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Nuclear Technologies Timeline


Even though the ancient Greeks correctly theorized that everything was made up of simple particles, which they called atoms, it wasn't until the beginning of the 20th century that scientists realized the atom could be split. Nuclear physicists such as Britain's Joseph John Thomson and Denmark's Niels Bohr mapped out the atom's elementary building blocks (the electron, proton, and neutron) and paved the way for the discovery of nuclear fission—the process that transformed the atom into a new and powerful source of energy. Today atomic energy generates clean, low-cost electricity, powers some of the world's largest ships, and assists in the development of the latest health care techniques.

  1905   Special theory of relativity

German-born physicist Albert Einstein introduces his special theory of relativity, which states that the laws of nature are the same for all observers and that the speed of light is not dependent on the motion of its source. The most celebrated result of his work is the mathematical formula E=mc2, or energy equals mass multiplied by the speed of light squared, which demonstrates that mass can be converted into energy. Einstein wins the Nobel Prize in physics in 1921 for his work on the photoelectric effect.

  1932   Neutron is discovered

English physicist and Nobel laureate James Chadwick exposes the metal beryllium to alpha particles and discovers the neutron, an uncharged particle. It is one of the three chief subatomic particles, along with the positively charged proton and the negatively charged electron. Alpha particles, consisting of two neutrons and two protons, are positively charged, and are given off by certain radioactive materials. His work follows the contributions of New Zealander Ernest Rutherford, who demonstrated in 1919 the existence of protons. Chadwick also studies deuterium, known as heavy hydrogen, an isotope of hydrogen used in nuclear reactors.

  1932   Cockcroft teams Walton to split the atom

British physicist John Cockcroft teams with Ernest Walton of Ireland to split the atom with protons accelerated to high speed. Their work wins them the Nobel Prize in physics in 1951.

  1937   5-million-volt Van de Graaff generator built

The Westinghouse Corporation builds the 5-million-volt Van de Graaff generator. Named for its inventor, physicist Robert Van de Graaff, the generator gathers and stores electrostatic charges. Released in a single spark and accelerated by way of a magnetic field, the accumulated charge, equivalent to a bolt of lightning, can be used as a particle accelerator in atom smashing and other experiments.

  1939   Uranium atoms are split

Physicists Otto Hahn and Fritz Strassmann of Germany, along with Lise Meitner of Austria and her nephew Otto Frisch, split uranium atoms in a process known as fission. The mass of some of the atoms converts into energy, thus proving Einstein’s original theory.

  1939-1945   Manhattan Project

The U.S. Army’s top-secret atomic energy program, known as the Manhattan Project, employs scientists in Los Alamos, New Mexico, under the direction of physicist J. Robert Oppenheimer, to develop the first transportable atomic bomb. Other Manhattan Project teams at Hanford, Washington, and Oak Ridge, Tennessee, produce the plutonium and uranium-235 necessary for nuclear fission.

  1942   First controlled, self-sustaining nuclear chain reaction

Italian-born physicist and Nobel winner Enrico Fermi and his colleagues at the University of Chicago achieve the first controlled, self-sustaining nuclear chain reaction in which neutrons released during the splitting of the atom continue splitting atoms and releasing more neutrons. Fermi’s team builds a low-powered reactor, insulated with blocks of graphite, beneath the stands at the university’s stadium. In case of fire, teams of students stand by, equipped with buckets of water.

  1945   Hiroshima and Nagasaki

To force the Japanese to surrender and end World War II, the United States drops atomic bombs on Hiroshima, an important army depot and port of embarkation, and Nagasaki, a coastal city where the Mitsubishi torpedoes used in the attack on Pearl Harbor were made.

  1946   First nuclear-reactor-produced radioisotopes for peacetime civilian use

The U.S. Army's Oak Ridge facility in Tennessee ships the first nuclear-reactor-produced radioisotopes for peacetime civilian use to Brainard Cancer Hospital in St. Louis.

  1946   Atomic Energy Commission

The U.S. Congress passes the Atomic Energy Act to establish the Atomic Energy Commission, which replaces the Manhattan Project. The commission is charged with overseeing the use of nuclear technology in the postwar era.

  1948   Plans to commercialize nuclear power

The U.S. government’s Argonne National Laboratory, operated in Illinois by the University of Chicago, and the Westinghouse Corporation’s Bettis Atomic Power Laboratory in Pittsburgh, announce plans to commercialize nuclear power to produce electricity for consumer use.

  1951   Experimental Breeder Reactor 1

Experimental Breeder Reactor 1 at the Idaho National Engineering and Environmental Laboratory (INEEL) produces the world’s first usable amount of electricity from nuclear energy. When neutrons released in the fission process convert uranium into plutonium, they generate, or breed, more fissile material, thus producing new fuel as well as energy. No longer in operation, the reactor is now a registered national historic landmark and is open to the public for touring.

