Is Fusion Better Than Fission?
Introductory Primer on Fusion Energy
Jun 12, 2024
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Thesis: Fusion has been consistently touted as the ultimate energy solution. Yet, it hasn’t been proven to work positively for an extended period of time. Current plans don’t project fusion to achieve this goal for at least 25 years. Compared to fission and other technologies that currently work effectively, fusion doesn’t seem worth the investment.
If you haven’t read my Nuclear Energy Primer, I’d highly recommend it before reading this article as some of the terminology associated with this subject may be difficult to understand.
Credit TU Graz
Fusion
Fusion seems like the next “big” technology, but what really is it? Is it actually possible or is it just a scientific legend?
Let’s dive in!
What is fusion?
Fusion powers the Sun and other stars by converting hydrogen into helium through the proton-proton chain reaction and other fusion processes. On Earth, researchers are working to develop controlled fusion as a potential future energy source, although achieving sustained, commercially viable fusion energy has proven to be an immense scientific and engineering challenge.
Credit Tecnicas Reunidas
How does fusion work?
Fusion works the opposite of fission. In fission, the nucleus of a heavy atom (uranium, for instance) is split apart to become a lighter atom, releasing large amounts of energy as it splits. In contrast, fusion happens when two nuclei combine to form a heavier atom, releasing large amounts of energy as they bond.
Fusion is the process that powers and drives the production of energy in stars, for instance, the energy of our Sun. On the Sun, the immense gravity and high temperatures naturally make fusion exist. However, the Earth does not have the same characteristics.
To achieve fusion on Earth, gases need to be heated to around 150 million degrees Celsius. Researchers have figured out that the easiest elements to achieve a fusion are two hydrogen isotopes: deuterium–extracted from water, and tritium–produced from lithium. How do you heat something to 150 million degrees Celsius? Currently, no material exists that could contain plasmas of 150 million degrees. So, there are many ways scientists have tried to contain these reactions.
What types of fusion are there?
Fusion can be achieved in four ways currently: magnets, lasers, others (volts, accelerators, pistons), and through gravity.
Credit Department of Energy
Magnets: The leading approach to fusion is through the use of magnetic fields, called magnetic confinement fusion. In this process, the fuel becomes so hot that electrons break off and nuclei begin to fuse. Magnetic fields control the shape and direction of the plasma, ensuring the device’s walls are not damaged. There are many different devices used to produce fusion through magnets, such as tokamaks, stellarators, spheromaks, field-reversed configurations, mirror machines, and many more.
Credit Forbes
Lasers: The laser approach uses large-scale lasers to target tiny capsules of atoms, sparking large bursts of energy. The lasers strike the capsule from all angles, dramatically compressing the capsule into a state where fusion reactions occur. This process is known as inertial confinement fusion.
Volts, Accelerators, and Pistons: Scientists have used a variety of different engineering approaches to generate fusion reactions. Z pinches use a self-generated magnetic field created by an electrical current. Particle accelerators have been used to collide bundles of plasma. Pistons have been used to physically compress plasma into fusion conditions.
Gravity: Fusion happens with extreme amounts of gravity, but, these conditions aren’t available on Earth, so scientists have to resort to other methods.
Credit ITER
History of Fusion
The science and physics of fusion started becoming clear in the 1920s when Arthur Eddington theorized that stars draw their energy from the fusion of hydrogen into helium. Following this, Robert d’Escourt Atkinson and Fritz Houtermans calculated the rate of nuclear fusion in stars. Then, in 1934, Ernest Rutherford showed the fusion of deuterium into helium and the large amount of energy produced. Soon after, fusion was first demonstrated in a lab.
In the 1950s, Soviet scientists Andrei Sakharov and Igor Tamm proposed the Tokamak design. Around that time, Lyman Spitzer developed the concept of the stellarator, but the tokamak was found as a more efficient concept.
In 1973, European countries began working on the Joint European Torus (JET). The JET would become the largest operational magnetic confinement experiment when completed in 1983. It produced the first plasmas.
In 1997, JET set a world record for fusion output using tritium, deuterium, and 24 MW of heating to produce 16 MW (only for about a second). This wasn’t breakeven yet, as more input was required than output produced. Since, then, numerous developments in fusion technology have occurred all around the globe.
In 2022, physicists at the National Ignition Facility in California extracted more energy from a fusion reaction than was required to trigger it. This achievement was completed using inertial confinement–where you shoot a bunch of lasers at a small target and make it explode, triggering a brief, but powerful fusion reaction. At the time, it was a global first and a huge step for fusion.
Credit ITER
Current Developments in Fusion
The most major current development in fusion technology is the ITER project. The International Thermonuclear Experimental Reactor (ITER) is an international nuclear fusion research project spearheaded by a large conglomerate of countries, including China, the European Union, India, Japan, South Korea, Russia, and the United States.
