Nuclear energy is the energy created in a nuclear reaction which is the changes can occur in the structure of the nuclei of atoms. Nuclear energy was discovered in the mid-twentieth century and first utilized in a military capacity in the atomic bombings of Hiroshima and Nagasaki. It all started rather innocently in 1896, when Antoine Henri Becquerel discovered radioactivity in Uranium. The next step came in 1902 when Marie and Pierre Curie isolated radioactive metal called Radium. In 1934, Enrico Fermi of Italy disintegrated heavy atoms by spraying them with neutrons. Unfortunately, he didn’t realize that he had achieved nuclear fission, In December 1938, Otto Hahn and Fritz Strassman in Berlin did a similar experiment with Uranium and were able to verify a world-shaking achievement. They had split an atom. They had produced nuclear fission and had transformed mass into energy as said by Einstein. In December 2, 1942, the first man-made nuclear reactor came on line in Chicago as part of the Manhattan Project, a widespread attempt by the United State Government to research nuclear power. The implementation of Plutonium led to creation of the first nuclear weapons. A Uranium based explosive named “little boy” and the Plutonium based “fat man” were dropped on Japan in 1945 to end World War II. After few years, in November 1, 1952, the first large version of the hydrogen bomb was exploded by the United States for testing purposes. And in February 21, 1956, the first major nuclear power plant opened in England.