I can see that a lot of good thought went into the Thorium bank and on one level I would like to congratulate John Kutsch and the other inventors on the Thorium Bank concept.

I regret that I must also say that the extreme measures (lead lined roof to stop gamma radiation from Thorium decay daughters - low temperature refrigeration to entrap radon (or Thoron) given off in Thorium decay) employed in this building create the wrong impression about Thorium for the public. Building over the top structures like this that greatly exceed any reasonable risk gives the public impression that there really is some reason to take these extreme measures. In fact, there is no health justification for these extreme measures at all, public fear of thoria ore is unjustified, and facilities like these only serve the anti-nuke strategy of unjustifiably pricing up Thorium technology (to the point no one ever builds Thorium reactors).

Note: The type of radon produced from Thorium is different from the type of radon produced from Uranium decay and is less dangerous. One of the fears about storing thorium, found naturally in the earth's crust is that as thorium decays, it produces the radioactive gas radon. The concern about radon is that it could cause lung cancer in humans.

The radon isotope produced in the decay of thorium-232 is radon-220. It has a half-life of 55 seconds. Which means that in 1-2 minutes this gas has to leave the ore it came from, drift into your lungs, and decay into polonium-216 to present an actual health danger. Refrigeration of a building to very low temperatures is unjustified in an effort to contain radon-220.

Uranium-238, on the other hand, produces radon-222, which has a half-life of 3.82 days, which lasts about 6000 times longer than the radon-220 produced by thorium.

(I would like to thank Kirk Sorensen who first made me aware of this difference in radon produced by Thorium and Uranium decay)

I agree, Robert, that the need for such measures is likely unnecessary and leading to unrealistic criticism of the overall idea.

A modest underground facility would be fine, since that's where the Thorium was in the first place.