Fusion Nuclear Technology Research Articles

Experimental insights on iron-based alloys corrosion in water cooled loops

This paper presents experimental findings on the behavior of iron-based alloys in environmental conditions typical of nuclear fusion technology, specifically focusing on material degradation, which is a critical aspect for the water cooling system of EU DEMO breeding blankets. The experimental campaign investigates potassium hydroxide’s role as an alkalizing agent, testing various concentrations to assess its impact on corrosion resistance. Additionally, it examines how oxygen levels affect localized corrosion development, which is crucial for mitigating corrosion risks in fusion applications. Seven 1000-hour tests were conducted to determine optimal conditions for corrosion reduction. Findings include identifying an oxygen concentration threshold to prevent piping cracking on EUROFER97 specimens.

Microelectrode-Based Diffusivity Measurements of Hydrogen in Molten 2LiF-BeF2

Detailed knowledge of the mass transport behavior of hydrogen isotopes in molten 2LiF-BeF2 salt (FLiBe) is essential to the design of new nuclear fusion technologies that make use of this molten salt to breed tritium to fuel the fusion reaction. However, typical studies of hydrogen transport using macroelectrodes are limited to solely measuring the permeability of an analyte—a property defined as the product of concentration squared and diffusivity. This challenge necessitates the development of microelectrodes capable of dynamically measuring diffusion coefficients when concentrations are variable. Unlike macroelectrodes, microelectrodes can measure diffusivity and concentration independently due to a steady-state current proportional to the product of diffusivity and concentration captured in addition to the Cottrellian current response.This steady-state current is established due to a continuously expanding diffusion layer from the electrode that cannot expand indefinitely within finite experimental setups. Therefore, COMSOL Multiphysics simulations mirroring experimental conditions were performed to validate the analytical mass transport model based on the solution of Fick’s Second Law in radial coordinates. These simulations employed a 2D axisymmetric model to examine the conditions under which the infinite bulk solution approximation is valid, confirming that our electrode design would yield true steady-state current responses indicative of radial diffusion.Platinum microelectrodes developed in this study served a dual purpose: they not only addressed previous limitations in high-temperature molten salt experimentation but also enabled dynamic measurements of both the diffusion coefficient and concentration of hydrogen in molten FLiBe introduced by lithium hydride. Square wave voltammetry and chronoamperometry were performed on a three-electrode cell using a platinum working microelectrode, a tungsten counter electrode, and a Ni/Ni2+ thermodynamic reference electrode. The successful measurement of hydrogen diffusivity in these experiments not only offers essential insights into molten FLiBe behavior but also sets the stage for future investigations into the effects of redox conditions, impurities, and equilibration time on tritium within nuclear fusion reactors.

Research on optimizing the controller configuration for high-power supply control system in nuclear fusion based on hybrid algorithm WOA-IAPSO

With the development of nuclear fusion technology, the high power supply control system plays a crucial role in the operation of nuclear fusion, and the PID controller is widely used in the field of power supply control. In this research, a novel hybrid algorithm is proposed that combines whale optimization algorithm (WOA) and the improved adaptive particle swarm optimization (IAPSO) to tune PID parameters in high-power supply. This organically combines the two methods into a new optimization strategy that is different from the simple weighted average method. By comparing the performance of WOA, IAPSO,SA,GA,SVM, and the hybrid WOA-IAPSO in step response under different working conditions, the simulation results show that the proposed algorithm can achieve more sensitive, stable and efficient response in high-power operation. This research is not only of great significance for the further development nuclear fusion technology, but also provides a useful reference for the application of adaptive optimization methods in other fields.

