page_title: Windscale Piles
section_title: Construction
hierarchical_section_title: Windscale Piles / Construction
caption_attribution_description: English: Windscale Schematic, English Labels.
context_page_description: The Windscale Piles were a pair of air-cooled graphite-moderated nuclear reactors on the northwest coast of England in Cumberland. The two reactors, referred to at the time as "piles", were built as part of the British post-war atomic bomb project.
  Their purpose was to produce weapons-grade plutonium for use in nuclear weapons. Windscale Pile No. 1 was operational in October 1950 followed by Pile No. 2 in June 1951. They were intended to last five years, and served for seven until shut down after the Windscale fire on 10 October 1957. Nuclear decommissioning operations commenced in the 1980s and are estimated to last beyond 2040.
context_section_description: The site was divided into three areas: a reactor area; a service area containing offices, boiler rooms, workshops, a fire station and other amenities; and a chemical area where the plant for separating plutonium was located, along with laboratories and other supporting infrastructure. Work commenced in September 1947. At its peak, the site employed a construction workforce of over 5,000 men, along with 300 professional staff such as architects, engineers and surveyors. It was difficult to find sufficient labour locally, so workers were lured to the site from other areas with the promise of high wages and overtime. Hutted camps were established for them with canteens and other amenities. Engineers were no less hesitant about moving to Windscale. The post of site engineer was given to W. Davies from Harwell, with T. G. Williams and A. Young as his assistants.
  The reactors and their surrounding structures each weighed 57,000 long tons (58,000 t), and it was extremely important that they not shift owing to ground movement. To determine the load bearing properties of the underlying soil and rock, holes were drilled at various points. On the basis of the results of this, it was decided that each reactor would sit atop a reinforced concrete slab 200 feet (61 m) wide, 100 feet (30 m) and 10 feet (3.0 m) thick. To avoid any chance of it shrinking, the ratio of water to cement was carefully controlled, and the order in which the concrete was poured was done so as to maximise drying time. The structure above had to be sited with a tolerance of ¹⁄₂ inch (13 mm) in 100 feet (30 m).
caption: Cutaway diagram of Windscale reactor
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