GLEEP, which stood for Graphite Low Energy Experimental Pile, was a long-lived experimental

nuclear reactor A nuclear reactor is a device used to initiate and control a Nuclear fission, fission nuclear chain reaction. They are used for Nuclear power, commercial electricity, nuclear marine propulsion, marine propulsion, Weapons-grade plutonium, weapons ...

Oxfordshire Oxfordshire ( ; abbreviated ''Oxon'') is a ceremonial county in South East England. The county is bordered by Northamptonshire and Warwickshire to the north, Buckinghamshire to the east, Berkshire to the south, and Wiltshire and Glouceste ...

, England. Reaching criticality for the first time on 15 August 1947, it was the first reactor to operate in western Europe, and the second in Eurasia, beat only by the F-1 in the USSR. In an effort led by

John Cockcroft Sir John Douglas Cockcroft (27 May 1897 – 18 September 1967) was an English nuclear physicist who shared the 1951 Nobel Prize in Physics with Ernest Walton for their splitting of the atomic nucleus, which was instrumental in the developmen ...

, GLEEP was built at the

Atomic Energy Research Establishment The Atomic Energy Research Establishment (AERE), also known as Harwell Laboratory, was the main Headquarters, centre for nuclear power, atomic energy research and development in the United Kingdom from 1946 to the 1990s. It was created, owned ...

, a former

Royal Air Force The Royal Air Force (RAF) is the Air force, air and space force of the United Kingdom, British Overseas Territories and Crown Dependencies. It was formed towards the end of the World War I, First World War on 1 April 1918, on the merger of t ...

airfield, near Harwell in Oxfordshire (then in

Berkshire Berkshire ( ; abbreviated ), officially the Royal County of Berkshire, is a Ceremonial counties of England, ceremonial county in South East England. It is bordered by Oxfordshire to the north, Buckinghamshire to the north-east, Greater London ...

), in an aircraft hangar. It was a

graphite Graphite () is a Crystallinity, crystalline allotrope (form) of the element carbon. It consists of many stacked Layered materials, layers of graphene, typically in excess of hundreds of layers. Graphite occurs naturally and is the most stable ...

moderated Moderation is the process or trait of eliminating, lessening, or avoiding extremes. It is used to ensure normality throughout the medium on which it is being conducted. Common uses of moderation include: * A way of life emphasizing perfect amo ...

, air-cooled reactor and used 11,500 natural uranium fuel

aluminium Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...

-clad rods inserted into 676 horizontal fuel channels. Radiation shielding was provided by 5 feet of baryte concrete. Designed for a power output of 100

kilowatts The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantify the rate of energy transfer. The watt is named in honor of ...

, for the first 1.5 years of its life GLEEP was run at 80 kW for the production of radioisotopes, until this activity was taken over by the BEPO reactor, after which time it was operated at 3 kW. GLEEP was also used for investigations into reactor design and operation, primarily the qualification of graphite and uranium, and the determination of cross sections of various materials, among other purposes. Later on, its primary use shifted to the calibration of instruments for measuring

neutron The neutron is a subatomic particle, symbol or , that has no electric charge, and a mass slightly greater than that of a proton. The Discovery of the neutron, neutron was discovered by James Chadwick in 1932, leading to the discovery of nucle ...

flux. It had an exceptionally long life for a reactor of 43 years, being shut down in 1990. The fuel was removed in 1994 and the

control rod Control rods are used in nuclear reactors to control the rate of fission of the nuclear fuel – uranium or plutonium. Their compositions include chemical elements such as boron, cadmium, silver, hafnium, or indium, that are capable of absorbing ...

s and external equipment the following year. A project to completely dismantle it was started in 2003 and completed in October 2004.

References

External links

Research Sites Restoration Limited

Aerial photographs of reactor site
{{authority control 1947 establishments in England 1990 disestablishments in England Graphite moderated reactors Nuclear research institutes in the United Kingdom Gleep Nuclear technology in the United Kingdom Research institutes in Oxfordshire Vale of White Horse Defunct nuclear reactors

See also

References

External links