K-25 is the site of the original gaseous diffusion plant. This was the largest structure ever erected, at the time of its construction, and took two years to build. Over 25,000 men worked around the clock, to get this facility into production. Construction was begun before it was even known if the process would work.  The building was up, and the membrane which actually performed the separation was delivered literally in the nick of time, for installation in the already existing piping. Even so, this building contributed no significant amount of uranium in time for WWII, though it provided much of the nuclear material used during the Cold War, and did provide some feedstock for the Calutron, and S-50. Enrichment here ended in 1964, and operation of the plant ended in 1985, as the Cold War had ended, and the over 100 tons of nuclear material stockpiled (it takes as little as 13 pounds to make a weapon pit) was considered adequate.

K-25 worked in quite a different manner than Y-12. In the gaseous diffusion process, uranium was first dissolved in acid, and then combined with fluorine to make uranium hexafluoride. This gas was then circulated through porous metal barriers, about 3000 times, to get a decent enrichment of U235. This was found to be superior to the magnetic process of the Calutron, or the thermal process of the S-50 system, which was also built here.

K-25 was such a huge project, that special housing had to be erected for the workers on the site. As it was about 13 miles from the city of Oak Ridge, it was considered to be a good idea to build worker housing out near the K-25 site. This was wartime, after all, and gas, rubber, and other commodities were rationed and in short supply. Temporary housing for around 12.000 K-25 construction workers was built in what came to be called Paradise Valley. The housing was crude and very temporary, and was torn down after construction of K-25 was complete. Little remains, as most of the buildings did not even have foundations.

K-25 is now the site of the East Tennessee Technology Park, and the Heritage Center. It is hoped to possibly reuse some portion of old K-25; but it has significant levels of highly hazardous waste. The K-25 plant still has enough uranium sitting in pipes, and machinery that there is a danger of a criticality accident, which is why the plant is still shut down, and guarded. The estimated amount of residue is classified (though this gives a pretty clear indication that it is a considerable amount); but there may well be enough here to make a bomb, or perhaps several bombs. The northern section will be restored, and preserved as a monument (can’t wait to visit there). For now, there is no public access to the site, due to the high levels of contamination, and possible pilferage of nuclear material.

The surrounding industrial park already uses some of the support buildings of the old K-25, and there has been considerable new construction. With all of the new construction, the clean up project, and the refurbishment of older buildings, Paradise valley may need to be rebuilt.

	The heritage center is the new industrial and research park, that sits on the site of the old K-25 plant.
	The Heritage Center has a more modern face than the old, massive K-25 plant.
	Left: A model of the future of isotope separation. This is the high temperature centrifuge separation plant. It is too small to separate anything like useful quantities of isotope; but it will serve as a test bed for the next generation of separation plants. Below: A look towards a part of the new Heritage Center.
	Many of the old buildings have been demolished, which saddens the preservationist. Some were too contaminated to be saved, while others have been replaced with new construction for the modern industrial park. The good news is that much of the original K-25 plant will be preserved.
	Left: Some cooling tours, with the every present water tower in teh background. Below: Some of the power lines, from the huge TVA generation facility which made all of this possible.
	Some fairly close views of the old K-25 plant. It is an obviously abandoned structure, though the caretakers hope to remedy that situation through clean up, and restoration.

Back to Y-12

Forward to more of K-25