OAK RIDGE, Tenn - Visiting a nuclear city may be an unusual tourist attraction but the US Department of Energy is finding growing interest in a uranium plant once so secretive it had no address and was not on maps.
From June to September visitors can tour parts of the facility at Oak Ridge in eastern Tennessee which was set up in 1943 and ran 24 hours a day separating uranium 235 from natural uranium.
It was part of the Manhattan Project that eventually produced atomic bombs dropped on Hiroshima and Nagasaki in Japan in August 1945.
But during World War Two staff recruited to the community that spread over 59,000 acres, frequently had little idea how their jobs fitted into the larger picture.
"I didn't know what I was doing or why I was doing it. I just knew how to do my job," said Gladys Owens, who operated a uranium enrichment machine.
At the time even the word uranium was rarely used and "tuballoy" was a frequent substitute.
"I was recruited straight from college as a junior chemist. I was greeted by a man in a three-piece suit who told us we would be working with uranium and that would be the last time we would hear or speak that word," said Bill Wilcox, 84.
US citizens can now get a look at parts of the original facility. Oak Ridge was the world's first fully operational nuclear reactor.
The 2.5 hour tour for 24 visitors, which runs once a day, is restricted to American citizens. The Department of Energy runs a nuclear and high-tech research establishment at the site and performs national security work.
The tours have proven so popular they are constantly booked and there is a waiting list for seats. Tourists from 46 states have visited the site. Visitors travel across the site to learn about the past and present missions of the facilities.
The Oak Ridge area was chosen for its sheltered land, plentiful water and power supply and ready workforce, according to Dick Raridon, a retired Oak Ridge scientist and a volunteer at the American Museum of Science and Energy in Oak Ridge.
The 1,000 residents originally farming there were given up to 30 days to evacuate families, animals and equipment. When building work began, houses sprang up every 30 minutes.
The average age of workers was 27. Marriages were common in the enclosed city that offered dances on tennis courts, a high school with a football team that played only away games and a church that hosted every denomination, Wilcox said.
Employees learned not to ask "what do you do?" and many did not even know there were three plants at the site.
Scientists had to experiment with different techniques to find the most efficient method of separating uranium 235. "Plant K25" used a gaseous process, while in "X10," laborers loaded chunks of natural uranium into a wall with holes leading to processing tubes.
From this plant came the uranium that fueled "Little Boy," the bomb that devastated Hiroshima, according to Judd Brown, exhibits manager at the museum in Oak Ridge.
Asked if he regretted his part in building the first nuclear bomb to have been used Wilcox said there were many bombing deaths on both sides.
"Our success was driving the (Japanese) emperor and his warlords to their knees. We helped end the most terrible war in history," he said.