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Post by Cyril R on May 8, 2012 18:29:00 GMT 9.5
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Post by Barry Brook on May 9, 2012 10:11:41 GMT 9.5
Cyril, off topic, you should register on this forum if you are going to continue to post here. You can then llogin to your account and post from that - you won't need to enter the SPAM check each time, and all your posts will be archived etc. All the cool kids are doing it...
BTW - when you do register (Mod talking now) be sure to register as cyrilr(all lower case, no gaps etc) you can alter your name to Cyril R in your membership details after you have registered. Many, including I, got caught (frustratingly) with the lower case enrolment necessity. Great to have you on board ;D
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Post by eclipse on Aug 31, 2014 20:17:07 GMT 9.5
Can I just ask a dumb question? Does a thorium reactor need plutonium in the fuel cycle somewhere? The reason I ask is this piece about India's planned FBR for next year seems to hint it.
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Post by David B. Benson on Sept 1, 2014 10:10:12 GMT 9.5
eclipse --- Yes, U or Pu is required for startup.
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Post by eclipse on Nov 10, 2014 15:57:28 GMT 9.5
Hi all, do you have a favourite youtube doco on LFTR's? I sat through this one, but it felt a bit 'Blair Witch' in the production values if you know what I mean. I learned a lot, and pushed it in the Australian Christian Environment group on Facebook. I dared them not to fall in love with nuclear power after watching this, and one guy came around! But sadly, of course, the very next doco I watched said LFTR's are probably 10 years of heavy R&D away. GE seem to have the S-PRISM ready to go, but that's an IFR. IFR's don't have the same sex-appeal to people freaked out by sodium burning and fizzing in water at the beginning of this doco! www.youtube.com/watch?v=8Pyq8kCeiYs
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Post by huon on Nov 12, 2014 12:18:15 GMT 9.5
eclipse- I recommend the following video. Leslie Dewan, who helped develop Transatomic's reactor, is a wonderful spokeswoman for her reactor, and for modern nuclear in general. The Transatomic power plant can use thorium, as well as nuclear "waste" and uranium. www.youtube.com/watch?v=4UXXwWOImm8
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Post by eclipse on Nov 12, 2014 13:57:34 GMT 9.5
Hi Huon, LFTR's can eat nuclear waste and warheads, can't they?
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Post by huon on Nov 13, 2014 16:32:36 GMT 9.5
Hi eclipse,
My layman's understanding is that burning up nuclear waste, as the Transatomic reactor does, requires a fast reactor. Thorium reactors are thermal, with slow neutrons. So I don't think they'd get much nourishment from waste. They might be able to snack on weapons, though.
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Post by eclipse on Nov 15, 2014 12:52:15 GMT 9.5
At about an hour and 4 minutes in (1:04) Kirk Sorenson says we should put plutonium and old nuclear warheads in a "Lifter". That's how he says LFTR, which I think is cool. Lifter. The reactor that can lift this whole civilisation out of dirty energy poverty and into clean energy abundance. I like it! This 2 hour documentary is my favourite so far: it takes a lay person like myself right through the history of the first reactors, trouble dealing with Xenon135, the original ideas behind a nuclear air-force! and how that lead to LFTR. www.youtube.com/watch?v=P9M__yYbsZ4
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Post by eclipse on Nov 16, 2014 15:20:22 GMT 9.5
Hi all, The 2 hour documentary above was very encouraging when Kirk started talking about the Chinese delegation sent to investigate Oak Ridge. Basically, now I'm wondering if we need to promote the IFR any more? I know the IFR has had decades more development, but now that the Chinese are going to fast track the LFTR, don't we have an opportunity to move to true passive safety? Where gravity never fails, and the reactor always drains to the drain tank, every time the power fails? Every time? Given that it's going to take decades to get enough fissile material to run a world of IFR's anyway, should we be uniting our campaign around something like the AP1000 and then mass producing that while all agreeing that the ultimate goal is the LFTR?
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Post by Roger Clifton on Nov 18, 2014 19:13:48 GMT 9.5
Eclipse, your correspondent speaks with forked tongue. He allows us to gather that uranium reactors are not safe, clean or cheap. He implies that their product can be used in nuclear weapons and presents a proliferation risk. Neither is he respectful of thorium. He leads us to believe that the metal is hazardous and has to be buried. Having implied that both thorium and uranium reactors are unsafe, unclean and uncheap, he then goes on to suggest that small versions of the LFTR (baths of radioactive liquid!) could end up at every steel mill and small town. We are expected to shudder at the idea. It seems to be an hoax by and presumably among the antinuclear brigade. By the way, AP1000s are not easily mass produced because they require massive forgings. It is the SMRs, the small modular reactors, that are designed so they can be mass produced under licence in any industrialised country. See BNC thread on SMRs.
