The K-25 site, now called the East Tennessee Technology Park (ETTP), was built in 1943 in a rural region of East Tennessee.
Office of Environmental Management
October 13, 2020
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OAK RIDGE, Tenn. – The K-25 site, now called the East Tennessee Technology Park (ETTP), was built in 1943 in a rural region of East Tennessee.
Almost overnight, farmland gave way to massive structures erected for the Manhattan Project — a top secret project that developed an atomic weapon to end World War II.
Oak Ridge was constructed in an area ideal for the government’s secret mission. Ridges and valleys provided natural barriers and security around the various sites, an isolated setting provided secrecy, and proximity to rivers provided access to abundant power.
By September 1943, construction was underway on the 44-acre, mile-long K-25 Building. When it was finished 18 months later, it would be the largest building in the world. Not only did employees erect the world’s largest building in record time, but the revolutionary technology they developed inside the building — known as gaseous diffusion — proved to be the most efficient method for enriching uranium.
Residents of the Elza, Scarboro, Wheat, and Robertsville communities were relocated to make way for Oak Ridge, which included the K-25 site; the X-10 site, which is now the Oak Ridge National Laboratory; and the Y-12 site, now known as the Y-12 National Security Complex.
Trailers and “hutments,” or housing encampments, dotted the landscape in the early days of Oak Ridge, which grew to a population of more than 70,000 in just over two years. While Oak Ridge was one of the largest towns in Tennessee at the time, it was not listed on any public map.
Creating housing quickly was a priority, and a construction camp dubbed Happy Valley was created for workers building the K-25 site. At its peak, Happy Valley housed 15,000 residents in hutments, dormitories, barracks, trailers, and houses. It included a school, cafeterias, bakery, post office, a refrigeration and cold storage plant, theater, recreation halls, and a bowling alley. A commercial center featured a grocery store, barbershop, shoe shop, and dry goods store.
After World War II, the K-25 site would expand and become known as the Oak Ridge Gaseous Diffusion Plant. Aside from its contribution to the Manhattan Project, it also played a pivotal role in the Cold War by producing large amounts of enriched uranium for defense and commercial purposes. It provided fuel to the first nuclear submarine, the U.S.S. Nautilus, and the first nuclear power plant in Shippingport, Pennsylvania.
Years later, engineers and scientists at the site began developing and testing new enrichment methods using centrifuge technology. Ultimately the site ceased operations in the mid-1980s and it was shut down permanently in 1987.
Today, the EM program has removed all of the old, contaminated structures and transformed the site into a multi-use industrial park, national park, and recreation area to give the site a new chapter for the community.
One of EM’s most recent completions was the construction of the K-25 History Center. The center provides an in-depth history, capturing the stories of the workers who constructed and operated the site. It offers visitors 7,500 square feet of exhibits with more than 250 original artifacts on display. Nearly 1,000 oral histories were collected over a 10-year span from former Manhattan Project and Cold War workers for exhibits and interactive galleries.