Most of the quibbles about nuclear fission energy can be overcome by using thorium instead of uranium. Thorium is about 150 times as abundant (and cheap) as the isotope uranium 235. All the thorium can be used, unlike uranium isotope mixes.
Thorium - Wikipedia, the free encyclopedia
I quote :
"Some benefits of thorium fuel when compared with uranium were summarized as follows:
- Weapons-grade fissionable material (233U) is harder to retrieve safely and clandestinely from a thorium reactor;
- Thorium produces 10 to 10,000 times less long-lived radioactive waste;
- Thorium comes out of the ground as a 100% pure, usable isotope, which does not require enrichment, whereas natural uranium contains only 0.7% fissionable U-235;
- Thorium cannot sustain a nuclear chain reaction without priming, so fission stops by default."
The main disadvantage is simply that, because it is less radioactive than uranium 235, it is harder to sustain an energy releasing action. However, researchers seem to have mostly overcome that, using uranium 233 (tiny amount) to initiate and maintain the reaction.