Energy From Thorium Discussion Forum

It is currently May 25, 2018 11:21 pm

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 35 posts ]  Go to page 1, 2, 3  Next
Author Message
PostPosted: Oct 06, 2007 6:29 pm 
Offline
User avatar

Joined: Nov 30, 2006 9:18 pm
Posts: 1950
Location: Montreal
04.10.2007 No. 219 / News
US Utilities Show Support For Laser Enrichment Technology
4 Oct (NucNet):
US utilities Exelon and Entergy have become the first companies to sign non-binding letters of intent to contract for uranium enrichment services from GE-Hitachi Nuclear Energy (GEH), it was announced today.

GEH is working to commercialise the next generation Silex laser enrichment technology, now known as Global Laser Enrichment (GLE) Technology.

GE said today the two utilities may also provide facility licensing and public acceptance support needed for the development of commercial-scale GLE technology to produce enriched uranium for use in commercial nuclear reactors.

In May 2006, GE signed an exclusive agreement with Australia-based Silex Systems that could lead to the construction of a third-generation commercial uranium enrichment facility in the US based on Silex’s laser technology.

GHE has since begun preparing a test loop at the nuclear fuel manufacturing facility operated by Global Nuclear Fuel in Wilmington, North Carolina – a joint venture of GE, Hitachi and Toshiba.

GE said that licensing activities and selection of a site for a commercial plant are under way and start-up of the commercial plant is scheduled for 2012. The commercial GLE facility would have a target capacity of between 3.5 and 6 million separative work units (SWU’s).

.


Top
 Profile  
 
PostPosted: Dec 10, 2007 5:29 am 
This is purely based on not the requirement point of view, but my opinion based on nuclear safety expertise.

Do we really need to produce more of the enriched uranium, which needs so much energy for the production?

Why not use plutonium / mixed oxide fuel? Lot of plutonium is around from the dismantled weapons?

PHWR types are still in demand in countries like India, which uses natural uranium.

Thourim fuel cycle should be the future option for nuclear power.

One should be concerned about so much fissile material inventry world-wide from terrorist considerations.


Top
  
 
PostPosted: Dec 10, 2007 7:47 am 
Offline
User avatar

Joined: Nov 30, 2006 9:18 pm
Posts: 1950
Location: Montreal
raja wrote:
Do we really need to produce more of the enriched uranium, which needs so much energy for the production?

It is precisely because of the much lower energy requirement that Silex technology is considered desirable.

As for India, besides the PHWRs which use NU, the new Kudankulam plant in Tamil Nadu comprises two large Russian VVERs (PWRs) with a combined capacity of 2,000 MW.
These reactors use LEU with a mixture of ~3.5% to 5% enriched fuel.
And while Russia will supply the fuel for these reactors, the need for enrichment technology remains, as long as these types of reactors are being used.

Moreover, India is looking to buy more of these Russian nukes.
For this deal to go ahead, the new international nuclear agreement with India must first be concluded (the Kudankulam purchase was grandfathered from an old Soviet deal...).

.


Top
 Profile  
 
 Post subject:
PostPosted: Dec 10, 2007 6:22 pm 
Offline

Joined: Dec 20, 2006 7:50 pm
Posts: 283
Also laser enrichment allows burning of reprocessed uranium more than once from light water reactors, whereas diffusion or centrifuge enrichment leaves U-234 and U-236 in the fuel stream, meaning REPU can only be used once.

Because laser enrichment is so fine in its control it can select the U-235 alone.


Top
 Profile  
 
 Post subject: Laser Isotope Separation
PostPosted: Dec 08, 2008 4:45 pm 
Offline
User avatar

Joined: Aug 21, 2008 12:57 pm
Posts: 1058
ondrejch wrote:
I like "virtually no TRU waste"!

Lars wrote:
We do have the advantage on IFR that we aren't very picky about the fuel content so we can afford to have some fission products in the fuel. I believe it is easier to keep the TRU's out of the waste stream if we tolerate some fission products in the fuel coming back to us.


