Nuclear fusion occurs when two or more atoms are fused into one larger one. This process generates a massive amount of energy as heat because the two particles that are being forced together actually repel one another by nature.
According to the Department of Energy, nuclear energy is a zero-emission energy source, but with fission it does produce radioactive waste that must be stored safely and carries safety risks—i.e. nuclear meltdowns like at the Fukushima and Chernobyl reactors.
Whereas fusion fuses two or more atoms together, fission does the opposite. Nuclear fission splits a larger atom into two or more smaller ones, the heat from which is also used to generate energy.
Nuclear fusion promises a virtually limitless form of energy that, unlike fossil fuels, emits zero greenhouse gases. Additionally, unlike nuclear fission power used today, it produces no long-life radioactive waste. Picture a world running on clean, carbon-free energy.
Nuclear fusion is humankind's attempt at copying the most powerful energy in our universe: the sun. The sun is a natural fusion factory, consisting of a giant burning ball of plasma that fuses several hundred tons of hydrogen into helium each second, providing a constant source of heat and energy. The man-made nuclear fusion process tries to replicate the same energy that powers the sun.
The source elements for nuclear fusion are mainly deuterium and tritium—two isotopes of hydrogen. Deuterium is abundant in both fresh and saltwater, and the deuterium from just 500 ml of water, with a little tritium, could power a house for a year, CNN reports. Tritium, on the other hand, is rarer and more difficult to obtain, although it can be made synthetically.
Nuclear fusion, on the other hand, doesn't carry the same safety risks as fission, and the materials used to power it have a much shorter half-life, CNN reports.
“Unlike coal, you only need a small amount of hydrogen, and it is the most abundant thing found in the universe,” Julio Friedmann, chief scientist at Carbon Direct and a former chief energy technologist at Lawrence Livermore, told CNN. “Hydrogen is found in water so the stuff that generates this energy is wildly unlimited and it is clean.”
By raising temperatures inside the tokamak to unfathomably high levels—plasma needs to reach at least 150 million degrees Celsius—the particles from the fuel are forced to fuse. At such a high temperature, the neutrons escape the positively charged plasma and hit a “blanket” lining the walls of the tokamak, transferring their kinetic energy as heat.
The greatest challenge of harnessing fusion energy is sustaining it long enough so that it can power electric grids and heating systems through power plants. The US breakthrough is important, but the energy generated is still far too small a scale than what's needed to run even a single power plant.
The heat produced from fusing two atoms can subsequently be used to warm water, create steam, and turn turbines to generate power.
A major breakthrough has happened at the National Ignition Facility at the Lawrence Livermore National Laboratory in California, where scientists have successfully produced a nuclear fusion reaction that resulted in a net energy gain, CNN reports. But what does that actually mean, and why is it so important?
Well, not only is this the first ever net energy gain, instead of just breaking even, but it signals something much bigger: hope. These results come after decades of scientists' quest to create what would be an infinite source of clean energy that could completely remove our dependence on fossil fuels and finally make a significant positive impact on the climate change crisis.
This is huge news for a planet that is increasingly plagued by the negative effects on the climate by fossil fuels, but it can be a bit intimidating to learn about. Click through to get a straightforward explanation of everything you need to know about this new form of nuclear energy that may be the world's biggest power source in the future.
Perfecting nuclear fusion could save humanity from the climate change crisis, which we did to ourselves by our excessive use of fossil fuels. Cleaning up our energy sources would hopefully alleviate the fatal floods, famine-inducing droughts, raging wildfires, deadly heat waves, and more disastrous effects of climate change, which increasingly put lives at risk.
Global energy usage—of which a reported 80% is derived from fossil fuels—has more than doubled since 1973, and with our world's population surpassing eight billion in 2022, it may actually triple by the end of the century. Nuclear fusion may be the saving grace that will free us from the chains of fossil fuels like coal, oil, and gas, which have dragged us into humanity's deepest existential crisis.
Sources: (Dummies) (CNN) (MIT Plasma Science and Fusion Center)
It may still take decades for scientists to master how to release energy from a fusion reaction slowly enough so that it can be transferred to the power grid as electricity. Some of us may not live to see fusion's ability to produce unlimited amounts of clean energy, and scientists are, of course, also racing against climate change.
It's hard to wrap your head around how much heat the tokamak must contain, but for reference: 150 million degrees Celsius is approximately 10 times hotter than the core of the sun. So how can that exist on earth? Fusion energy scientists and engineers have impressively overcome this hurdle already by designing giant magnets that create a strong magnetic field that keeps the heat bottled up. Any other material would easily melt.
