my understanding re: cost of nuclear is that general consensus is that even if you factor in the energy density, the cost per unit of energy is still higher, but a large part of that has to do with how expensive it has to build a reactor, which includes dealing with all sorts of red tape, insurance, etc.

i could be speaking outta by butt, but that's the sense i got talking with an engineering friend of mine, and a friend whose brother works as a nuclear inspector