Completion is estimated around late 2025. If completed, it will be the world’s largest magnetic confinement plasma physics experiment and the largest tokamak reactor (by a factor of 10).
Put simply, the mission of the ITER project is to demonstrate the technological abilities of a large fusion reactor–however, without demonstrating significant long-term electricity generation. The goal is to produce 10 times as much output power than input power–in a short period of time.
Construction of ITER began in 2013 in France and assembly began in 2020. But, it hasn’t exactly been smooth sailing. The initial budget was estimated at around $6B, but current estimates are projecting final costs of $20B+ (some estimates–from the United States Department of Energy–are as large as $65B).
Wikipedia states:
It’s only getting more and more expensive, especially as roadblocks continue to be hit and deadlines continue to get pushed back. The ITER project formally began in 2006, with an estimated completion date of 2016.
A detailed chart of the timeline is available below from Scientific American:
As you can see, the ITER plant exhibits similar characteristics to the recently completed fission Vogtle plant where the timeline is constantly being pushed back and costs continue to increase over time.
Moving beyond the ITER plant, the next plant planned is the DEMO plant or demonstration power plant. These reactors are intended to demonstrate extended net production of electricity. Most of the ITER partner countries have plans for their own DEMO-class reactors, intended to build on the knowledge gained from the ITER experiment.
However, these DEMO-class plants are not coming anytime soon. It’s estimated that the European Union DEMO plant, the farthest along plant, is continuing to be designed today. The plan is for the design to be completed before 2030, engineering to be completed by 2040, and construction hopefully completed by 2050.
Given that timetable, it’s time to pose the question again.
Is Fusion a Viable Solution?
The ultimate goal of this piece is to compare fission to fusion. But, that’s more difficult than it may seem. It’s not just comparing solar energy to wind energy. It’s like comparing flying cars to the new cybertruck.
Wow, that’s one of the more niche analogies I’ve cooked up, so let me explain it so I don’t sound like a lunatic.
Let’s start with the easy side of the equation, fission.
Fission, known practically as nuclear energy, is like the new cybertruck. It works as a vehicle, but it’s not practical and is hated by most. It’s ugly, full of extremely complex technology, and overall, considered to be a poor solution to an already solved problem.
Fusion, in this scenario, is like flying cars. The technology works in theory, but it’s super niche and has not made its way through to the public view. Many countries have experimented with it, as the technology is extremely exciting from the public’s point of view.
Why isn’t fusion a viable solution yet?
It’s not through the lack of trying. Fusion research has been carried out in more than 50 countries. Many successful experiments have been completed, but only a small few with net energy gain.
But, this gain isn’t sustainable yet.
What will it take to get there?
Since the 1950s, it’s been estimated that the United States has spent an estimated $20B on fusion research.
Furthermore, that isn’t just the government spending money to develop fusion reactors. Across the globe, it’s estimated that more than 30 companies are competing to be the first to complete a fusion reactor.
If there are so many different entities investing time, resources, and money into developing a sustainable fusion reactor, how long will it take?
An article by Scientific American in 2023 states the following:
Like fission, fusion has always been 30 years away.
In reality, progress is being made constantly. Melanie Windridge, the United Kingdom Director of the Fusion Industry Association, states the following:
Despite these advancements, there are still many who believe fusion won’t be here for at least 30 years. For instance, consider this quote from Ian Chapman, CEO of the United Kingdom Atomic Energy Authority:
Why, what more still needs to happen?
Suppressing and managing fluctuations in plasma in fusion reactors is of key importance. Mastering this allows for further sustained reactions.
In addition, it’s unclear if the materials of the magnetic-confinement chamber can withstand the treatment from the plasma reactions. Material degradation and potential lifetime will be unclear until the first plant is in operation for a longer period of time.
Furthermore, it’s difficult to make the fuel possible for fusion. Deuterium is abundant–available in large oceans. However, tritium is much harder to find as it has a half-life of 12 years, so it’s always disappearing. Many reactors nowadays have been made to incorporate a breeding process to synthetically produce this tritium, but the technology is unproved at a large scale.
Will fusion be a viable future solution?
I think the quote from the inventor of the tokamak design, Russian Lev Artsimovich, says it all:
Has society needed it? Potentially yes, but fusion hasn’t been ready. And, it seems like if society needs it in the next 25 years, fusion will not be ready.
Ultimately, is it worth spending more time, resources, and money on fusion technology for potentially no results when we can spend that on technology that already works like renewables or fission?
That’s for you to decide.
Anywho, that’s all for today.
-Drew Jackson
Disclaimer:
The views expressed in this blog are my own and do not represent the views of any companies I currently work for or have previously worked for. This blog does not contain financial advice - it is for informational and educational purposes only. Investing contains risks and readers should conduct their own due diligence and/or consult a financial advisor before making any investment decisions. This blog has not been sponsored or endorsed by any companies mentioned.