Editing Manhattan Project (section)

=== Chicago ===
{{Main|Metallurgical Laboratory}}
[[File:ChicagoPileTeam.png|thumb|Some of the [[University of Chicago]] team that worked on the [[Chicago Pile-1]], the first nuclear reactor, including [[Enrico Fermi]] and [[Walter Zinn]] in the front row and [[Harold Agnew]], [[Leona Woods]] and [[Leó Szilárd]] in the second]]
An Army-OSRD council on 25 June 1942 decided to build a [[pilot plant]] for plutonium production in the [[Palos Forest Preserves|Argonne Forest preserve]], southwest of Chicago. This was designated [[Site A]]. In July, Nichols arranged for a lease of {{convert|1025|acre|ha}} from the [[Cook County Forest Preserve District]], and Captain James F. Grafton was appointed Chicago area engineer. It soon became apparent that the scale of operations was too great for the area, and it was decided to build the pilot plant at Oak Ridge and keep a research and testing facility in Chicago.<ref>{{harvnb|Jones|1985|pp=67–71}}.</ref><ref name="Red Gate Woods" />

Delays in establishing the plant at Site A led [[Arthur Compton]] to authorize the Metallurgical Laboratory to construct the first nuclear reactor beneath the [[bleacher]]s of [[Stagg Field]] at the University of Chicago. The reactor required an enormous amount of highly purified [[graphite]] blocks and uranium in both metallic and powdered oxide forms. At the time, there was a limited source of pure [[uranium]] metal; [[Frank Spedding]] of [[Iowa State University]] was able to produce only two [[short ton]]s. Three short tons was supplied by [[Westinghouse Lamp Plant]], produced in a rush with makeshift process. A large square balloon was constructed by [[Goodyear Tire and Rubber Company|Goodyear Tire]] to encase the reactor.<ref>{{Cite web|title=FRONTIERS Research Highlights 1946–1996|publisher=Office of Public Affairs, Argonne National Laboratory|page=11|osti=770687|doi=10.2172/770687|year=1996|url=https://digital.library.unt.edu/ark:/67531/metadc725589/m2/1/high_res_d/770687.pdf}}</ref><ref>{{cite journal |last=Walsh|first=John|title=A Manhattan Project Postscript|journal=Science|date=19 June 1981|volume=212|pages=1369–1371|url=http://pbadupws.nrc.gov/docs/ML0533/ML053340429.pdf|access-date=23 March 2013|issn=0036-8075|doi=10.1126/science.212.4501.1369|pmid=17746246|issue=4501|bibcode= 1981Sci...212.1369W}}</ref>

On 2 December 1942, a team led by Enrico Fermi initiated the first artificial{{efn|[[Natural nuclear fission reactor|Natural self-sustaining nuclear reactions]] have occurred in the earth's crust in the very distant past.<ref>{{harvnb|Libby|1979|pp=214–216}}.</ref>}} self-sustaining nuclear chain reaction in an experimental reactor known as [[Chicago Pile-1]].<ref>{{cite web |title=CP-1 (Chicago Pile 1 Reactor)|url=http://www.ne.anl.gov/About/reactors/early-reactors.shtml|publisher=Argonne National Laboratory; U.S. Department of Energy|access-date=12 April 2013}}</ref> The point at which a reaction becomes self-sustaining became known as "going critical". Compton reported the success to Conant in Washington, D.C., by a coded phone call, saying, "The Italian navigator [Fermi] has just landed in the new world."<ref>{{harvnb|Compton|1956|p=144}}.</ref>{{efn|The allusion here is to the Italian navigator [[Christopher Columbus]], who reached the Caribbean in 1492.}}

In January 1943, Grafton's successor, Major [[Arthur V. Peterson]], ordered Chicago Pile-1 dismantled and reassembled at the Site A in the forest preserve, as he regarded the operation of a reactor as too hazardous for a densely populated area.<ref>{{harvnb|Jones|1985|pp=195–196}}.</ref> Site A continued scientific research as a secret extension of the Metallurgical Laboratory at the university. [[Chicago Pile-3]], the first heavy water reactor, also went critical at this site, on 15 May 1944.{{sfn|Holl|Hewlett|Harris|1997|p=428}}<ref name="fermi">{{cite journal |last=Fermi |first=Enrico |title=The Development of the first chain reaction pile |journal=[[Proceedings of the American Philosophical Society]] |year=1946 |volume=90 |issue=1 |pages=20–24 |jstor=3301034}}</ref> After the war, operations at Site A were moved about {{convert|6|mi}} to [[DuPage County, Illinois|DuPage County]], the current location of the [[Argonne National Laboratory]].<ref name="Red Gate Woods">{{cite web |url=http://www.lm.doe.gov/SiteA_PlotM/fact_sheet_site_a.pdf|archive-url=https://web.archive.org/web/20141026070527/http://www.lm.doe.gov/SiteA_PlotM/fact_sheet_site_a.pdf|archive-date=26 October 2014 |title=Site A/Plot M, Illinois, Decommissioned Reactor Site Fact Sheet |access-date=3 December 2012}}</ref>