Staff Reports
WCM Monitor
9/4/2015
URS/CH2M Oak Ridge (UCOR), the Department of Energy’s cleanup manager in Oak Ridge, is stepping up the pace of pre-demolition activities at the K-27 building – the last of five gaseous diffusion plants slated for demolition at a former uranium enrichment site.
UCOR confirmed that it has begun removing the transite panels that contain asbestos from the exterior of the old K-27 building at what is now the East Tennessee Technology Park. The DOE contractor said special teams of workers will remove about 5,500 of the transite panels over the next few months and prepare them for disposal, a hazardous activity UCOR has performed at multiple locations over the past few years.
Ken Rueter, UCOR president and the Oak Ridge project manager, said he was pleased with the progress being made this summer at the site that is being converted into an industrial park. Once the K-27 building is removed, a huge parcel will be available for possible development under DOE’s reindustrialization program.
At one time, the site was the world’s largest uranium-enrichment complex, producing fuel for the early generations of nuclear reactors and the fissionable basis for much of the Cold War nuclear arsenal.
At the time it was constructed in the 1940s, K-27 was a companion building to K-25, the original, and largest, gaseous diffusion plant.
The K-27 building houses nine processing units once used to concentrate the fissionable U-235 for nuclear fuel. The facility has a footprint of 383,000 square feet. The total floor area in the multistory building is about 1.1 million square feet.
Pre-demolition work at K-27 has ramped up since the completion of the K-31 building in June.
Anne Smith, a spokeswoman for URS/CH2M Oak Ridge, said demolition of K-27 is scheduled to begin in January 2016. If the trend on recent projects continues, however, that date could be moved up.
K-27 presents significantly challenges because the original equipment remains in place, with a substantial number of radioactive and chemical hazards. The pre-demolition tasks include removal of significant deposits of enriched uranium and foaming of pipelines to stabilize the conditions, as well as a measure to prevent the spread of contaminants during the tear-down of the structure.
UCOR is taking special precautions at areas known to contain technetium-99, a radioactive material of particular concern because of its solubility and easy migration in the environment. Lessons learned are coming into place because Tc-99 contamination got washed away by rainfall during the demolition work at K-25 and ended up in a city of Oak Ridge sewage-treatment plant a few miles away.
As for some of the progress made this summer, Smith said UCOR completed component removal at K-27, including compressors and converters that needed to be extracted prior to demolition. The teams also removed high-level deposits of uranium that exceeded criticality thresholds and other high-risk equipment, as well some non-K-27 components that had been stored in the plant’s vaults. “Foaming inside the facility is almost complete,” Smith said.
Nearly 200 people are currently working on the project in the field, with a number of other office and support personnel.
Smith said the K-27 team expects in about three weeks to reach the “crit incredible” milestone – the point at which a nuclear criticality event is no longer deemed credible because of the removal of fissile deposits, etc..
Rueter said in a summary statement, “Deactivation work on K-27 is progressing ahead of schedule. We are approaching this job with the same attention to detail and commitment to safety as we did with K-25 and the other gaseous diffusion buildings along with factoring in the lessons learned from our previous experiences. We expect to complete building demolition ahead of schedule by the end of next year, consistent with the Department of Energy’s Vision 2016. The K-27 demolition is significant in that it is the last of five gaseous diffusion buildings at the East Tennessee Technology Park and will mark the first time a complete gaseous diffusion complex has been demolished and cleaned up anywhere in the world.”
