Energy From Thorium Discussion Forum

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PostPosted: Aug 21, 2007 7:39 pm 
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SPM wrote:
I wonder if the choice of reactor type is tied to using imported fuel and non-proliferation controls, and the form of fuel that other countries are willing export to India. Thorium oxide mixed with plutonium and uranium oxides are supposedly difficult to process due to chemical stability of thorium oxide the radioactive decay components of the small amount of U232 produced.

I'm not sure I follow your argument:
India certainly doesn't need to import thorium, as its the one element they've got in spades.
What they're looking for is importing natural uranium, and possibly more LEU, like the fuel that goes into the Russian-built VVER-1000's (~4% U235).
Of course they also want to be able to reprocess the SNF, to get the Pu, to get the Th cycle going...

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PostPosted: Aug 22, 2007 7:53 am 
jaro wrote:
SPM wrote:
I wonder if the choice of reactor type is tied to using imported fuel and non-proliferation controls, and the form of fuel that other countries are willing export to India. Thorium oxide mixed with plutonium and uranium oxides are supposedly difficult to process due to chemical stability of thorium oxide the radioactive decay components of the small amount of U232 produced.

I'm not sure I follow your argument:
India certainly doesn't need to import thorium, as its the one element they've got in spades.
What they're looking for is importing natural uranium, and possibly more LEU, like the fuel that goes into the Russian-built VVER-1000's (~4% U235).
Of course they also want to be able to reprocess the SNF, to get the Pu, to get the Th cycle going...

.


Importing uranium as the fissile component is one option. Another possibly better option is to import surplus weapons grade and reactor grade plutonium earmarked for disposal and high level radioactive waste from spent open cycle uranium reactors. These are costing their owners lots of money to keep in storage, and secure from theft. If Uranium fertile material is left out of a thorium reactor, these existing unwanted stockpiles can be incinerated in thorium reactors to produce safe low level waste while breeding U233 for future use in thorium reactors.

I doubt if the US would export these materials on their own, but if plutonium and thorium mixed oxide rods can be produced with say Pu240 added to make the plutonium unsuitable for reactor use, and if they are difficult to process chemically to separate thorium from plutonium (because of the inertness of thorium and the radioactivity of the mixture), then the US and other countries may be persuaded to export plutonium fuel in this form to India.

This would effectively kill three birds with one stone.
1) It incinerates and makes safe existing high level radioactive waste and unwanted plutonium weapons stockpiles, and turns them into low level waste.
2) At the same time it creates fissile U233 which is proliferation safe: it cannot be used for nuclear weapons, and is impossible to smuggle or hide because of it's high gamma radiation signature due to the decay products of a few tens of parts per million of U232 which is a byproduct of producing U233 which cannot be avoided.
3) Using the U233 produced with thorium in a closed fuel cycle, allows the generation clean energy indefinitely with just input of thorium and produces low level waste which returns to background radiation levels of thorium in just 500 years.

I think the US has been thinking of this as the solution of both the nuclear proliferation issue and the global warming/fossil fuel depletion/control of energy resources by the middle-eastern oil states issues. Maybe there was a kind of meeting of minds between US and India as to the use of homogeneous solid fuel rods incorporating thorium plus a fissile material as a tradeable, proliferation safe fuel and spent fuel commodity.

It is easier to separate plutonium in MSR salts because it can be distilled from thorium and uranium compounds, so it presents more of a proliferation risk.

The more I think about it, the more thorium power seems to be THE solution to all our energy and global warming problems. It is actually greener than wind, hydro-electric, solar or wave power, because it also disposes of our current nuclear stockpiles in storage.


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PostPosted: Aug 22, 2007 8:13 am 
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SPM wrote:
I think the US has been thinking of this as the solution of both the nuclear proliferation issue and the global warming/fossil fuel depletion/control of energy resources by the middle-eastern oil states issues.

I would love to think this, but I see absolutely no evidence to support it.

In fact, a colleague of mine was in a high-level meeting with elected officials and representatives of the Department of Energy, and he brought up thorium (but kept the fluoride reactor quiet) and the DOE representative immediately dismissed the thorium option because it "makes weapons-grade material". As my colleague spoke with me about it later, he said, "I don't think this guy knows much about how thorium really works."


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PostPosted: Aug 22, 2007 8:34 am 
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SPM wrote:
these existing unwanted stockpiles can be incinerated in thorium reactors to produce safe low level waste while breeding U233 for future use in thorium reactors.

Yes, some people in India have made such proposals for weapons Pu disposition before.
If its done at an IAEA-supervised facility, I don't see much of a problem.
The Indians are already using Th rods in their HWRs as a burnable poison, for fresh core reactivity suppression, and the Pu-Th combo is slated to be used anyway, in their AHWR (albeit with RG-Pu, not WG-Pu).

There is no talk of MSRs in India in regards to any of this, but its still a win-win proposition for everybody, as you say.

.


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PostPosted: Aug 24, 2007 11:17 am 
Kirk Sorensen wrote:
SPM wrote:
I think the US has been thinking of this as the solution of both the nuclear proliferation issue and the global warming/fossil fuel depletion/control of energy resources by the middle-eastern oil states issues.

