Explore Research

Nuclear energy can play a role in carbon free production of electrical energy, thus making it interesting for tomorrow's energy mix. However, several issues have to be addressed. In fission technology, the design of so-called fourth generation reactors show great promise, in particular in addressing materials efficiency and safety issues. If successfully developed, such reactors may have an important and sustainable part in future energy production. Working fusion reactors may be even more materials efficient and environmental friendly, but also need more development and research. The roadmap for development of fourth generation fission and fusion reactors, therefore, asks for attention and research in these fields must be strengthened.

The development of advanced nuclear energy systems, known for their cleanliness and sustainability, is a key strategy for achieving a low-carbon energy transition. Liquid metal (LM)-powered advanced nuclear energy systems demonstrate sustainability and environmental friendliness, as well as being irreplaceable in specific areas. This paper charts a comprehensive scene of applications, challenges, and prospects of LMs in advanced nuclear energy (fusion and fission). First, next-generation fission reactors that use LM coolants, such as sodium or lead, are currently under design and construction. However, the coupling mechanisms of multiphase and multiphysics interactions remain unresolved due to various challenges, including corrosion and lead-water interactions. Second, the exploration of new LM-cooled reactors should emphasize sustainable development while ensuring basic performance. Lastly, the unique properties of LMs, including efficient energy transport and tritium breeding, position them as crucial materials in fusion system design. However, surface characteristics and the magnetohydrodynamic (MHD) effect remain major technical challenges. LMs have already left their mark in nuclear energy and are expected to be an effective solution to overcoming the energy crisis.

Thermonuclear fusion of deuterium and tritium constitutes an enormous potential for a safe, environmentally compatible and sustainable energy supply. The fuel source is practically inexhaustible. Further, the safety prospects of a fusion reactor are quite favourable due to the inherently self-limiting fusion process, the limited radiologic toxicity and the passive cooling property. Among a small number of approaches, the concept of toroidal magnetic confinement of fusion plasmas has achieved most impressive scientific and technical progress towards energy release by thermonuclear burn of deuterium-tritium fuels. The status of thermonuclear fusion research activity world-wide is reviewed and present solutions to the complicated physical and technological problems are presented. These problems comprise plasma heating, confinement and exhaust of energy and particles, plasma stability, alpha particle heating, fusion reactor materials, reactor safety and environmental compatibility. The results and the high scientific level of this international research activity provide a sound basis for the realisation of the International Thermonuclear Experimental Reactor (ITER), whose goal is to demonstrate the scientific and technological feasibility of a fusion energy source for peaceful purposes.

Today the applications of nuclear physics span a very broad range of topics and fields. This review discusses a number of aspects of these applications, including selected topics and concepts in nuclear reactor physics, nuclear fusion, nuclear non-proliferation, nuclear-geophysics, and nuclear medicine. The review begins with a historic summary of the early years in applied nuclear physics, with an emphasis on the huge developments that took place around the time of World War II, and that underlie the physics involved in designs of nuclear explosions, controlled nuclear energy, and nuclear fusion. The review then moves to focus on modern applications of these concepts, including the basic concepts and diagnostics developed for the forensics of nuclear explosions, the nuclear diagnostics at the National Ignition Facility, nuclear reactor safeguards, and the detection of nuclear material production and trafficking. The review also summarizes recent developments in nuclear geophysics and nuclear medicine. The nuclear geophysics areas discussed include geo-chronology, nuclear logging for industry, the Oklo reactor, and geo-neutrinos. The section on nuclear medicine summarizes the critical advances in nuclear imaging, including PET and SPECT imaging, targeted radionuclide therapy, and the nuclear physics of medical isotope production. Each subfield discussed requires a review article unto itself, which is not the intention of the current review; rather, the current review is intended for readers who wish to get a broad understanding of applied nuclear physics.

Nuclear energy is an environmental issue that needs to be carefully considered regarding its consequences. The environmental effects of nuclear energy encompass a complex interplay of factors, ranging from managing radioactive waste to the potential for accidents, emissions, and resource depletion, necessitating a thorough examination of its impact on our planet. This study examines the relationships between nuclear energy, nuclear fission, nuclear fusion, and load capacity factor for the eight countries (Canada, China, France, Germany, Japan, Russia, Spain, USA) that consumed the most nuclear energy from 1993 to 2018 using the time (Emirmahmutoglu & Kose, 2011) and frequency domain (Croux & Reusens, 2013) panel causality tests. The results differ according to time and frequency domain causality tests. While the time-domain causality test results showed no causal relationship between the nuclear energy consumption, nuclear reactors, and the load capacity factor variables, the frequency-domain causality test revealed that there are causal relationships between these variables in the short, intermediate and long run. According to the frequency-domain causality test results, there is a bidirectional causality relationship between nuclear reactors, energy consumption and load capacity factor. In line with the main findings of this study, it is recommended that these countries implement effective policies to increase environmental quality and make investments and incentives in nuclear energy and technologies.

