Tony M, look at this this and some of these images. Those rotting cylinders are all full of DUF6. That’s one of three such yards in the US alone. The UK has one somewhere; Russia, China, France, Israel, Iran, Pakistan and India – every nation that has enriched uranium – presumably have similar. All disasters waiting to happen, if it were to get into the ground water.
Do you know if dispersal in the oceans has been considered? It may be the best thing to do. I expect you’re horrified at the thought, but my estimate is that it would increase ocean concentration of uranium by around 1%, and of course there’s already loads of fluorine in the oceans. At present the US and UK plan is to turn it back into uranium metal, but then what?