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Post by eclipse on Nov 19, 2014 11:30:53 GMT 9.5
"they require massive forgings" Ooo ooo! (Arnold Horshack noises from "Welcome Back Cotter"). I think even I know what that means! Are you talking about the 6 inch thick single mould required for the Shell Flanges for Reactor Pressure Vessels? Kirk really learned me good. OK, thanks for the heads up. These things designed for 70 atmospheres up are not so easy to mass produce. SMR's at one atmosphere are! Good stuff.
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Post by eclipse on Dec 7, 2014 14:02:30 GMT 9.5
This one was *really* interesting. Jiang Mianheng (son of former Premier of China!) takes half an hour to explain why China is pursuing nuclear energy and especially thorium energy. As well as the usual *rave* about thorium's incredible energy density, the Molten Salt Reactor's ability to eat nuclear waste, and the fact that it *cannot* melt down, he also talked about “Who killed the electric car?” He said it was a very scary story, and compared it to something that sounded like “World War 2 Nazi’s” but I couldn’t quite catch it as his accent was a little thick here. Anyone good at lip reading? (The audio and video get a little out of sync, but you can see him say it). www.youtube.com/watch?v=TZD1zfW4E1s
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Post by eclipse on Dec 21, 2014 8:41:34 GMT 9.5
Can I just ask a dumb question? I've been quite happy that breeders 'eat' nuclear waste: but what about the coolants? Don't they become radioactive? How do we process all the sodium from an IFR or fluoride from LFTR's?
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Post by David B. Benson on Dec 22, 2014 9:46:08 GMT 9.5
eclipse --- Neither sodium nor helium nor lead-bismuth have radioactive isotopes and do not fission.
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Post by eclipse on Dec 23, 2014 18:26:28 GMT 9.5
Sure, but I thought things could 'pick up' radioactivity? Not sure what the terminology was. Don't containment vessels and other metal bits and non-radioactive (in and of themselves) parts of a reactor become radioactive?
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Post by Roger Clifton on Dec 25, 2014 19:43:13 GMT 9.5
Don't containment vessels and other metal bits and non-radioactive (in and of themselves) parts of a reactor become radioactive? Although minimised during design, many reactor materials do have isotopes that absorb neutrons, with various probabilities in proportion to their "thermal neutron absorption cross-sections". To answer the question of whether that makes a problem, you could explore their different values in the last column, "Abs xs" of the table: www.ncnr.nist.gov/resources/n-lengths/list.html. When you figure an absorption is likely, check elsewhere whether the resulting isotope (ie with an extra neutron) has a beta decay, and if so, if its half-life is long enough to be of concern. In the process you'll see one reason why fluorine is preferred over chlorine for LTFR.
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Post by eclipse on Sept 23, 2016 16:08:35 GMT 9.5
Moltex in the UK claim they could build an MSR with almost off-the-shelf parts as soon as they have the money. Anyone got contacts near Elon Musk? 6 minute video does justice to the MSR. www.youtube.com/watch?v=R4GSDRqah-0
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Post by Greg Kaan on Sept 26, 2016 1:16:17 GMT 9.5
To answer the question of whether that makes a problem, you could explore their different values in the last column, "Abs xs" of the table: www.ncnr.nist.gov/resources/n-lengths/list.html. When you figure an absorption is likely, check elsewhere whether the resulting isotope (ie with an extra neutron) has a beta decay, and if so, if its half-life is long enough to be of concern. In the process you'll see one reason why fluorine is preferred over chlorine for LTFR. Another thing to note is that this table provides cross section data for THERMAL neutrons. www.ncnr.nist.gov/resources/n-lengths/The vast experience with moderated reactors makes this the most relevant information for most current reactor environments The fast neutron relative cross sections are almost always quite different and as a result, optimum material choices are also different. Kirk Sorensen has a nice article with discussion about chloride and fluoride salts and their suitabilities for fast and thermal reactors. energyfromthorium.com/2016/01/16/doe-terrapower/The LFTR is moderated for thermal neutrons hence the much greater suitability of fluoride salts.
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