EPTThe Green Nuke - LFTR - Page 3
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Leftwing
Canada229 Posts
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GeneralStan
United States4789 Posts
When faced with the decision of spending millions in funding to test a new type of reactor with unproven results (the LFTR), or using a safe and proven technology, the decision for most governments was easy to make. It also helps that the PWR has a higher energy output per unit volume of reactor space compared to a LFTR (though this is mainly for ships I guess). In regards to Chernobyl, it was a PWR, not a LFTR. The design was not inherently stable in the way most American PWRS are (this accident could never happen on a Navy nuke anyway), but it was not particularly unsafe either. The accident was due to a safety test which involved trying to shut down the reactor under some worst case conditions. The test was an egregious violation of all reason in a nuclear plant, which lead to the catastrophe. | ||
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Chaosvuistje
Netherlands2581 Posts
Of course, doing so would require oil companies to reinvest into a technology that would gain them less money because the cost for energy would go down. So obviously they will invest into energy that is even less efficient but more 'green' so they can price it even more. I see this as a pretty logical approach to why major energy companies would work like this if what they said was true. The only problem is if your energy is obsolete while anothers is better, there will be a struggle with the old and the new. Unfortunately the old and the new in this case are the US and China. Now I'm pretty glad the Cold war has ended and I don't really want another one in my lifetime. In any case, I will look up to the first that proves that this is possible. | ||
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Perdac Curall
242 Posts
On January 25 2012 22:45 GeneralStan wrote: The reason why PWRs dominated is because of their development in the US Navy's Submarine program. Rickover did all the leg work in developing the PWR (which is also inherently stable due to negative temperature coefficient of reactivity, btw), thus obviating the need for a secondary type of reactor. When faced with the decision of spending millions in funding to test a new type of reactor with unproven results (the LFTR), or using a safe and proven technology, the decision for most governments was easy to make. It also helps that the PWR has a higher energy output per unit volume of reactor space compared to a LFTR (though this is mainly for ships I guess). As Kirk Sorensen details in the movie, Alvin Weinberg, who was instrumental in the invention of the PWR and BWR, did not like either design due to safety concerns and the solid fuel aspect and was pushing LFTR. The U-235 and Pu-239 fuel cycles were better understood than Thorium, no question. But Weinberg with the MSRE did prove the viability and safety of the concept, and in the 1960s it was expected by many that PWRs would not last very long because they would be replaced by better technologies like LFTR. The reason this did not happen is primarily due to Cold War considerations. You can't make nuclear bombs with a LFTR, just electricity. With PWRs or LMFBRs you can do both, so that is why both the US and the USSR pursued those technologies. Yes PWRs do have a negative temperature coefficient of reactivity, but they are by no means walk away safe as a LFTR is. On top of constantly worrying about pipe shears, pressure drops and meltdowns, none of which are possible in a LFTR but are entirely possible in a PWR, you also have to constantly monitor Xenon-135 levels in a PWR, since in solid fuel reactors the Xenon-135 stays in the fuel and as a neutron absorber causes a lot of problems in your reactor. In a LFTR since the fuel is a liquid the Xenon-135 just bubbles right out of the solution. This is yet another of the many safety advantages LFTR has over PWRs. PWRs are ready to explode, begging to explode even. LFTRs can never explode. | ||
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Ercster
United States603 Posts
On January 25 2012 22:45 GeneralStan wrote: It also helps that the PWR has a higher energy output per unit volume of reactor space compared to a LFTR (though this is mainly for ships I guess). This doesn't make any sense. On land the reactors would be smaller, the amount of nuclear material would be smaller, and the amount of energy would be greater than that of the current method. Why would it be any different on a ship? | ||
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Soleron
United Kingdom1324 Posts
On January 25 2012 10:51 Perdac Curall wrote: matter-antimatter annihilation sometime after that. How would that even work? Unless you have a supply of antimatter (which we do not), it will take more energy to create the fuel than we get out of it. It's useful for interstellar propulsion because it has the lowest mass per unit energy output of any fuel, but not as an energy source. | ||
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WTFZerg
United States704 Posts