Theoretical and experimental research on the reversed-field pinch (RFP) is reviewed. The basic theoretical properties of the RFP are considered including equilibrium, toroidal displacement, diffusion, confinement, and ideal and dissipative MHD stability. A general review of RFP experiments is presented including fast experiments, which utilize small-bore insulating tori in which the distribution is usually set up by fast programming on microsecond timescales; and slow experiments, carried out in large metal-walled tori in which the field configuration is set up slowly by self-reversal on millisecond timescales.

The book focuses on the properties of gaseous plasmas needed in the attainment of controlled fusion reactions. The first five chapters develop the fundamentals of plasma physics and present the conditions of nuclear fusion reactions. The next four provide a magnetohydrodynamic description of plasmas, followed by four chapters that explain wave phenomena and instabilities by means of a kinetic model. The three final chapters deal with the problems of heating, diagnostics, and confinement.

Global warming is the ongoing rise in the average temperature of Earth's climate system. Over the past 50 years, the average temperature has increased at the fastest rate in recorded history due to uncontrolled generation of greenhouse gases. Nuclear power is low carbon energy, and it is contributing on a large scale to a low carbon economy and a green energy grid. 442 nuclear power reactors are operating worldwide generating 393 GWe of electricity providing continuous and reliable low carbon power. Nuclear electricity accounts for 11% of total global electricity generation, and this amounts to a third of the low-carbon electricity produced in the world. New innovations are taking place which make nuclear power a more affordable and attractive energy option. These include advances in large reactors, emerging technologies such as advanced fuel and small modular reactors, engineering breakthroughs extending the operational lifetime of existing reactors, and new developments in materials and better waste management. Fast breeder reactor technology has become a commercial reality and it helps not only in generating electricity, but also in producing more fuel than it consumes, besides burning nuclear waste more efficiently compared to any of the existing commercial reactor technologies. The Sun's energy is generated by nuclear fusion. Mastering nuclear fusion technology can guarantee energy security in terms of clean, safe and affordable energy. Nuclear fusion, and plasma physics research of very complex nature are being carried out in many countries. Fusion reactions have been successfully demonstrated although for a fraction of a second and without demonstrating a net gain of electric power. The world's largest international fusion reactor facility called ITER is in an advanced stage of construction with the aim of demonstrating the scientific and technological success of fusion energy research for commercial production. Fusion fuel is plentiful and easily accessible. It is expected that fusion energy is the pathway towards energy security for thousands of years. Nuclear fission and fusion reactors do not emit greenhouse gases into the atmosphere and play a major role in mitigating climate change.

Deuteron-deuteron fusion, detected via the 3-MeV protons produced, is shown to occur when singly charged clusters of 25 to 1300 D<SUB>2</SUB>O molecules, accelerated to 200 to 325 keV, impinge on TiD targets. The energy and cluster-size dependence of the fusion rate are discussed. The fusion events are shown to originate from the cluster-ion impacts rather than from D<SUP>+</SUP> or D<SUB>2</SUB>O<SUP>+</SUP> ions in the beam. The observed rates may be correlated with the compressions and high energy densities created in collision spikes by cluster-ion impacts.

Radiation resistant camera system was constructed for monitoring deuterium plasma discharges in the Large Helical Device (LHD). This system has contributed to safe operation during two experimental campaigns without serious problems due to radiation (neutrons and gamma-rays). The cameras steadily functioned even in the plasma discharge with the maximum neutron emission rate in FY 2017, though some bright specks temporarily appeared on the images. The cameras have been installed in shield boxes which consist of lead boxes covered with 10% borated polyethylene blocks in all directions. For optimizing the design of the shield box, the radiation flux distribution was calculated by MCNP-6 code, which reveals the reduction of the radiation flux and the change of the energy spectra in the shield box. Thanks to the optimization, significant extension of the lifetime of the cameras has been realized. Investigation of the influence of the radiation on the CCD image sensor shows that the number of bright specks generally increases with the radiation flux to the camera, which also indicates that some bright specks disappear by the self-annealing process on the image sensor. This phenomenon also highly contributes to the further extension of the lifetime of the radiation resistant cameras.

Structural materials represent the key for containment of nuclear fuel and fission products as well as reliable and thermodynamically efficient production of electrical energy from nuclear reactors. Similarly, high-performance structural materials will be critical for the future success of proposed fusion energy reactors, which will subject the structures to unprecedented fluxes of high-energy neutrons along with intense thermomechanical stresses. Advanced materials can enable improved reactor performance via increased safety margins and design flexibility, in particular by providing increased strength, thermal creep resistance and superior corrosion and neutron radiation damage resistance. In many cases, a key strategy for designing high-performance radiation-resistant materials is based on the introduction of a high, uniform density of nanoscale particles that simultaneously provide good high temperature strength and neutron radiation damage resistance.