Nuclear Reactor

Nuclear reactor concrete sheild

cooling water converted to steam, which drives turbine

Key words fission isotope uranium

Nuclear reactor

atoms splitting inside core of the reactor give off heat

carbon dioxide gas carries heat away from uranium in the core of the reactor

generator cooling water turbine

electricity

cooling tower

either the metal or the metal oxide, is used as fuel in nuclear reactors. The fuel is in the form of fuel rods, which are suspended in the reactor. ● Naturally occurring uranium contains 99.3 percent uranium-238 and only 0.7 percent of the radioactive isotope uranium-235. The uranium-235 content must be increased to approximately 3 percent before the uranium can be use as a fuel. ● Uranium-235 undergoes spontaneous fission. However, in a nuclear power station, the fission is brought about by bombarding the uranium nuclei with neutrons. ● The fission of one atom of uranium235 absorbs one neutron and releases three others. In order to increase the chances that these neutrons will strike other uranium-235 atoms, they are slowed down by a moderator. ● Control rods are suspended between the fuel rods. These can be raised or lowered as needed to control the nuclear reaction. The control rods are made of alloys that absorb neutrons. When they are lowered, more neutrons are absorbed. ● The heat produced by the fission reaction is removed through a heat exchanger. The loop between the nuclear reactor and the heat exchanger is sealed so there is no danger of radioactive material escaping into the environment. ● The heat is used to convert water into pressurized steam. The high pressure steam drives a turbine connected to a generator, which produces electricity.

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● Uranium,