Nuclear fusion has expanded dramatically in the past two years. Although scientists at Lawrence Livermore National Laboratory’s National Ignition Facility (NIF) in California achieved a breakeven in 2022 with a laser-powered fusion reaction, the method was extremely complicated. Fusion technology has a long way to go before it will be possible to create practical fusion reactors to produce electrical power.
How does nuclear fusion work, and how close is it to reality? Video used courtesy of TED
However, fusion developments continue, especially in three areas: technological challenges, increasing worldwide investment, and legal and regulatory concerns, including how governments will deal with the new technology and the justice and equity concerns it raises.
Concept of nuclear fusion. Image used courtesy of Thea Energy
Nuclear Fusion Technology
Unlike nuclear fission—splitting uranium or plutonium atoms to produce energy and the method currently used for commercial nuclear power—nuclear fusion creates energy by fusing hydrogen atoms to create helium atoms and a large amount of energy.
Scientists at Lawrence Livermore National Laboratory’s National Ignition Facility (NIF) in California achieved a breakeven in 2022 with a laser-powered fusion reaction. Using 192 ultraviolet laser beams to deliver 2.05 million joules (MJ) of energy to a deuterium-tritium fuel pellet resulted in a nuclear fusion reaction with an output of 3.15 MJ (about the energy contained in three sticks of dynamite)—more energy was produced than was used to start the reaction and breakeven for the first time in history.
However, the challenges of developing a commercially viable fusion reactor are immense. Nuclear fusion demands extremely high temperatures and pressures, with the hydrogen plasma needing to be heated to roughly six times the temperature of the sun’s core. Superconducting magnets generate powerful magnetic fields to contain the plasma long enough for fusion to occur. Although scientists have successfully achieved fusion on a very small scale, scaling up to a full-sized reactor presents significant difficulties for the materials scientists and engineers working on fusion projects worldwide.
The NIF has achieved breakeven five times. Image used courtesy of NIF
The plasma inside a fusion reactor must reach a temperature high enough to produce net power, but if it gets too hot, it could damage the vessel’s interior. Princeton Plasma Physics Laboratory researchers are investigating methods to dissipate excess heat, including liquid metal techniques. One approach is circulating liquid lithium through slats in the tiles lining the vessel’s bottom. This liquid metal could also shield the components exposed to the plasma from the intense bombardment of high-energy particles known as neutrons that form during the fusion reaction. The neutron interactions produced from the fusion reaction with liquid lithium metal can produce tritium, a hydrogen isotope used as a fuel (fusing with deuterium, a hydrogen isotope found in seawater) for the fusion reaction.
Containing Nuclear Plasma
Containing the plasma is a significant research area. The Wisconsin HTS Axisymmetric Mirror (WHAM) is a cutting-edge fusion research project developed through a collaboration between the University of Wisconsin-Madison, MIT, and Commonwealth Fusion Systems. WHAM uses high-temperature superconducting (HTS) magnets, specifically made from REBCO material, which can generate magnetic fields up to 17 Tesla. This sets a world record for magnetic field strength in magnetically confined plasmas and allows for better plasma confinement than previous magnetic mirror devices.
WHAM employs an axisymmetric linear configuration, unlike traditional magnetic confinement systems like tokamaks, which use a toroidal design. This design aims to stabilize magnetohydrodynamic modes and improve particle confinement through advanced techniques such as electron cyclotron heating and high-harmonic fast-wave heating. WHAM represents a modern take on the magnetic mirror fusion concept, leveraging high-temperature superconducting magnets and innovative heating techniques to improve plasma confinement and stability. Compared to traditional methods, the approach aims to provide a faster and potentially more cost-effective path to achieving practical fusion energy.
