What is Source Material according to NRC?
Uranium or thorium, or any combination thereof, in any physical or chemical form, or ores that contain, by weight, one-twentieth of one percent (0.05 percent) or more of (1) uranium, (2) thorium, or (3) any combination thereof. Source material does not include special nuclear material. For additional detail, see Source Material.
Thorium 232 has a half life of 14 billion years, about the same as the generally accepted age of the universe until the dell telescope discovered much more than was known
Uranium 238 has a half life of 4.5 billion years and Uranium 235 has a half life of 700 million years.
In addition Uranium has as its first transition Thorium generation on its path down to the final stable state, Lead. This means that Uranium is at least four times as radioactive as Thorium.
It is interesting to observe that in the decay path of both Uranium and Thorium they pass through Radon and emit two alpha particles on the way.
The definition for Source material should therefore be changed to:
Uranium or thorium, or any combination thereof, in any physical or chemical form, or ores that contain, by weight, one-twentieth of one percent (0.05 percent) or more of (1) uranium, 0.2 percent of (2) thorium, or (3) any proportional combination thereof.
Why is this important? The U.S. used to be world leader in rare earth metals production. Then when the regulation on Source Material was instituted, mining rare earth metals with a small amount of Thorium became unprofitable and China took over, and developed a near monopoly on the market, in effect making rare earth metals single sourced. Rare earth metals, as well as Thorium is of great strategic value.
Here is an example:
This is the Mount Weld Rare Earth Mine in Western Australia. It is owned by Lynas Corporation. The mined ore, after concentration is shipped to Malaysia for final refining. The concentrated ore contains 30% rare earth metals ready for separation, but the ore also contains 0.16% Thorium. For the moment, only the most sought after rare earth metals are refined, the rest are left on the slag heap, which includes Thorium. This makes it nuclear waste according to a multitude of protestors, after all it is source material. To complicate matters further, China is looking to grab the mine, so they stir up as much trouble as possible
Len Bilén's blog, a blog about faith, politics and the environment. 