While only a limited number of countries maintain stockpiles of fissile material suitable for nuclear weapons—highly enriched uranium (HEU) and separated plutonium—radioactive materials are routinely stored and used throughout the world. Today, tens of thousands of radiological sources are located in more than 100 countries around the world. Unlike a nuclear weapon, a dirty bomb would not cause catastrophic levels of death and injury, but depending on its chemistry, form, and location, it could leave billions of dollars of damage due to the costs of evacuation, relocation, and clean-up—and the inevitable follow-on threats could have severe economic and psychological repercussions.
See: https://www.nti.org/media/documents/Central_Asia_Report_Dec_2018_English.pdf
