Energy From Thorium Discussion Forum

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PostPosted: Mar 27, 2016 9:40 pm 
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34 metric tonnes of fissile plutonium are at risk of being buried by the United States because we cannot economically turn it into fuel. The agreement requires the USA and Russian to both eliminate 34 Metric tonnes of Plutonium that could be used for nuclear weapons. The Russians are in the process of irradiating the plutonium in their fast reactors to change the isotope composition to decrease the usefulness for weapons. The USA???? The plan to make commercial reactor fuel (MOX) for light water reactors seems to be going nowhere.
Can the Molten Salt Reactor community kill two birds with one stone? Can a MSR (Chloride/Fast fluoride) be used to spoil the isotope composition of the plutonium to meet the requirements of the agreement and can useful data be used to further the commercial development of a MSR reactor? I think it is possible.
Keep the plutonium within the department of Defense, so the potential of proliferation will be eliminated. Use the money to be spent on the fuel fabrication plant, since fuel fabrication is not needed in a MSR, and fund multiple reactors to spoil the isotope composition. The reactors could be very simple and short lived since their function would be only to spoil the isotope composition. Reactor materials could be inserted into the test reactors for defined intervals to test for durability.
The "spoiled" plutonium salts could be used for future commercial MSR's. The plutonium would be in a form that would be most useful to MSR's and could drive research into to areas that would be useful to the MSR community in general (waste disposal, fission product removal, etc)
Eventually, the MSR fuel could be used to fuel reactors at Military bases as a cost saving measure for the Military and as a revenue source (selling to the grid). The reactors present on the Military bases could be a major revenue source for the Military. They may have some utilities in the US mainland upset that they are undercutting their generating plants, but there are may locales around the world that would welcome cheap, dependable energy that came with a US Military presence to defend the reactor. Electricity sales could offset some of cost of the Military base.
The General Atomics EM2 fast reactor would also be useful in this endeavor. 2.6 tonnes of U235 in a fuel load of 42.8 tonnes (balance U238) for a 500Mw thermal reactor. 13 (500 Mw (thermal)) EM2 reactors could be fueled with the plutonium to be disposed by this agreement.
Michael


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PostPosted: Apr 02, 2016 5:11 am 
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Just burn it in a MSR.

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PostPosted: Apr 08, 2016 10:03 pm 
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Is that plutonium in such a format that it can be directly inserted on a running DMSR / LFTR (in small quantities) ? If it requires processing (like fluorination) what would be the cost ? Specially compared with making MOX solid fuel.

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PostPosted: Apr 09, 2016 4:43 am 
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macpacheco wrote:
Is that plutonium in such a format that it can be directly inserted on a running DMSR / LFTR (in small quantities) ? If it requires processing (like fluorination) what would be the cost ? Specially compared with making MOX solid fuel.

Plutonium production in any reactor that contains U238 in the fuel salt is inevitable. The reactor is going to have to be designed to manage this. If the plutonium is introduced as part of the starter fuel then the plutonium proportion in the salt would not have to be any more than it would be in steady state operation.

As you point out the processing of the plutonium should be nothing more than fluorination. I can imagine this being not much more complicated than taking a sample of metallic plutonium or plutonium oxide and "burning" it with fluoride gas. No doubt a task that must be undertaken with care but something that I'd think a chemistry lab at most any university could manage. The cost should be minimal but then nothing the government does seems to be cheap.

This should be as simple as KitemanSA points out, just burn it in a MSR. The problem seems to be with the DOE not taking a liking to MSRs right now.

I will again point out something that I've stated many time in other posts, the state governments in the USA have the authority to license nuclear reactors on their own. The federal government has only those powers granted to it by the states. I'll give the recent legalization of marijuana on the state level as evidence. I have greater faith in the several states in this federation to come up with a solution to this problem than the federal government.

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PostPosted: Apr 09, 2016 8:11 am 
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The primary problem here is that the treaty says the material must be put beyond use.

Otherwise the cheapest solution would be to adopt the British model and just store it pending some use for it materialising.

I wonder if they would be permitted to downblend it with reactor grade plutonium.


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PostPosted: Apr 09, 2016 3:27 pm 
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Maybe the easiest way to get rid of this weapon grade plutonium is to sell it to France which already has the facilities to use it in its PWRs. I don't even know if it is "legally" possible though. I guess it would also be politically difficult even if France already has nuclear weapons.


