About 140 cases of missing or unauthorized use of nuclear and radioactive material were reported to the U.N. atomic agency in 2013, highlighting the challenges facing world leaders at a nuclear security summit next week.
Any loss or theft of highly enriched uranium, plutonium or different types of radioactive sources is potentially serious as al Qaeda-style militants could try to use them to make a crude nuclear device or a so-called "dirty bomb", experts say.
Denis Flory, deputy director general of the International Atomic Energy Agency (IAEA), said most of the reported incidents concerned small quantities of radioactive material.
But, "even if they can't be used for making a nuclear weapon, they can be used in radioactive dispersal devices, which is a concern," Flory told Reuters in an interview.
In a "dirty bomb", conventional explosives are used to disperse radiation from a radioactive source, which can be found in hospitals, factories or other places that may not be very well protected.
Holding a third nuclear security summit since 2010, leaders from 53 countries - including U.S. President Barack Obama - are expected to call for more international action to help prevent radical groups from obtaining atomic bombs.
TVNL Comment: What in the hell is 'unauthorized use' of nuclear material? How in the hell does it go 'missing"? Radioactive stuff gets stolen, sold or smuggled. Just max out your credit cards and wait for someone to use this in your back yard. Geez.