Note: This story was last updated at 8:30 a.m. June 2.

A building that was mostly demolished on Wednesday once helped to protect enriched uranium at Y-12, and it was used by military police and the Oak Ridge Police Department to help protect the city.

The building at 101 Bus Terminal Road was once connected by radio to a Y-12 building that stored the world’s only supply of enriched uranium-235, according to a 2010 newspaper article published by D. Ray Smith, who cited Bill Sergeant, head of security after World War II.

A small section of the Bus Terminal Road building that still had historic artifacts—two holding cells and a heavy, bulletproof steel door—remained standing, surrounded by demolition debris, on Wednesday and Thursday. It’s not clear why that one section hadn’t been demolished yet, but the 2010 newspaper article by Smith said it had been a secure federal communications center and was built to be safe from attack. That small section of the building, which had no external windows, was reported to have a concrete ceiling that was one foot thick.

The building, which is at the intersection with Oak Ridge Turnpike, is now being completely demolished so a Taco Bell restaurant can be built there. The building had been extensively modified, and it’s not clear how much of it might have been considered historic.

Smith said the Bus Terminal Road building was once connected by radio to Building 9213, which stored uranium-235 for about a year at Y-12. Building 9213 is on the south side of Chestnut Ridge, which is on the south side of Y-12. After it briefly stored uranium, Building 9213 was used for criticality experiments for years, Smith said. It’s also been used to train the National Guard to identify and isolate radioactive sources as part of their training for homeland security. [Read more…]