Watch How the U.S. and China Worked Together to Get Weapons-Grade Uranium out of Ghana

An airlift 10 years in the making occurred in August, when a highly enriched uranium reactor was flown out of Ghana and replaced with a more efficient core, the product of the first cooperation between U.S. and Chinese nuclear researchers in 20 years. Science's Richard Stone was on the ground in Ghana, and talks about his experiences traveling the world and reporting on these international efforts to improve nuclear security.