A toe-tapping performance by Oak Ridge High School’s choir and Jazz Kats band kicked off the celebration of Oak Ridge’s 80th birthday at the Historic Grove Theater.

Addressing the young musicians seated among the audience, the keynote speaker Cynthia C. Kelly said, “You’re only a year or a few years younger than many people who populated this city in the early 1940s. It boggles your mind when you think how young everybody here was” during the Manhattan Project to produce fuel for the first atomic bomb that helped end World War II in August 1945.

“It is mind boggling that this sleepy farming community was transformed into a powerhouse of innovation and technology. How did this happen? It almost didn’t. There were many times when people were about to give up and it looked hopeless.”

Kelly, president of the Atomic Heritage Foundation, was lauded a few minutes earlier by Jim Campbell, former editor of The Oak Ridger and retired director of the East Tennessee Economic Council.

He said, “Cindy has done more than anyone I know to preserve the history of the Manhattan Project.”

The evening celebration on Sept. 10 was arranged by the Oak Ridge Heritage and Preservation Association during which funds were raised for a statue of the late Ed Westcott, famed local Manhattan Project photographer.

The young choir singers and jazz band members, along with their friends and family and many others, were treated to a fascinating summary of the history of the Manhattan Project and Oak Ridge’s involvement, as well as the science behind Oak Ridge’s three processes for producing sufficient enriched uranium for the first atomic bomb.

Before her talk, D. Ray Smith, city historian, read Mayor Warren Gooch’s proclamation approving the plans for the celebration of Oak Ridge’s 80th anniversary. It mentioned that on Sept. 19, 1942, Gen. Leslie Groves, an officer of the U.S. Army Corps of Engineers, approved the government procurement of what became Oak Ridge as a site for the World War II, top-secret Manhattan Project. As a result, 3,000 local residents were displaced.

The proclamation noted that Oak Ridge grew to become the fifth largest city in Tennessee in three years and that Oak Ridge workers were not only successful in their wartime mission, but also played an important role in the birth of the Atomic Age, including the production of stable and radioactive isotopes that benefited nuclear medicine and industry.

Kelly spoke about the men who delayed the project or pushed it forward, the daunting technical challenges and the equipment failures that made producing an atomic bomb before the German Nazis did “a race against time.”

The discovery of nuclear fission – the splitting of uranium atoms into smaller atoms with a release of energetic neutrons – was published in February 1939 by the Jewish physicist Lise Meitner and her nephew Otto Frisch. But, President Franklin D. Roosevelt did not officially approve the Manhattan Project until January 1942. The construction of the Oak Ridge plants did not start until early 1943, so a tremendous amount was accomplished in less than three years.

In telling the story about Meitner, an important, but often forgotten woman, Kelly was interrupted by a loud feedback noise.

“Oh,” she said. “Maybe that’s because I just said the word uranium. Saying that word was forbidden here. Sorry.” The audience laughed.

Kelly mentioned two problems that Y-12 plant engineers encountered with the machines with strong magnets (calutrons) that were designed to separate the abundant uranium-238 isotope from the rare uranium-235 isotope capable of fission and needed for the bomb.

“The first calutrons shut down almost immediately. Groves went berserk. The electromagnetic coils had been shorted because of dirt in the system. The coils were sent back to the manufacturer, the Allis-Chambers factory in Milwaukee. The workers took the innards out of the machines and cleaned them.”

When the uranium chloride ions were shot into the calutron vacuum, the lighter ions containing radioactive U-235 bent more than the heavier ions with U-238, but only 10% were collected in pockets a half inch apart. Many of the ions deposited on the outside walls of the calutron receivers and were difficult to recover.

Clarence Larson, a chemist who later became Oak Ridge National Laboratory's director, “invented a way to copper plate the stainless-steel receivers, making it easier to retrieve the uranium material,” Kelly said. Manhattan Project chemists, she added, “were often forgotten because the physicists got most of the credit. One reason was that much of the chemistry had to be kept secret for a long time.”

Kelly credited the Oak Ridge women with some of the success of the Manhattan Project, citing the stories told in the 2013 New York Times best-selling book, “The Girls of Atomic City” by Denise Kiernan.

Kelly noted that hundreds of “calutron girls,” who were mostly teenagers, showed that they were better than Ph.D. physicists in manipulating the dials for controlling the machines at the Y-12 plant. She also mentioned the hundreds of “leak detector girls,” including the late, much-beloved Colleen Black, who worked at the K-25 Gaseous Diffusion Plant carrying portable mass spectrometers that detected leaks in pipes and tubes sprayed with helium. Once leaks were detected around welds and joints, their locations were marked so they could be repaired. Detection and repair required thousands of workers.

“Colleen did say that at first, much like the calutron girls, the girls serving as leak detectors were not trusted,” Kelly said. “We need Ph.D. scientists to use the detectors, the male leaders said. They had no choice; they didn’t have any Ph.D. scientists to spare for this task. So, they trained the Tennessee women and discovered they could do the job well.”

Kelly explained that leak detection was important because at K-25 the uranium isotopes had to be separated from a “nasty uranium hexafluoride gas that reacts with water and air viciously and corrodes most metals.” This gas is passed through the tiny pores of a barrier material, which separates the isotopes over 3,000 stages to increase the enrichment of the uranium product in fissile uranium-235. Air and water had to be kept out of the system because they would turn the gas to powder, clogging the pores.

Oak Ridge would not have produced enough uranium enriched in fissile U-235 without the S-50 liquid thermal diffusion plant.

“It was kind of a Hail Mary,” Kelly said. “The plant was built in 69 days, a ridiculously short time.”

The isotopes were separated by exposure to temperature differences as the gas ran between inner and outer pipes barely spaced apart.

“The $25 million S-50 plant did help win the war, seven days early, it has been calculated,” Kelly said. “The war was costing $1 billion a day. It saved $7 billion at the cost of $25 million.

“The S-50 plant achieved 2% enrichment of the uranium feedstock put into K-25, which increased the product’s U-235 enrichment to 20%. That was fed into Y-12 to achieve the enrichment level needed for the atomic bomb. Oak Ridge needed all three systems to work together. How lucky was that! There are a lot of things about this project that boggle the mind.”

The celebration ended with the ORHS choir singing the World War II classic composed in 1939: “We’ll Meet Again.”