Total Number of Seizures (April 2001) by Material

The Low Grade Nuclear material is uranium or plutonium that may be suitable for use in a nuclear reactor, but cannot be

made into a nuclear weapon.

The weapons usable material is uranium or plutonium that is the right type to be used in a nuclear bomb.  Most of these seizures have been very amounts, not enough to make a nuclear bomb out of.

REF: The picture shows a standard Russian radiological material container used in nuclear industries in Russia (model BGI-45A)