Depleted uranium
Some organizations have linked the BLU-116 design to Depleted uranium, with references to a DU penetrator option in US Patent 6,389,977 "Shrouded Aerial Bomb" which describes a weapon similar to the BLU-116. Two of the claims make reference to the use of tungsten or depleted uranium to make the casing of the bomb, however there is no evidence that either material was used in this weapon and specifications indicate use of a nickel-cobalt steel alloy.