THE DAYTON PROJECT, 1943-1945

Places > Other Places

Locations in and around Dayton, Ohio, served as production facilities for polonium, a key element in the Manhattan Project's aims. Early in 1943, radiochemists at Los Alamos working on the initiator for the gun assembly found that polonium would be the best material to use. At the time, however, polonium existed only in theory, and it was unclear if sufficiently pure polonium could be manufactured. The Monsanto Chemical Company, in close cooperation with Los Alamos, was contracted to solve the twin problems of polonium production and purification. Properties rented by Monsanto in Dayton, Ohio became the primary laboratories working on this task. The Dayton Project's success in developing manufacturing processes for polonium in sufficient purity and quantity were "of incalculable value in the later development of the initiator (or 'urchin') for the implosion bomb and was perhaps essential to the success of that bomb," according to the official Manhattan District History.

Charles Allen Thomas, Executive Vice-President and Technical Director of Monsanto Chemical Company, was recruited into the Manhattan Project by James Conant, Richard Tolman, and Gen. Leslie Groves in early 1943 to aid in the chemical work required. When the polonium problem arose, Thomas helped organize the Dayton Project through Monsanto as Project Director. Dr. Carroll Hochwalt became Assistant Project Director and Dr. James Lum was named Laboratory Director. The initial plans for the Dayton Project started small, estimating about twelve chemists total.

Based on this estimate, Thomas, Hochwalt and Lum began the selection and acquisition of appropriate laboratory space. Initial plans for polonium production included facilities in Clinton Engineering Works in Oak Ridge, Tennessee. No suitable buildings were available, and Laboratory Director Hochwalt deemed it undesirable from an administrative standpoint. In June 1943, Hochwalt settled on Room 30 in Unit 1, the Monsanto Chemical Company Central Research Station in Dayton, as the temporary administrative headquarters. This sufficed for early interviews and conferences, but was soon clearly inadequate and Hochwalt sought additional facilities. Rental space in Dayton was extremely limited, however. A thorough search resulted in the acquisition of a three-story Bonebrake Seminary, built in 1879 and owned by the Dayton Board of Education. This space, later occupied by the Grace A. Greene Normal School, was dubbed Unit 3. After extensive renovations and the construction of guard posts, Unit 3 was occupied in November 1943.

Still more space was needed for production. The only location found that could be occupied immediately was Runnymeade Playhouse, the estate of the wealthy Talbott family. The Talbott family was initially loathe to lease the space, but Project Director Charles Thomas, married to Margarett Talbott, promised his mother-in-law that they would return the building in its original condition. The estate included a corrugated glass roof, several greenhouses, a tennis court with cork floors, a stage, squash court, ballroom, lounges, a boiler room, and an outdoor swimming pool. The one and a half story garage became a locker room and carpenter shop. This location, now 'Unit 4,' underwent minimal renovations and opened for production. Thomas eventually broke his promise to his in-laws, as the site was irradiated by the production process and torn down in 1950.

Lum began recruiting personnel at soon as he was hired in 1943. University professors, graduate students, and commercial chemists were enlisted, though almost none with direct experience in radiochemistry were available. The first set of recruits travelled to the University of California in September 1943 for first-hand training in the field. By 1946, over 300 employees worked in the Dayton Project. The initial plan for producing polonium involved separating the polonium from lead dioxide, itself a by-product of uranium production. As there was a substantial source of lead residue immediately available on loan from the Port Hope refinery in Canada, this became a short-term solution for meeting monthly production quotas. By June 1945, however, it became clear that the tedious extraction of polonium from lead dioxide was much less efficient than a newly developed method involving irradiating bismuth. The bismuth method involved bombarding pure metallic bismuth with an intense neutron flux, resulting in a decay to polonium. Extraction and purification of the resultant polonium was still a multi-stage, difficult process, but proved sufficient to meet production quotas. In the early stages of the project, the bismuth was bombarded at the pile at Clinton Laboratories, then processed at Dayton. Later, the Hanford reactors took this over, shipping the irradiated slugs to Dayton for processing into purified polonium.

The costs of the Dayton Project grew quickly as personnel, facilities, and demand increased and as the Manhattan Project moved towards the Trinity test and manufacture of the weapons used over Japan. From $133,000 in 1943, the Dayton project cost over $1,600,000 in 1946, totaling about $3,867,000 by the end of 1946. For these expenses and efforts, the Manhattan Project received all the polonium necessary for initiator production. Having met its wartime goals, the Dayton Project began work on a permanent production facility to allow efficient polonium production in the postwar world.

For more information about Dayton and its results after 1945, follow the link below to Dayton after 1945.

Sources and notes for this page

The text for this page is original to the Department of Energy's Office of History and Heritage Resources. Portions were adapted or taken directly from Manhattan District History, Book VIII, Los Alamos Project (Y) – Vol. 3, Auxiliary Activities, Ch. 4, Dayton Project; Lillian Hoddeson, et al, Critical Assembly: A Technical History of Los Alamos during the Oppenheimer Years, 1943-1945 (Cambridge: Cambridge University Press, 1993), 123-125, 254; Jim DeBrosse, "The Dayton Project" at the Atomic Heritage Foundation website.