Timeline
1905	Einstein's theory of special relativity.
1932	English physicist and Nobel laureate James Chadwick discoveres the neutron.
1932	Atom split by John Cockcroft and Ernest Walton.
1937	Westinghouse builds 5-million volt Van de Graff generator ("atom smasher").
1939	Otto Hahn, Fritz Strassman, Lise Meitner, and Otto Frisch demonstrate fission.
1939-45	Manhattan Project develops atomic bomb.
1942	Enrico Fermi and colleagues at the University of Chicago achieve the firstcontrolled, self-sustaining nuclear reaction.
1945	Atomic bombs dropped on Hiroshima and Nagasaki, Japan, ending World War II.
1946	Atomic Energy Act passes, establishing the Atomic Energy Commission.
1946	Oak Ridge facility ships first nuclear reactor-produced radioisotopes for civilian use to Barnard Cancer Hospital in St. Louis.
1948	Argonne Naitonal Laboratory and Westinghouse announce program to commercialize nuclear power.
1951	Experimental Breeder Reactor 1 (EBR-I) produces the world's first usable amount of electricity from nuclear energy.
1953-55	Three Boiling Reactor Experiment (BORAX) reactors are built at the Idaho National Engineering and Environmental Laboratory.
1954	United States launches the U.S.S. Nautilus, the world's first nuclear-powered submarine.
1954	The second Atomic Energy Act is passed by the U.S. legislature.
1954	Arco, Idaho, population 1200, becomes the world's first community to have all electrical power provided by nuclear energy.
1957	The International Atomic Energy Agency is formed with 18 member countries to promote peaceful uses of nuclear energy. Today it has 130 members.
1957	First U.S. large-scale nuclear power plant begins operation in Shippingport, Penn.
1962	First nuclear-powered surface ship, N.S. Savannah, put to sea.
1962	First advanced gas-cooled reactor is built in England.
1966	The Advanced Testing Reactor at the Idaho National Engineering and Environmental Laboratory begins operation for materials testing and isotope generation.
1969	The Zero Power Physics Reactor goes operational at Argonne National Laboratory-West in Idaho.
1974	Atomic Energy Commission splits into the Energy Research and Development Administration and the Nuclear Regulatory Commission.
1979	Three Mile Island accident.
1986	Chernobyl accident.
1990s	The U.S. Naval Nuclear Propulsion Program pioneers new materials, including uranium-dioxide fuels systems, the use of zirconium and its alloys, boron, and hafnium, and develops material fabrication, radiological control, and quality control standards.