Chinese Academy of Science Journal Ranking System (2015–2023)

This work examines China's mainstream journal ranking system from the Chinese Academy of Science (CAS), including its history, recent reforms, and current operation, with a particular focus on Physics of Fluids. Using official statistics, this paper analyzes the Physics of Fluids standings in the CAS system from 2015 to 2023. During these years, Physics of Fluids experienced a significant increase in both popularity and impact. Meanwhile, the CAS system underwent substantial reforms, including the newly proposed Advanced edition, which universally boosted fluids journal academic weights in China. Most notably, the brand-new Field Normalized Citation Success Index (期刊超越指数 or FNCSI) offered a new lens through which to assess academic journal impact. Statistics reveal that Physics of Fluids is in a promising position to become the fourth Tier 1 fluids journal to enter any of CAS's Major Categories (after the Annual Review of Fluid Mechanics, Nuclear Fusion, and Plasma Sources Sciences and Technology) and the first-ever non-review-only Tier 1 fluids journal to enter the Engineering and Technology (工程技术 E&T) Major Category. Finally, this paper suggests several directions for Physics of Fluids to direct future endeavors as it enjoys heightening popularity in China.

Study of small tensile specimen thickness effects in copper oriented for IFMIF-DONES irradiation

Small specimen testing technology (SSTT) refers to the examination of tiny samples of materials to evaluate their suitability for use in fusion reactors. This includes assessing their thermal, mechanical, and radiation properties, as well as their ability to withstand extreme conditions. SSTT plays a critical role in the development of nuclear fusion technology, which holds the potential to provide a virtually limitless and clean energy source. SSTT is imperative in cases where not much material is available or must be subjected to special conditions that limit it.One of the main challenges in nuclear fusion is the development of materials that can withstand the harsh environment inside a fusion reactor. These materials must be able to withstand high temperatures, intense radiation, and mechanical stress, and be able to maintain their structural integrity for long periods. Small specimen testing allows characterizing and evaluating these properties in a controlled and efficient manner.Small specimen samples, under conditions similar to those in a fusion reactor, will provide crucial information for the design and development of fusion components when irradiated at IFMIF- DONES. The results of SSTT are used to refine materials, optimize production processes, and develop new materials with improved properties.In this work, numerous tensile tests (SSTT) have been carried out on pure copper, a material of interest for fusion with different thicknesses, analyzing the effect of the variation of this variable in the determination of mechanical properties.

Global Development and Readiness of Nuclear Fusion Technology as the Alternative Source for Clean Energy Supply

Nuclear fusion is understood as an energy reaction that does not emit greenhouse gases, and it has been considered as a long-term source of low-carbon electricity that is favourable to curtail rapid climate change. Fusion offers a pathway to resolve energy security and the unequal distribution of energy resources since seawater is its ultimate fuel source and a few grams of fuel can generate mega kilowatts of power. The development and testing of new materials and technologies are unceasing to achieve the net fusion energy through national and international collaboration as well as private partnerships. The ever-growing number of research works report various designs and magnet-based fusion devices, such as stellarators, lasers, and tokamaks. This article provides an overview on the utilization of nuclear energy as a clean energy source, as well as the strategies and progress towards establishing successful commercial fusion energy to the grid and transition to a reliable clean energy source. The overview focuses on the fusion nuclear development in five major countries, UK, US, China, Japan, and Russia. Identified technical and financial challenges are also described at the end of this article. The International Thermonuclear Experimental Reactor (ITER) has been an international reference program for fusion energy development and most developed countries with nuclear development capacity are aiming to complete their in-house fusion energy facilities in parallel to ITER. Many fusion programs are finishing the conceptual design and shifting into the phase of engineering design for the planned DEMO fusion facilities. The significant challenges were identified from the perspective of device efficiency and robustness, sustainable funding, and facility maintenance and safety, which must be addressed diligently to realize fusion energy as alternative clean energy that mitigates climate change and supports the goals of energy security.

Quantum algorithm for the radiative-transfer equation

The radiation transfer equation is widely used for simulations, for example, heat transfer in engineering, diffuse optical tomography in healthcare, and radiation hydrodynamics in astrophysics. By combining the lattice Boltzmann method, we propose a quantum algorithm for radiative transfer. This algorithm encompasses all the essential physical processes of radiative transfer: absorption, scattering, and emission. Although a sufficient number of measurements are required to precisely estimate the quantum state, and the initial encoding of the quantum state remains a challenging problem, our quantum algorithm exponentially accelerates radiative-transfer calculations compared to classical algorithms. In order to verify the quantum algorithm, we perform quantum circuit simulation using IBM Qiskit Aer and find good agreement between our numerical result and the exact solution. The algorithm paves the way for applications, such as fault-tolerant quantum computers for plasma engineering, telecommunications, nuclear-fusion technology, healthcare, and astrophysics. Published by the American Physical Society 2024

