Our Hidden Past: Precious Metals (captioned)

Time: 

4:24 min.

Y-12's calutrons required electrical conductor material, but during the war, copper was in short supply. The U.S. Treasury loaned Y‑12 14,700 tons of silver, valued at $600M. All but 67 tons was returned after the war, and those 67 tons remained in Building 9731 until 1970 for use in separating isotopes for medical research.