Nuclear Fusion And Why It Matters
Nuclear fusion is going to matter to the world more than ever. This has to do with the potential of providing a clean, abundant, and virtually limitless source of energy.
This is beneficial for meeting the world’s growing demands for energy, as an alternative to fossil fuels. This can help to drive sustainable energy production which has less harm to the environment since it is cleaner but also more dense to provide an abundance of energy.
What Is Nuclear Fusion?
The energy created in a fusion reaction is different from a fission reaction that is used in conventional nuclear power plants. In contrast to nuclear fission, which involves splitting heavy atomic nuclei, nuclear fusion is a process in which two light atomic nuclei combine to form a heavier nucleus.
During this process a large amount of energy is released. This is the same process that takes place in the core of the sun and other stars to produce energy.
The key elements involved in nuclear fusion on Earth comes from water (H₂O). These are from isotopes of hydrogen (H), such as deuterium (²H) and tritium (³H).
The isotopes naturally repel each other, the same way as like charges in magnets. When these isotopes are heated to extremely high temperatures and pressure, they can overcome their natural repulsion and fuse together. They then release energy in the form of heat and light.
The fusion reaction can be written in the following form:
Deuterium + Tritium → Helium + Neutron + Energy
The byproduct of fusion is helium. It is a non-radioactive stable inert gas, which is not harmful to the environment. This also leads to the release of a significant amount of energy that researchers hope can be harnessed for utilization scaled for consumption.
The Advantages
Here are the advantages of nuclear fusion:
- Abundant Fuel Supply: Deuterium can be extracted from water, and tritium can be produced from lithium, which are abundant. This makes fusion fuel sources widely available.
- Cleaner Energy: Unlike fossil fuels, nuclear fusion doesn’t produce greenhouse gases or long-lived radioactive waste in large quantities. The primary byproduct is helium.
- Safety: Fusion reactions are not chain reactions like those in fission, so the risk of a runaway reaction or meltdown is significantly reduced.
- Higher Energy Density: Fusion has the potential to generate large amounts of energy with relatively small fuel quantities compared to traditional energy sources.
We can see the benefits of harnessing this energy as a power source. There are challenges though that need to be addressed.
The Challenges
The problem in modern times (as of 2023) is that no standard procedure has been established to mass produce fusion energy at scale. Fusing atoms to produce energy is a difficult process that offers scientists and engineers many challenges.
Here is a summary of challenges that need to be addressed:
Sustaining Ignition: Ignition is the point at which the energy produced by a fusion reaction surpasses the energy input required to initiate and sustain the reaction. Maintaining the conditions necessary for ignition is a significant challenge, as the plasma must be heated to extremely high temperatures and confined for a sufficient period.
Plasma Confinement: The fuel for fusion reactions is typically a hot, ionized gas known as plasma. Plasma needs to reach at least 150 million degrees Celsius. Containing and stabilizing this plasma within a magnetic or inertial confinement system is challenging, as it tends to interact with magnetic fields and generate turbulence, leading to energy losses.
Strength And Durability Of Materials: The extreme conditions inside a fusion reactor, including high temperatures and radiation, can cause damage to the reactor’s structural materials. Developing materials that can withstand these harsh conditions over extended periods is a critical challenge.
Economic Viability: It can be very expensive to build and maintain fusion reactors. This requires substantial initial costs in construction and operation. Achieving a net positive energy output (more energy produced than invested) is crucial for the economic viability of fusion power. Current experiments are not yet at the point of producing energy at a level suitable for practical power generation.
Fuel Production Process: Tritium, one of the fuel isotopes used in fusion reactions, is not naturally available and has a short half-life. Developing efficient methods for tritium production and managing its supply sustainably are important.
Complexity of Fusion Devices: Fusion reactors are complex systems that require precise control and management of plasma parameters, magnetic fields, and other factors. Designing and building these intricate devices to operate reliably and safely is a significant challenge.
Technological Innovations: Advances in technology, such as the development of high-powered superconducting magnets and efficient heating methods, are crucial for improving the performance and efficiency of fusion reactors.
Scaling-up : Demonstrating successful fusion at a small scale is not sufficient for practical energy production. Scaling up fusion reactors to larger, more powerful systems poses additional engineering and logistical challenges.
Regulatory and Public Acceptance: As with any new technology, regulatory frameworks need to be established to ensure the safety and environmental impact of fusion power. Additionally, gaining public acceptance and addressing concerns related to fusion energy are essential. Efforts are needed to provide the public with more education about the topic.
International Collaboration: Fusion research often involves collaboration between multiple countries and organizations. Coordinating international efforts, sharing resources, and addressing political and economic considerations are ongoing challenges. If wars and economic conflicts get in the way, it can stunt further developments in knowledge sharing that can speed up progress.
Research Funding: Like any other venture, new technology requires funding. Investors will put money into a project if there are expected high yields on their ROI (Return On Investment). Fusion research development will require that, but unfortunately if the high costs do not produce any significant results the investments can dry up and hinder progress. Fortunately, other sources of funding can come from foundations, government and organizations that share an interest.