RETRACTED ARTICLE: Preliminary risk assessment of in-vessel leakage accident in ITER

The ITER project is one of the largest international cooperative scientific projects in the world, aiming to verify the feasibility of magnetic confinement controlled nuclear fusion technology and provide a technical basis for the subsequent construction of fusion energy power stations. The success or failure of ITER will greatly affect the commercialization process of fusion energy. The probabilistic safety assessment (PSA) was a powerful means to evaluate the risk and reliability of nuclear facility and achieved great success in safety assessment of fission power plants. Based on this, the PSA progress for ITER was proposed in this paper. And the in-vessel leakage accident was investigated to verify the effectiveness of proposed method. The result shows the maximum possible radiological consequences of ITER in-vessel leakage accident of ITER is 1.6E−3 mSv, and the frequencies of this consequence is 1.63E−8/year. The reason of this consequence was also discussed in this paper. Those result could provide some valuable reference for radiation risk assessment and safety supervision of fusion commercial reactor in the nuclear future.

Effect of the C/N ratio modification on the corrosion behavior and performance of carbonitride coatings prepared by cathodic arc deposition

This study focuses on investigating carbonitride coatings, specifically CNTi-(Zr, ZrNb, and ZrSi), as promising candidates for enhancing the durability and efficiency of Ti6Al4V materials used in nuclear fusion technology. X-ray diffraction analysis identified distinct phases, including TiN, ZrN, ZrC, and TiC. The corrosion studies showed complete degradation of the TiN, ZrC, and ZrN phases in the TiZrCN coating after tests, while the TiC phase exhibited relative stability. The surface morphologies and elemental mapping analysis demonstrated the loss of homogeneity in element distribution after corrosion process. The addition of Si and Nb elements into TiZrCN significantly influenced the coatings' corrosion behavior, with breakaway corrosion observed in CNTi- (Zr and ZrSi) coatings and localized corrosion in CNTi-(ZrNb) coatings. Notably, the CNTi-(ZrSi) coating formed an oxide phase in the presence of NaCl, whereas the CNTi-(ZrNb) coating exhibited continuous resistance and a low corrosion rate. Irradiation was carried out for the generation of active isotopes, showing that no radioactive isotopes were formed in any of the investigated samples.

Quodon Current in Tungsten and Consequences for Tokamak Fusion Reactors

Tokamak fusion reactors produce energetic He ions that penetrate surfaces less than 20 μm and neutrons that spread throughout the reactor. Experiments with similar swift He ions in heavy metals show that the vibronic coupling of nonlinear lattice excitations creates mobile lattice excitations, called quodons. These are decoupled from phonons, move ballistically at near sonic speed, and propagate easily in metals and insulators. They can couple to and transport electric charge, which allows their observation in experiments. They rapidly disperse heat throughout a fusion reactor and carry charge through electrical insulators. In this article, an experimental design is presented that separates quodon current and conduction current and therefore makes it possible to measure the former. Also, the time‐of‐flight experiments are presented that lead to an estimation of quodon speed which is of the order of the sound velocity and therefore much faster than the drift of electrons or holes in conduction currents. Herein, results are presented on quodon current in tungsten, a material widely used in nuclear fusion technology, showing that many quodons are produced in fusion reactors. It is predicted that at high output powers, quodons created by He ions and neutrons may adversely impact on cryogenic systems.

Characterization and Resource Potential of Li in the Clay Minerals of Mahai Salt Lake in the Qaidam Basin, China

