Both of you need to read the Wikipedia page about nuclear fuels, as it says something surprising: there is a window in half lives, that is the half lives are either less than ten years, or more than a couple hundred years, or something along those lines. So the decay profile of half lives is not continuous, you have some very hot and dangerous stuff, but that also blows out its punch relatively fast, and relatively mild and less dangerous stuff, but that takes a couple hundred thousand years to go away. (As in, you might almost be willing live next to it, but you don't want to ingest it for sure. There are things like cinnabar minerals in nature, that you don't want to ingest, or arsenic minerals, also toxic mushrooms, but might be willing to coexist with, and live next to them.) So these days the protocol is to hold spent nuclear fuel on site for the less than ten years part, and then when that's gone, all you got is the very low radiating but extremely long half life stuff left, which is kinda safe to ship around by rail and store. But indeed, the stuff fresh out of the reactor is deadly, and needs to be aged on site to give out its punch first. If you read up on the Fukushima disaster on Wikipedia, you'll see mention of such aging ponds.