Perhaps one could engineer a way to get the FPs selectively out of the fuel salt, leaving everything else inside. Then the reaction kinetics would not require any TRU leakage, and there will be no TRU waste, period. The old salt would be reused in a new (or fixed) reactor vessel.

It should be emphasized that none of this is necessary to be part of the first generation of Liftrs, and anyway until some of them are built, there will not be a rock solid number to quote. IMHO the important consideration is (second to many orders of magnitude reduction of TRU waste in the first place) an idea how to solve the TRU issue in principle, showing that we can now deal with the pressing issues (Yucca, uranium supply to 80% nuclear-powered civilization, proliferation etc) as well, making the TRU problem easily manageable and solvable in similar steps in the next centuries (such as fast (TR)UF4 based MSR, selective separation of FPs from the salt, warping the time space fabric and sending unusable rad waste to the black hole in the middle of the Milky Way ;-) etc.)


I posted a proposal to do this with tuned lasers, but no one was interested.

_________________
The old Zenith slogan: The quality goes in before the name goes on.


Top
 Profile  
 
PostPosted: Dec 08, 2008 5:01 pm 
Offline
User avatar

Joined: Dec 19, 2006 11:01 am
Posts: 395
Location: Knoxville, TN
Axil wrote:
I posted a proposal to do this with tuned lasers, but no one was interested.


Could you link it?

< :mrgreen: > I hope you refer to the warp drive proposal </ :mrgreen: >


Top
 Profile  
 
PostPosted: Dec 08, 2008 5:09 pm 
Offline

Joined: Jul 28, 2008 10:44 pm
Posts: 3068
The thought of going after removing the worst fission products (beyond those that come out with He sparging) instead of extracting the TRU's occurred to me as well. I haven't seen any research on this though.

I expect we will have on-site recycling of the U,Np,Pu to put right back into the reactor using fluorination or liquid bismuth reduction. Then onsite vacumn distilling will return most of the salt to the reactor.

The remaining salt, fission products, and some TRUs (including Am, Cm, and some ~1% of the U, Np, and Pu) goes into on-site storage for a cool time period (10-30 years). The cooling period serves to make transport of the dirty salt easier (less heat and radiation given off) as well as to reduce the consequence should something bad happen.

At a central recycler we do a fancier process to pick out the U+TRUs - something like counter current liquid bismuth reduction. This process will likely involve tradeoffs between how much U+TRUs land in the waste and how much fission products land in the returned fuel. This is a spot where we do have an advantage over IFR.

Axil, Did I misunderstand the tunable lasers post? I thought it had to do with isotope isolation.


Top
 Profile  
 
PostPosted: Dec 08, 2008 5:20 pm 
Offline
User avatar

Joined: Aug 21, 2008 12:57 pm
Posts: 1058
ondrejch wrote:
Axil wrote:
I posted a proposal to do this with tuned lasers, but no one was interested.


Could you link it?

< :mrgreen: > I hope you refer to the warp drive proposal </ :mrgreen: >



I posted a way to do this with tuned lasers, but no one was interested.

viewtopic.php?p=10146#p10146

viewtopic.php?p=10155#p10155

viewtopic.php?p=10173#p10173

excerpt:

As I read the patent on this technology, it is possible to remove any isotope of any element selectively by adjusting the tuning of the laser to the appropriate frequency. I think of it as the inverse of spectroscopy where an element emits a unique light signature. Laser turning can produce the right light emission to select the associate element. That is there is a laser tuning for U233, U234, U235, Np237, PU239, Cs137, 151sm …. Etc.

The important point is that one technique can selectively remove whatever element you want from a floride salt and whenever you want by the right laser tuning. Do you not need this capability? This process can be done inside the reactor radiation zone continuously on a small scale. I.E. No inspectors required!

