[ExI] Could Thorium solve our energy problem?

Brent Neal brentn at freeshell.org
Fri Jul 9 10:40:30 UTC 2010

On 9 Jul, 2010, at 0:17, Max More wrote:

> Brent: Am I missing something in what you say? It seems that you are taking the *current* world thorium reserves and then figuring out how long they would last. Even then, you get almost a thousand years of supply. But obviously the current reserves would be replenished and added to once there was actually a demand for thorium. It make no sense to take the current relatively stock -- which is only a tiny fraction of what we could extract -- and then say it won't last long, while ignoring new supplies. Yet that's what you *seem* to be saying. Please correct this impression if I'm wrong.
> Max

The OECD reserve number, according to their notes, is an estimate of the amount of thorium in ores that are potentially accessible via mining. There is, of course, a lot more thorium in the crust that even given an optimistic extrapolation of improvement in mining technology will not be economically feasible to recover - think gold in seawater type of concentrations. Barring nanoassemblers that sift through volcanic dust recovering single thorium atoms, its very unlikely that we can tap that for energy.

The real issue is that, even if you double the figure of the reserves, you don't double the time to depletion. If you put the same spreadsheet together that I did, then you can dick around with the "reserves" number and see how relatively insensitive the time to depletion is to even fairly large changes in that number. Energy is wealth, and if we are going to continue to increase energy demand per capita (and note that I'm not even talking about population growth, which I assume optimistically to level out after 2050), then that 1.8% CAGR becomes a huge burden. 

John's suggestion of mining thorium on the moon is a much better solution, IMO. We need to break the constraints placed on us by limiting ourselves to the crust of the Earth. Whether that's lunar mining or solar power satellites, that's the right solution. 

Please understand that I'm not bashing the idea of molten salt reactors on the thorium cycle. I have defended those vociferously against both so-called "greens" who wet their pants at the mere mention of nuclear power and the right wing neo-con set who believe that if GE and Westinghouse got their LWR designs blessed by the government, then the holy market has spoken and no more needs to be said. :P


Brent Neal, Ph.D.
<brentn at freeshell.org>

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