Major operations for the Manhattan Engineer District (Manhattan Project) took place in remote site locations in the states of Tennessee, New Mexico, and Washington, with additional research being conducted in university laboratories at Chicago and Berkeley.
At the Metallurgical Laboratory in Chicago, Enrico Fermi's experiments at the CP-1 pile took place to determine the exact amount of neutron reduction needed for a safe and controlled sustained nuclear reaction. A second pile (CP-2), with external cooling, was built at Argonne in order to move the continuing experiments away from populated areas.
Under the umbrella of Clinton Engineer Works near Oak Ridge, Tennessee, the X-10 experimental plutonium pile and separation facilities, the Y-12 Electromagnetic Plant, and the K-25 Gaseous Diffusion Plant were constructed.
In February 1943, ground was broken at X-10 for an air-cooled experimental pile, a pilot chemical separation plant, and support facilities. On November 4, the pile went critical and it produced plutonium by the end of the month. The chemical separation plant completed the steps needed for producing pure plutonium by extracting the plutonium from the irradiated uranium. Chemical separation techniques were so successful that Los Alamos received plutonium samples in the spring of 1944.
Because of security requirements, fear of radioactive accidents, need for a long construction season and abundant water for hydroelectric power, an isolated area near Hanford, Washington (Site W) was chosen for the production plants. Three water-cooled piles and three chemical separation plants were constructed.
At Y-12, using a design that was based upon research at Berkeley Lab, the first electromagnetic plant began to take shape in 1943. By the end of February 1944, 200 grams of twelve-percent enriched uranium was produced. Part of this was sent to Los Alamos and part was used to feed continuing production at Y-12. Site preparation for the gaseous diffusion plant at K-25 was begun in June 1943. This plant ultimately provided feed material for Y-12 at around fifty percent enriched uranium. A thermal diffusion plant (S-50) to produce enriched uranium was added in early 1945.
In New Mexico, the Los Alamos Scientific Laboratory, under the direction of J. Robert Oppenheimer, was set up to design and fabricate the first atomic bombs. To do this, it was necessary to start a chain reaction in a mass that would release the greatest possible amount of energy before it was destroyed in the explosion. Two types of bombs became the focus of the work: The uranium gun design (the Little Boy) and the plutonium implosion design (the Fat Man).
- Edited excerpts from The Manhattan Project: Making the Atomic Bomb
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