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Fusion Vs. Fission 

When making a fire, would you rub together sticks to make just enough heat in tried and true fashion, or would you buy gasoline and a firestarter, creating a larger fire for the price of a couple of dollars? Quite similarly, the reactions harnessed within nuclear reactors to create energy are direct opposites of each other, yet they produce the same byproduct, with one method being widely employed and the other still in development but creating more energy than the other. These reactions are nuclear fission and fusion, some of the most potent methods of creating electrical energy for our everyday use. 

They are both nuclear processes that change the structure of atoms to create energy. However, while the product of these reactions are the same, the process these reactions take are opposites of each other. On one hand, fission occurs under the condition where one larger atom is split into two smaller ones. This split occurs when high-speed neutrons strike at an unstable isotope to break it into two smaller isotopes and three more high-speed neutrons, releasing a large amount of energy. These high-speed neutrons go on to initiate other fission reactions, creating a chain reaction until the atoms can no longer split. When the unstable isotope splits, it creates a large amount of heat energy, used to boil water and turn the steam turbines inside nuclear reactors. Most often, Uranium and Plutonium are used for fission reactions as they are the easiest to control. After the reaction ends, the initial element is broken up into Iodide, Caesium, Strontium, Xenon, Barium, and much more, all of which are highly radioactive and can severely harm the environment. On the other hand, fusion is the combination of two smaller atoms, typically Hydrogen atoms, into one larger atom, Helium. To have this reaction take place, the smaller atoms must be under the conditions of extreme pressure and temperature. Unlike fission, the combination of these two atoms has the ability to create much larger amounts of energy in the form of more heat to create more steam for a steam turbine (For reference, fusion is what powers the sun by uniting Tritium and Deuterium atoms to produce a neutron and helium isotope). Compared to nuclear fission, nuclear fusion creates three to four times more energy than its counterpart. Along with this, fusion does not leave behind radioactive byproducts like nuclear fission does. 

If fusion produces much larger amounts of energy than fission, why aren’t they being used in nuclear reactors? At the current moment, there isn’t a safe way to control fusion and it is too expensive to create the specific conditions needed for fusion. Scientists are still trying to research a better way to harness the power of fusion, but until then, nuclear reactors will rely on the power of fission for energy.

What are Fission and Fusion?


Energy, Duke. “Fission vs. Fusion – What's the Difference?” Duke Energy | Nuclear Information Center, 30 Jan. 2013, 


EUROfusion. “Fusion vs Fission.” Eurofusion, 


“Fission and Fusion: What Is the Difference?”, Office of Nuclear Energy, 1 Apr. 2021, 

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