As stated in the patent

DISCLOSURE OF INVENTION

Accordingly, it is an object of the present invention to provide improvements in the application of the CRISLA laser isotope separation process. It is another object of the present invention to provide a process for the selection of chemical coreactants RX that will lead to an improved CRISLA isotope separation process when used with an isotopic molecule *MY.
Illustrations are provided for the application of the RX selection criteria to the isotope separation of UF6 (that is for fM-Y « lUF5-F) and specific molecules RX are identified which yield improved CRISLA enrichments of Uranium. However, the criteria are general and can be applied equally well to the separation of other isotopic molecules such as 'zrFt, 'zrCl(, 'zrBr4, *WF6, and many other volatile halides. As utilized herein, the pre- superscript "iM is used on an atom to indicate that different isotopes exist which one wishes to separate.


You can remove anything from the salt percisly.

_________________
The old Zenith slogan: The quality goes in before the name goes on.


Top
 Profile  
 
PostPosted: Dec 08, 2008 5:22 pm 
Offline

Joined: Mar 30, 2008 8:37 am
Posts: 145
Location: Stumbling out of a van, head full of zombie
Well, damn. Isn't this much like the Silex process?

_________________
Circular logic - see self-referential

Self-referential - see circular logic

imbibo ergo fnord


Top
 Profile  
 
PostPosted: Dec 08, 2008 5:43 pm 
Offline
User avatar

Joined: Aug 21, 2008 12:57 pm
Posts: 1058
fnord wrote:
Well, damn. Isn't this much like the Silex process?



The Sixex laser is tuned for only U235selectively, but this process can be generalized to extract one or more desired elements/isotopes by returning the laser to the appropriate spectral frequency.

_________________
The old Zenith slogan: The quality goes in before the name goes on.


Top
 Profile  
 
PostPosted: Dec 08, 2008 10:13 pm 
Offline
User avatar

Joined: Nov 22, 2008 9:22 pm
Posts: 123
Need some material development efforts for AVLIS. You are working with metal vapor, ionizing the selected isotope, using magnetic fields to sweep it to collectors, then removing it from the collectors. LLNL was close to solving these problems before AVLIS was shut down.


Top
 Profile  
 
PostPosted: Dec 08, 2008 10:17 pm 
Offline
User avatar

Joined: Nov 30, 2006 3:30 pm
Posts: 3585
Location: Alabama
If this could work, we could extract U236 online and prevent ALL TRU formation...


Top
 Profile  
 
PostPosted: Dec 08, 2008 10:49 pm 
Offline
User avatar

Joined: Aug 21, 2008 12:57 pm
Posts: 1058
Kirk Sorensen wrote:
If this could work, we could extract U236 online and prevent ALL TRU formation...


The Silex technology fits very well with the Lftr. Silex uses UF6 gas. The Silex tunable laser can be adjusted in short order to extract the desired element (U236) from gaseous Lftr fluoride salt.

http://www.world-nuclear.org/info/inf28.html

<snip>

The only remaining laser process on the world stage is SILEX, an Australian development which is molecular and utilises UF6. In 1996 USEC secured the rights to evaluate and develop SILEX for uranium (it is also useable for silicon and other elements) but relinquished these in 2003.

_________________
The old Zenith slogan: The quality goes in before the name goes on.


Top
 Profile  
 
PostPosted: Dec 08, 2008 11:09 pm 
Offline
User avatar

Joined: Nov 30, 2006 3:30 pm
Posts: 3585
Location: Alabama
That's pretty cool! If the feed to SILEX is UF6, which we'll have anyway from the fluorination of the core salt, then we really could conceivably prevent all TRU formation in the reactor.

U236 has a half-life of 23.4 million years, so we just wait around a little while and it will decay to Th-232, then we just throw it back in the blanket and keep going! :lol:


Top
 Profile  
 
PostPosted: Dec 09, 2008 12:02 am 
Offline

Joined: Mar 30, 2008 8:37 am
Posts: 145
Location: Stumbling out of a van, head full of zombie
Being able to enrich your carrier salt onsite as well must be a bit of a bonus, especially if you don't have to pay someone else's markup.

_________________
Circular logic - see self-referential

Self-referential - see circular logic

imbibo ergo fnord


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 35 posts ]  Go to page 1, 2, 3  Next

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group