In the UK and the ITER project in France, nuclear fusion scientists are working with tokamaks, which are huge donut-shaped machines outfitted with giant magnets. After a small amount of fuel is put into the tokamak, its magnets are turned on and the temperature inside is cranked unbelievably high to create plasma, often called the fourth state of matter. Plasma is a matter so hot that the electrons are ripped away from the atoms and form an ionized gas, like a soup that is electrically charged, according to the Plasma Science and Fusion Center.
“It's about what it takes to boil 10 kettles of water,” Jeremy Chittenden, co-director of the Centre for Inertial Fusion Studies at Imperial College in London told CNN of the net energy gain in the breakthrough experiment. “In order to turn that into a power station, we need to make a larger gain in energy—we need it to be substantially more.”
If we master nuclear fusion, there's no reason it couldn't power much of the world. A single gram of fuel as input can reportedly create the equivalent of eight tons of oil in fusion power—that's a yield of eight million to one!
Several fusion projects are in the works in the US, UK, and Europe. France is home to the International Thermonuclear Experimental Reactor (ITER) project, which has 35 countries collaborating on the most ambitious energy project yet. The main ITER members are China, the US, the European Union, Russia, India, Japan, and South Korea.
In May 2022, CNN reported that ITER's new tokamak will weigh 23,000 tons—which is equivalent to three Eiffel towers. It will consist of a million components that further differ into 10 million smaller parts, and will include some of the largest magnets ever created—some with diameters of up to 24 m (79 ft).
The first demonstration of nuclear fusion, the hydrogen bomb, was conducted by the military. The isotopes of the hydrogen fusion reaction were placed around a regular fission bomb whose explosion released the energy needed for the fusion process. Since the bomb was approximately 1,000 times as powerful as an ordinary atomic bomb, it made the general public less enthusiastic about nuclear fusion research.
Managing the political, ideological, and economic relationships of the member countries has been one of the biggest challenges of the ITER, particularly surrounding Russia, a case which only worsened with the invasion of Ukraine. Russia provides ITER much funding and even one of the big magnets for the new tokamak. ITER's head of communications, Laban Coblentz, explained, "ITER is really a child of the Cold War. It's a deliberate collaboration by countries that are ideologically unaligned who simply share a common goal for a better future.”
In the US, much of the nuclear fusion work is happening at the National Ignition Facility, where they're using a process called “thermonuclear inertial fusion.” Essentially, as CNN reports, scientists fire pellets containing hydrogen fuel into an array of 192 lasers, which creates a series of rapid, repeated explosions at the rate of 50 times per second.
In February 2022, UK scientists announced that they had generated and sustained a record 59 megajoules of fusion energy for five seconds in a tokamak, the highest sustained energy pulse ever. Though it was only enough energy to power a house for a day, and more energy went into the process than came out, it was historic because it proved that it was indeed possible to sustain nuclear fusion on earth.
The search for fusion energy began in the 1930s with various machines tested out over the decades, but it was the tokamak, created in the Soviet Union, that was first able to achieve the high temperatures and containment method required for the plasma in 1968. The tokamak quickly became the machine to replicate, and even its name is from the Russian language (it's a portmanteau for “toroidal magnetic confinement").
By using lasers, scientists can zap the hydrogen isotope mixture, providing the necessary energy for the fusion while bypassing the containment problem. That said, this process presents another problem when it comes to protecting the lasers themselves from the fusion reaction.
The European Union is reportedly covering 45% of ITER's construction costs, and the other member countries are estimated to be contributing a little over 9% each. The construction was initially estimated at US$6.4 billion, but has more than tripled since.
Though there's a long way to go before making nuclear fusion commercially available, this breakthrough was the first time scientists have been able to show that they can create more energy than they started with—an essential trait for a potential commercial energy source.
Experts must now figure out not only how to produce the energy on a larger scale, but also how to reduce the cost of nuclear fusion so that it makes sense to use it commercially. Every experiment costs a huge amount of time and money, and even a single day's delay at ITER, for example, reportedly costs over US$1 million.
Nuclear fusion for dummies: The energy breakthrough that could change everything
Everything you need to know about this potentially limitless source of clean energy
LIFESTYLE Science
A major breakthrough has happened at the National Ignition Facility at the Lawrence Livermore National Laboratory in California, where scientists have successfully produced a nuclear fusion reaction that resulted in a net energy gain, CNN reports. But what does that actually mean, and why is it so important?
Well, not only is this the first ever net energy gain, instead of just breaking even, but it signals something much bigger: hope. These results come after decades of scientists' quest to create what would be an infinite source of clean energy that could completely remove our dependence on fossil fuels and finally make a significant positive impact on the climate change crisis.
This is huge news for a planet that is increasingly plagued by the negative effects on the climate by fossil fuels, but it can be a bit intimidating to learn about. Click through to get a straightforward explanation of everything you need to know about this new form of nuclear energy that may be the world's biggest power source in the future.