Energy From Thorium Discussion Forum

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PostPosted: Sep 21, 2011 3:54 pm 
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David wrote:
Lars wrote:
It is also likely that there will develop other application for the technology as it is proved out.
For example, 7Li or 37Cl.



Does SILEX require a gaseous form for enrichment? That is the main problem for Lithium, no gaseous forms for the centrifuges. If SILEX is a game changer for 7Li enrichment then it is a more interesting development than I thought.

David L.


So the mass difference between 6Li and 7Li is too small to do chemical enrichment as is done in deuterium?


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PostPosted: Sep 21, 2011 6:19 pm 
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The technique used before involved the use of lots of elemental mercury. Unfortunately, a large amount of mercury was released into the environment resulting in one of the largest mercury contamination sites.


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PostPosted: Sep 22, 2011 6:12 am 
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dezakin wrote:
David wrote:
Lars wrote:
It is also likely that there will develop other application for the technology as it is proved out.
For example, 7Li or 37Cl.



Does SILEX require a gaseous form for enrichment? That is the main problem for Lithium, no gaseous forms for the centrifuges. If SILEX is a game changer for 7Li enrichment then it is a more interesting development than I thought.

David L.


So the mass difference between 6Li and 7Li is too small to do chemical enrichment as is done in deuterium?


According to this reference, multiple chemical processes work, but they all involve mercury apparently.

https://netfiles.uiuc.edu/mragheb/www/N ... chment.pdf

This patent suggests laser enrichment for lithium is possible, but requires elemental lithium under hard vacuum and high temperatures, in order to get significant amounts of it to a gaseous phase.

http://www.freepatentsonline.com/4149077.html

Does anyone know liquid lithium metal can be centrifuged to achieve isotope seperation? Or does it require the reduced interaction kinetics of a gas?


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PostPosted: Sep 27, 2012 4:11 am 
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They have now received the license from the NRC:

http://www.world-nuclear-news.org/NN-La ... ssued.html


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PostPosted: Sep 27, 2012 10:56 am 
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Re liquid centrifuging of lithium.

I looked into this.
http://www.c4tx.org/ctx/pub/infeasible.pdf

Doesnt look good. Centrifuging pretty much needs immiscible liquids.

Jack


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PostPosted: Sep 27, 2012 11:39 am 
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Los Alamos did some speculation on liquid centrifuges to separate fission products from molten salts in the 1990s. I think later papers admitted even that wasn't feasible. Can't recall if they ever even mentioned isotope separation.

David LeBlanc

Attachment:
Centrifuge94onepaper.pdf [1.97 MiB]
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PostPosted: Sep 27, 2012 12:40 pm 
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This (short) article claims energy use is much less for laser enrichment.

http://www.nature.com/news/laser-plant- ... el-1.10945


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PostPosted: Sep 28, 2012 12:32 am 
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Would this process separate 235U from 236U or is the separability based on mass?


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PostPosted: Sep 28, 2012 11:50 am 
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There is information on isotopic separation for several elements, such as Li and U, at: https://netfiles.uiuc.edu/mragheb/www/NPRE%20402%20ME%20405%20Nuclear%20Power%20Engineering/Isotopic%20Separation%20and%20Enrichment.pdf

For the laser enrichment of uranium, on page 61 of that PDF, it shows that U235 absorbs light of wavelength 5027.3 angstroms greatly, while U238 much less so. And U238 absorbs at 5027.4 angstroms greatly while U235 much less so. It seems like U236 would fall in between, so if you had VERY tight wavelength control of your laser then you could avoid U236. But my understanding of SILEX and lasers is that just controlling the wavelength enough to excite U235 preferentially over U238 was very challenging.


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PostPosted: Sep 29, 2012 4:19 am 
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djw1 wrote:
Re liquid centrifuging of lithium.

I looked into this.
http://www.c4tx.org/ctx/pub/infeasible.pdf

Doesnt look good. Centrifuging pretty much needs immiscible liquids.

Jack


Yes, that was discussed on the forum some time ago. Centrifuge needs low interactive materials, either liquid immiscible or gaseous. But if you have immiscible liquids, most of the time you don't need a centrifuge, a simple settling tank is enough.


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PostPosted: Sep 29, 2012 4:24 am 
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SteveK9 wrote:
This (short) article claims energy use is much less for laser enrichment.

http://www.nature.com/news/laser-plant- ... el-1.10945


I think it's mostly hype with poorly founded calculations. I've calculated previously that the GE plant uses a bit more electricity than a modern centrifuge. Though it is much better than diffusion of course. The main economic advantage is probably in better seperation and lower total cost per SWU - IF it works as advertised.

Note that GE has not yet commited the actual $ to the project. That worries me, considering the recent discussion of GE very likely moving out of nuclear new build. Though GE's enrichment and fuel services is seperate from the new build programmes.


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PostPosted: Oct 02, 2012 3:13 pm 
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This laser enrichment facility being killed off by the non-proliferation faction in the U.S. Government wouldn't surprise me at all. They will use the same arguments that were used to stop reprocessing as well as the IFR reactor. In their view, terrorists or rogue nations might get hold of this laser and might proceed with the enrichment of uranium virtually undetected.


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PostPosted: Oct 08, 2012 4:33 am 
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The new facility can be designed to enrich the uranium to a standard of maximum authorized (by IAEA) 20%. Reducing the enrichment by adding thorium will burn some of the U-233 in situ. The commercial benefits will be:-
a. Higher power from the uranium mined. Additional power will come from burning of U-233.
b. Fuel will have a higher burn up. Fabrication effort will go a longer way.
c. It could be possible to provide a thorium blanket, which, on reprocessing, will give U-233 for thorium fueled reactors.
http://www.dae.nic.in/writereaddata/.pdf_38


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PostPosted: Oct 08, 2012 7:50 am 
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camiel wrote:
This laser enrichment facility being killed off by the non-proliferation faction in the U.S. Government wouldn't surprise me at all. They will use the same arguments that were used to stop reprocessing as well as the IFR reactor. In their view, terrorists or rogue nations might get hold of this laser and might proceed with the enrichment of uranium virtually undetected.
It is going to happen. Technology is not limited to the US. But these folks who would trade freedom for security will have neither and they will lose the benefit of that freedom too.

_________________
DRJ : Engineer - NAVSEA : (Retired)


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PostPosted: Oct 08, 2012 9:53 am 
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USA is trying to prevent S. Korea from developing its nuclear fuel technology, in terms of uranium enrichment and spent-fuel processing. http://www.japantimes.co.jp/text/eo20121008a4.html This article poses the issue in the context of an apparent US attempt to retard any S. Korean nuclear missile technology. But in so far as S.Korea clearly intends to be a major player in nuclear reactor exports; and this necessarily implies some ability to include provisions for providing fuel for these reactors, I somewhat doubt that the U.S. attempts to restrain the S. Koreans will succeed. As well, S.Korea has spent-fuel piling up from their domestic reactors. They wish to reprocess it. My bet is they'll find a way to do it. As for domestic U enrichment, I also suspect that S. Korea has the ability to develop the SILEX process for themselves, in due time. The USA seems to be standing athwart technological progress, yelling "stop!"


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