Atomic Energy Research Establishment - Early Reactors

Early Reactors

Such was the interest in nuclear power and the priority devoted to it in those days that the first reactor, GLEEP, was operating by 15 August 1947. GLEEP (Graphite Low Energy Experimental Pile) was a low power (3 kilowatt) graphite-moderated air-cooled reactor. The first reactor in Western Europe, it was remarkably long-lived, operating until 1990. The engineers at Harwell eventually decided that this small reactor should be put to some use, so the air that flowed over it was directed through an underground trench were it some pipes filled with water that connect to a secondary group of water filed pipes that used by the near by establishments to heat offices. (This is not quite the case - see talk)

A successor to GLEEP, called BEPO (British Experimental Pile 0) was constructed based on the experience with GLEEP, and commenced operation in 1948. BEPO was shut down in 1968.

LIDO was an enriched uranium thermal swimming pool reactor which operated from 1956 to 1972 and was mainly used for shielding and nuclear physics experiments. It was fully dismantled and returned to a green field site in 1995.

A pair of larger 26 MW reactors, DIDO and PLUTO, which used enriched uranium with a heavy water moderator came online in 1956 and 1957 respectively. These small reactors were used primarily for testing the behaviour of different materials under intense neutron irradiation to help decide what materials to build reactor components out of. A sample could be irradiated for a few months to simulate the radiation dose that it would receive over the lifetime of a power reactor. They also took over commercial isotope production from BEPO after that was shut down. DIDO and PLUTO themselves were shut down in 1990 and the fuel, moderator and ancillary buildings removed. The GLEEP reactor and the hangar it was situated in were decommissioned 2005. The current plans are to decommission the BEPO, DIDO and PLUTO reactors by 2020.