> it's safer to transport the materials without the added attention from armored escorts A colleague of mine who once worked at a nuclear power plant said this

> it's safer to transport the materials without the added attention from armored escorts A colleague of mine who once worked at a nuclear power plant said this is precisely the reason. Also, as mentioned below, this material, while decidedly dangerous, is considerably less so than, say, spent nuclear fuel, which is actually moved in giant police escorts. (Interestingly, they told me that some states actually refuse to have spent fuel trucked through their land, so often it has to be rerouted many hundred more miles between plant and destination.)