How do nuclear reactors harness energy from fission?

Nuclear reactors harness energy from fission by using the heat generated to produce steam, which drives turbines to generate electricity.

In a nuclear reactor, the process of nuclear fission is controlled and sustained in a chain reaction. The fuel used in most nuclear reactors is uranium-235 or plutonium-239. These are heavy, unstable isotopes that can be split apart when struck by a neutron. When a neutron hits the nucleus of one of these atoms, it causes the nucleus to split, releasing a large amount of energy in the form of heat. This is the fission process.

The fission of a single atom also releases more neutrons, which can then go on to cause the fission of other atoms, creating a chain reaction. This chain reaction is carefully controlled in a nuclear reactor to ensure that it does not become too fast or too slow. Control rods made of materials that absorb neutrons, such as boron or cadmium, are used to regulate the chain reaction. By adjusting the position of these control rods, operators can control the rate of the fission reaction and thus the amount of heat produced.

The heat generated by the fission process is used to heat water, producing steam. This steam is then used to drive turbines, which are connected to generators. As the turbines spin, they turn the generators, producing electricity. This is essentially the same process used in other types of power plants, such as coal or gas-fired plants, but the source of the heat is different.

The process of nuclear fission also produces radioactive waste, which must be carefully managed and disposed of. This is one of the main challenges associated with nuclear power. Despite this, nuclear power is considered a low-carbon energy source, as the fission process does not produce greenhouse gases like burning fossil fuels does.

In summary, nuclear reactors harness energy from fission by controlling a chain reaction of nuclear fission to produce heat. This heat is used to generate steam, which drives turbines to produce electricity.