A life cycle assessment would indeed be useful, and I feel it has been done. The problem is time. When dealing with particles whose half-life range from seconds to millions of years, the only real solutions are either incineration or storage.

Currently, the most effective way to "dispose" of spent fuel in nuclear power plants is to store them, indefinitely, in specialized casks that remain on-site at the facility. The technology is impressive. One spent fuel bundle puts out enough radiation to kill someone in seconds. These casks house several dozen spent fuel cells, and the cask will put out radiation that's slightly above background radiation levels.

For conventional radioactive waste, I know Belgium has been incinerating theirs for a couple of decades. Their process is pretty sound.

Ultimately, the problem of half-life still remains a significant factor of difficulty in dealing with radioactive waste. Theoretical solutions that attempt to solve that problem involves utilizing fast reactor systems or fast laser pulses. The fast laser pulse concept is pretty far out there as it proposes to reduce the half-life of atoms from "a million years to 30 minutes".