[Enthalpy]

...CANDU reactors coolant need to be detritiated...

CANDU reactors are the main source of tritium worldwide, the only one used presently - and they can't possibly suffice to sustain the needs of D-T fusion reactors if these get feasible some day.

[vmelkon]

Instead of D-T fusion, some are betting on D-He3 for fusion power plants.

They want to mine Helium 3 from the surface rocks of the moon.
http://www.youtube.com/watch?v=a2xChmfLlMo

The reaction would be :
D + Helium 3 => Helium 4 + p
and the proton could easily be stopped since it is a charged particle.

Besides the moon, I think there was some other video that talked about getting helium 3 from other planets in our system.

But I guess the next step would be thorium rather than helium 3 since there is plenty of it on our planet.

[Enthalpy]

Instead of D-T fusion, some are betting on D-He3 for fusion power plants. They want to mine Helium 3 from the surface rocks of the moon...

Which are two unrealistic conditions on one single proposal.

D-³He is much more difficult than D-D which is much more difficult than D-T which is very far from practical use. As intuition should shout, nearing one proton to two others (helium) needs more heat than one proton to one other.

Mining anything on the Moon is obviously more expensive than renewable energy.

[Enthalpy]

...I guess the next step would be thorium...since there is plenty of it on our planet.

No thorium reactor works up to now, despite India investing much research in it.

All proposals, including Rubbia's one, need to mix some plutonium with the thorium, and the ²³³U they breed doesn't replace Pu to start the reactor. Which, if you put proper figures, means 10 uranium reactors for 1 thorium reactor. In other words, they'd make insignificant use of the thorium deposits.

Details there http://saposjoint.net/Forum/viewtopic.php?f=66&t=2026

As an alternative, existing PWR can burn Pu+Th instead of U. It's done in Russia and planned elsewhere. Same result for cheaper.