Nuclear fission
nuclear fissionThe splitting of a large nucleus to produce two smaller ones. Two or three neutrons are also released in the process. The energy from the neutrons powers a nuclear reactor. is the splitting of a large atomic nucleus into smaller nuclei.
In a nuclear reactorA piece of equipment in which nuclear fission or fusion takes place., a slow-moving neutronUncharged subatomic particle, with a mass of 1 relative to a proton. The relative charge of a neutron is 0. is absorbed into a nucleus (typically uranium-235). This causes the nucleus to become uranium-236, which is unstable.
The entire nucleus splits into two large fragments called 鈥daughter nucleiThe nuclei (centres of atoms) that are produced by a nuclear reaction. In nuclear fission the parent nucleus splits into two smaller daughter nuclei and releases energy.鈥. In addition to the 鈥榙aughter鈥 products, two or three neutrons also explode out of the fission reaction and these can collide with other uranium nuclei to cause further fission reactions. This is known as a chain reactionA nuclear chain reaction occurs when a neutron splits a nucleus, releasing more neutrons, which in turn go on to split even more nuclei..
The fast moving neutrons carry most of the energy from the reaction with them (99%) but before the neutrons can collide with fresh uranium nuclei, they need to be slowed down.
Their energy is passed on to other components in the nuclear reactor, which is used to heat water to drive the turbineRevolving machine with blades that are turned by wind, water or steam. Turbines in a power station turn the generators. that turn the generatorAn electromagnetic device that produces electricity when it is turned on..