Oak Ridge, Tennessee is a town that I'm betting many people haven't heard of, and most have never considered visiting. It's about 30 minutes outside of Knoxville, and what it may lack of in size (population 29,000) it definitely makes up for in history. Although established in 1942, it was what we now refer to as a "secret city" meaning that it didn't exist on any maps. It was created by the United States federal government as a site to create uranium for the Manhattan Project.
The Manhattan Project included the research and manufacturing of the first nuclear weapons; specifically Oak Ridge produced the uranium-235 that was used for the atomic bomb that was dropped on Hiroshima in WWII. Oak Ridge contained two uranium enrichment plants (K-25 & Y-12), a plutonium production reactor (X-10) and a liquid thermal diffusion plant (S-50). It wasn't until 1947 that Oak Ridge was released to the public so-to-speak and was published on maps. The town then became incorporated in 1959. All of the facilities are still government owned and a lot of the locations require clearance at a checkpoint to get in to. In short, don't try to visit on your own.
The American Museum of Science and Energy (AMSE) offers a 2.5 hour bus tour for $5 (at the time of writing) and it also includes admission to the museum. The tour fills up fast though, so if you don't buy your ticker in advance you'll need to line up at the museum before they open at 9:00am. I'm serious about that- I didn't have an advance ticket, got there at 9:00am and just barely got a ticket. You'll need photo identification and you must be a U.S. citizen. This isn't an ADA friendly tour. Their website says that they need 48 hours notice if you have a wheelchair, but I'm not sure just how accommodating they can be. Not to say they don't want to be, everyone I talked to was very friendly, and the tour guides are former employees of these facilities (which was awesome), the bus just didn't look equipped for wheelchairs.
On the tour you drive by the K-25 & Y-12 sites, stop at the Y-12 New Hope Center and go to the New Bethel Baptist Church and cemetery.
You also drive by the Oak Ridge National Laboratory (ORNL) and get to go inside and see the X-10 graphite reactor:
While you're in Oak Ridge you should also check out the Friendship Bell at AK Bissell Park and the Secret City Commemorative Walk. The Bell is from Japan and stands as "an expression of the hope for everlasting peace, friendship, and understanding among all people of the world." The Walk has a ton of information about the creation of Oak Ridge and the people who founded it. Both of these are right around the corner from AMSE and both are ADA accessible.
Now, a history lesson:
Full disclaimer: I took a lot of notes in order to *try* to explain all of this accurately. Please don't crucify me if I got something wrong!
On 11/3/1943 the X-10 graphite reactor became the world's first continuously operating nuclear reactor and was used for plutonium production and separation. It closed 20 years later and is now a national historic landmark. You can see this on the tour that AMSE offers. This is the coolest part of the tour in my opinion! The K-25 "gaseous diffusion" site enriched uranium through the gaseous diffusion process. At the time of construction this building was the largest building under one roof in the world. It was a u-shaped building that was half a mile long and 1,000 feet wide. Operations stopped in 1987 and then it was demolished. Now the area is called the East Tennessee Technology Park and is being redeveloped as office space. This is also included on the tour that AMSE offers. You drive by the site, which is nothing since it was demoed, so it's a very short part of the tour. In 1942 the Y-12 "electromagnetic separation" plant used 1,152 calutrons (which filled 9 large buildings) via electromagnetic separation to collect uranium-235 by separating it from uranium-238. Y-12 supplied the uranium-235 for "little boy" the atomic bomb that dropped on Hiroshima, Japan on 8/6/1945. Y-12 continues to operate today, although now with different missions including providing nuclear fuel for Navy submarines, nuclear weapon storage, and producing materials for peaceful uses such as medical isotopes and radiation research. There's a new uranium processing facility being built with a scheduled completion date in 2025; it will connect to the Highly Enriched Uranium Materials facility (nuclear weapons storage). This is not included on the AMSE tour, however they do take you to the entrance of the facility to the New Hope Center where you can see some artifacts and watch a video. A couple of employees from Y-12 will also be there to explain what the Y-12 plant is currently used for and answer any questions. Once a year in June the Y-12 plant is open for tours during the Secret City Festival and that's it. I didn't learn that until after the fact, and found out I had missed the festival by ONE WEEK. Looks like I know where I'll be going next June!
That was a lot of info, I know, but it's really kinda fascinating don't ya think?