Editing Manhattan Project (section)

=== Separation process ===
[[File:Hanford Engineer Works.png|thumb|upright=1.6|Map of the Hanford Site. Railroads flank the plants to the north and south. Reactors are the three northernmost red squares, along the Columbia River. The separation plants are the lower two red squares from the grouping south of the reactors. The bottom red square is the 300 area.|alt=A contour map showing the fork of the Columbia and Yakima rivers and the boundary of the land, with seven small red squares marked on it]]
Meanwhile, the chemists considered how plutonium could be separated from uranium when its chemical properties were not known. Working with the minute quantities of plutonium available at the Metallurgical Laboratory in 1942, a team under Charles M. Cooper developed a [[fluoride selective electrode|lanthanum fluoride process]] which was chosen for the pilot separation plant. A second separation process, the [[bismuth phosphate process]], was subsequently developed by Seaborg and Stanly G. Thomson.<ref>{{harvnb|Hewlett|Anderson|1962|pp=184–185}}.</ref> Greenewalt favored the bismuth phosphate process due to the corrosive nature of lanthanum fluoride, and it was selected for the Hanford separation plants.<ref>{{harvnb|Hewlett|Anderson|1962|pp=204–205}}.</ref> Once X-10 began producing plutonium, the pilot separation plant was put to the test. The first batch was processed at 40% efficiency but over the next few months this was raised to 90%.<ref name="Jones 1985 209" />

At Hanford, top priority was initially given to the installations in the 300 area: buildings for testing materials, preparing uranium, and assembling and calibrating instrumentation. One of the buildings housed the canning equipment for the uranium slugs, while another contained a small test reactor. Notwithstanding its priority, work on the 300 area fell behind schedule due to the unique and complex nature of the facilities, and wartime shortages of labor and materials.<ref>{{harvnb|Jones|1985|pp=214–216}}.</ref>

Early plans called for the construction of two separation plants in each of the areas known as 200-West and 200-East. This was subsequently reduced to two, the T and U plants, in 200-West and one, the B plant, at 200-East.<ref>{{harvnb|Jones|1985|p=212}}.</ref> Each separation plant consisted of four buildings: a process cell building or "canyon" (known as 221), a concentration building (224), a purification building (231) and a magazine store (213). The canyons were each {{convert|800|ft}} long and {{convert|65|ft}} wide. Each consisted of forty {{convert|17.7|by|13|by|20|ft|adj=on}} cells.<ref>{{harvnb|Thayer|1996|p=11}}.</ref>

Work began on 221-T and 221-U in January 1944, with the former completed in September and the latter in December. The 221-B building followed in March 1945. Because of the high levels of radioactivity involved, work in the separation plants had to be conducted by remote control using closed-circuit television, something unheard of in 1943. Maintenance was carried out with the aid of an overhead crane and specially designed tools. The 224 buildings were smaller because they had less material to process, and it was less radioactive. The 224-T and 224-U buildings were completed on 8 October 1944, and 224-B followed on 10 February 1945. The purification methods that were eventually used in 231-W were still unknown when construction commenced on 8 April 1944, but the plant was complete and the methods were selected by the end of the year.<ref>{{harvnb|Hewlett|Anderson|1962|pp=219–222}}.</ref> On 5 February 1945, Matthias hand-delivered the first shipment of 80&nbsp;g of 95%-pure plutonium nitrate to a Los Alamos courier in Los Angeles.<ref name="Thayer 1996 141" />