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PostPosted: Nov 16, 2013 8:27 am 
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3 questions:

1) Has anyone done a complete breakdown of the waste (isotopes names, mass, and radioactivity) that would come from, for example, a once-through of 1000kg of Th in a 2-Fluid LFTR? Assuming it has reached equilibrium after the initial fissile inventory has been burnt through a bit.

2) Is it realistic for the higher level waste products to be continually fed through until only fission products remain? I often hear this aspect being championed, but can it actually be done? ie. Can the green "fission products" line be achieved on the graph on page 92 of the following link? *PDF*
http://www.platinummetalsreview.com/pdf ... 02-208.pdf

This guy claims that the waste of a LFTR will be less radioactive than the dirt under your feet after 300 years, and I can't help but think that kind of blatant championing does the technology more hurt than good - http://bravenewclimate.com/2009/12/17/l ... australia/

3) Has anyone done a complete breakdown of the quantity and value of sellable fission products that can be partitioned during fuel processing?

I look forward to your replies! (Thanks)


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PostPosted: Nov 16, 2013 8:34 am 
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(Looking for something a bit more reliable than this so I can reference it in my report, haha)

http://www.thoriumenergyalliance.com/do ... um-238.pdf


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PostPosted: Nov 16, 2013 8:35 am 
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Yes, I've done each of those.


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PostPosted: Nov 16, 2013 6:30 pm 
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Haha, I'd be surprised if you hadn't!

Anything I can reference for my report though?


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PostPosted: Nov 16, 2013 6:40 pm 
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Probably not at this time.


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PostPosted: Nov 16, 2013 6:48 pm 
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Ok, thanks!

I'll be using the phrase:

"there are currently no peer reviewed papers to support the feasibility of these claims. A comprehensive study will have to be performed to verify these claims and assess the value of the separated fission products."


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PostPosted: Nov 16, 2013 10:36 pm 
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Can someone let me know if I'm reading this graph correctly?

http://www.aps.org/units/fps/newsletter ... graves.cfm

Sorry if this is a stupid take on the graph...

The yellow line represents the radioactivity of natural uranium ore when it is dispersed in the ground?

Meaning that after 100 years, the LFTR actinides are at the same level as the uranium ore, assuming they were dispersed in the same way in the ground?

The blue line is the fission products released by both the LFTR and PWR, which are at the same levels as the uranium ore within ~400 years?

And the red line is clearly PWR actinides, which even after 10 million years is only at the level of the actinides that are released from the LFTR?


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PostPosted: Nov 17, 2013 2:38 am 
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Luke Moylan wrote:
Can someone let me know if I'm reading this graph correctly?

http://www.aps.org/units/fps/newsletter ... graves.cfm

Sorry if this is a stupid take on the graph...

The yellow line represents the radioactivity of natural uranium ore when it is dispersed in the ground?

That is a tricky question actually. It represents the radioactivity of the amount of natural uranium needed for an LWR to generate the same electricity as a LFTR. The radioactivity in the mined fuel for a LFTR is 100x lower.
Quote:
Meaning that after 100 years, the LFTR actinides are at the same level as the uranium ore, assuming they were dispersed in the same way in the ground?

That is, the actinides released by very good processing of LFTR wastes are minor. The processing assumed I think is 0.1% leakage which is as good as we hope we can do but haven't done yet. We have some basis for the hope for plutonium but for Am and Cm I don't know of even laboratory scale experiments on which to base this.
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The blue line is the fission products released by both the LFTR and PWR, which are at the same levels as the uranium ore within ~400 years?

And the red line is clearly PWR actinides, which even after 10 million years is only at the level of the actinides that are released from the LFTR?

Sounds about right.


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PostPosted: Nov 17, 2013 3:54 am 
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I think I'm even more confused! haha

So, if the LFTR and PWR were generating 1000MWe, the yellow line represents the radioactivity of ~35t of enriched uranium, all in one place? That is, it has nothing to do with the levels of radiation coming from natural ore underground?


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PostPosted: Nov 17, 2013 6:25 am 
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Actually, I got it! Thanks! I just had to read your entire explanation several hundred times before it clicked. :oops:


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