“(395 million troy ounces, according to Wikipedia). It was all returned when electromagnetic processing became obsolete; about 0.036% was unaccounted for”
142,200 ounces of silver missing.
Yeah, not a trivial amount.
I don’t think they had metal detectors at the employee entrances back then, but I’m not sure.
The did have radiation detectors, IIRC.
They had to work the silver bars into a form that could be run through wire-drawing machines; they also had to make bus-bar connectors that had holes drilled in them, were machined on lathes, etc. I’m sure a substantial amount ended up as filings, turnings, etc.
Silver was about $6/oz back in the WWII days, so 142,000 oz is about $860K. The Y-12 plant cost several hundred million dollars to build and many millions a year to operate, so the silver lost is more or less a rounding error.
The towns and cities around the Manhattan District plants were crawling with FBI agents and other law-enforcement types back then, so I think anyone wanting to cash in hundreds of thousands of dollars worth of silver would have drawn attention pretty fast. Of course, it could have been stored away until after the war.