Clean-up of US enrichment complex is completed

Jay Mullis, manager of DOE's Oak Ridge Office of Environmental Management, said it was hard to convey the magnitude of the achievement. "They safely took down hundreds of deteriorated and contaminated structures, some of which were the largest buildings in the world. We've now arrived at the finish line on this marathon effort, and I couldn't be more proud of the skilled, talented men and women who made this accomplishment possible for the first time ever," he said.

Uranium enrichment facilities were first built at the site in the 1940s to produce enriched uranium for defence purposes, under the code name K-25. Later renamed the Oak Ridge Gaseous Diffusion Plant, the site expanded and began also producing enriched uranium for the commercial nuclear energy industry and also to explore new enrichment technologies. Operations continued until the mid-1980s, and the site was shut down permanently in 1987. This left hundreds of contaminated facilities that had to be remediated and removed, including five large gaseous diffusion enrichment buildings.

DOE EM drew up plans to clean up the site and transform it into an asset that could generate new economic opportunities for the community, a first-of-a-kind approach within the DOE complex. In 1996, the site was renamed the East Tennessee Technology Park to reflect these plans. The first major structure to be removed - the K-1001 Administration Building - was demolished in 1999.

Demolition of the five enrichment facilities began in 2006, with the K-29 facility which was built in 1951. This was followed over the next decade by the demolition of buildings K-25, K-27, K-31, and K-33 under a plan called Vision 2016. According to EM, the largest and most challenging demolition project was the four-storey, 44-acre K-25 facility which took years of planning as workers removed uranium deposits throughout the facility and addressed other contaminants. Demolition of K-25 began in 2008, and took five years to complete.

The site showing, in green, the locations of buildings that have now been demolished (Image: DOE EM)

Following the successful completion of Vision 2016, EM set the goal to take down the remainder of the facilities in the former enrichment complex by the end of 2020 in a plan called Vision 2020. This has included removal of the TSCA Incinerator, which operated from 1991 to 2009; the Central Neutralisation Facility, a former wastewater treatment plant; the K-1037 Barrier Production Facility, originally built in 1945 and used until 1982 to produce the barrier material used in the gaseous diffusion process; the so-called Poplar Creek area - some of the most contaminated facilities at the site - which supported the uranium enrichment buildings; and the Centrifuge Complex, a group of facilities built to develop, test, and demonstrate centrifuge technology for uranium enrichment.

To date, 14 facilities and nearly 1300 acres (over 520 hectares) of land have been transferred for economic development, according to DOE EM. A further 600 acres of land is slated for economic development in the years ahead, and 100 acres set aside for historic preservation. Some 20 businesses are now located at the site.