Plasma control room at WHAM. Image used courtesy of the University of Wisconsin
Flow-stabilized Z-pinch nuclear fusion confines plasma using the Z-pinch effect, where a powerful electric current generates a magnetic field that compresses a plasma filament. This method aims to achieve the conditions necessary for nuclear fusion by stabilizing the plasma through a technique known as sheared-flow stabilization. In a Z-pinch, electric currents create magnetic fields to compress the plasma, potentially reaching the high temperatures and pressures needed for fusion. Sheared-flow stabilization involves introducing a flow within the plasma that varies in velocity across its radius. The sheared flow helps stabilize the plasma against common instabilities that typically disrupt Z-pinch configurations, such as the sausage and kink modes. Z-pinch fusion does not require the large facilities, superconducting magnets, or high-powered lasers needed by other fusion methods, potentially making it a more compact and cost-effective approach to nuclear fusion.
Z-pinch experiment. Image used courtesy of Zap Energy
LLNL has made significant advancements in flow-stabilized Z-pinch fusion. LLNL researchers have confirmed that neutrons produced in a sheared-flow stabilized Z-pinch device result from thermonuclear reactions rather than being driven by other instabilities. This confirmation is crucial for validating Z-pinch’s potential as a viable fusion energy pathway. LLNL is working closely with Zap Energy, a company focused on commercializing Z-pinch fusion. This collaboration has improved the understanding of plasma pressure profiles and stability, which is critical for achieving sustained fusion reactions.
Investment in Fusion
According to the Fusion Industry Association, funding for nuclear fusion has seen significant growth in recent years. The investment in the fusion industry has exceeded $7.1 billion. In the past year alone, more than $900 million has been invested in the fusion industry.
Public investment in private fusion companies has risen significantly, increasing more than 50% in one year. Specifically, public funding grew from $271 million to $426 million. This rise in public investment reflects governments’ growing recognition of fusion technology potential and the importance of public-private partnerships in advancing fusion research.
The U.S. government has provided record funding for fusion energy, with $1.4 billion allocated for fusion research in the 2023 Appropriations bill, including $763 million for the Fusion Energy Sciences program and $630 million for Inertial Confinement Fusion research.
China has ambitious goals for nuclear fusion, aiming to build an industrial prototype fusion reactor by 2035 and achieve large-scale commercial production by 2050. China is investing significantly in nuclear fusion research and development, with an approximately $1.5 billion annual expenditure. This investment is nearly double the current budget for nuclear fusion in the United States, highlighting China’s commitment to advancing fusion technology.
Despite challenges in raising capital for deep-tech ventures, the additional funding underscores confidence in fusion technology’s potential to revolutionize the global energy landscape. The fusion industry remains optimistic about achieving commercial viability, with many companies expecting to provide electricity to the grid by the end of the 2030s. Financial support is crucial for overcoming technical challenges and accelerating fusion development to a viable energy source.
Nuclear Energy Justice and Regulation
Fusion energy is expected to be regulated differently than nuclear fission due to the fundamental differences between the two processes, particularly regarding safety and environmental impacts. The U.S. Nuclear Regulatory Commission has proposed a regulatory framework that focuses on a byproduct materials approach rather than the utilization facility framework used for fission.
The Fusion Energy Act and other legislative efforts, such as the ADVANCE Act, attempt to provide regulatory clarity and streamline commercial fusion power plant development. These acts aim to establish clear, risk- and performance-based licensing frameworks, which are essential for encouraging investment and innovation in the fusion sector.
The International Atomic Energy Agency (IAEA) promotes international cooperation and develops best practices for fusion energy regulation. This includes integrating lessons learned from fission energy and coordinating efforts across member states to address scientific and technological challenges.
As fusion energy becomes a reality, an opportunity exists to address energy equity and justice by ensuring that fusion power plants are placed in locations to provide clean energy access to diverse communities. Additionally, workforce development initiatives are crucial to training individuals with the necessary skills for the fusion industry and promoting diversity and inclusion. Equitable distribution of fusion energy will likely require international collaboration so that all regions benefit from this technology. The IAEA and other international bodies are expected to facilitate information and resource sharing to support global fusion energy deployment.
Achieving a Nuclear Future
Overall, regulating and distributing nuclear fusion energy will involve combining clear regulatory frameworks, international cooperation, and efforts to promote energy equity and justice. These measures are essential to ensure that fusion energy is developed and deployed to benefit all communities.
