Think you know Oak Ridge history? 13 Manhattan Project facts that might surprise you

Oak Ridge is a constant source of pride for East Tennesseans more than 80 years after it was created by the U.S. government as the first site of the Manhattan Project.

In the space of a few years, a workforce of around 50,000 people would construct massive facilities and enrich all the uranium used in the first nuclear weapon used in war. They also lived in a brand new city built on rural farmland outside of Knoxville, which included schools, churches, theaters and shopping centers.

With some help from D. Ray Smith, the official historian of the city of Oak Ridge and a popular author, here are 13 facts you might not have known about the Secret City that helped end World War II and continues as a national center of scientific excellence and national security.

Oak Ridge Schools modeled after NYC schools

As the city of Oak Ridge was speedily being built by the Army Corps of Engineers, Gen. Leslie Groves, who led the Manhattan Project, knew the city needed excellent schools to attract the best engineers and scientists in the country.

In July 1943, he hired Alden Blankenship, a graduate of Columbia University in New York City, as the first superintendent of the Oak Ridge Schools. He wanted Blankenship to make the schools typical of a public education in a large city, even though the schools were in rural East Tennessee.

"(Groves) told him to build the best school system in the nation and to pay the teachers the same salaries that they would have gotten if they were in New York City," Smith said. "He knew that he had scientists and engineers moving in here that would have come from places where there were good schools."

Oak Ridge Schools now has 768 employees and has made the Knox News list of Top Workplaces for three consecutive years. Its student body is still composed largely of the children of scientists and engineers, and over 75% of its teachers hold master's degrees. The percentage of teachers with a master's degree in Tennessee is 46.1%, according to the latest data from the National Center for Education Statistics.

Army Corps of Engineers kept land grab secret from governor

After Oak Ridge was selected as the first site of the Manhattan Project, the Army Corps of Engineers began acquiring 60,000 acres of farm land. Often, homeowners were given only weeks to move off their land and were told little more than that the government needed their land for the war effort.

Some of the first people to hear about the land grab were high school students, said Smith. U.S. Sen. Kenneth McKellar, Democrat of Tennessee, called the principal of Oliver Springs High School, who informed an assembly of students that they would have to find a new place to live.

Not even the leader of Tennessee, Gov. Prentice Cooper, knew that his state had been selected as the site to help the U.S. build a nuclear bomb and win the war.

Cooper found out about Oak Ridge, then called the "Clinton Engineer Works," in a series of letters from army officers, the first of which he ripped up in frustration at the intrusive and secretive federal government. Some others tried to assuage his fears.

"It must be emphasized at this time that the Clinton Engineer Works is not an experiment in Socialism, but a direct war project of vital importance to the best interests of the nation," Lt. Col. Thomas Crenshaw said in a letter to Gov. Cooper in July 1943.

Cooper would later visit Oak Ridge in November 1943.

Smith said a "large percentage" of displaced families moved to surrounding communities and worked in Oak Ridge during the war.

Before Oppenheimer and Los Alamos, entire Manhattan Project was meant for Oak Ridge

Why were 60,000 acres needed for the Clinton Engineer Works? When the area that's now Oak Ridge was selected as the first site of the Manhattan Project, the army believed it might be the only site of the project, Smith said.

This was before Groves hired J. Robert Oppenheimer, the now-famous physicist who led the science behind the bomb and got star treatment in Christopher Nolan's summer blockbuster. It was also before two other sites were selected. One was Los Alamos, New Mexico, where the bombs were built and tested, and the other was Hanford, Washington, which produced plutonium for the second bomb.

Oak Ridge still needed a lot of space to enrich uranium, which proved to be a tedious process. The K-25 building, which used gaseous diffusion to enrich uranium, was the largest building in the world when it was completed in 1945. It was a U-shape, half a mile long and 1,000 feet wide, and eclipsed the recently completed Pentagon.

At the height of the Manhattan Project, around 50,000 people were employed in Oak Ridge.

Code names likely have no meaning

Everything that happened in Oak Ridge during the war was top secret, and the sites that enriched uranium each had a code name.

The X-10 site was home to the graphite reactor and is now Oak Ridge National Laboratory. The Y-12 site, now the Y-12 National Security Complex, used electromagnetic calutrons to enrich uranium. There were also the S-50 liquid thermal diffusion plant and the K-25 gaseous diffusion plant, both of which have since been torn down.

When George O. Robinson Jr. was writing his book "The Oak Ridge Story," originally published in 1950, he reached out to Gen. Leslie Groves to ask where the code names came from. Groves responded that he couldn't remember how they came up with the names.

More than likely, the code names have no rhyme or reason, Smith said. The only exception could be K-25, which may have combined the first initial of the Kellex corporation which built the plant and a shorthand number for uranium-235, the fissile isotope used in nuclear weapons.

The word 'uranium' was not used

Another secret in Oak Ridge was the word "uranium" itself, which was not used, Smith said. The element was referred to by a variety of other names, perhaps "tube alloys," the name of a secret British project to study nuclear weapons.

At the Y-12 plant, leaders had assigned a 4-digit code name to each building which began with "92," the atomic number of uranium. When Groves discovered the naming scheme, he was upset that the number had been used in a project sworn to secrecy.

"He didn't think that was a good idea," Smith said. "But he also didn't make them change it because he just didn't want to call that much attention to it."

Those code names are still sometimes used for so-called "legacy" buildings still standing at the Y-12 National Security Complex.

Oak Ridge first to desegregate schools in Southeast

In 1955, 85 students from the Black community of Scarboro in Oak Ridge began attending Robertsville Junior High and Oak Ridge High School, making them the first desegregated schools in Tennessee and the Southeast up to that point.

