Nuclear reactors use control rods (Figure \(\PageIndex{8}\)) to control the fission rate of the nuclear fuel by adjusting the number of slow neutrons present to keep the rate of the chain reaction at a safe level. The collision results in nuclear fission. All nuclear weapons require a nuclear fission reaction to work, but "pure" fission bombs, those that use a fission reaction alone, are known as atomic, or atom, bombs. The nuclear fission of uranium-235 is shown in the following equation: […] Radioactive decay of both fission products and transuranic elements formed in a reactor yield heat even after fission has ceased. Physics of Uranium and Nuclear Energy (Updated February 2018) Nuclear fission is the main process generating nuclear energy. Learn about and revise nuclear fission, nuclear fusion and how energy is released from these processes with GCSE Bitesize Physics. When nuclear fission is used to generate electricity, it is referred to as nuclear power. Atomic mass of unknown element = 98 - 52 = 46 Other isotopes that can be induced to fission like this are plutonium-239, uranium-233, and thorium-232. Fission reactions may be moderated to increase fission, or unmoderated to breed further fuel. In this particular reaction, one uranium nucleus breaks into a barium nucleus, a krypton nucleus, and two neutrons. nuclear fission: Radioactive decay process in which the nucleus of an atom splits into lighter nuclei.

Lots of fission products are possible e.g.

Control rods are made of boron, cadmium, hafnium, or other elements that are able to absorb neutrons. 0 Page 59 NP-01 … BE BE products BE reactants BE Rb 93 BE Cs 140 BE U 235 809 MeV 1176 MeV 1786 MeV 199 MeV 1 0 n 235 92 U 236 92 U 140 55 Cs 93 37 Rb 3 1 0 n Mass difference Mass of Reactants Mass of Products 236.052589 amu 235.85208 amu 0.200509 amu E Inst 0.020059 amu 931.5 MeV amu 186.8 MeV Atomic and Nuclear Physics DOE-HDBK-1019/1-93 ENERGY RELEASE FROM FISSION Rev.
The nuclear fission equations below are a gross simplification of the process! The atomic number too must be the same. Nuclear Fission The graph of binding energy per nucleon suggests that nuclides with a mass larger than about 130 amu should spontaneously split apart to form lighter, more stable, nuclides. Scientists usually accomplish this task (for some controlled nuclear reactions) by bombarding a large isotope with a second, smaller one — commonly a neutron. In nuclear power plants, energetic neutrons are directed into a sample of the isotope uranium-235. Nuclear fission occurs when a larger isotope breaks apart into two or more elements.
This implies that the mass number on both side of the equation be the same.

Nuclear Fission Examples Chernobyl Accident Difference Between Fission and Fusion.