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PostPosted: Apr 09, 2016 8:21 pm 
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I don't think there would be any treaty stipulations that automatically prevent that, assuming the Russians are allowed to inspect the Melox plant during the process to confirm that it is infact the weapons grade plutonium going into the fuel elements.

The US already did and (potentially still does) trade small amounts of weapons grade enriched uranium to the UK in exchange for other materials (historically weapons grade plutonium)


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PostPosted: Apr 10, 2016 4:43 am 
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The best use for plutonium would be Th-Pu fuel. If the US costs are too high, it could be outsourced to a lower cost location. IAEA routinely inspects such activities. There is so much fissile lying around that it should be done routinely. U-233 created could be recovered at low cost by fractional distillation using chloride volatility.


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PostPosted: Apr 10, 2016 7:51 am 
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fab wrote:
Maybe the easiest way to get rid of this weapon grade plutonium is to sell it to France which already has the facilities to use it in its PWRs. I don't even know if it is "legally" possible though. I guess it would also be politically difficult even if France already has nuclear weapons.


Yes, that would be an interesting option, but I am not sure whether France should buy it. Perhaps, France should collect a "waste disposal fee" instead.


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PostPosted: Apr 11, 2016 11:43 am 
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Unless somebody manages to build a molten chloride reactor soon, making Th-Pu MOX to burn in water cooled reactors makes the most sense. When a commercial LFTR design is ready for mass production, fluorinate the spent Th-Pu MOX for startup fuel.


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PostPosted: Apr 11, 2016 2:10 pm 
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Thorium plutonium mixed oxide fuel would give an extended fuel cycle with the breeding of U233.
Does any one know if Lightbridge has evaluated using plutonium in their Metallic fuel?
A metallic Thorium, Plutonium fuel would also give and extended fuel cycle with the addition of the U233 breeding.
They make mention of Thorium Uranium metallic fuel but I have not seen any mention of Plutonium.

Plutonium fuelled Naval reactors for submarines and aircraft carriers could also be considered if you were to go the metallic fuel route.
Michael


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PostPosted: Apr 11, 2016 2:21 pm 
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I would still like to see some useful data come out of the agreement. The use of the Plutonium in a MSR would get the national labs back in the MSR game.
Make a MSR/ Medical isotope reactor that burns the plutonium and creates medical isotopes. Sell it as helping cancer patients. I would just like to see the inertia of inaction overcome.

Michael


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PostPosted: Apr 14, 2016 3:28 pm 
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michaelw wrote:
Thorium plutonium mixed oxide fuel would give an extended fuel cycle with the breeding of U233.
Does any one know if Lightbridge has evaluated using plutonium in their Metallic fuel?
A metallic Thorium, Plutonium fuel would also give and extended fuel cycle with the addition of the U233 breeding.
They make mention of Thorium Uranium metallic fuel but I have not seen any mention of Plutonium.

Plutonium fuelled Naval reactors for submarines and aircraft carriers could also be considered if you were to go the metallic fuel route.
Michael


Light Bridge is an american company, since USA doesn't do commercial SNF reprocessing, they're likely going with the flow and trying not to change anything in the game that isn't absolutely necessary. They're essentially creating the solid fuel equivalent of the original DMSR proposal (80% Th232 + 15% U238 + 5% U235 or 20% enrichment on the Uranium side).
Assuming Plutonium will be available could be a mistake, as it involves US Government interest, which in theory would be a no brainer, but DOE red tape would likely make the whole process inviable.
It would however make a lot of sense after they attain commercial operations on the Thorium+Uranium fuel to then try to certify a MOX equivalent to use weapons grade Pu, if some is still available.

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PostPosted: Apr 15, 2016 6:35 pm 
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All fissile assets can be used to burn thorium in reactors.
file:///C:/Users/Sony/Downloads/glbrchth.pdf
If the blending with thorium is not economical in the US, get global tenders.


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PostPosted: Apr 15, 2016 8:45 pm 
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macpacheco wrote:
Light Bridge is an american company, since USA doesn't do commercial SNF reprocessing, …

"Doesn't", not "is prohibited from doing". Come up with a good repro-fuel design for current generation reactors and maybe we will start.

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