How do fission reactors work

Some of the neutrons that are released then hit other atoms, causing them to fission too and release more neutrons. This is called a chain reaction. The fissioning of atoms in the chain reaction also releases a large amount of energy as heat. The generated heat is removed from the reactor by a circulating fluid, typically water. This heat can then be used to generate steam, which drives turbines for electricity production. In order to ensure the nuclear reaction takes place at the right speed, reactors have systems that accelerate, slow or shut down the nuclear reaction, and the heat it produces.

This is normally done with control rods, which typically are made out of neutron-absorbing materials such as silver and boron. A similar process generates heat inside a nuclear reactor. Inside each uranium fuel pellet, there are millions of uranium nuclei. When these nuclei are split, a huge amount of energy is released. Some of this energy is from radiation, but the biggest source is kinetic energy. This is the energy that produces heat inside a reactor, which in turn is used to generate steam, and ultimately creates electricity.

For more than 60 years, nuclear energy has provided the world with reliable electricity. Today, more than reactors are operating in more than 30 countries. More nations are exploring the use of nuclear energy, particularly as electricity demand increases and concerns about climate change rise. International Atomic Energy Agency. World Association of Nuclear Operators. Radiation is energy in motion. Transporting and storing Uses of hydrocarbon gas liquids Imports and exports Prices.

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Also in Hydrogen explained Hydrogen Production of hydrogen Use of hydrogen. Nuclear power comes from nuclear fission Nuclear power plants heat water to produce steam. Country Nuclear electricity generation capacity million kilowatts Nuclear electricity generation billion kilowatthours Nuclear share of country's total electricity generation United States Moderator - graphite core - a graphite core, for example, slows the neutrons down so that they are more likely to be absorbed into a nearby fuel rod.

Control rods - these are raised and lowered to stop neutrons from travelling between fuel rods and therefore change the speed of the chain reaction. Coolant - this is heated up by the energy released from the fission reactions and is used to boil water to drive turbines in the power station. Concrete shield - the daughter products of the fission reaction are radioactive and can be a hazard.

Advantages and disadvantages of nuclear power stations Generating electricity using nuclear reactors carries high risk but offers large rewards. Advantages Disadvantages Produces no polluting gases.