The strategic importance of lithium in global development has become increasingly prominent due to the rapid growth of the new energy automotive industry and the continuous advancements in controllable nuclear fusion technology. Lithium minerals in salt lakes possess advantageous characteristics, such as abundant reserves, environmental sustainability, and economic viability. Furthermore, with ongoing improvements in the lithium extraction process, the availability of lithium minerals in salt lakes is expected to further increase. The Qaidam Basin Salt Lake in China has served as the location for the establishment of numerous lithium carbonate production enterprises, resulting in a lithium carbonate production volume of 7 × 104 t/yr in 2022. How to meet the growing need for lithium resources has become an enterprise focus. Nevertheless, there are large amounts of clay minerals in and around the bottom and periphery of the salt lake in the Qaidam Basin, and whether these minerals are of exploitable value, regardless of the state of the occurrence of lithium resources, remains unexplored. To ascertain the attributes, extent, and distribution of the lithium occurrence within the clayey layer of the Qaidam Basin, as well as to assess its resource potential, a total of 87 drill holes were conducted within a designated area of the Mahai Basin, which is a secondary basin in the Qaidam Basin. The subsequent analysis encompassed the examination of the lithium content within the clay minerals, the mineral composition of the clay, and, ultimately, the evaluation of the resource potential within the region. Compared with Quaternary salt lake deposits, brine deposits in gravel pores, and the Paleogene–Neogene Li-bearing salt deposits that have been studied, it is suggested that this is a novel form of a clay-type sedimentary Li deposit within the Qaidam Basin. The findings of this research will serve as a fundamental basis for future endeavors pertaining to the exploration and exploitation of lithium deposits within salt lake areas.

Back to the future: Revisiting the perspectives on nuclear fusion and juxtaposition to existing energy sources

This article reviews and launches perspectives on the progress of nuclear fusion research and development. To this end, the current state of nuclear fusion technology, the recent breakthroughs in nuclear fusion research occurred in the US, Japan, and China, the role of private companies and investments in nuclear fusion research and development are investigated for both advanced and emerging economies. The survey draws upon academic sources and media contributions from experts in the field of nuclear fusion. While nuclear fusion has reached the break-even point in the generation of nuclear fusion electricity, there are still serious challenges that will obviate the market alignment of nuclear fusion energy until the early 2030s – and more realistically the mid-2050s. Nonetheless, never in history, the level of public support and private engagement for nuclear fusion energy research and development has been as high as now. Furthermore, the study shows that there is a steadily increasing accumulation of scholarly knowledge on nuclear fusion and a broad consensus among the leading experts that nuclear fusion is the “holy grail” of the transition toward a post-resource, and hence, fully circular energy system.

Analysis of the possible contribution of different nuclear fusion technologies to the global energy transition

Despite the huge uncertainties related to the possibility of a quick development of nuclear fusion technologies - being disputed that it may come too late to effectively contribute to emission mitigation - research is focusing on a wide set of options for fusion reactors. This paper presents a global scenario analysis using the energy system optimization model EUROfusion TIMES to analyze the possible future role of fusion according to three different technologies and using capacity curves based on historical trends for the electricity sector. The analyzed fusion options are based on ARC, EU-DEMO and Asian-DEMO reactor concepts, characterized in terms of techno-economic features according to publicly available literature and considering a set of educated growth rate for their penetration. Results concerning installed capacity trends and contribution to the electricity mix are presented up to 2100 in three socio-economic storylines and for different scenarios considering either the availability of competing technologies or delays in the development of fusion plants. Despite not contributing at all to the energy transition in Europe and the US, fusion may gain share in contexts characterized by highly growing electricity demand, contributing to satisfy stringent environmental constraints together with other low-carbon technologies in the second half of the century.

Review of commercial nuclear fusion projects

Nuclear fusion technologies have re-gained momentum in the last decade thanks to their disruptive potential in different fields, such as energy production and space propulsion, and to new technological developments, especially high temperature superconductor tapes, which allow overcoming previous performance or design limits. To date, reviews of recent nuclear fusion designs are lacking. Therefore, this paper aims at giving a comprehensive overview of nuclear fusion concepts for industrial applications with a focus on the private sector. The designs are classified according to the three leading concepts for plasma confinement, namely, magnetic confinement, inertial confinement and magneto-inertial confinement. The working principles of the main devices are described in detail to highlight strengths and weaknesses of the different designs. The importance of the public sector on private projects is discussed. The technological maturity is estimated, and the main criticalities for each project are identified. Finally, the geographical distribution of the companies (or public institutions) pursuing the design of fusion devices for commercial applications is reported.

