Tennessee Firsts & Inventions, sixty seconds at a time. We’ve swapped the battlefield for uranium-glass green, and there’s a new voice on the mic, Lulu, who’s warmer than Adam and a lot less likely to sound like he’s reading you a siege report. Our first act is the town that officially didn’t exist: Oak Ridge, the Secret City.
Site X
In September 1942, General Leslie Groves, two days into running the Manhattan Project, approved a stretch of ridges and valleys along the Clinch River about twenty miles west of Knoxville. The Army called it Site X, and later the Clinton Engineer Works. More than a thousand families were moved off their land, and many of them felt they were underpaid for it. Fences went up, armed guards patrolled in vehicles and on horseback, and a town was built at a speed that still sounds made up. By the summer of 1945, Groves put the population at about 75,000.
Almost nobody inside knew what the place was for. A billboard summed up the house rules: “What you see here, what you do here, what you hear here, when you leave here, let it stay here.”
Three plants, three code names
The letters and numbers meant nothing on purpose.
Y-12 separated uranium with calutrons, giant electromagnetic machines that bent a beam of uranium ions so the lighter, bomb-useful U-235 landed in a slightly different spot than U-238. The operators were mostly young women, many fresh out of high school, who watched dials all shift and were told only that the work mattered for the war. One often-told story says they kept the machines tuned better than the PhD scientists, because they followed instructions and didn’t tinker.
K-25 did the same job a different way: it pushed uranium hexafluoride gas through thousands of porous barriers, one stage after another, letting the lighter atoms get a tiny bit ahead each time. The U-shaped building covered 44 acres, each leg about half a mile long, and it was the largest building in the world at the time. (Our video calls those barriers “filters.” Close enough for sixty seconds, not close enough for a physicist.)
X-10 is the real “first” of this episode. The Graphite Reactor went critical in the early morning of November 4, 1943. It wasn’t the first reactor; Chicago Pile-1 beat it by about eleven months. But it was the first one designed to run continuously, a pilot for the big plutonium reactors at Hanford, and it made some of the world’s first plutonium.
~75,000people in Oak Ridge by summer 1945, per General Groves
44 acresunder one roof at K-25, then the largest building in the world
1,248fuel channels in the face of the X-10 Graphite Reactor
August 6, 1945
The bomb dropped on Hiroshima, “Little Boy,” was fueled by uranium enriched at Oak Ridge. For many Oak Ridge workers, that news was the first time they learned what they had been building. We kept this beat quiet in the video: no explosion animation and no casualty bar, because death estimates for Hiroshima vary widely by source and method, and a single number on screen would claim more certainty than the records give.
The peacetime first
On August 2, 1946, X-10 sent a small container of carbon-14 to the Barnard Free Skin and Cancer Hospital in St. Louis. Oak Ridge National Laboratory calls it the first official shipment of a reactor-made radioisotope. In the first year, Oak Ridge sent out more than a thousand shipments of sixty different isotopes, the start of the isotope supply that nuclear medicine still depends on.
Today
The fences came down in 1949, and the gates officially opened on March 19 with a ceremony. Since 2015, Oak Ridge has been one of the three sites of Manhattan Project National Historical Park, along with Los Alamos and Hanford. The K-25 building is gone, but the K-25 History Center tells its story. As of 2025, the National Park Service lists the X-10 Graphite Reactor as closed to the public, so check the current tour schedule at the American Museum of Science and Energy before you go.
Behind the curtain
Claude did the research and wrote the script, and Dave read it into ElevenLabs with a new voice, Lulu. Her take ran 1:03. We trimmed the long pauses and sped it up six percent to land at 57 seconds, so this is the first episode in either series that actually fits in 60 seconds. Then we aligned every word against the script so the captions could light up word by word. The valley maps, the fence, the calutron, K-25’s blueprint and the glowing reactor face are all React code rendered in Remotion. The music is the same Suno track as the Battles series, with the drop landing on “August sixth.”
What we flagged: Sources give two dates for the site choice, September 19 (Groves’s approval, per the National Park Service) and September 29, 1942 (the formal purchase), so the video says only “September 1942.” The claim that Oak Ridge was left off maps until 1949 comes from secondary sources, so the video says “kept off public maps.” X-10 was the first reactor designed for continuous operation, not the first reactor. The 75,000 population figure is Groves’s own. Maps and diagrams are schematic and not to scale.
Sources
- National Park Service: Manhattan Project site selection
- National Park Service: 1943, Graphite Reactor goes critical
- National Park Service: X-10 Graphite Reactor
- National Park Service: K-25 Gaseous Diffusion Plant
- National Park Service: 1946, Radioisotope production
- National Park Service: Oak Ridge guided tours
- Oak Ridge National Laboratory: Isotopes, 80 years
- Oak Ridge National Laboratory: Graveyard shift recollection, Nov. 4, 1943
- U.S. Department of Energy: Five fast facts about the Calutron Girls
- APS News: Reactor-powered plutonium production
- Y-12 history, part 5 (Groves on Oak Ridge’s population)
- Tennessee General Assembly: SJR 211
- Atomic Heritage Foundation: Theodore Rockwell on the calutrons
- WW2DB: Clinton Engineer Works
Narration voice: ElevenLabs. Music: Suno. Research, script support, and animation code: Claude, with a human holding the whip.
Leave a Reply