According to this report, you can buy a "dirty bomb" nuclear warhead on the Bulgarian black market. Reportedly, French journalists bought a warhead from the man in the interview. The contractor that sold the warhead has strong ties to individuals in the Middle East and Pakistan. He claims to have met Osama bin Laden. This is a very scary video.
From the video:
Bulgaria is the world's portal for black-market weapons. Its abandoned nuclear plants are a veritable garden of material for illegal bombs. We traveled to the squalid gypsy camps of the capital city of Sofia and the luxury resorts on the Black Sea to see the effects of capitalism in overdrive - where everything is for sale - to meet a criminal-turned-real-estate-mogul who met with Osama bin Laden and sold a dirty bomb to French journalists.