In BriefNuclear fusion is the long sought “holy grail” of energy research. It could supply a nearly limitless source of energy—energy that is both clean and safe. Here's where we are and where we have to go.
Nuclear fusion is not a pipe dream. It’s a proven process that occurs naturally everyday in nature (just look up at the sky during the day, you’ll see a fusion reactor right there in the form of the Sun). It could mean an almost limitless supply of clean energy, and we’re nearly there.
Fusion power is the reaction by which nucleosynthesis transmutes (changes) atomic nuclei, normally hydrogen atoms, by smashing them together to form a new nucleus, which releases energy. This is made possible in fusing stars thanks to the high gravity. The same can be accomplished on Earth by using magnetic fields to constrict extremely high temperature plasma (really high temperature, like, millions of degrees).
Scientific communities have been honing the process for years and have actually accomplished real, clean fusion reactions…but only for abysmally short periods of time. In 2013, the EAST tokamak reactor gave a sustained fusion reaction of about 30 seconds, which is a huge step forward considering that reactions up to that point had been measured in mere milliseconds.
The following is everything that you need to know about nuclear fusion, its problems and perils, and how it could utterly transform our world.
WHY IS FUSION SO DIFFICULT?
Since the necessary temperatures that cause a sustainable reaction are so high, the material that’s used to contain the reaction would normally melt. The alternative, which is the generally accepted method of containing a fusion reaction, is to use magnetic fields to constrict the resulting plasma, thus keeping the plasma a fair distance away from the reactor’s internal walls – however, this presents problems in and of itself.
Euro-Fusion explains the process: “By setting up magnetic field lines toroidally around the interior of the tokamak, the ions and electrons in the plasma are forced to travel tightly around these field lines, preventing them from escaping the vessel. Extra fields help shape the plasma and hold it stable within the tokamak interior. The magnetic fields are generated by coils which surround the tokamak vessel.”
However, the technology used to create powerful magnetic fields is simply not yet advanced enough, although we are very close to accomplishing it.
WHY IS FUSION BETTER THAN FISSION?
In short, the process of nuclear fission is breaking atoms apart; the process of nuclear fusion is sticking atoms together.
Fission reactors, the ones typically found operating on power grids today, use uranium 235 bombarded by high speed neutrons, breaking apart the uranium atoms and releasing energy that’s then harnessed in the form of heat. The problem with this process is that the resulting fission products, the most notable of which are gamma emissions, are dangerous—they cause cancer in small amounts and can be outright lethal if a large enough dose is received.
In addition to the harmful radiation emitted from a fission reaction, the resulting nuclear waste remains radioactive, in practical terms, forever. Chernobyl Proper, for example, will not be habitable for about 20,000 years, although the Chernobyl exclusion zone might be habitable sometime within the next 200 years.
Fusion reactors, on the other hand, while they do produce radioactive waste, its radioactive half-life is far shorter lived, and is initially much less dangerous than fission by products by far. In fact, the primary byproducts of fusion are helium, neutrinos, and heat; helium is harmless in terms of you and me, as it is an inert gas; heat is captured and used as the motive device for powering steam generators; neutrino emissions are easily countered with shielding and under normal circumstances aren’t found in high enough concentration to irradiate the surrounding environment.
WHAT TYPE OF FUEL DOES A FUSION REACTOR USE?
The most commonly accepted types of fuel used to power a fusion reaction are deuterium, tritium, helium-3 or boron-11. These elements are used in comparatively small amounts, and deuterium can be extracted from plain seawater.
FUSING and Non-Fusing STARS
The Sun at the center of our solar system is so massive, and the elements inside it are crushed under so much pressure (caused by the Sun’s tremendous gravity well), that hydrogen atoms combine to create helium, releasing heat, light, and other types of radiation that both sustain and afflict Earth.
We will probably never have Sun-like fusion on Earth due to our inability to create the powerful artificial gravity wells required, but we can constrict and pressurize similar reactions, producing roughly the same result.
A neutron star is an example of a formerly fusing star that has burned all of its fuel and likely gone nova, leaving behind a collapsed kernel of degenerate matter.
While this type of star is far smaller in physical dimensions than its former self, the degenerate matter itself is extremely dense, weighing in at about 5000 tons per teaspoon.
WHY ARE WE SO INTERESTED IN CLEAN FUSION?
The environmental impact of fusion alone (or lack thereof) is more than enough to research and perfect this technology. Fusion has the potential to make inexpensive electricity far more readily available and ultimately cheaper to operate in terms of raw materials, waste disposal, and manpower.
Imagine a pocket fusion reactor transported on the back of a semi truck to remote areas and plugged into the local power grid. Think this can be done safely or quickly with a nuclear reactor? Nope.
Commercially, fusion power will be able to be operated more safely, with less waste emissions and material, more efficiently than current methods of producing power, at lower cost per megawatt and higher energy output.
OK, BUT HOW WILL FUSION ENERGY AFFECT ME?
Potentially, the only end result you and I might see is a change in our power bills, probably for the better – but keep in mind that, since fusion energy isn’t quite available yet, we really have no idea what the end cost is going to be. I personally suspect that we’ll initially see zero change in our power bills, but over time the regularly inflating cost of buying power will become steadier, more predictable and less severe.
Consider that fusion energy is not reliant upon fossil fuels, wind speeds or solar exposure as are the current methods of energy production; this means that the material required to operate a tokamak reactor are more dependable than our steadily decreasing supply of oil and coal. While the same can be said of fission reactors, the cost is higher, the safety is lower, and waste disposal is more problematic (as outlined above).
HOW WILL FUSION ENERGY EFFECT THE WORLD?
Commercially, big corporations would initially hold the monopoly on practical fusion power. After all, it’s the corporations that are mostly funding fusion research, even on the academic level, although the U.S. government isn’t entirely divested. But competition should keep costs down.
Fusion may spell the death of renewable energy sources such as wind, solar and kinetic tide power production.
Helium balloons to become more prolific? I hope so. Space travel will become cheaper and faster. A trip to Mars could take one month, instead of the current 6 months.
Future generations will actually have something for which to thank us.
Some notable and promising fusion projects:
Disclaimer: The views and opinions expressed are solely those of the author. They do not necessarily represent the views of Futurism or its affiliates.