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

Oxfordshire Oxfordshire is a ceremonial and non-metropolitan county in the north west of South East England. It is a mainly rural county, with its largest settlement being the city of Oxford. The county is a centre of research and development, primarily ...

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

Atomic Energy Research Establishment The Atomic Energy Research Establishment (AERE) 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 and funded by the British Governm ...

, a former Royal Air Force airfield, near

Harwell Harwell may refer to: People * Harwell (surname) * Harwell Hamilton Harris (1903–1990), American architect Places * Harwell, Nottinghamshire, England, a hamlet *Harwell, Oxfordshire, England, a village **RAF Harwell, a World War II RAF airfield, ...

in Oxfordshire (then in

Berkshire Berkshire ( ; in the 17th century sometimes spelt phonetically as Barkeshire; abbreviated Berks.) is a historic county in South East England. One of the home counties, Berkshire was recognised by Queen Elizabeth II as the Royal County of Berk ...

), in an aircraft hangar. It was a graphite moderated, air-cooled reactor and used 11,500 natural uranium fuel aluminium-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, 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 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.

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

External links