that fuel goes into the reactor, in the reactor it becomes hugel radioactive and more dangerous. by getting so dangerous it becomes less portable. it will kill you if you are around it. the agreement reached at president obama's nuclear summit in 2010 was that mexico would change this reactor. it will now use just lowenrich ed uranium. there's three things that are in motion. the u.s. brought mexico low enriched uranium to use as the fuel in their reactor. we brought that into the country. the u.s. took away on this enormous plane the fresh highly enriched uranium that mexico had. the u.s. took away mexico's highly enriched uranium that has been through already. this is the super dangerous to handle stuff. that wasn't by ship. that cannot travel by plane. watch this. >> why is the fresh fuel, which is the less hot, not e radiated fuel, why is that leaving by plane and the spent fuel, the more hot stuff leaving by ship? >> for two reasons. the fresh material because it's the more attractive target, we wouldlike to get out of the country as quickly as possible, hence the plane. >>