From Federal Research Facility to Modern Business Park: The History of the Mound Site

By Anne Slattery / June 2026

The site that is now home to Mound Business Park was once known as Mound
Laboratory, which was formerly a top secret government nuclear research facility. The Mound
Laboratory operated from 1948 until 2003, and at its peak 2,500 people were employed across
116 buildings on the site. The laboratory neighbors the largest conical Indian mound in the state
of Ohio which inspired its name. Mound Laboratory was the first Atomic Energy Commission
site that was built following World War II, with the task of continuing Dayton’s work for the
Manhattan Project and consolidating production of polonium-210 and polonium-based initiators
for the first atomic bombs.

Constructing an atomic bomb required polonium, but the processing of polonium
involved taking extensive safety and security measures. Mound Laboratory began processing
polonium in 1949 with great secrecy. To prevent unauthorized access, armed guards were on site
24 hours a day and employees were not authorized to discuss their work outside of the
laboratory. Few if any of the employees actually knew that their work contributed to the atomic
bomb.

Production work happened in the Technical (T) building, an underground building built to
stand against the most powerful conventional weapon in the U.S. arsenal: a 2,000 lb. semi-armor
piercing jet-assisted torpedo. This reinforced concrete building has 16 ft. thick walls and roof,
with an 8 ft. thick floor. Building the T building involved digging out the side of a hill,
constructing the building, and then backfilling to cover the building. The building has two floors
with dimensions of about 1 acre each, on both floors three sections are divided by two 30 inch
thick fire walls. An elevator and stairway tower is located at each end of the building, and a truck
tunnel is on the upper floor.

T building was designed and equipped to be operated by 200 people for a month without
any additional supplies or services from outside. Features of the facility that supported this
included large water reservoirs, electric generators, fuel tanks, air compressor, steam generator,
operating supplies, office, and janitorial supplies. The work that was done in Mound Laboratory
for the almost 60 years it operated was essential for national security at the time, in addition to
the institution’s other major accomplishments