Its been done since days of nuclear plants. And no - there are no security issues, since as the name indicates, its a “waste”; you can’t make a bomb out of it and spreading it would not be as efficient as some type of gas that you would have easier access to. I imagine actually officials would love just to give away that nuclear waste to ISIS, preferrably deliver it to them for further handling by their peers, without gloves of course ;)
http://nuclearconnect.org/know-nuclear/technology/nuclear-wa...