A Gas Cooled Reactor (more commonly called a GCR) is a generation I nuclear power plant that uses graphite as a neutron moderator and carbon dioxide as coolant. Although there are many other types of reactor cooled by gas, the terms GCR and to a lesser extent gas cooled reactor are particularly used to refer to this type of reactor. A nuclear power station. ... Graphite (named by Abraham Gottlob Werner in 1789 from the Greek γραφειν (graphein): to draw/write, for its use in pencils) is one of the allotropes of carbon. ... This does not adequately cite its references or sources. ... Carbon dioxide is a chemical compound composed of one carbon and two oxygen atoms. ...

The GCR was able to use natural uranium as fuel, enabling the countries that developed them to fabricate their own fuel without relying on other countries for supplies of enriched uranium, which was at the time of their development only available from the United States or Soviet Russia. These pie-graphs showing the relative proportions of uranium-238 (blue) and uranium-235 (red) at different levels of enrichment. ...

There were two main types of GCR:

• The Magnox reactors developed by the United Kingdom.

• The UNGG reactors developed by France.

The main difference between the types is in the fuel cladding material. Both types were mainly constructed in their countries of origin, with a few export sales. Both types used fuel cladding materials that were unsuitable for medium term storage under water, making reprocessing an essential part of the nuclear fuel cycle. Schematic diagram of a Magnox nuclear reactor showing gas flow. ... // Nuclear reprocessing separates any usable elements (e. ... The nuclear fuel cycle, also called nuclear fuel chain, is the progression of nuclear fuel through a series of differing stages. ...

Both types were, in their countries of origin, also designed and used to produce weapons-grade plutonium, but at the cost of major interruption to their use for power generation despite the provision of online refuelling. General Name, Symbol, Number plutonium, Pu, 94 Chemical series actinides Group, Period, Block n/a, 7, f Appearance silvery white Standard atomic weight (244) g·mol−1 Electron configuration [Rn] 5f6 7s2 Electrons per shell 2, 8, 18, 32, 24, 8, 2 Physical properties Phase solid Density (near r. ...

In the UK, the Magnox was replaced by the AGR; In France, the UNGG was replaced by the PWR. More recently, GCRs based on the declassified drawings of the early Magnox reactors have been constructed by North Korea, leading to fears of their use for nuclear proliferation. AGR is a three-letter abbreviation with multiple meanings, as described below: Active Guard Reserve of the United States Army National Guard Adjusted Gross Revenue, an accounting term Advanced gas-cooled reactor, a type of nuclear reactor Agere Systems, a ticker symbol on the New York Stock Exchange AgriTec Systems... A pressurized water reactor (PWR) is a type of nuclear power reactor that uses ordinary (light) water for both coolant and for neutron moderator. ... World map with nuclear weapons development status represented by color. ...

See also

• Generation II reactor.