Editing Sellafield (section)

{{short description|Nuclear site in Cumbria, England}}
{{For|the company|Sellafield Ltd}}
{{Use British English|date=January 2013}}
{{Use dmy dates|date=November 2019}}
{{Infobox power station
| name = Sellafield nuclear site
| name_official = Sellafield Site. Known 1956-1971 as Windscale & Calder Works, known 1947-1956 as Windscale Works.
| image = File:Aerial view Sellafield, Cumbria - geograph.org.uk - 50827.jpg
| image_caption = 2005 view of the site
| coordinates = {{coord|54.4205|-3.4975|region:GB_type:landmark|display=inline,title}}
| country = United Kingdom
| location = [[Seascale]], [[Cumbria]]
| owner = [[Nuclear Decommissioning Authority]]
| operator = [[Sellafield Ltd]]
| employees = 10,000+
| np_reactor_type = [[Magnox]] (Calder Hall)<br /> [[Advanced Gas-cooled Reactor|AGR prototype]] (Windscale)
| commissioned = Windscale Piles (non-power generating): 1950 <br />Calder Hall: 1956<br /> Windscale AGR: 1962
| ps_units_decommissioned = Units taken out of service: Calder Hall: 4 x 60{{nbsp}}MWe (gross) <br /> Windscale AGR: 1 x 36{{nbsp}}MWe.<br />Final decommissioning for complete site 2120
| ps_units_operational = No nuclear power generation since 2003. <br />Processes still active: spent fuel storage, waste processing and storage, and plant decommissioning.
| extra = {{gbmapping|NY034036}}
}}

'''Sellafield''', formerly known as '''Windscale''', is a large multi-function nuclear site close to [[Seascale]] on the coast of [[Cumbria]], England. As of August 2022, primary activities are [[nuclear waste storage|nuclear waste processing and storage]] and [[nuclear decommissioning]]. Former activities included [[nuclear power generation]] from 1956 to 2003, and [[nuclear fuel reprocessing]] from 1952 to 2022.

The licensed site covers an area of {{convert|265|ha}},<ref>NDA draft strategy, August 2020</ref> and comprises more than 200 nuclear facilities and more than 1,000 buildings.<ref>Sellafield Ltd, annual report 2017-2018, retrieved Sept 2019</ref> It is Europe's largest nuclear site and has the most diverse range of nuclear facilities in the world on a single site.<ref>Sellafield context plan, published May 2017 by assets.publishing.service.gov.uk, retrieved Sept 2019</ref> The site's workforce size varies, and before the [[COVID-19 pandemic]] was approximately 10,000 people. The UK's [[National Nuclear Laboratory]] has its Central Laboratory and headquarters on the site.

Originally built as a [[Royal Ordnance Factory]] in 1942, the site briefly passed into the ownership of [[Courtaulds]] for [[rayon]] manufacture following [[World War II]], but was re-acquired by the [[Ministry of Supply]] in 1947 for the production of [[plutonium]] for nuclear weapons which required the construction of the [[Windscale Piles]] and the First Generation Reprocessing Plant, and it was renamed "Windscale Works". Subsequent key developments have included the building of [[Calder Hall nuclear power station]] - the world's first nuclear power station to export electricity on a commercial scale to a public grid, the Magnox fuel reprocessing plant, the prototype [[Advanced Gas-cooled Reactor]] (AGR) and the [[Thermal Oxide Reprocessing Plant]] (THORP). Decommissioning projects include the Windscale Piles,<ref name="Kragh">{{Cite book |last=Kragh |first=Helge |url=https://archive.org/details/quantumgeneratio0000krag |title=Quantum Generations: A History of Physics in the Twentieth Century |publisher=Princeton University Press |year=1999 |isbn=978-0-691-09552-3 |location=Princeton NJ |pages=[https://archive.org/details/quantumgeneratio0000krag/page/286 286] |url-access=registration}}</ref> Calder Hall nuclear power station, and a number of historic reprocessing facilities and waste stores.

The site is owned by the [[Nuclear Decommissioning Authority]] (NDA) which is a [[non-departmental public body]] of the UK government. Following a period 2008–2016 of management by a private consortium, the site was returned to direct government control by making the Site Management Company, [[Sellafield Ltd]], a subsidiary of the NDA. [[nuclear decommissioning|Decommissioning]] of legacy facilities, some of which date back to the UK's first efforts to produce an atomic bomb, is planned for completion by 2120 at a cost of £121{{nbsp}}billion.<ref name="sellafield_indep-2018"/>

Sellafield was the site in 1957 of [[List of nuclear and radiation accidents by death toll|one of the world's worst nuclear incidents]]. This was the [[Windscale fire]] which occurred when uranium metal fuel ignited inside [[Windscale Piles|Windscale Pile no.1]]. Radioactive contamination was released into the environment, which it is now estimated caused around 240 [[cancers]] in the long term, with 100 to 240 of these being fatal.<ref name="BBC Windscale">{{cite news |last1=Black |first1=Richard |title=Fukushima – disaster or distraction? |url=https://www.bbc.co.uk/news/science-environment-12789749 |access-date=30 June 2020 |work=BBC News |date=18 March 2011 |archive-date=11 April 2020 |archive-url=https://web.archive.org/web/20200411003052/https://www.bbc.co.uk/news/science-environment-12789749 |url-status=live }}</ref><ref name="Irish Times Windscale">{{cite news |last1=Ahlstrom |first1=Dick |title=The unacceptable toll of Britain's nuclear disaster |url=https://www.irishtimes.com/news/the-unacceptable-toll-of-britain-s-nuclear-disaster-1.970400 |access-date=15 June 2020 |newspaper=The Irish Times |date=8 October 2007 |archive-date=25 October 2021 |archive-url=https://web.archive.org/web/20211025202227/https://www.irishtimes.com/news/the-unacceptable-toll-of-britain-s-nuclear-disaster-1.970400 |url-status=live }}</ref><ref name="2007 Telegraph">{{cite news |last1=Highfield |first1=Roger |title=Windscale fire: 'We were too busy to panic' |url=https://www.telegraph.co.uk/news/science/science-news/3309842/Windscale-fire-We-were-too-busy-to-panic.html |access-date=15 June 2020 |work=The Telegraph |date=9 October 2007 |archive-url=https://web.archive.org/web/20200615223147/https://www.telegraph.co.uk/news/science/science-news/3309842/Windscale-fire-We-were-too-busy-to-panic.html |archive-date=15 June 2020 |url-status=live }}</ref> The incident was rated 5 out of a possible 7 on the [[International Nuclear Event Scale]].<ref name="BBC Windscale" />