Graphite-moderated reactor

A graphite reactor is a nuclear reactor that uses carbon as a neutron moderator, which allows un-enriched uranium to be used as nuclear fuel.

The very first artificial nuclear reactor, the Chicago Pile-1, used graphite as moderator. Two graphite moderated reactors were involved in major accidents: An untested graphite annealing process contributed to the Windscale fire (but the graphite itself did not catch fire), and a graphite fire during the Chernobyl disaster contributed to the spread of radioactive material (but was not a cause of the accident itself).

There are several types of graphite-moderated nuclear reactors that have been used in commercial electricity generation:

There have been a number of Research or Test Reactors built that use graphite as the moderator.

The first artificial nuclear reactor, Chicago Pile-1, a graphite-moderated device that produced a microscopic amount of heat, was constructed by a team led by Enrico Fermi in 1942. The construction and testing of this reactor (an "atomic pile") was part of the Manhattan Project. This work led to the construction of the X-10 Graphite Reactor at Oak Ridge National Laboratory, which was the first nuclear reactor designed and built for continuous operation, and began operation in 1943.

There have been several major accidents in graphite moderated reactors, with the Windscale fire and the Chernobyl disaster probably the best known.

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