Nuclear Energy

Discussion in 'Chemistry' started by lambogiggy, Jul 11, 2009.

  1. ElectricFetus Sanity going, going, gone Valued Senior Member

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    We don't have high speed train tracks. We would have to completely redesign american cities to be able to utilize public transport for everything, it simply to cost prohibitive, PHEV, BEV and smart grids are easy drop in solutions that do no requiring rebuilding everything. I have nothing against electric trains that go 150+ mph, cars can't do that (safely) and planes suck to much fuel, but such trains have a future only in connecting cities.
     
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  3. spidergoat Valued Senior Member

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    Fuck high speed tracks, 100 is fast enough. High speed tracks require different radius curves with banking, and that means buying more land, and creating a whole new infrastructure we can't afford.
     
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  5. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    China has the money for that:

    "...China is revolutionizing its rail system, introducing high-speed trains and expanding its network of rails at an unprecedented pace. The world's most populated country plans to spend the equivalent of hundreds of billions of dollars and add 25,000 miles of track between now and 2020. The idea is to move people and goods in a transportation system that can fuel economic development without adding any more cars or trucks on the country's roads.*
    Five years from now China will have more high-speed passenger rail than all the rest of the world put together. ..."

    From: http://www.forbes.com/2009/07/08/hi...p-stimulus.html?partner=globalnews_newsletter

    --------------------
    * Just another example of how serious China is about controlling polution, not to mention that in 2009 BYD is projecting to make 400,000 electric hybrid cars, which will travel 30% further on electric only than GM's volt and cost about half the price. It is a very nice looking four door model too.
     
    Last edited by a moderator: Jul 13, 2009
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  7. spidergoat Valued Senior Member

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    That's fine if they have planned for it. I wonder if they will be able to afford it, though, when the time comes. We have the luxury of existing tracks and right-of-ways. What's so wrong with starting there? No, we can't have practical solutions, we need pie-in-the-sky technological monstrosities to feel better about ourselves? What is that, pride? China is doing alot of things wrong now too, they are imitating our cities and skyscrapers, our highways, our worship of the automobile. But they know they have plenty of coal to burn.
     
  8. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    BYD is already producing them at the 400,000/ year rate. The first were made at the end of 2008. GM's volt is planned for late 2011 delivery - I doubt any significant number will actually ever be made.

    If you are speaking of the rail expansion that too is already under way. - Much of the Chinese stimulus is for building railroads as that creates a lot of jobs and is a long term investment in economical efficient transport. China has the advantage that there will not be years of public hearing / EPA approvals etc get etc. They just tell whoever is in the way to move.

    China is making modern energy efficient housing, not wasteful urban sprawl.

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    It may not appeal to you now, but when Gasoline is $20/ gallon it will.
    Note the tree lined street and fact that ground floor is a "walk to"shopping complex.

    Many more (>1000 ) photos of Chinese apartment units at:
    http://images.google.com/images?q=C...&sa=X&oi=image_result_group&ct=title&resnum=1
     
    Last edited by a moderator: Jul 13, 2009
  9. spidergoat Valued Senior Member

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    They destroyed existing ancient neighborhoods to build this crap. It's a caricature of sustainable urbanism. As if people will continue to go shopping for disposable plastic garbage at the "complex". I'd like to see them have to walk up the stairs when the power goes out.
     
  10. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    You would prefer that they spread out around cities on 1/3 acre lots that cover what was once the surrounding farms so now the food, on average, travels more than 1000 miles to feed Americans?
     
  11. spidergoat Valued Senior Member

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    No, both models are doomed. I'm all for dense urbanism, but not the kind that makes you want to kill yourself.
     
  12. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    Judging by the number of Chinese there are, despite the one child policy, that must be the Chinese POV also.

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    BTW Bloomberg just put up:
    "... China’s economy may have expanded 7.8 percent in the second quarter as record lending and surging investment drove a rebound from the weakest growth in almost a decade, a survey shows. ..."
    See: http://www.bloomberg.com/apps/news?pid=20601087&sid=aR1UWWYwzcds
     
    Last edited by a moderator: Jul 14, 2009
  13. ElectricFetus Sanity going, going, gone Valued Senior Member

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    Are present rail moves cargo, and does that well, there not enough of it to commute everyone from city to city let alone from suburbia to the city!
     
