Is nuclear waste transported around the US used as a disposal method?

Well, a few years ago I was a caretaker in a house across from a railroad switching-yard in Illinois. We'd occasionally see a kind of low railcar, like a roof on a flatbed, with a pill-box in the middle - painted all black w/a few safety yellow pipes & markings on it. I asked a friend, who worked for the rail line what it could be & was told 'rad-waste'. The transportation of nuclear waste is not a disposal method but a manner of conveyance to its place of disposal which is somewhere remote and underground. The only real disposal method at this time is "safe" storage in a remote location.