Comment un-mine it! (Score 3, Interesting) 394
uranium comes from ore dug out of the ground, at something like 0.1%-1.0% uranium oxide concentrations, so why not just take the radioactive waste and mix it with filler to dilute it down to ore concentrations (suspended in concrete, glass, whatever, something cheap and relatively durable) and drill some really deep holes, deep enough it won't affect any ground water tables, and away from oil fields - ideally near a subduction zone trench where over time the waste would get carried down further into the crust as the waste impregnated plate dives downward.
Far out of reach from civilization and in concentrations no more dangerous than already exist in nature. Surely that has to be more cost effective in the long run than maintaining highly guarded secret storage bunkers indefinitely....