciplinary characteristics of RHEAs research has revealed the trend of the field evolving from fundamental research to practical applications. Furthermore, with the aid of advanced characterization techniques and computational methods, the review elucidates the controlling effects of chemical short-range order, defect structures, and other factors on the performance evolution of RHEAs, highlighting the importance of multi-principal element synergistic effects. Based on summarizing the key scientific issues and technological bottlenecks faced by RHEAs, the article provides a forward-looking perspective on future research directions, emphasizing development strategies that integrate computation and experiments, and accelerate the transformation of fundamental research into engineering applications, thus providing insights and guidance for developing a new generation of high-performance RHEAs.

Fabrication of highly thermally conductive and irradiation resistant UHMWPE-based composites for nuclear shielding applications

With the advancement of nuclear energy, the safety of both humans and the surrounding environment necessitates the adoption of effective nuclear radiation shielding materials. Polymer-based shielding materials have garnered attention due to their lightweightness and ease of moldability. However, they normally possess low thermal conductivity (λ) and easy deformation at high temperatures, which potentially cause catastrophic disasters during service if they are mechanically failed due to heat accumulation. To address the above concerns, highly thermally conductive and irradiation resistant ultra-high molecular weight polyethylene (UHMWPE)-based composites were fabricated. Planar fillers such as boron nitride (BN) and graphite (Gt) along with lead (Pb) powders were employed to construct a densely packed filler network for improving the λ and mechanical properties of UHMWPE-based composites. The λ was increased from 3.81 to 6.20 W/mK when 20 wt% Pb (2.88 vol%) was added to BN30/Gt20 (i.e., UHMWPE composite with 30 wt% BN and 20 wt% Gt), representing an increase of 62.73 %. Moreover, the λ of Pb80 was increased from 0.87 to 3.29 W/mK by merely adding 5 wt% (9.99 vol%) Gt, representing a remarkable increase of 278.16 %. GEANT4 simulation results indicated that BN30/Gt20/Pb20 exhibited excellent neutron shielding performance. Samples which were irradiated using 60Co γ-rays at a total dosage of 1.15×105 Gy exhibited enhanced mechanical performance, which indicated excellent irradiation resistance of UHMWPE-based composites. Therefore, a facile method was proposed to prepare multi-functional UHMWPE-based composites that demonstrate promising application in nuclear sectors.