A primer on nuclear material

 "This week we've heard plenty about policy, about who has all of this plutonium and highly enriched uranium and about the risk of a kilo falling into the wrong hands," said Morning Edition host Robert Siegel.  "But we've heard far less about the practical side of the nuclear conversation. How is this material actually stored and moved, and what can be done to make it safe besides simply locking it up?"  For answers, Siegel turned to Ploughshares Fund grantee  Robert Alvarez, a senior scholar at the Institute for Policy Studies, who began by describing the highly-enriched uranium that Ukraine has agreed to hand over.