A possibility for long term storage on the earth is burial in the sea bed. The rock formations in the sea bed are generally more stable than those on dry land reducing the risk of exposure from siesmic activity. As well there is little water flow under the sea bed reducing the possibility of radioactive material escaping into the ground water. The greatest appeal of under sea burial is also its greatest drawback. The enormous cost and difficulty of burying the waste would likely prevent accidental or malicious disturbing of the waste. This cost is also keeping us from burying the waste at sea.
Ezra Gold ezrg_ltd@uhura.cc.rochester.edu