Structural material nuclear data basic research

The nuclear data evaluation for deuteron-induced reactions andα-particle emission by neutron interactions is addressed within “Nuclear data for fusion technology, from basic research to full-scale applications.” The status and open questions related to these subjects in the area of nuclear data for fusion technology, specifically for the nuclear design of the ITER fusion device, the European DEMO fusion reactor, and the IFMIF-DONES Irradiation Facility, are briefly reviewed. A firm demand for accurate cross-sections of reactions induced by neutrons and deuterons exists, in this respect, within a more enlarged energy range up to 50 MeV than for fission applications. The current requirements are closely met by the TENDL Evaluated Nuclear Data Library, settled using the TALYS nuclear model code, which is one of the most widely used codes in basic research and applications including nuclear fusion technology. However, further improvement of this data library has recently been suggested, while, with respect to fission applications, not only the aforementioned energy range but also the diversity of nuclear data for fusion technologies is plainly stretched. Consequently, the progress of nuclear data activities conducted more recently on deuteron-induced reactions andα-emission by neutron interactions, throughout the European Fusion Program and subsequent to previous achievements within F4E and EUROfusion programs, is wholly summarized.

Double Pulse LIBS Analysis of Metallic Coatings of Fusionistic Interest: Depth Profiling and Semi-Quantitative Elemental Composition by Applying the Calibration Free Technique

In this work we report the characterization of thin metallic coatings of interest for nuclear fusion technology through the ns double-pulse LIBS technique. The coatings, composed of a tungsten (W) or tungsten-tantalum (W-Ta) mixture were enriched with deuterium (D), to simulate plasma-facing materials (PFMs) or components (PFCs) of the next generation devices contaminated with nuclear fuel in the divertor area of the vacuum vessel (VV), with special attention to ITER, whose divertor will be made of W. The double pulse LIBS technique allowed for the detection of D and Ta at low concentrations, with a single laser shot and an average ablation rate of about 110 nm. The calibration free (CF-LIBS) procedure provided a semi-quantitative estimation of the retained deuterium in the coatings, without the need of reference samples. The presented results demonstrate that LIBS is an eligible diagnostic tool to characterize PFCs with high sensitivity and accuracy, being minimally destructive on the samples, without PFCs manipulation. The CF-LIBS procedure can be used for the search for any other materials in the VV without any preliminary reference samples.

(Digital Presentation) Electrochemical Sensors for Hydrogen/Deuterium Speciation

By the end of the century, global energy demand is expected to increase by a factor of three due to population growth. In this context, fossil fuels should not be the main power source due to the elevated environmental cost. Nuclear fusion technology is planned as an alternative to this demand as it is expected to generate large quantities of energy without all the inconveniences of fossil fuels. The most feasible reaction to take place is the fusion between two hydrogen nuclei. Specifically, deuterium and tritium will react releasing helium, neutrons, and large amounts of energy [1]. 2H + 3H → 4He + n + 17.59 MeV (1)In the present work, BaCe0.6Zr0.3Y0.1O3-α electrolyte (BCZY) was used to construct amperometric sensors for hydrogen monitoring. Firstly, BCZY powder was synthesized by the solid-state method and characterized using SEM and XRD. Secondly, it was sintered as a pellet and bound to an alumina tube to construct the electrochemical sensors. Finally, amperometric measurements were performed inside a stainless-steel reactor at 500 °C and applying 0.15 V between electrodes. The response of the sensors was evaluated using hydrogen and deuterium calibration mixtures. The concentration in the WE ranged from 150 to 300 ppm H2 or D2 in Ar. Argon was used in the CE as a cover gas. Finally, measurements with hydrogen and deuterium were compared to determine the isotope effect on the response.[1] J.Kenneth. Shultis, R.E. Faw, Fundamentals of nuclear science and engineering, Marcel Dekker, 2002.[2] E.C.C. de Souza, R. Muccillo, Properties and applications of perovskite proton conductors, Materials Research. 13 (2010) 385–394. https://doi.org/10.1590/S1516-14392010000300018.[3] A. Benes, A. Molinari, R. Witte, R. Kruk, J. Brötz, R. Chellali, H. Hahn, O. Clemens, Proton Conduction in Grain-Boundary-Free Oxygen-Deficient BaFeO2.5+δ Thin Films, Materials. 11 (2017) 52. https://doi.org/10.3390/ma11010052.[4] A. Hinojo, I. Soriano, J. Abellà, S. Colominas, Evaluation of High-Temperature Hydrogen Sensors Based on BaCe0.6Zr0.3Y0.1O3-α and Sr(Ce0.9Zr0.1)0.95Yb0.05O3-α Perovskites for Industrial Applications, Sensors. 20 (2020) 7258. https://doi.org/10.3390/s20247258.

