Highly enriched uranium residue contaminates processing facilities more than a decade after production stopped.

Highly enriched uranium (HEU) is a component of nuclear bombs.  If you aren’t making nuclear weapons, you don’t need to be making HEU.  That’s why places like the Department of Energy’s Savannah River Facility have been shut down.  Well, it’s more accurate to say they are being shut down, because even though they haven’t produced new material for more than a decade, they still have radioactive residue.  One place, for example, is in the ultrasonic cleaning facilities that were used to clean HEU components.  That’s why the Savannah River Technology Center measured the residual contamination in the cleaning facilities.