I find it interesting that spent nuclear fuel contains a fair amount of weapons grade Pu, but it also contains other isotopes of Pu which you wouldn't want and

I find it interesting that spent nuclear fuel contains a fair amount of weapons grade Pu, but it also contains other isotopes of Pu which you wouldn't want and would be difficult to separate. It could definitely be used for a dirty bomb, which could, if nothing else, cause significant economic damage from the fear of radiation.