Nuclear energy is the use of nuclear reactions that release nuclear energy to generate heat, which most commonly is then used in steam turbines to produce electricity in a nuclear power plant.
A large number of countries around the world have built nuclear reactors and depend on them for a significant part of their energy needs. In 2015, 10% of the world’s electricity came from 441 atomic reactors.
The first successful commercial reactor was Calder Hall in England, which started operating in 1956. The Soviet Union followed with its own facility soon after. The United States developed Shippingport Atomic Power Station, the first full-scale commercial pressurized water reactor (PWR) in 1957. France build several smaller PWRs called UNGGs before going with larger ones later on. Nuclear weapons testing introduced plutonium into the civilian economy starting from 1945 at sites such as Alamogordo and Trinity in New Mexico as well as Hanford Site and Savannah River Site in Washington state and South Carolina respectively in the United States, Río Tinto Zinc Works and Windscale Piles in England, Kazatchok test site near Krasnoyarsk Krai settlements Novaya Zemlya archipelago Russia among others around the world.
The cost of generating electricity from new nuclear plants has decreased steadily since 1977 while coal and natural gas prices have increased during roughly the same period making it an economically attractive option given proper governance structures are put into place such as proper risk management via insurance schemes and/or sovereign wealth funds as demonstrated by countries like Finland which has been able to bring down its overall costs significantly.