Demolition of the historic K-25 facility will begin Tuesday, with a media event scheduled for the afternoon at the Oak Ridge plant.

The actual demolition, which will be a carefully staged "deconstruction," follows many months of preparations and series of readiness reviews by Bechtel Jacobs and the Dept. of Energy. The initial tear down will take place on the uranium-enrichment facility's west wing, which recently was declared "crit incredible'' -- meaning there was no longer a chance of a nuclear critically event.

As such, the critical alarm system in the west wing was deactivated, according to Bechtel Jacobs spokesman Dennis Hill. The alarms are still in place at the north end of the mile-long structure, as well as K-25's east wing, he said.

The significant deposits of U-235 have reportedly been removed from the processing piping and converter systems, and the remaining material was stabilized in place through a foaming process to prepare for dismantlement.

"There were a lot of tests that had to be done," Hill said. "It was determined that the threat of critically no longer existed in the west wing." That, along with meeting a series of other requirements, meant demolition was ready to begin, he said.

About 850 people are working on the K-25 dismantlement and demolition project.That includes Bechtel Jacobs and subcontractors.