Hell it would be simple to dispose of if we dropped into the inter-tectonic-plate division where the hot sulfur vents come up at the bottom of the Marianas. But no-one has figured out how to do that.
As to the best option for energy, I am not sure I agree. Solaar and wind are no more costly to build for, require no fuel at all, and are driven by pretty long-term resources. They cause no fatal accidents (even occasional ones like Three Mile) and are within a generation of becoming cost competitive. So wherefore is nuclear a better option?