The trailblazing students received little nationwide fanfare, perhaps, as an exhibit at the American Museum of Science and Energy in Oak Ridge suggests, because the students lived on a federal reservation.

Oak Ridge was incorporated in 1959, and those who lived on reservation land were able to purchase their homes for what Smith said was "a very reasonable price." The city's other schools integrated in 1967.

Today, Oak Ridge has a population of 32,000 and many still live in Manhattan Project-era houses in the eastern part of the city, Smith said.

Col. Kenneth Nichols was mistaken with electricity estimate

It's a popular fun fact that communicates the scale of the Manhattan Project in Oak Ridge. In his 1987 memoir "The Road to Trinity," Col. Kenneth Nichols, who oversaw the Oak Ridge and Hanford sites, claimed Oak Ridge used one-seventh of all electricity produced in the United States between 1943 and 1945.

But is it true? Smith says no.

From his work with physicist Bruce Cameron Reed, who has written extensively about the Manhattan Project, Smith said Oak Ridge used one-seventh of all electricity produced by the Tennessee Valley Authority between 1943 and 1945.

It's still a huge amount of electricity, similar to how much New York City used at the time, Smith said.

TVA was a vital early partner with the Army Corps of Engineers, which selected Oak Ridge in large part because of its proximity to Norris Dam. Fontana Dam, completed in 1944, provided electricity for the war effort as well.

All Oak Ridge uranium during Manhattan Project would fit in gallon jug

For how huge the production sites in Oak Ridge were, they didn't crank out a huge volume of highly enriched uranium, which comes in small quantities. The roughly 64 kilograms, or 140 pounds, of enriched uranium produced in Oak Ridge during the war could have fit inside a gallon jug.

That was enough to power Little Boy, which was dropped on Hiroshima on Aug. 6, 1945, and became the first nuclear weapon ever used in war. The bomb destroyed almost all of the city and killed tens of thousands of Japanese civilians.

Enriched uranium carried in secret to Los Alamos

If you've seen the "Oppenheimer" film, you might remember the scientist keeping track of how much uranium had been enriched in Oak Ridge by filling a fish bowl with metal pellets.

But how did the uranium make the trip from Tennessee to New Mexico?

To avoid notice and the risk of shipment by air, the army placed the powdered enriched uranium in gold-lined containers the size of a coffee cup and placed these in a briefcase.

An undercover army lieutenant dressed as a salesman would take the briefcase on a train headed for Chicago and then for Los Alamos. All uranium from Oak Ridge was transported this way, Smith said.

Most workers during Manhattan Project were contractors

Today, the workforce at Oak Ridge National Laboratory and Y-12 National Security Complex is overwhelmingly contract workers and not federal employees. The Department of Energy Office of Science contracts UT-Battelle to manage the lab and the National Nuclear Security Administration contracts Consolidated Nuclear Security to manage Y-12.

Around 15,000 people are employed by UT-Battelle and CNS and a handful of subcontractors. Only a few hundred workers in Oak Ridge are federal employees.

That's much the same way that it was during the Manhattan Project, Smith said. Tennessee Eastman, now the Eastman Chemical Company, was hired by the Army Corps of Engineers to manage Y-12 during the war. DuPont managed the X-10 Graphite Reactor and the Union Carbide and Carbon Corporation managed the K-25 site.

Union Carbide, as it was later known, ran the Oak Ridge sites from after the war until 1984, when they were split up.

Half of Manhattan Project land has been returned to community

While the federal government originally took close to 60,000 acres to create Oak Ridge, the Department of Energy now owns only about 30,000 acres in what's called the Oak Ridge Reservation.

Of those acres, the vast majority is undeveloped natural land. Some 20,000 acres make up the National Environmental Research Park, or NERP, a biosphere reserve.

What about the land that once belonged to the federal government? It's largely been turned back over to the community for private use, such as the Heritage Center Industrial Park at the site of the gaseous diffusion plants.

Most highly-enriched uranium came from Oak Ridge

Until 1964, the U.S. produced highly enriched uranium for nuclear weapons, and much of it came from gaseous diffusion plants in Oak Ridge following the war, Smith said.

The U.S. reached its peak number of 31,255 nuclear warheads in 1967. Since then, thousands have been retired and dismantled, but the highly enriched uranium in them has been refurbished and stored for other purposes.

Most of it is stored at the Highly Enriched Uranium Materials Facility at Y-12 in Oak Ridge, a heavily guarded building sometimes called the "Fort Knox" of highly enriched uranium. The plant no longer enriches uranium.

Mere mention of Oak Ridge in 'Oppenheimer' film boosts tourism

The "Oppenheimer" film didn't give much to Oak Ridge history buffs. The city is referenced once by Gen. Groves, played by Matt Damon, as he tries to convince Oppenheimer to join the project.

Still, as Oak Ridge's historian, Smith has seen the film boost interest in the city.

"I've done 17 bus tours here in Oak Ridge since the movie came out and there's been an increase in tourism because of the mere mention of Oak Ridge," Smith said.

Smith has seen the three-hour film four times and he said there's just one understandable inconsistency with that moment in the film. Oak Ridge did not exist by that name yet. It was still just the "Clinton Engineer Works" and would be a secret to the world for many years to come.

Daniel Dassow is a growth and development reporter focused on technology and energy. Phone 423-637-0878. Email daniel.dassow@knoxnews.com.

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This article originally appeared on Knoxville News Sentinel: Manhattan Project Oak Ridge history to know amid Oppenheimer craze