  14. Trippy ALEA IACTA EST Staff Member

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    These the ones you were after Billy?
    \(\mathrm{n}+{}_{\ 90}^{232}\mathrm{Th}\rightarrow {}_{\ 90}^{233} \mathrm{Th} \rightarrow{\beta^-}+{}_{\ 91}^{233}\mathrm{Pa} \rightarrow{\beta^-}+ {}_{\ 92}^{233}\mathrm{U}+\mathrm{n}\rightarrow {}_{\ 92}^{232} \mathrm{U}+2\mathrm{n}\)

    \(\mathrm{n}+{}_{\ 90}^{232}\mathrm{Th}\rightarrow {}_{\ 90}^{233} \mathrm{Th} \rightarrow{\beta^-}+ {}_{\ 91}^{233}\mathrm{Pa}+\mathrm{n} \rightarrow {}_{\ 92}^{232}\mathrm{U}+2\mathrm{n}\)

    \(\mathrm{n}+{}_{\ 90}^{232}\mathrm{Th}\rightarrow {}_{\ 90}^{231} \mathrm{Th} + 2\mathrm{n} \rightarrow{\beta^-}+ {}_{\ 91}^{231}\mathrm{Pa}+\mathrm{n} \rightarrow {}_{\ 91}^{232}\mathrm{Pa} \rightarrow{\beta^-}+{}_{\ 92}^{232}\mathrm{U}\)

    \({}_{\ 92}^{232}\mathrm{U} \rightarrow{\ \alpha\ }+ {}_{\ 90}^{228}\mathrm{Th}\ \mathrm{(73.6\ a)}\)

    \({}_{\ 90}^{228}\mathrm{Th} \rightarrow{\ \alpha\ } +{}_{\ 88}^{224}\mathrm{Ra}\ \mathrm{(1.9\ a)}\)

    \({}_{\ 88}^{224}\mathrm{Ra} \rightarrow{\ \alpha\ }+ {}_{\ 86}^{220}\mathrm{Rn}\ \mathrm{(3.6\ d,\ 0.24\ MeV)}\)

    \({}_{\ 86}^{220}\mathrm{Rn} \rightarrow{\ \alpha\ }+ {}_{\ 84}^{216}\mathrm{Po}\ \mathrm{(55\ s,\ 0.54\ MeV)}\)

    \({}_{\ 84}^{216}\mathrm{Po} \rightarrow{\ \alpha\ }+ {}_{\ 82}^{212}\mathrm{Pb}\ \mathrm{(0.15\ s)}\)

    \({}_{\ 82}^{212}\mathrm{Pb} \rightarrow{\beta^-\ }+ {}_{\ 83}^{212}\mathrm{Bi}\ \mathrm{(10.64\ h)}\)

    \({}_{\ 83}^{212}\mathrm{Bi} \rightarrow{\ \alpha\ }+ {}_{\ 81}^{208}\mathrm{Tl}\ \mathrm{(61\ s,\ 0.78\ MeV)}\)

    \({}_{\ 81}^{208}\mathrm{Tl} \rightarrow{\beta^-\ }+ {}_{\ 82}^{208}\mathrm{Pb}\ \mathrm{(3\ m,\ 2.6\ MeV)}\)
     
  15. Walter L. Wagner Cosmic Truth Seeker Valued Senior Member

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    2,543
    Trippy:

    Do you know what the production cross-section would be for producing U-232? Certainly if you 'age' the Th-233 you've formed by keeping it in the reactor for weeks/months, you will increase the amount of U-233 that can be neutron irradiated with one neutron in, two out, forming U-232. Of course, there will always be a little bit present, even when you first start irradiating the Th-232.

    One neutron in, two out, is not generally a favored nuclear reaction, and I suspect only a very little would take place - but Billy seems to believe it would be sufficient to cause problems with too much U-232 formation. Any information you might have on that would be appreciated. I haven't worked in this area for decades.
     