While significant progress has been made in recent years, overcoming these challenges will require sustained research, development, and collaboration on a global scale. The ITER project aim to address many of these challenges and demonstrate the feasibility of controlled nuclear fusion for practical energy production.
According to some reports, we are still years away (circa 2023) from a working fusion reaction power plant if one can actually be possible. There are only estimates, but no exact date can be given. It will also require funding over time, so investment in this field requires a heavy inflow of capital.
The Power Of Fusion Reactions
Let us take a brief look at the amount of power nuclear fusion reactions are capable of compared to conventional nuclear energy. The energy released in nuclear reactions is measured in terms of energy per reaction or energy per unit mass.
Fusion reactions involve combining light nuclei. Fission reactions involve splitting of the heavy nuclei of an atom. Both types of reactions then release energy due to the conversion of mass into energy.
In the nuclear fission used by conventional nuclear power plants, the nucleus of a heavy atom, such as uranium-235 or plutonium-239, splits into two or more smaller nuclei, along with the release of energy. The energy released in fission reactions is in the order of millions of electron volts (MeV) per reaction.
In fusion reactions, larger amounts of energy are released compared to fission reactions. The energy released per reaction is in the order of millions to billions of electron volts (MeV to GeV) per reaction.
In terms of power generation, fusion reactions have the potential to produce much more energy than fission reactions for the same amount of fuel. Overall, that means that fusion reactors will require much less fuel over time to generate power.
Lawrence Livermore Fusion Experiment
There has been a breakthrough in the field of nuclear fusion research. Scientists and researchers at the National Ignition Facility (NIF), part of the Lawrence Livermore National Laboratory in California, achieved a significant milestone in nuclear fusion on December 5, 2022.
Using an array of lasers, they fired 2.05 Megajoules (MJ) of energy at a small pellet containing frozen deuterium and tritium. The resulting fusion reaction released 3.15 MJ of energy, surpassing the energy input for the first time. It was brief though, lasting for only a billionth of a second.
This demonstrates that the reactor can achieve ignition, a state sustaining a fusion reaction. Since it lasted for only a short amount of time, it doesn’t make fusion a viable power source yet. It does mark a major step forward in harnessing fusion energy.
The takeaway here is that it still required more energy to produce the energy for the laser input. That is of course, not cost effective or efficient for operations. 3.15 MJ is also nothing unless it can be sustained for long periods of time.
The lasers used required a total of 300 MJ of energy, emphasizing that this is a foundational achievement rather than the discovery of a killer app. The net total energy output was still less than the net total energy input used in the experiment. However it was a net positive, rather than net zero or breakeven when comparing the test’s input energy to the output energy (not taking into account the net total energy).
It is not yet there at this stage, because you are actually consuming more energy than you are producing. It could still be considered a milestone reached since it offered new insights into the conditions needed for sustained fusion reactions.
In a more recent experiment, the Lawrence Livermore National Laboratory made a successful repeat of the breakthrough in August 2023. As of this writing, the data was being analyzed. With the data gathered and sharing of information, researchers can begin to explore new ways to sustain ignitions.
It is not an easy feat to replicate the energy production that naturally occurs in the sun’s core. The hope is that there will be a way to make this work properly, for the benefit of not just science but also industry and therefore society.
Is Fusion Energy Renewable?
This is the question that will be asked. Nuclear fusion is often considered a sustainable and clean energy form, but it may not fit the conventional definition of renewable energy.
Renewable sources can be sustainable and replenished easily, without further processing. Examples are sources that occur naturally that include sunlight, wind, tides, waves, geothermal heat, water flow, and biomass.
Fusion energy is replenishable from abundanance of supply (i.e. water and lithium), but it cannot renew itself. Compare that to sunlight and wind, which are produced and replenished by nature.
While the inputs like deuterium and tritium may be abundant in nature, they are not readily usable unless they undergo an extraction procedure. They also cannot be renewed naturally after being used. Producers will need to process more of these inputs to sustain energy production in other places.
There will be debates regarding the definition. The distinction often lies in the specifics on whether sources are self-sustaining or still require an artificial process.
The Future Of Energy
If energy can be produced at scale with fusion, then the energy markets would have less need for fossil fuels. This can transform the entire energy market around the world, which is why it will be a holy grail of energy production if it can be achieved.
It can also enable new use case of applications ranging from electric vehicle charging, intelligent infrastructure, deep space exploration, clean power generation, grid stability and new industries that revolve around fusion energy.
The changing geo-political atmosphere would also favor fusion energy production. The control of fossil fuel production by a few producers can be problematic to prices due to demand.
With more energy produced, price of electricity can go down. This makes clean and cheaper energy available, which can also have the effect of lowering prices in other industries.
With the entry of fusion energy, a shift away from fossil fuels is going to have an impact on the world. It can help address the concerns regarding climate change. At this point it is not yet known, until we see an operating fusion reactor at scale.
The future powered by nuclear fusion would be transformative in the decarbonization of the global economy by providing clean and sustainable energy. This herculean task is like an impossible dream, but fusion researchers worldwide continue to work on making fusion a practical energy solution.
Note: As fusion reaction research develops updates will be added to this story.
