Nuclear Fusion: The Power of Tomorrow

Salvador, Mikko Chino R.

2013-70157

STS Individual Project

Nuclear fusion is considered by many as the front-runner in being the source of energy of the future. This type of nuclear reaction is not yet used in today’s generation of nuclear power. This is because of the conditions required in nuclear fusion. In a fusion reaction, the atoms basically need to be close enough so that their residual nuclear force would fuse them together. Because of that, it requires a very high temperature of about one hundred million Kelvin; this gives the atoms enough energy to overcome the electrical repulsion between the protons. It also requires a very high pressure in order to squeeze the atoms together because they must be within 1x10^-15 meters of each other to fuse. (Freudenrich, 2005, p. 3) 

Fusion power is currently being researched upon by scientists and currently has two proposed ways that can be used to use nuclear fusion as an energy source. The first one is “magnetic confinement”, which will be used in the ITER (International Thermonuclear Experimental Reactor) project in France. This uses super-conducting magnets to squeeze the “plasma”, thus allowing fusion to occur. The “plasma” is formed by heating a stream of hydrogen gas through the use of microwaves, electricity and neutral particle beams from accelerators. Since the “plasma” is charged, magnets could repel it. Super-conducting magnets are used to compress it. The magnet forces the “plasma” inwards and creates a huge amount of pressure. This makes it possible for fusion reaction to occur since the two requirements for fusion, extremely high temperature and pressure, are satisfied. The most efficient shape for the magnetically confined “plasma” was found to be a donut shape (toroid). A reactor of this shape is called a “tokamak”. (Freudenrich, 2005, p. 4)  This is what most models of “magnetic confinement” use, including the ITER project. The power needed to start the fusion reaction in this way will be about 70 megawatts, but the power yield from the reaction will be about 500 megawatts. It also follows the same concept as nuclear fission in transforming the heat obtained into electricity by using steam to operate turbine generators. (Freudenrich, 2005, p. 5)

Tokamak (“Magnetic confinement”, nd)
The second type of nuclear fusion reactor uses “inertial confinement” which is currently being experimented on in the National Ignition Facility of Lawrence Livermore Laboratory in the United States. It uses laser beams to induce fusion by focusing on a single point in a 10-meter-diameter target chamber called a “hohlraum” which is a cavity whose walls are in radiative equilibrium with the radiant energy within the cavity. At the focal point inside the hohlraum, there will be a pea-sized pellet of “deuterium-tritium” fuel encased in a small, plastic cylinder. The power from the lasers will heat the cylinder and generate X-rays. The heat and radiation will convert the pellet into plasma. It would also produce shock waves and compress the plasma inwards, creating a very high pressure. Like “magnetic confinement”, it also satisfies the two requirements in fusion reaction. The fusion reaction will be short-lived, about one-millionth of a second, but will yield 50 to 100 times more energy than is needed to initiate the fusion reaction. This also uses the same concept as the fission reactors in converting heat into electricity. (Freudenrich, 2005, p. 6)

Inertial Confinement (“Nuclear Fusion: Inertial Confinement”, nd)

Overall, nuclear fusion has the most potential of being the energy source of the future. It could produce tremendous amounts of energy using only a small amount of fuel and unlike nuclear fission, it uses hydrogen isotopes which can be found everywhere and is one of the most abundant elements in the universe and it also doesn’t produce any radioactive substances. It could be of great help to our problems with economy and energy without affecting the environment. Like any other source of energy, it isn’t without risks but with extensive research and proper execution, it could be the ideal source of energy for the future.

References : 

Chem Connections. Nuclear Fusion: Inertial Confinement. Retrieved from http://chemconnections.org/crystals/new/graphics/icfprocess.gif. March 8, 2014.

Freudenrich, C. (2005, August 11). How Nuclear Fusion Reactors Work. Retrieved from http://science.howstuffworks.com/fusion-reactor.htm. March 8, 2014.

INPE. Magnetic Conefinement. Retrieved from http://www.plasma.inpe.br/LAP_Portal/LAP_Site/Figures/Tokamak_Schematic.gif. March 8, 2014.