Identifying the key development areas for small nuclear power plants

The paper considers the key characteristics of the small nuclear power plant (SNPP) modular design, demonstrates the possibility for reducing the construction cost and time for this class of plants due to factory fabrication, the effect of series manufacturing, and less redundant safety systems. It has been shown that it is possible to extend considerably the fields of application for nuclear technologies thanks to modularity and the possibility of ensuring high safety indicators. Potential applications for SNPPs have been analyzed, including power supply to remote (Arctic) territories, switchover from (renovation of) coal-based electricity generation, high-potential heat and hydrogen production for commercial consumers, and other applications. Rationale has been provided for most typical consumer requirements that define the greatest efficiency of the SNPP application in the given field. The need has been shown for developing and introducing a new technology platform for the SNPP-based nuclear power to decarbonize globally the world economy thanks to expanding greatly the application of nuclear power technologies in addition to the technology platform currently developed for the CNFC with fast reactors (addressing the objective of fuel supply and waste recycling) and the controlled nuclear fusion technology platform (addressing the objective of long-term global energy supply). The new platform needs to be based on an extensive international cooperation involving the formation of international consortiums. It has been proposed that a test site be set up to elaborate hydrogen (heat) production technologies for an individual commercial consumer (captive production) and other technologies for the practical use of SNPPs based on a pilot demonstration nuclear power plant.

Preliminary assessment of the safety factors in K-DEMO for fusion compatible regulatory framework

We open an avenue for discussing how we can pave the way for compliance with existing regulations is a far-reaching factor for settling nuclear fusion technology. Based on a model of the Korean Fusion Demonstration Reactor (K-DEMO) with a target fusion power of 2.2 GW, we assess the intrinsic safety determinants of internal energy sources, the expected radioactive waste, and the tritium management. Regarding these safety factors, we scrutinize the compatibility of the current legislative environment in Korea with K-DEMO and envisage foreseeable obstacles, such as licensing of the nuclear facilities and acceptability of the radioactive waste. Based on precedent licenses for the Korean Superconducting Tokamak Advanced Research (KSTAR) and lessons learned from the International Thermonuclear Experimental Reactor (ITER), we examine hazardous factors that would threaten regulatory compliance of K-DEMO. This approach can help shape a fusion-compatible framework for consolidating the necessary technical provisions and regulatory baselines reflecting social acceptance with a sense of safety. Fusion-compatible aspects in the regulatory environment are discussed, from fusion philosophy to subordinate administrative and technical guidelines, facility classification, and detailed methods guaranteeing integrity and safety. This paper will contribute to the timely settlement of fusion demonstration facilities and subsequent commercial plants.

Triple ion beam irradiation of glass-ceramic materials for nuclear fusion technology

The analysis of the radiation damage associated with energetic neutrons is a key factor for the application of glass-ceramics as joining materials in nuclear fusion plants. Triple ion beam irradiation is, currently, the only way to emulate the displacement damage and the effects of transmutation products induced by high energy neutrons at elevated doses by producing a high level of displacements per atom (dpa) and implanting high concentrations of low solubility gases on the glass-ceramic microstructure. In this paper, we investigate calcia-alumina glass-ceramics in which the damage expected in the working conditions of a nuclear fusion plant were reproduced by simultaneous irradiation with Si, He and H ions at different temperatures. TEM analysis of irradiated calcia-alumina samples shows amorphization (due to the Si beam) and partial recrystallization of the irradiated portion and the formation of He bubbles/cavities. The irradiation temperature plays a prominent role in determining the induced damage in terms of recrystallization, phase mixing and bubble size, density and aggregation.