pluto was a nuclear reactor used for civilian purposes at a time when nuclear development was at the forefront of scientific research after world war ii. ==background== pluto was a materials testing nuclear reactor housed at the atomic energy research establishment, a former royal air force airfield at harwell, oxfordshire in the united kingdom. it was one of five reactors on the site. the site was selected as the scientific center for research and development of uk's expanding nuclear programs. designed by the united kingdom atomic energy authority (ukaea), the reactor was built by head wrightson processes ltd, an industrial firm in teeside, england.bangash, m. y. h. structures for nuclear facilities. london: springer, 2011. print. pluto was one of two high flux reactors; the first, dido, was its prototype. pluto was the second of three dido class reactors to become operational. pluto and dido were located at harwell; the third, dounreay (dmtr) in caithness, scotland.the development of multi-purpose type pluto reactors gave rise to many countries building their own materials testing reactors based on dido's design. on 27 october 1957, the pluto reactor was commissioned and operated for thirty three years before decommissioning in 1990. ==design== pluto was based on the design of dido and used enriched uranium metal fuel, and heavy water as both neutron moderator and primary coolant. the core was a cylinder with a diameter of 87.5&nbsp;cm and a height of approximately 61&nbsp;cm. the radioactive shielding consisted of 0.65&nbsp;cm boral, 10.2&nbsp;cm lead, 45&nbsp;cm of iron shot concrete, and, 120&nbsp;cm of barytes concrete.bangash, m. y. h. structures for nuclear facilities. london: springer, 2011. print. there was a graphite neutron reflector surrounding the core. the fuel element was an eighty-percent enriched uranium, u-235, alloyed with aluminum plates, producing a specific power of 3,850,000&nbsp;kw/kg. the pluto reactor started operating at 10 mw thermal power but increased during upgrades to 25 mw during its operation.paul mobbs."the safety of the ukaea harwell establishment and in particular the safety of the harwell materials testing reactors".november/december, 1989. web. 8 november 2014. ==tests performed== the multipurpose pluto reactor had many diverse functions; testing materials for commercial reactors to investigating crystal structures. its main functions were fuel production, materials testing and sample activation experiments which involved testing the effects of graphite behavior under irradiation. materials testing at the harwell site involved irradiating materials using the reactors. this happened in one of 3 locations, a mark v hollow fuel element in the pluto reactor, a flux position in dido, and the flux converter in pluto. the aim of the flux converter was to give the materials the spectrum of low spatial variati
Nuclear_research_reactors Nuclear_technology_in_the_United_Kingdom Science_and_technology_in_the_United_Kingdom