Thanks for the link…but I don’t understand point #2(the half-life over 14billion years). Doesn’t this still make thorium significantly radioactive…or am I missing something?

Hi Bob
Sorry about that. I will add an explanation to the blog – The point wasn’t made clearly. The thing with radioactive material is that if they have a short half life such as radioactive iodine, they give out all their radioactivity quickly as they transmutate into other elements. You don’t want to be near any of these isotopes. If they have a very long half life, the total radioactivity they give out may be more or less than a short lived isotope but it really doesn’t matter. The half life is so long that the flux of radioactivity over a short period (a human life time for instance) is small. Thorium may be close to the ultimate long lived isotope with a 14b year half life which is at least part of the explanation of why there is much more of it available that for Uranium 235. The U235 has almost all disappeared since its creation.

…in other words(if I have understood correctly) the harmful effects of the release of thorium radiation would be negligible over a human lifespan or at least much less than that of uranium. If this is the case, then it kind of begs the question of why it wasn’t used in the Japanese reactors since they don’t have our fossil fuel lobby. Any thoughts on this?

That’s right and in order to get power from Thorium you first have to bombard it with Neutrons and the rate of neutron bombardment determines the rate of energy release. The Physicist express this by saying that Thorium is fertile while Uranium is fissile. As to the reasons why the world doesn’t use Thorium, assuming I have the technical side right, the second half of the blog is a list of the vested interests against the use of Thorium. It seems crazy.

Thanks, William…I think I learned something.