On January 26 2012 01:03 Perdac Curall wrote: As Kirk Sorensen details in the movie, Alvin Weinberg, who was instrumental in the invention of the PWR and BWR, did not like either design due to safety concerns and the solid fuel aspect and was pushing LFTR. The U-235 and Pu-239 fuel cycles were better understood than Thorium, no question. But Weinberg with the MSRE did prove the viability and safety of the concept, and in the 1960s it was expected by many that PWRs would not last very long because they would be replaced by better technologies like LFTR. The reason this did not happen is primarily due to Cold War considerations. You can't make nuclear bombs with a LFTR, just electricity. With PWRs or LMFBRs you can do both, so that is why both the US and the USSR pursued those technologies. Yes PWRs do have a negative temperature coefficient of reactivity, but they are by no means walk away safe as a LFTR is. On top of constantly worrying about pipe shears, pressure drops and meltdowns, none of which are possible in a LFTR but are entirely possible in a PWR, you also have to constantly monitor Xenon-135 levels in a PWR, since in solid fuel reactors the Xenon-135 stays in the fuel and as a neutron absorber causes a lot of problems in your reactor. In a LFTR since the fuel is a liquid the Xenon-135 just bubbles right out of the solution. This is yet another of the many safety advantages LFTR has over PWRs. PWRs are ready to explode, begging to explode even. LFTRs can never explode. As far as I know, the more modern pebble-bed reactor design is virtually meltdown proof, but I'm not sure if that design is utilized in any modern reactor. | ||
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Perdac Curall
242 Posts
On January 26 2012 01:31 Soleron wrote: How would that even work? Unless you have a supply of antimatter (which we do not), it will take more energy to create the fuel than we get out of it. It's useful for interstellar propulsion because it has the lowest mass per unit energy output of any fuel, but not as an energy source. There was a meeting back in 2004 on this very subject detailing the need for a dedicated antiproton facility in the US, but it was ignored by the Bush administration. The amount of energy in matter-antimatter reactions is 1000 times as energy dense as fusion, so it is not implausible that we can achieve a net energy gain there in the future (50-75 years from now when commercial fusion reactors are (hopefully) a reality.) http://arxiv.org/PS_cache/astro-ph/pdf/0410/0410511v1.pdf | ||
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Perdac Curall
242 Posts
On January 26 2012 01:31 WTFZerg wrote: As far as I know, the more modern pebble-bed reactor design is virtually meltdown proof, but I'm not sure if that design is utilized in any modern reactor. UC Berkeley and Oak Ridge are working on a pebble-bed fluoride salt high temperature reactor right now. And yes you are right pebble-bed technology is very safe, being Generation IV technology, but I still believe LFTR is an even better idea. Here is a short video presentation done at the last Thorium Energy Alliance Conference (TEAC3) done by a doctoral student at UC Berkeley explaining the details of the reactor design. | ||
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Sanctimonius
United Kingdom861 Posts
On January 25 2012 12:56 Perdac Curall wrote: It is impossible to limit the amount of thorium available, we already have too much. But Thorium does not obey the economic laws you quoted above because it is an ore and requires processing which is very expensive and if there isnt a market for it no one invests in the processing facilities and getting processed ore becomes very expensive. The military are interested in LFTR for mobile modular power supplies that can power a base in the middle of the desert or other remote locations, not for bombs. I would not characterize nuclear power as being decades of mismanagement, though I definitely would characterize Tepco as that. Nuclear power in the United States has never killed anyone, ever. Coal annually kills over 10,000 people. Annually!! So while you are right that public opinion is against nuclear, I wouldn't say decades of mismanagement is a fair characterization. Nuclear power actually has one of the safest track records of any industry, but public opinion reflects the opposite. Tepco is just the latest and most obvious example of nuclear mismanagement. Nuclear power stations across the world have in numerous cases been found to have low-level leaks and failing safety systems, but discounting those what about the more well-known leaks - Three Mile, Chernobyl etc. Spread over decades. Mismanaged  Thing is it doesn't matter what is a fair characterisation when it comes to public opinion. Public opinion is very strongly against nuclear power, regardless of the safety record of the industry. You can show the figures to people but we always have that fear of nuclear meltdown in our minds. | ||
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OneWhoIsMany
Canada292 Posts
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Flamingo777
United States1190 Posts
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Perdac Curall
242 Posts
