Ruthie Nelson, age 16, of Chester, Pa., for her question:
WHEN WAS THE FIRST NUCLEAR REACTOR BUILT?
The world's first nuclear reactor consisted of a large pile of graphite blocks and chunks of uranium metal. It was built at the University of Chicago and its construction was directed by the Italian physicist Enrico Fermi.
The first nuclear chain reaction was produced at the University of Chicago on this reactor on December 2, 1941.
A nuclear reactor is a device that produces a large amount of energy from a small amount of fuel. It is sometimes called an atomic reactor or an atomic pile.
A nuclear reactor generates energy mainly in the form of heat by means of a process known as nuclear fission. Nuclear fission is the splitting of the nuclei of atoms of uranium or plutonium.
A first experimental breeder reactor was built in 1951 by scientists at the National Reactor Testing Station near Idaho Falls, Idaho.
In 1954, the United States Navy launched the submarine Nautilus. This craft was the first ship to be powered by energy from a nuclear reactor.
In 1955, electricity for public use was first generated from a reactor at the National Reactor Testing Station. But this was done only on a very limited basis.
The world's first large scale nulcear power plant was constructed by a team of British scientists and engineers in a plant called Calder Hall on the west coast of England. Construction on this project was completed in 1956.
A year later, in 1957, the first large nuclear power station in the United States was completed. This station is located in Shippingsport, Pa., near Pittsburgh.
At the present time, more than 50 huge plants in the United States are using nuclear energy to generate electric power.
By the early 1990s, scientists expect to build power plants equipped with plutonium breeding reactors.
An atom bomb gets its destructive power from uncontrolled fission. A nuclear reactor, however, keeps fission under control. As a result, the energy it produces can be used for the generation of electricity and for other peaceful purposes.
Reactors also are used to make various substances radioactive. These radiactive materials, called radioisotopes, have important uses in agriculture, industry and medicine.
Growing concern about the possibility of future shortages of reactor fuel has encouraged the development of breeder reactors. These special reactors can produce more fuel than they use to produce energy. The surplus fuel can be utilized by other nuclear reactors.