This policy issue has both a technical and a political aspect.
USA OLD POLICY. In the U.S., the long-preferred site was Yucca Mountain, Nevada, where the geological features apparently give an excellent prospect for the required very-long-term stability. The Federal government long ago began promoting the site for these reasons, as reflected in many U.S. policies. Unfortunately, the State of Nevada and its residents were not asked first, and they have not been particularly welcoming. And then the senior Senator from Nevada, Harry Reid, became Senate Majority Leader, and following the election of President Obama in 2008 he obtained the appointment of one of his Nevada proteges as head of the U.S. Nuclear Regulatory Commission. All this was not so positive for the idea of using Yucca Mountain as a permanent waste depository. Another decade or more of delay and back to the drawing board.
|Yucca Mountain -- The Outside|
USA NEW POLICY. In the U.S., the government realized its mistake in trying to force Nevada to accept Yucca Mountain, and inspiring the mobilization of a vocal and effective opposition. So the U.S. is now switching to a policy of looking for someplace to "raise its hand" -- someplace that wants the investment, jobs, stability and "carrots" that will come with this role.
|Yucca Mountain -- The Inside|
So Japan has pretty much adopted the former U.S. approach.
And the U.S. has pretty much adopted the former Japanese approach.
And despite this issue floating around (at least in the U.S.) for the past 40 years or more ... it is still not resolved. The problem is not, primarily, technical, though the technological questions are complex. It is a political challenge. Can a representative democracy actually do this? When? And what will it take to get it done?