The Dayton Project was a research and development project that was part of the larger Manhattan Project to build the first atomic bombs. Work on the Dayton Project took place at several sites in or near Dayton, Ohio. Those working on the project were ultimately responsible for creating the polonium triggers which were used to begin the chain reactions in the atomic bombs.1
Charles Allen Thomas, an executive of the Monsanto Company corporation, was assigned to extract and purify the polonium used in the neutron generating devices that triggered the nuclear detonation of the atomic bombs once the critical mass had been "assembled" by the force of conventional explosives. The Dayton Project ran from 1943 to 1949, when Mound Laboratories were completed and the work moved there.2
In 1943, Thomas was called to a meeting in Washington DC with Brig. Gen. Leslie Groves, commander of the Manhattan Project, and James Conant, president of Harvard University and chairman of the National Defense Research Committee (NDRC).3 They urged Thomas to become co-director at Los Alamos with Robert Oppenheimer, but Thomas was reluctant to leave Dayton and Monsanto.3 Thomas joined the NDRC, and Monsanto's Central Research Department began to conduct research for the Manhattan Project under contract from the US government.4:vii
Thomas established the project in the Runnymede Playhouse on the grounds of the estate of his wife's family -the Talbott family estate- in a wealthy residential section of Oakwood, a suburb of Dayton. The Playhouse was a leisure facility that included a ballroom, indoor squash and tennis courts as well as a stage for community theater. The project was located at the intersection of Runnymede Road and Dixon Avenue. The Talbotts were among the heirs of the Delco, which was by then a part of General Motors fortune. There were ultimately four sites around Dayton that became part of the project. One was the site at the Runnymede Playhouse site in Oakwood, while other sites were developed at the original Monsanto research laboratory at 1515 Nicolas Road, the General Electric Supply Warehouse on 601 East Third Street, and at Bonebrake Theological Seminary at 1601 West First Street (which is now United Theological Seminary).5
Thomas' first job was as a chemist for Delco/GM and he was married to Margaret Talbott. He promised his mother-in-law that he would return the Runnymede Playhouse building to the family intact after the war. He was unable to keep his promise because the building became contaminated with radioactivity. The facility (also known as Dayton Unit IV) was in use for nuclear work until 1949 when Mound Laboratories was opened in Miamisburg, Ohio. The Playhouse was dismantled in 1950 and later buried in Tennessee.6
The neutron generator used on the implosion design (such as the Fat Man bomb that was dropped on Nagasaki) was coded named "Urchin". It was composed of alternating layers of polonium-210 (Po-210) and beryllium separated by gold foil. The initiator, located in the center of the bomb, was carefully designed to ensure that during the implosion of the bomb core, the polonium and beryllium mixed. Once the elements mixed, alpha particles emitted by the polonium were absorbed by the beryllium causing it to emit neutrons. The precise timing of the neutron pulse was necessary to avoid pre-detonation of the bomb which would have resulted in a "fizzle" rather than the desired blast. In modern nuclear weapons a pulsed neutron emitting tube has replaced polonium/beryllium initiators, as polonium-210 has a relatively short half-life and thus would need to be replaced every few months.
In 2007 Russian president Vladimir Putin posthumously awarded Zhorzh Abramovich "George" Koval a gold star making him a hero of the Russian Federation for his work as the GRU spy "Delmar". Russian officials stated that the initiator for their Joe-1 bomb had been "prepared to the recipe provided by Delmar".7
Koval was a US citizen born in Sioux City, Iowa in 1913 to parents of Belorussian origin. In 1932 his family returned to the Jewish Autonomous Oblast in the Soviet Union. In 1939 he was drafted into the Soviet Army, joining the GRU intelligence service. Koval returned to the US in 1940 and was drafted into the US Army in 1943. He was inducted into the Special Engineering Detachment of the Manhattan project. Koval was initially assigned to Oak Ridge where his job as a health physics officer gave him access to much of the plant. He began passing secrets relating to the production of polonium at Oak Ridge to his GRU handler code named "Clyde". In 1945 Koval was transferred to Dayton. Again his job as a health physics officer gave him wide access to the secret installation.
In 1946 he left the Army. Koval returned to the Soviet Union via Europe in 1948. In 1949 the Soviets detonated their first atomic bomb. The FBI did not begin to suspect Koval until the mid-1950s, long after he had left the US. In 2002 Vladimir Lota published "The GRU and the Atom Bomb" explaining Delmar's role. Koval died in 2006.
- DeBrosse, Jim (2004-12-05). "The Dayton Project". Dayton Daily News. p. A1.
- Staff, Ohio Environmental Protection Agency. Department of Energy, Formerly Utilized Sites Remedial Action Program (FUSRAP) – Southwest Ohio: The Dayton Sites
- Dayton Daily News. September 18, 1983 Building the Bomb in Oakwood
- Harvey V. Moyer, ed., Polonium. TID-5221, Atomic Energy Commission U.S.A., July 1956
- Dayton still pushing for national park to note role in Manhattan | www.daytondailynews.com
- Staff, US Army Corps of Engineers, Buffalo Division. Dayton Project
- Michael Walsh (May 2009). "Iowa-Born Soviet Trained". Smithsonian (Washington, D.C.: Smithsonian Institution): 40–47.