There are two main forms of nuclear reaction which have the potential to generate energy, nuclear fission and nuclear fusion. Nuclear fission is already being used to generate electricity and the potential for nuclear fusion is being explored.
1. In nuclear fission uranium atoms are “split” to produce smaller atoms together with a release of energy.
2. Nuclear fusion combines light element atoms at extreme temperatures, leading to the release of energy.
A significant portion of the world's electricity comes from nuclear fission technology via utility-scale nuclear reactors. These reactors harness nuclear fission to heat water and produce steam to power turbines that generate electricity. Two generic types of nuclear power plant have been developed and deployed in the UK since the first commercial production of nuclear electricity from Calder Hall in 1956. Magnox gas cooled reactors and advanced gas cooled reactors (AGR) were most common until the 1990’s when water cooled pressurised water reactors (PWR) like Sizewell B in the UK became the prevalent design.
Power production from nuclear fusion is still at the development stage and is not expected to be available for commercial deployment as an electricity production technology before 2050. The key issue is the massive cost of experimental and prototype fusion power plants. This has encouraged a high degree of international collaboration to build test facilities.