Reply #12: Yes, very much so.

[NNadir]

The difference in binding energy between tritium + deuterium and helium and a neutron is enormous when compared to the difference between an actinide and a fission product, so lithium resources are very likely to extend for a much longer period than Uranium/Thorium resources. I do not know, however, the world reserves of lithium.

http://www.wou.edu/las/physci/ch371/lecture/lecture4/sld008.htm

There is also the possibility that over a very long time the deuterium-deuterium fusion reaction will become technologically feasible, and nuclear resources will in fact become nearly infinite. This is, I think, a very long way off. The caveat is that the deuterium-deuterium reaction releases most of its energy in the form of gamma rays, which must be transformed to usable energy through some sort of thermalization. In the tritium deuterium case, the kinetic energy of the neutron released helps to provide thermal energy through collisions. The helium-4 also has considerable kinetic energy. Actually, no one is really sure how to effect the transformation of existing fusion reactors into usable work. Such systems have only been considered at a low level.