  16. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    To Trippy: Yes. Thank you. The top three equations in post 31 show how small amounts of U232 are produced (while converting thorium into the desired* U233 ) and the remainder give the radioactive decay chain of U232 to lead.

    Thus U232 is a source of intense radiation and, as I noted and explained before, very hard (only one mass unit difference) and expensive (remote handling required) to separate from the desired Thorium neutron capture uranium isotope, U233, which is a much better nuclear fuel than the U235 current used. Essentially 100% of the more abundant thorium is easily** converted in a reactor making heat for electric power into a useful nuclear fuel, U233. In contrast, the currently used U235 is only 0.7% of natural uranium and must be enriched relative to the 99.3% of natural uranium to become a useful reactor fuel.

    Almost all of natural thorium is converted to the desired U233 with neutron capture. Only a little becomes the dangerous U232. - Almost as if god intended for man to use the more abundant Thorium instead of uranium and made sure the fuel would be contaminated with a little radioactive U232 so it would be almost impossible to make nuclear bombs as one made energy. God did not appreciate how perverse government would be. If he had then U235 would have been less than 0.1% instead of 0.7% of natural uranium to make it too expensive for even rich governments to make nuclear bombs.

    -------------
    *"Desired” in part because when U233 undergoes fission it yields twice as many neutron as U235 does so continuing the chain reaction is easy even if many of the neutrons are used to convert Thorium in to more U233 than the U233 which is used in the reactor.
    As thorium is stable some source of neutrons is required as the “match” to light up the Thorium fission chain. I’m not sure, but think even non-enriched natural uranium can and there are other ways to generate a few neutrons for the “match.” (Some of the best are secret as used to turn on atomic bombs quickly before they blow themselves apart with little energy release. I.e. a well made nuclear bomb is more than just assembling a critical mass of U235. That was accidently done in a LASL lab before the first bomb was ever made and only killed the technician with radiation, not by the tiny energy release blast. There was no use of any chemical explosives in the test he was conducting.)

    **Thorium is three times better than U235 or U238 at capturing neutrons, so easy to make the desired better fuel, U233, in a reactor. I.e. breeding more fuel than used from thorium is easy, even in a conventional thermal neutron reactor while it is producing heat for electric power.
     
  17. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    I am just repeating what I have read at Wiki etc. However, the one in two out you refer to is in this RELATIVELY RARE reaction taking place. It certainly is not a "problem" with the reactor operation as also makes heat.

    The reaction chain is sustained mainly by the fission of U233 (and if present as the "Match" -see post 33's first footnote - a little by fission of U235 ). I do not know, but think the fission of U233 gives more than three out for each absorbed on average. Much better than fission of U235.

    I too would like to know what fraction of the thorium ends up as U232 instead of the more desired U233, but it must be not too small as it does contaminate the U233 enough that trying to make bomb material from thorium is not practical. (The bombs would be radioactively too hot to use, except by radiation resistant robots. Especially when one can breed Plutonium and chemically separate it out for your bomb.)

    BTW it is not too hard to sustain a reaction with less than two neutrons out for each absorbed. As I recall, the standard U235 fission gives significantly less than two on average. That is why the reactors cannot be too small* - too many would leak to the outside. Also why usually the core has some "neutron reflector" outside to return part of the fraction that do escape. Also why only a few materials, like very pure carbon or water are used to “thermalize” the neutrons - most materials have too high a neutron capture cross section to be used. The neutron capture cross section of Deuterium water is even smaller than H2O water so a well designed (for neutron economy) reactor can run on natural (not enriched) uranium if DOH water is used to thermalize - the Canadians lead the world in this approach and their design is called CANDO or CanDu or something like that.

    -----------
    *I do not know but as a wild guess, I bet if U233 does yield three neutrons on average when it under goes fission, then more smaller reactors could be used to reduce electric distribution losses and cost. Probably security considerations, rather than neutron economy, would set the reactor size. Possibly a large industrial complex, which needed a lot of heat, might even run one, just for the heat instead of burn natural gas etc. Especially if "cap and trade" plus "carbon credits" could add to their profits.
     