  1953   First of a series of Boiling Reactor Experiment reactors

BORAX-I, the first of a series of Boiling Reactor Experiment reactors, is built at INEEL. The series is designed to test the theory that the formation of steam bubbles in the reactor core does not cause an instability problem. BORAX-I proves that steam formation is, in fact, a rapid, reliable, and effective mechanism for limiting power, capable of protecting a properly designed reactor against "runaway" events.

  1954   Atomic Energy Act of 1954

The U.S. Congress passes the Atomic Energy Act of 1954, amending the 1946 act to allow the Atomic Energy Commission to license private companies to use nuclear materials and also to build and operate nuclear power plants. The act is designed to promote peaceful uses of nuclear energy through private enterprise, implementing President Dwight D. Eisenhower’s Atoms for Peace Program.

  1955   BORAX-III provide an entire town with electricity

In July, BORAX-III becomes the first nuclear power plant in the world to provide an entire town with all of its electricity. When power from the reactor is cut in, utility lines supplying conventional power to the town of Arco, Idaho (population 1,200), are disconnected. The community depends solely on nuclear power for more than an hour.

  1955   First nuclear-powered submarine

The USS Nautilus SSN 571, the world’s first nuclear-powered submarine, gets under way on sea trials. The result of the efforts of 300 engineers and technicians working under the direction of Admiral Hyman Rickover, "father of the nuclear navy," it is designed and built by the Electric Boat Company of Groton, Connecticut, and outfitted with a pressurized-water reactor built by the Westinghouse Corporation’s Bettis Atomic Power Laboratory. In 1958 the Nautilus is the first ship to voyage under the North Pole.

  1957   International Atomic Energy Agency

The International Atomic Energy Agency is formed with 18 member countries to promote peaceful uses of nuclear energy. Today it has 130 members.

The first U.S. large-scale nuclear power plant begins operation in Shippingport, Pennsylvania. Built by the federal government but operated by the Duquesne Light Company in conjunction with the Westinghouse Bettis Atomic Power Laboratory, the pressurized-water reactor supplies power to the city of Pittsburgh and much of western Pennsylvania. In 1977 the original reactor is replaced by a more efficient light-water breeder reactor.

  1962   First advanced gas-cooled reactor

The first advanced gas-cooled reactor is built at Calder Hall in England. Intended originally to power a naval vessel, the reactor is too big to be installed aboard ship and is instead successfully used to supply electricity to British consumers. A smaller pressurized-water reactor, supplied by the United States, is then installed on Britain’s first nuclear-powered submarine, the HMS Dreadnaught.

  1966   Advanced Testing Reactor

The Advanced Testing Reactor at the Idaho National Engineering and Environmental Laboratory begins operation for materials testing and isotope generation.

  1969   Zero Power Physics Reactor

The Zero Power Physics Reactor (ZPPR), a specially designed facility for building and testing a variety of types of reactors, goes operational at Argonne National Laboratory-West in Idaho. Equipped with a large inventory of materials from which any reactor could be assembled in a few weeks, ZPPR operates at very low power, so the materials do not become highly radioactive and can be reused many times. Nuclear reactors can be built and tested in ZPPR for about 0.1% of the capital cost of construction of the whole power plant.

  1974   Energy Reorganization Act of 1974

The Energy Reorganization Act of 1974 splits the Atomic Energy Commission into the Energy Research and Development Administration (ERDA) and the Nuclear Regulatory Commission (NRC). ERDA’s responsibilities include overseeing the development and refinement of nuclear power, while the NRC takes up the issue of safe handling of nuclear materials.

  1979   Three Mile Island

The nuclear facility at Three Mile Island near Harrisburg, Pennsylvania, experiences a major failure when a water pump in the secondary cooling system of the Unit 2 pressurized-water reactor malfunctions. A jammed relief valve then causes a buildup of heat, resulting in a partial meltdown of the core but only a minor release of radioactive material into the atmosphere.

  1986   Chernobyl

The Chernobyl nuclear disaster occurs in Ukraine during unauthorized experiments when four pressurized-water reactors overheat, releasing their water coolant as steam. The hydrogen formed by the steam causes two major explosions and a fire, releasing radioactive particles into the atmosphere that drift over much of the European continent.

  1990s   U.S. Naval Nuclear Propulsion Program

The U.S. Naval Nuclear Propulsion Program pioneers new materials and develops improved material fabrication techniques, radiological control, and quality control standards.

  2000   World record reliability benchmarks

The fleet of more than 100 nuclear power plants in the United States achieve world record reliability benchmarks, operating annually at more than 90 percent capacity for the last decade—the equivalent of building 10 gigawatt nuclear power plants in that period. In the 21 years since the Three Mile Island accident, the fleet can claim the equivalent of 2,024.6 gigawatt-years of safe reactor operation, compared to a total operational history of fewer than 253.9 gigawatt-years before the accident. Elsewhere in the world, nuclear power energy production grows, most notably in China, Korea, Japan, and Taiwan, where more than 28 gigawatts of nuclear power plant capacity is added in the last decade of the century.


     Nuclear Technologies
     Splitting the Atom
     Manhattan Project
     Peacetime Use
     Power Plants
     Essay - Shirley Ann Jackson

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