Dounreay materials test reactor

The fast reactor project also needed a considerable amount of ancillary work, particularly in respect to the new technology of liquid metal cooling. Research rigs were set up to study the behaviour of liquid sodium in bulk, and since one of the purposes of a fast reactor was to breed more fuel, a reprocessing plant was needed. But the first reactor to go critical at the site was not the fast reactor, but the Dounreay materials test reactor (DMTR), which was of the same design as the DIDO and PLUTO reactors at Harwell. 

Unlike the Harwell reactors, the third DIDO reactor at Dounreay went by the rather more mundane name of Dounreay materials test reactor or DMTR. This system of naming seems to have been a tradition confined to Harwell and Winfrith. 

DIDO and PLUTO were built at Harwell DMTR stands for Dounreay materials test reactor, and was the first rector to be built at Dounreay. Various experiments could be set up in loops with these reactors. When applying to the Treasury for funds, a loop was described thus ... 

The Dounreay site was established as the site of the UK Fast Breeder Nuclear programme in 1955 and became operational in 1958. It accommodated three reactors, the Materials Test Reactor, (DMTR, 1958-1969), the Dounreay Fast Reactor (DFR, 1959-1977) and the Prototype Fast Reactor (PFR, 1974-1994). With all reactor operations now finished and the reactors already de-fuelled the site is undergoing active decommissioning which is planned to be completed by 2032. The Dounreay site has been cited by UKAEA as being the second biggest nuclear decommissioning challenge in the UK with similar liabilities to those at Sellafield but with smaller waste volumes. 

The authority has three Material Testing Reactors essentially of the same design Dido and Pluto at Harwell and DMTR at Dounreay. Their main purpose is to test fuel, coolants and materials which may be used in future rectors, principally to study the effects of radiations under reactor conditions. Dido and Pluto are also used for the production of isotopes of high specific activity and for research in physics, chemistry and metallurgy. 

Materials testing Reactor at Dounreay (DMTR) is closed down. 

This section does not cover the prototype reactors, nor the reactors built to investigate particular designs. Instead, the reactors described below were used for research and general materials testing. They were based at various sites mainly Harwell and Winfrith, but also Aldermaston, Dounreay and Windscale. They are described in no particular order. 

The Prototype Fast Reactor, PFR, was built and operated at the United Kingdom Atomic Energy Authority s site at Dounreay in Scotland to validate and provide operational experience of a large pool-type fast reactor and as a test bed for the fuel, components, materials and instrumentation needed for an eventual commercial-sized station It represented... 

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