A Permanent Disposal Solution for Nuclear Waste
My dad always talked about how dangerous he thought nuclear power was and so I always had a certain interest in the subject.  His main argument is that the waste from this type of energy source has no safe disposal method.  What do you do with the leftover stuff?
It is deadly to any life for huge lengths of time as the half life of many of the materials is thousands of years.  We have no containers that last even hundreds of years (much less thousands) and you simply bury it, it might come back in the water system after a few hundred years go by as the geography changes.  Terrorists want to steal it to make dirty bombs and no one wants to have the stuff stored near them (for obvious reasons). You don't want to shoot it into space because if it blows up, you just screwed everyone by throwing a bunch of radioactive crap into the air that will turn up in the rain, then plants and then animals and so on.

I suggest this.  Send it back into the earth and let it dissipate in the mantel.

How? By using the Earth's own plates to do the job for us. It is understood today that the earth's crust is not a solid shell like an egg, but rather it is a collection of vaious sized slabs of crust that are moved about by the thermal activities of the manel and core of the Earth. Plates slide about, grind around each other and smash into each other on a constant basis.
Below is a simple illustration of what is known as a Subduction Zone.
A Subduction Zone is a fault line on the earth's crust where 2 plates collide with one another. One plate is pushed below the other and down into the Earth's Mantel where is melts down and is recycled so to speak. Subduction zones often form deep trenches along the fault line of the 2 plates.
Subduction zones are the fault lines between 2 plates that are pushed together.  More specifically, a subduction zone is where 1 plate is pushed under the other plate typically resulting in a  deep trench for a fault line.  The most spectacular example of this is the Pacific Plate and the Philippine Plate in the Pacific Ocean.  The collision of these 2 plates has created the deepest trench in the world; the Marianas Trench.
At its deepest point the Marianas Trench reaches a depth of up to 35,838 feet (almost 7 miles) and is hundreds of miles in length.
Suppose you were to place your radioactive waste at this fault line where one of these plates got pushed under another and back into the mantel of the Earth?  You would not have to design a container that would last thousands of years (maybe not even hundreds).  You would not have to guard the contents from terrorists as there are only a handful of machines capable of operating at that depth.  You would not run out of space because you are continually sending it back to where it came from.  And best of all it all gets melted back down and dissipated throughout the mantle.  It would be thousands of years before any of it returned to the surface in a  volcanic eruption. Since the stuff came from the earth and arrived at the surface where we dug it out and refined it, it harely seems outraegous that sending it back in this manner will give rise to some "radioactive" volcanic eruption or magma flow (no more than how much radioactive material comes up in a normal eruption)
The biggest challenge to making this happen in my opinion is not the transportation of the waste or its placement in such a trench but rather the environmentalist opposition.  Regardless of what statistics you pull up relating to relative safety of placing waste at the bottom of the ocean or in a salt mine in the Yucca Mountain, opposing any solution is easier than getting behind the best one.

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