Nuclear Energy in the World Nuclear information by countries Nuclear energy amounts to 11,5 % of the electricity production consumed in the world. Currently, there are 441 nuclear reactors in operation, with a total net installed capacity of around 381,936 MWe. At the end of 2015 there were 67 reactors under, construction, of which seven had started new construction (1 in the United Arab Emirates and 6 in China). Ten units were connected to the grid (1Russia, 1 in South Korea and 8 in China) and seven units were definitely shut down (1 in Germany, 1 in the United Kingdom and 5 in Japan). In 2015, the five countries with the world's highest nuclear electricity generation capacity in terms of percentage were: France (76.9%), Slovakia (56.8%), Hungary (53.6%), Ukraine (49.4%) and Belgium (47.5%). All the nuclear programmes and facilities in the different countries around the world are under the supervision and control of the International Atomic Energy Agency, with headquarters in Vienna (www.iaea.org). A brief history of nuclear power In the second half of the 1960's, the United States launched the first nuclear programme destined to electricity generation, although four years earlier the United Kingdom had inaugurated Calder Hall, the world's first nuclear power plant. Shortly afterwards, other industrialised nations followed suit and undertook their own nuclear power plant construction and operation programmes. The motor of the development of this energy source were economic stability, the strong growth of electricity demand and its promising economic expectations. At the beginning of the 1970's, the oil crisis provided the definitive drive for nuclear energy in the energy plans of many industrialised nations such as Germany, Canada, Italy and Japan. Especially noteworthy was the emphasis placed on nuclear energy by France, which abandoned graphite-gas reactors in favor of American pressurised water technology. In turn, other countries such as Mexico, Brazil, Taiwan and Korea prepared to initiate their nuclear programmes.