In this blog, I talk about Hydrogen Fusion, a nuclear reaction that releases incredible amounts of energy. Should we develop the technology to harness this process, we would have access to untold amounts of cheap power, a shift that would profoundly affect our day-to-day lives.
How much do you know about stars? I’d hope that you at least know that they’re very bright and very hot. In short, they give of an unfathomable amount of energy. But where do stars get all of this energy from?
Stars, like us, come from humble beginnings. As you may know if you’ve read my blogs, there is a lot of gas and dust just floating out in space. If there’s enough matter in a certain area, the gas and dust will slowly begin to clump together. Over a large amount of time, this clump will grow, becoming hotter and hotter as it is smushed under the force of its own gravity. Once the clump gets hot enough, something amazing happens. Some of the hydrogen that the clump is made of gets enough kinetic energy (heat) to fuse with other hydrogen atoms.
This process, known as hydrogen fusion, releases incredible amounts of energy, and, when it happens, a star is born. Imagine if we could somehow harness this process that powers stars to power Earth. These days, many people are trying to do just that.
Obviously, if it takes the weight of an entire star to initiate a fusion reaction, it can’t be an easy thing to recreate here on Earth, even on the small scale. The sheer amount of energy required and released by fusion creates all sorts of practical problems, one of the foremost among them being containment. What kind of material could possibly hope to house a fusion reaction without melting or bursting under pressure? Luckily, Earth’s incredibly innovative engineers have found a solution to this problem. The answer, it seems, is no material at all. Instead, the super-heated plasma that the fusion reaction takes place in is controlled by employing an extremely strong magnetic field.
So have any of these types of fusion reactors been built? Yes. There are two in the UK (JET and MAST), and, surprisingly, one right here in the US, at Princeton (TFTR).
However, these reactors are strictly being used for research at the moment, as they are not yet energy positive. This means that they require more energy than they give off, so trying to power anything with them would be a waste. But there are very promising reactors on the way.
Back in 1985, Russia proposed an international fusion reactor venture with the US, Europe, and Japan. In a rare showing of cooperation, these nations finished plans on the International Thermonuclear Experimental Reactor (ITER) in 1990, and, in 1996, these plans were approved. Unfortunately, the US abandoned the project around this time, vastly reducing the program’s funding. But, in 2003, the US returned, along with other nations. China, India, Japan, Russia, South Korea, the US, and the EU finalized a financial agreement in 2006, and, as of 2013, construction is underway in Cadarache, France. Everything is expected to be ready to go around 2020. Currently, this reactor seems to be our best chance for energy-positive fusion, and it’s refreshing to see the project getting the funding it needs.
If ITER or another reactor ends up working out, it’ll be an absolute game-changer for humanity. The fuels for fusion, hydrogen isotopes, are abundant throughout nature, and, as is often the case with energy that employs nuclear reactions, the amount required is insignificant in proportion to power output. Fusion is also very green. No greenhouse gases are emitted by the process, and the radioactive waste produced decays much faster than waste from nuclear fission, the process used by traditional reactors to generate power. This technology seems almost too good to be true. Granted, it’ll be a long time before these reactors are commercialized and in use, if they’re successful at all, but, just like LFTRs, the tremendous upside of fusion and the amount of international effort that’s going into harnessing its power should at least earn it a spot in any “energy of the future” discussion. With any luck, we’ll see if fusion is all talk or not in the 2020’s. Be very, very excited.
Sources:
http://www.world-nuclear.org/info/Current-and-Future-Generation/Nuclear-Fusion-Power/
http://www.windows2universe.org/sun/Solar_interior/Nuclear_Reactions/Fusion/Fusion_in_stars/H_fusion.html
http://science.howstuffworks.com/fusion-reactor.htm