Creating our own sun
Earthlings currently facing global warming threat higher compared to previous years as the demand of energy increase. Fossil fuel is the main source of energy which cause carbon emission and lead to global warming. Nuclear energy is one of the alternative sources of electricity to replace carbon emission problem. When talking about nuclear energy, uranium and plutonium are the main elements that being used in all nuclear power plant today. This conventional nuclear reactor uses fission process which is highly risk due to unstable process and could cause a nuclear meltdown in the reactor. Looking back to the history, earthquake with the scale of 9.0 that hit Japan’s Fukushima Daiichi power plant plumes of radiation over a placid landscape and into the sea. Chernobyl nuclear disaster shows that the area won’t be safe for human habitation for at least 20,000 years. We all know at least some of the problems it creates some of the most persistent and dangerous pollutants and waste. The materials used can be repurposed for some of the most appalling weapons the world has ever made and if anything goes wrong, the consequences can be so immense.
Somehow, there is another type of nuclear energy that is lot safer and produce less harmful waste called fusion. Fusion is the process by which a gas is heated up and separated into its ions and electrons. When the ions get hot enough, they can overcome their mutual repulsion and collide, fusing together. When this happens, they release a lot of energy, about one million times more powerful than a chemical reaction and 3–4 times more powerful than a fission reaction. Our sun uses nuclear fusion to generate energy which fuse light atoms together, such as hydrogen at extremely hot temperature. The basic fuels use deuterium and lithium that produce helium which are not radioactive. In open space, this electron only capable in travel a few millimetres and cannot even penetrate a piece of paper (less radiation). The main advantage in terms of safety is that if you pull the plug on fusion, it stops. Pull the plug on fission and it just keeps on fissioning. Another big bonus is that the radioactive elements at play in a fusion reaction decay over a matter of years rather than centuries or millennia as the do in a fission reaction. Several safety studies show that a fusion reactor could be designed in such a way to ensure that any incident would not require the evacuation of the local population.
Why we never have a nuclear fusion power plant yet? The answer to that is because the difficult process to replicate this process on earth. Gases need to be heated to extremely high temperatures about 100 millions degrees C (same condition on the sun surface) whereby atoms become completely ionised. To reach these temperatures there must first be powerful heating, and thermal losses must be minimised by keeping the hot fuel particles away from the walls of the container. This is achieved by creating a magnetic “cage” made by strong magnetic fields, which prevent the particles from escaping The fusion reaction that is easiest to accomplish is the reaction between two hydrogen isotopes. Deuterium can be extracted from sea water and tritium produced during fusion reaction through contact with lithium. When deuterium and tritium nuclei fuse, they form a helium nucleus, a neutron and a lot of energy. The heat energy created using the fusion reactor will drive turbine generators by replacing the combustion chambers with simple heat exchangers. In turn, the turbines will then generate electricity or the propulsive power for a number of applications. Imagine a source of electrical power that uses water for fuel, produces byproducts that are totally safe and releases no air pollution at all.
Scientists are becoming increasingly excited about the prospects that within the foreseeable future a reactor can replicate the sun’s energy source on earth. In October 2014, an American global aerospace and advanced technology company called Lockheed Martin announced that they will attempt to develop a compact fusion reactor in a decade. This reactor will fit “on the back of a truck” and capable of producing 100 MW output which is enough to power a town of 80,000 people. On the other hand, German researcher already started building their nuclear fusion reactor earlier which in 1993 and finished in 2014. It took almost 19 years of the period to complete due to the complexity of the reactor and currently waiting for government approval to start testing the reactor.
Science may only be a few years away from showing that fusion can work. This is the break-even point, where we able to create unlimited energy for the usage of mankind. It will then be a number of years before a functioning fusion reactor is developed. But scientists are optimistic that controlled fusion power will be achieved. The rewards are great, an unlimited source of nonpolluting energy. More precisely it is hope that once a sustainable fusion reactor is invented, it will repay the investment many times over. So the question is will fusion energy will tackle the only dependent fossil fuel once and for all?