[jec41]

Actually these scanners also check for density in case of any shielding. However you can't put shielding on a radiation device without having radiation on the outside of the shielding. Its in the air.. these scanners are so accurate that they pick up the small amount of radiation put off by marble and because of it's density containers with marble in them are checked further. I stoop shipping marble when I found out why they were tearing up my container shipments.

[defenderSD]

"Actually these scanners also check for density in case of any shielding. However you can't put shielding on a radiation device without having radiation on the outside of the shielding. Its in the air.. these scanners are so accurate that they pick up the small amount of radiation put off by marble and because of it's density containers with marble in them are checked further. I stoop shipping marble when I found out why they were tearing up my container shipments."

Shhhhhhh, keep this quiet. Don't let those diabolical nuclear terrorists know what we're doing.