Can you imagine a practically inexhaustible source of energy, requiring very little fuel, and capable of generating millions of times more energy per unit mass than old, polluting fuels like coal? It’s called nuclear fusion power – it delivers promising efficiency results and, more importantly, with virtually no waste.
A few months ago, the American anthropologist and ecologist Michael Shellenberg, co-founder of the Breakthrough Institute and founder of Environmental Progress , described nuclear energy in an interview with Very Interesting as the “true environmental dream” . Like him, other professionals versed in the field place their hopes on fusion as a safe and inexhaustible source of energy, with vast advantages over fission, which entails a series of waste management problems that fusion would not make it necessary to contemplate.
According to the supervisor of nuclear power plants, telecommunications engineer and disseminator Alfredo García, better known as Nuclear Operator: “Fusion could be the solution to all our energy problems. We would have an almost inexhaustible source of energy, with practically harmless waste ”.
So why aren’t we all already enjoying almost unlimited energy thanks to a nuclear fusion reactor? Manufacturing it is not easy. Although scientists know how to carry out fusion, very strong materials are required, capable of withstanding thousands of degrees and extreme pressure and radiation. But especially, financing is required.
Humanity is already committed to several projects at the international level to achieve a commercial fusion reactor to provide clean energy to all of humanity; however, the horizon is still distant and fraught with challenges.
What is fusion and how is it different from fission? When will we be able to have energy by fusion? Is this energy source a candidate to mitigate climate change?
Next, we will answer this and other questions about nuclear fusion energy.
Which is nuclear fusion?
Above our heads, on an 11-year journey by plane, we already have a fusion reactor that is billions of years old: the Sun. Nuclear fusion energy is found naturally in stars as the primary engine of the operation of the universe. Fusion is the source of energy for stars and hydrogen, the most abundant element in the universe, is its source of energy.
The fusion that occurs in stars, as its name suggests, consists of the union of two hydrogen atoms (H) to generate a single heavier nucleus, helium (H2). The resulting energy is emitted in the form of radiation outside the star, and it is what we perceive from the Earth as light and heat.
But inside the Sun, temperatures reach 15 million degrees. In addition, the conditions of gravity create the ideal environment for fusion to occur, also called thermonuclear energy.
What advantages does fusion have over other energy sources?
Before drawing conclusions, we should know how a fusion reactor would work a priori.
Fusion reactions require a fundamental element, as occurs in the Sun: hydrogen; specifically, its isotopes, deuterium (D) and tritium (T). In order for the nuclei to fuse, we must achieve extremely high temperatures, almost recreating the conditions inside the stars, through kinetic energy.
Nuclear fusion fuels
Deuterium
To obtain both deuterium and tritium we need water. As stated in the virtual encyclopedia energy-nuclear.net, in sea water, there is a concentration of 34 grams of deuterium per cubic meter of water. This means that the energy that can be obtained from the deuterium of one liter of seawater is equivalent to the energy that can be obtained from 250 liters of oil. Taking into account that the planet Earth is covered with liquid water in three quarters of its surface, from this point of view, fusion can be considered an energy source, a priori, inexhaustible.
Tritium and lithium
For its part, although tritium is less abundant in nature, it can be obtained from lithium , which is found both in seawater and in the earth’s crust. Lithium is a mineral that is also used to make batteries for energy storage. The nuclear engineer and president of Jóvenes Nucleares Pablo García García considers that the amount of lithium required for this purpose is “a few grams”, which would not compromise the planetary reserves of lithium, which many call ‘the new gold ‘.
But how do you create the ideal temperature and pressure conditions for fusion to take place? Inside the reactor, it would be necessary to confine the atoms in the plasma state (understanding plasma as the state of aggregation of matter, similar to the gaseous state) with a sufficiently high temperature and density and for a specific period of time.
Conventional confinements are not viable in fusion; therefore, there are two confinement methods applied to nuclear fusion energy.
– Nuclear energy of fusion by magnetic confinement : it traps the atoms in a very small space to which they are attracted thanks to the action of a magnetic field.
– Nuclear energy of fusion by inertial confinement : achieves a very high plasma density and temperature through the impact of a laser beam.
What nuclear fusion projects are underway?
As we can imagine, making a human-like Sun-like reactor on an Earth scale is hard work.
At present, nuclear fusion is not feasible, for now. But there are several research projects trying to create this long-awaited artificial ‘Sun’ in miniature, investigating how to carry out both types of confinement. Thanks to international cooperation, it is expected that soon some of these projects will be able to manufacture a nuclear fusion reactor with commercial uses, to provide energy to civilization.
Regarding inertial confinement, the most important research projects that exist are the NIS, in the United States; and the LMJ, in France. In both, private financing has a much greater role than in the following that we are going to mention.
On magnetic confinement, the most relevant research project that exists is ITER ( International Thermonuclear Experimental Reactor , or International Thermonuclear Experimental Reactor), of international cooperation, and mainly public funding. The European Union, Japan, Korea, India, China, the United States and Russia are involved in different subprojects, all of them aimed at manufacturing the first commercial fusion reactor, whose base is installed in France.
So when do you need a nuclear fusion reactor? The most optimistic place the border, still, in the middle of the century.
Future perspectives
The prospect of an inexhaustible and renewable source of energy is a hopeful promise, considering the pessimistic projections that experts make about the sustainability of our current energy model.
The IPCC, the world’s leading scientific authority on issues related to climate change, has been warning for years of dire consequences for the planet and its inhabitants of the increase in global temperature. Fossil fuels are an unsustainable energy source, which makes it necessary for them to be progressively replaced by renewable energies.
Is nuclear fusion power on this candidate list? Unfortunately, everything indicates that it is not.
As the engineer Pablo García acknowledges: “We are far from having nuclear fusion energy available. For the problem of climate change, we have to have the solutions that are available to us now, or within 10 to 15 years. And the merger is not going to arrive in time ”.
But, for Pablo, the main obstacle is financing: “International cooperation projects such as ITER, which is one of the most important efforts of humanity, only have 15 billion euros of financing . It may seem like a lot, but it is very little for the dimensions of the initiative. “
Beyond all this: although nuclear fusion energy is not available to form part of the measures for adaptation and mitigation of climate change , it is relevant for its economic and knowledge return: “All the physics and knowledge that we are going to generate has an economic return that must be taken into account “, explains the nuclear engineer Pablo García, who also qualifies what the advent of fusion would mean as a human technological milestone: ” When we achieve fusion, it will be a leap equivalent to that of place the first man on the Moon ”.
Despite the fact that no scientific institution has nuclear fusion energy as part of the mitigation of climate change; other nuclear experts do consider that fission (more problematic due to waste management) is already part of the solution.
As García details again: “In Spain, 20% of the energy produced comes from nuclear fission. If we shut down all nuclear power plants today, that 20% would be ‘filled’ with gas, a polluting energy source ”.
It is a fact. The current energy model is no longer sustainable. For this reason, human effort must be directed to reducing the use of fossil fuels as much as possible, which must be replaced, mainly, by renewable energies; And, for many experts, nuclear power also has to be in the picture. We count on our ingenuity and cooperation to provide us with the long-term solutions that humanity requires; and the merger, predictably, will end up being one of them.
This article has been prepared with the help of Pablo García García, nuclear engineer and president of Jóvenes Nucleares.