I would love to think this, but I see absolutely no evidence to support it.

In fact, a colleague of mine was in a high-level meeting with elected officials and representatives of the Department of Energy, and he brought up thorium (but kept the fluoride reactor quiet) and the DOE representative immediately dismissed the thorium option because it "makes weapons-grade material". As my colleague spoke with me about it later, he said, "I don't think this guy knows much about how thorium really works."


Well, the US DOE has been studying thorium reactors with regard to non-proliferation. http://www.bnl.gov/est/files/pdf/FactSh ... actors.pdf
However, there may be vested interests in the DOE for oil, coal industries etc. I presume the DOE guy wasn't a nuclear guy.


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PostPosted: Jun 27, 2008 1:45 am 
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AHWR is a development from the existing Indian design/practice of Pressurized Heavy Water Reactors. MSR or LFTR is a new concept as far as actually building a power reactor is concerned. I am personally against using 'Light Water' as coolant as it shall absorb too many neutrons and result in lower conversion Ratio. Thorium-plutonium Mixed Oxide or Thorium-U233 Mixed Oxide in an existing PHWR would have been a better idea both in terms of CR and time and cost. As for the anti-proliferation comments, one-sixth of mankind is capable of and entitled to preserving its self interest. It is however true that in absence of nuclear fuel, India shall have to use more coal for energy requirements till later. Use of thorium fuel (and also U238 in fast reactors) is an accepted policy and can only be delayed by a few years by creating a shortage of access to fissile material through restrictive trade.


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PostPosted: Feb 15, 2010 1:59 pm 
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Did anyone hear about the Advanced Heavy Water Reactor-Low Enriched Uranium (AHWR-LEU) that BARC has "designed"?

I am not a nuclear engineer, can someone tell me how this system works without enriched uranium?


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PostPosted: Feb 15, 2010 3:20 pm 
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nitinmittal wrote:
AHWR-LEU..... can someone tell me how this system works without enriched uranium?

LEU means "Low-Enriched Uranium", up to a limit of 19.9% U235.
NU (Natural Uranium) is 0.71% U235.


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PostPosted: Feb 15, 2010 4:39 pm 
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Hey Jaro!

So the idea behind this AHWR-LEU thing is to use a combination of LEU and Thorium? Thats it?

If that be the case, then the biggest bottleneck for India, which is the availability of Plutonium as seed fuel will be solved.

Any ideas if India can rapidly produce LEU? Are there enough reserves and enrichment capacity?

- Nitin


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PostPosted: Feb 15, 2010 5:06 pm 
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If I understand correctly, the AHWR-LEU is intended for export -- since India up 'till now didn't even have enough NU for operating its existing plants, never mind the large surpluses need for enrichment plant feed...


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PostPosted: Feb 16, 2010 4:18 am 
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Hey Jaro,

You are right! But recently India has invested a lot in Uranium mining. Many mines are going online in 2011. So, I was not sure what the plan there is!

Thanks,
Nitin


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PostPosted: Feb 16, 2010 6:56 am 
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At present, to the best of my knowledge, Russia is the only country with uranium mining and enrichment resources to produce 20%LEU on a commercial scale. US may have old HEU stocks. The latest brochure has value only as a calculation exercise which can be realized by or with help from Russia. The Russians are already trying to use thorium fuel in VVER with consultation from Thorium Power /Lightbridge. One can always hope that they may try out an alternative. There are two VVER's nearing completion in India and would be available for trials, if required. It will be no problem for Indians to repeat the exercise on VVER.
Construction of AHWR appears to be on a back burner due to paucity of fissile feed for any commercial development. Of course Russians have enough to spare and sell it commercially to Americans, the biggest customers available. I only hope they realise the value of 20% LEU and do not down blend all the spare HEU to 4-5%. 20%LEU could be used with solid or liquid thorium fuel.


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PostPosted: Feb 16, 2010 8:27 am 
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That is strange, always thought US has a lot of uranium processing capacity. I know it is buying U from Russia but thought that is only because it wants to insentivize Russia to dismantle its nuclear arsenal.

Is the reactor core for VVER built onsite or are they imported from Russia? I guess the rest of the reactor has to be fabricated onsite!

If Russia has something (technology) that India needs, it makes me happy. Somehow we know what is available with Russia is available to us, and mostly at a non-obscene price. :twisted:

US has no interest in using Thorium, it seems. Can't see why they should hold on to the U-20%. I guess you are a LFTR fan! 8)


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PostPosted: Feb 17, 2010 3:54 am 
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Pressure vessel forging capacity is quite limited in the world. Japan has the best. Russia and France follow. VVER pressure vessels are imported. India has yet to build the capacity though some negotiations are on.
France imports all its uranium from African countries. They also have good enrichment capacity. US is now lagging in enrichment capacity but are it building up.
http://www.ne.doe.gov/np2010/neScorecar ... plant.html
http://www.business-standard.com/india/ ... gs/382179/
http://www.world-nuclear.org/info/inf28.html
http://www.world-nuclear.org/info/defau ... el+forging


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PostPosted: Feb 17, 2010 4:32 am 
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Wow! You know something about all this, Jagdish!


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