Sylacauga, Alabama

Alabama Ordnance Works, July 17, 1943

Manhattan District, Public domain, via Wikimedia Commons

Alabama Ordnance Works

The discovery of heavy water (D₂O) won Dr. Harold Urey the 1934 Nobel Prize in chemistry; he was the third American to do so. Dr. Urey would later make vital contributions to Manhattan Project, including helping develop gaseous diffusion methods for enriching uranium. However, it was his D₂O discovery that was produced at three sites known as Project 9 or P-9 — the Alabama Ordnance Works in Alabama, Wabash River Ordnance Works in Indiana, and Morgantown Ordnance Works in West Virginia.

The P-9 codename for the sites stood for “Project 9.” Oversight fell under the U.S. Army’s Ordnance Department, but P-9 was so secret the members of the Ordinance Department were never even allowed on-site. Only project officials were involved with the sites’ design and knew their purpose and what they produced.

D₂O is like water (H₂O), except the hydrogen isotope is called “deuterium” and contains a neutron. D₂O is about 10% more dense than regular water and melts at a higher temperature. D₂O moderates nuclear reactions to slow down the neutrons and sustain the chain reaction.

Making D₂O requires distillation — a process that separates liquids through evaporation and condensation. However, the distillation process was time consuming and inefficient at the scale required by the Manhattan Project. Instead, graphite became the popular control medium. The declining need for D₂O led to the Alabama Ordinance Works closing after World War II.

Afterwards, other companies tried to claim the land before it was finally released by the Ordnance Department nearly two decades later. Eventually this former Manhattan Project site became an industrial park.

Bibliography

Atomic Heritage Foundation, 2022. “Sylacauga, AL,” https://ahf.nuclearmuseum.org/ahf/location/sylacauga-al/, accessed November 27, 2024. 

Atomic Heritage Foundation, 2022. “Harold Urey” https://ahf.nuclearmuseum.org/ahf/profile/harold-urey/#:~:text=Scientific%20Contributions&text=For%20this%20discovery%2C%20Urey%20received,%2D235%20from%20uranium%2D238 

U.S. Department of Energy, Office of Nuclear Energy. Nuclear 101: How Does a Nuclear Reactor Work?, August 2, 2023.  https://www.energy.gov/ne/articles/nuclear-101-how-does-nuclear-reactor-work#:~:text=Inside%20the%20reactor%20vessel%2C%20the,or%20withdrawn%20to%20increase%20it. Accessed February 14, 2025. 

Fiore, J., 1987. J. Fiore, director Division of Facility and Site Decommissioning Projects, Office of Nuclear Energy, letter (about AL.02-1) to C. Schafer, director of environmental policy, Office of the Deputy Assistant Secretary of Defense for Installations, https://lmpublicsearch.lm.doe.gov/lmsites/5899-al.02-1.pdf, accessed November 27, 2024.