Nuclear power is the use of nuclear reactions that release nuclear energy to generate heat, which most frequently is then used in steam turbines to produce electricity in a nuclear power plant. Nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion. Presently, the vast majority of electricity from nuclear power is produced by nuclear fission of elements in the actinide series of the periodic table. Nuclear decay processes are used in niche applications such as radioisotope thermoelectric generators. The possibility of generating electricity from nuclear fusion is still at a research phase with no commercial applications. This article mostly deals with nuclear fission power for electricity generation.
Nuclear power is one of the leading low carbon power generation methods of producing electricity. In terms of total life-cycle greenhouse gas emissions per unit of energy generated, nuclear power has emission values comparable or lower than renewable energy.From the beginning of its commercialization in the 1970s, nuclear power prevented about 1.84 million air pollution-related deaths and the emission of about 64 billion tonnes of carbon dioxide equivalent that would have otherwise resulted from the burning of fossil fuels in thermal power stations.
As of April 2018, there are 449 operable fission reactors in the world, with a combined electrical capacity of 394 gigawatt (GW). Additionally, there are 58 reactors under construction and 154 reactors planned, with a combined capacity of 63 GW and 157 GW, respectively. Most of reactors under construction are of generation III reactor design, with the majority in Asia. Over 300 more reactors are proposed.