[ExI] Could Thorium solve our energy problem?

Max More max at maxmore.com
Sat Jul 10 18:54:33 UTC 2010

>You're still missing the point, though. Even if you triple the 
>number, you're still up against a power law.

But you mentioned a CAGR of 1.8%. That's pretty weak power law. That 
means a doubling time of 38.51 years. After a century, energy 
consumption would be only 6.05 times what it is now. Given that you 
agree that more thorium could actually be extracted than current OECD 
reserve figures suggest, it seems that growth is not a huge problem 
for quite a few decades at least.

>And if you heard me say that it wasn't worth it, that certainly 
>wasn't what I intended to convey. I'm very much in favor of MSRs 
>using the thorium cycle. Just not to the exclusion of everything else. :)

I wasn't suggesting using it to the exclusion of everything else. As 
I said (and as you quoted):
> > Besides, thorium can be well worth using for decades, especially if
> > you don't require that it replace practically *all* other energy
> > sources. It doesn't have to be a perfect and permanent solution to be
> > worth adopting.
> >

So, I don't think we disagree as much as you seem to suggest. Thorium 
can make a major contribution to meeting our energy needs, whether or 
not it can do it alone. The latter is a separate question, which 
seems to depend on (a) one's views about how much could actually be 
extracted with improved techniques and technologies; (b) whether 
thorium's energy density is 85TJ per kilogram or 85TJ per ton.

gives the number 16.3 TJ/kg for Radium-228 (which is in the 
Thorium-232 decay chain), but I don't see the relevant figure for 
thorium. I was disappointed not to find a clear answer here: 
<http://en.wikipedia.org/wiki/Thorium> nor here: 
<http://en.wikipedia.org/wiki/Nuclear_fuel> Nor did Asimov's 
Understanding Physics answer the question (although it did provide a 
lot of other information about thorium).

So far as I've been able to determine so far, it does sound like 
John's number of 85 TJ per *KG* is right -- *if* you can burn all the 
thorium. There seems to be agreement that, while you can use only a 
small fraction (0.7%) of natural uranium in a reactor, you can use 
all of the thorium. With fast breeder reactors, the situation seems 
even better.

But then there's this:

So, I'm still a bit baffled, and especially baffled that you guys 
(who know much more about this than I do) can't seem to agree on the 
numbers to within four orders of magnitude.

>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.

Space mining is good, but probably won't be feasible for a while. 
Fortunately, it looks like there's enough Terra-based thorium to make 
a major contribution for quite a few decades.


Max More, Ph.D.
Strategic Philosopher
The Proactionary Project
Extropy Institute Founder
max at maxmore.com

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