On January 26 2012 12:23 Sanctimonius wrote: Tepco is just the latest and most obvious example of nuclear mismanagement. Nuclear power stations across the world have in numerous cases been found to have low-level leaks and failing safety systems, but discounting those what about the more well-known leaks - Three Mile, Chernobyl etc. Spread over decades. Mismanaged Thing is it doesn't matter what is a fair characterisation when it comes to public opinion. Public opinion is very strongly against nuclear power, regardless of the safety record of the industry. You can show the figures to people but we always have that fear of nuclear meltdown in our minds. Chernobyl was absolutely bad in every way. Bad design, bad management, a clusterfuck. And people should be concerned about meltdowns and safety with PWRs. Eugene Wigner, who invented the PWR, was against PWRs because it was only a matter of time before an accident occurs with water held at that much pressure. That is why Wigner was such a huge advocate for LFTR for civilian power, because it is so much safer. People would not have to worry about meltdowns anymore if we transitioned to LFTRs. | ||
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Dynastywar
United States59 Posts
After shutdown the salt was believed to be in long-term safe storage, but beginning in the mid-1980s, there was concern that radioactivity was migrating through the system. Sampling in 1994 revealed concentrations of uranium that created a potential for a nuclear criticality accident, as well as a potentially dangerous build-up of fluorine gas — the environment above the solidified salt is approximately one atmosphere of fluorine. The ensuing decontamination and decommissioning project was called "the most technically challenging" activity assigned to Bechtel Jacobs under its environmental management contract with the U.S. Department of Energy's Oak Ridge Operations organization. In 2003, the MSRE cleanup project was estimated at about $130 million, with decommissioning expected to be completed in 2009.[17] A detailed description of potential decommissioning processes is described here.  18] uranium is to be removed from the fuel as the hexafluoride by adding excess fluorine, and plutonium as the plutonium dioxide by adding sodium carbonate.That was from the Molten-Salt Reactor Experiment held in the 1960s. https://en.wikipedia.org/wiki/Molten-Salt_Reactor_Experiment | ||
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Perdac Curall
242 Posts
On January 27 2012 12:10 Dynastywar wrote: Got interested by the article and read up on it. Definitly intrieged me, but one thing caught my eye on wikipedia. That was from the Molten-Salt Reactor Experiment held in the 1960s. https://en.wikipedia.org/wiki/Molten-Salt_Reactor_Experiment There are a few known technical challenges left to master with LFTR, and this is one of the biggest. However in the grand scale of things engineering-wise this is not that difficult of problem to overcome. This is basically a storage and containment problem. When compared to the technical hurdles still facing other reactor designs such as Fusion reactors, Integral Fast Reactors or the Travelling Wave reactor that Bill Gates is so keen on funding, the challenges associated with LFTR are almost "easy" relative to them. | ||
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Rafael
Venezuela182 Posts
Conclusion I made so far: Even though it really looks promising, I think humans need to to take nuclear energy way more seriously (even LFTR). I still don't understand how can we use nuclear energy as of now with the current problems radioactive waste presentes, right now we don't have the understanding in science to treat and handle this substances correctly to ensure the well-beeing of the generations of livings things to come. I do think LFTR still have many challenges before dreaming of implementation. And finally LFTR does produce radiactive waste just in smaller quantity and faster radioctive decay (this means that the radioctive element desactivates faster) Although it really looks promising, but let's see only a lot of research and time will tell. PS.: We only have one earth it really worries me, that we are directioning to our auto-anihilation by the hazardous subproducts of our current technology (i.e. contamination) and the unforgiving exploitation of our resources. I think it's a responsability of this generations technic and scientific professionals to stop and prevent this madness and improve the current human process for the better of ourselves and our planet. | ||
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meegrean
Thailand7699 Posts
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Roe
Canada6002 Posts
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CapnAmerica
United States508 Posts
On January 27 2012 13:13 Roe wrote: isn't thorium just some mineral from world of warcraft? Yes, that's why this new technology is being developed in China. All of their gold farmers have built up a large surplus over the time that WoW has been out, and now they're making use of it to generate power. Also, http://en.wikipedia.org/wiki/Thorium | ||
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furymonkey
New Zealand1587 Posts
On January 26 2012 00:37 Chaosvuistje wrote: Of course, doing so would require oil companies to reinvest into a technology that would gain them less money because the cost for energy would go down. So obviously they will invest into energy that is even less efficient but more 'green' so they can price it even more. You made it sound like the whole world's energy is generated by 1 company. If a company is able to come up a super efficient and green energy, it will dominate the market, earning way more money. | ||
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