The only reason the costs per joule in dollars are near each other (true factor of about 1.5-3x the cost in dollars between nuclear and the coal everyone knows and loves, according tothe EIA ) is that a lot of the true costs of nuclear power plants are not borne in dollars and are instead externalized. Fifty years of waste have been for the most part completely un-dealt-with in the hopes that something will come along, nuclear power plants are almost literally uninsurable to sufficient levels in the market such that governments have to guarantee them substandard insurance by legal fiat (this is also true of very large hydroelectric dams which are probably also a very bad idea), and power plants that were supposed to be retired long ago have had their lifetimes extended threefold by regulators who don't want to incur the cost of their planned replacements and refurbishments. And the whole thing was rushed forwards in the mid 20th century as a byproduct of the national desire for nuclear weapons, and remarkably little growth has occurred since that driver decreased.
If true, how do you know it's going to remain true in the future?
How do you know it won't? More to the point, it's not a question of technology. It's a question of how much you have to concentrate rare radionuclides in expensive gas centrifuge equipment and how heavily you have to contain the reaction and how long you have to isolate the resultant stuff. Technology does not trump thermodynamics and complexity and fragility.
What happens when we reach a level of technology in which energy production is completely automatic?
What does this mean and why is it relevant?
What about nuclear fusion?
Near as I can tell, all the research on it so far has shown that it is indeed possible without star-style gravitational confinement, very difficult, and completely uneconomic. We have all the materials you need to fuse readily available, if it were easy to do it economically we would've after fifty years of work. It should be noted that the average energy output of the sun itself is about 1/3 of a watt per cubic meter - fusion is trying to produce conditions and reactions of the sort you don't even see in the largest stars in the universe. (And don't start talking about helium three on the moon, I point to a throwawy line in http://physics.ucsd.edu/do-the-math/2011/10/stranded-resources/ regarding that pipe dream.)
Is it possible I'm wrong? Yes. But literally any future other than a future of rather less (But not zero!) concentrated energy available to humanity requires some deus ex machina to swoop down upon us. Should we really bank on that?
And the whole thing was rushed forwards in the mid 20th century as a byproduct of the national desire for nuclear weapons, and remarkably little growth has occurred since that driver decreased.
The obvious explanation of the timing is Three Mile Island and Chernobyl.
Do you believe that Japan and Germany built nuclear plants for the purpose of eventually building weapons?
You know the drill - If it's worth saying, but not worth its own post (even in Discussion), then it goes here.