    Last edited by a moderator: Jul 14, 2009
  18. Trippy ALEA IACTA EST Staff Member

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    The closest i've seen so far is a paper from the IAEA talking about the Thorium based technology that essentially states or implies that U-232 is present in amounts of a few ppm. I'll try and find the time to have a more detailed look after work.
     
  19. ElectricFetus Sanity going, going, gone Valued Senior Member

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    its very small, parts per million are present or possible to produce.
    www.princeton.edu/sgs/publications/sgs/pdf/9_1kang.pdf
     
  20. Walter L. Wagner Cosmic Truth Seeker Valued Senior Member

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    Good article. As I suggested, by doing short periods of irradiation, removing the channelled Th-232 and separating out the U-233, the U-232 contaminant can be significantly reduced by an order of magnitude or more compared to leaving the Th-232 in the reactor to 'cook' for longer periods of time.

    While the article talks about the dose rate in Rem/hour, that is a misnomer as per my postings regarding the Sievert/Rem being wrong. However, the dose rate is high enough that they recommend no more than 80 hours at 1 meter distance to give one year's dose at 5 Rads/year. While that might be a fabrication problem for weapons under US standards, it is not insurmountable. Indeed, some countries might simply ignore it as a consideration [as they used to do in the former USSR].

    All in all, I believe the weapons-proliferation problem remains a serious concern. We need international control over all weapons-production capability via the IAEA, with actual enforcement, in order to implement the Thorium cycle.
     
  21. Trippy ALEA IACTA EST Staff Member

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  22. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    I partially replied to this in post 25, with photo of how China is making environmentally friendly housing with walk to shopping on the ground floor of the apartment building complex and tree lined streets, instead of the US suburban sprawl on 1/3 acre lots. (I gave link to more than 1000 other photos of Chinese residential buildings in post 25 also.)

    Now I direct your attention to:
    http://www.forbes.com/2009/07/16/china-green-energy-business-energy-china.html?partner=globalnews_newsletter
    but my making part bold spoiled it so click on:
    http://www.forbes.com/2009/07/16/ch...ergy-china.html?partner=globalnews_newsletter
    where you can read:
    “…The first phase involves a smart grid pilot to be finished by 2010. Initial implementation of its smart grid will be complete by 2015, followed by a rollout phase to 2020. Plug in Hybrid Vehicles will benefit from the smart grid strategy, as will BYD (Public, HKG:1211), which focuses on electric vehicles …”

    “In 2006 the government passed the China Renewable Energy Law and in 2007 it released a mid- and long-term renewable energy implementation plan with a target of 15% of primary energy consumption to come from renewable sources by 2020, and the government will likely raise this to 20%. It recently revised the wind target from 30 gigawatts to 150 gigawatts of generating capacity by 2020. The government has launched a "Three Gorges on Land" wind project in Gansu Province that will equal the generating capacity of the 22 gigawatt 3-Gorges Dam. …China will surpass the United States as the biggest wind turbine market in 2009. …”

    “…China is already the largest solar panel producer in the world. … Global demand has been hit by credit crisis, and as a result there is huge overcapacity in China. In response, the Chinese government has launched a plan to increase the domestic market. According to a recent speech by public officials, China's solar power target will be revised upward from 1.8 GW to 20 GW ... by 2020. The government launched a solar rooftop program to absorb the domestic capacity and is now promoting solar power stations. …”
    Etc.

    SUMMARY: You do not have any basis for your totally wrong statement.
    To be “On Thread,” I again remind you that China is adding more nuclear power each year than the rest of the world is and developing some of the lastest generation reactors as well as the very efficient super-critcal steam coal fired plants. They need to rapidly increase their energy supply to support their now 8% GDP growth rate Which will be double digits in a about a year again. I might add that 2/3 of all the new hydroelectric power plant in the world are being made by China, but about half of them are in Africa. Where they are does not matter if speaking of global warming.
     
    Last edited by a moderator: Jul 17, 2009
  23. X-Man2 We're under no illusions. Registered Senior Member

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    Why can't the US be aggressive like China on green energy? We just fall behind more and more every year.US? Who's that? It really sucks.
     

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