Fission vs Fusion

• Fission reaction does not normally occur in nature
• Fission produces many highly radioactive particles
• The energy released by fission is a million times greater than that released in chemical reactions; but lower than the energy released by nuclear fusion
• One class of nuclear weapon is a fission bomb, also known as an atomic bomb or atom bomb
• Fission is the splitting of a large atom into two or more smaller ones
• Critical mass of the substance and high-speed neutrons are required
• Takes little energy to split two atoms in a fission reaction
• Nuclear fission is the splitting of a massive nucleus into photons in the form of gamma rays, free neutrons, and other subatomic particles. In a typical nuclear reaction involving 235U and a neutron:

  23592U + n = 23692U followed by 23692U = 14456Ba + 89 36Kr + 3n + 177 MeV

• Fusion occurs in stars, such as the sun
• Few radioactive particles are produced by fusion reaction, but if a fission “trigger” is used, radioactive particles will result from that
• The energy released by fusion is three to four times greater than the energy released by fission
• One class of nuclear weapon is the hydrogen bomb, which uses a fission reaction to “trigger” a fusion reaction
• Fusion is the fusing of two or more lighter atoms into a larger one
• High density, high temperature environment is required
• Extremely high energy is required to bring two or more protons close enough that nuclear forces overcome their electrostatic repulsion
• Nuclear fusion is the reaction in which two or more nuclei combine together to form a new element with higher atomic number (more protons in the nucleus). The energy released in fusion is related to E = mc^2 (Einstein’s famous energy-mass equation). On earth, the most likely fusion reaction is Deuterium–Tritium reaction. Deuterium and Tritium are both isotopes of hydrogen. 2 1Deuterium + 3 1Tritium = 42He + 10n + 17.6 MeV
• Fusion of deuterium with tritium creating helium-4, freeing a neutron, and releasing 17.59 MeV of energy

Advantage of Nuclear Fusion over Nuclear Fission

• In case of fusion reactions, fusion reactors cannot sustain a chain reaction so they can never melt down like fission reactors
• Fusion reaction produces very less or, if the right atoms are chosen, no radioactive waste
• In case of nuclear fission large radioactive waste is produced and disposal of radioactive waste is a complicated problem
• For nuclear power, fusion is the better choice
• The energy released by fusion is three to four times greater than the energy released by fission. This is because the amount of mass transformed into energy is that much greater in a fusion reaction than in a fission reaction
• Fusion is essentially inexhaustible, low-cost fuel, available worldwide
• High energy-density of fuel in fusion, allowing straightforward base-load power production without major transportation cost
• In fusion there is no production of greenhouse gas, soot or acid rain, and no possibility of runaway reaction or meltdown that could pose a risk to public safety with minimal proliferation risk
• Fusion has only short-lived radioactive wastes

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