Viewing 15 posts - 1 through 15 (of 23 total)
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  • #10226
    zapkitty
    Participant

    Ivy Matt wrote:
    Then there’s this puzzling paraphrase of Mike Dunne of LLNL:

    Washington is comfortable that this technology provides no opportunities “for nuclear proliferation or advancement of other country’s weapons capability,” said Dunne. The development of commercial fusion, he says, has no defense applications.

    Apparently the US Navy disagrees; otherwise they wouldn’t be funding EMC2’s research.

    Note what he said: “commercial” fusion.

    What is “commercial” fusion from a Foggy Bottom point of view?

    ITER.

    How much of a military threat is ITER?

    You can stop laughing any time now;…

    But it does point out the very real threat, despite treaties to the contrary, of an “official” fusion process vs. “commercial” plants. in an inverse analogy to the telecoms and broadband in the U.S.

    (The telecoms were allowed to suck in extra fees from customers for decades for the express purpose of building up nationwide broadband while simultaneously refusing to do that and gambling the money away on Wall Street… only to turn around and declare that only the wired net was actually the “public” internet and that the new wireless nets are now the “commercial” internet… all the while simultaneously dropping future wired net buildout and going full speed ahead on wireless.)

    So, a possible future in which ITER gives the world nothing for decades and then very limited fusion access for the public while fusion-powered aircraft carriers float by overhead…

    … the plutocracy at the top of the oligarchic heap would love that scenario.

    #10230
    pzgndr
    Participant

    As always, Tri Alpha gets a mention, despite not having so much as a website to link to.

    I first heard about this related to a closed VC meeting in LA last month, which got me wondering about pB11 fusion, which led me here. It’s all quite hush-hush about Tri Alpha. I’m curious to see what happens next.

    #1182

    CNN Tech has a new article on General Fusion:

    http://www.cnn.com/2011/TECH/innovation/06/27/fusion/index.html

    The usual suspects, ITER and NIF, are mentioned. As always, Tri Alpha gets a mention, despite not having so much as a website to link to. %-P Helion Energy also gets a mention. I’m guessing the Popular Mechanics article helped put Helion on more people’s radars. No mention of EMC2 or LPP, though. I guess they’re old news. %-P

    There’s a nice quote on small(er) fusion projects from the US ITER project manager:

    “I would love to see that fusion can be done so economically, and so I hope they succeed,” Sauthoff says. “ITER is the way that you go if you really want high confidence. But you have to pay more for high confidence.”

    Then there’s this puzzling paraphrase of Mike Dunne of LLNL:

    Washington is comfortable that this technology provides no opportunities “for nuclear proliferation or advancement of other country’s weapons capability,” said Dunne. The development of commercial fusion, he says, has no defense applications.

    Apparently the US Navy disagrees; otherwise they wouldn’t be funding EMC2’s research.

    #10251
    dennisp
    Participant

    Re: defense, it sounds like they’re talking about nuclear proliferation issues. Fusion powered ships would revolutionize the Navy…aircraft carriers are nuclear but all the support ships are fossil, and they hold the carriers back.

    #10252
    TimS
    Participant

    From the CNN article,

    General Fusion aims to achieve net gain fusion experimentally in 2012. By 2018, it plans to complete a power plant prototype that would generate 100 megawatts, enough to power about 100,000 homes.
    “We would like to be in a commercial stage of being able to take orders and build power plants by the end of the decade,” said Michael Delage, General Fusion VP of business development.

    If I understand correctly from this and several other sources, the General Fusion guys are building a demonstration reactor right now, not just a research device. As far as I know this is a new thing and breaks the current fusion paradigm. Instead of being some giant (ITER, NIF, etc) project, or some cool little plasma research project (LPPX, PWELL, etc), they are using an already developed plasma manipulation technology (MTF) that has not provided critical plasma parameters for fusion tied to a chamber with 200 air hammers… Basically about as brute force as you can get, ugly, expensive, radioactive, but they are building a fusion reactor out of it right now. If it works it will shatter the Tokamak paradigm that you need 10-100 billion dollars and 20-40 years to build a demonstration fusion reactor, and finally more sensible fusion technologies, such as DPF, might get some real funding.

    General Fusion Reactor Diagram
    They are building a 3m diameter sphere with places for 200 big air hammers on the outside, and MTF spheromak (semi-stable plasma rings, like plasmoids but much larger) generators at the top and bottom. The MTF technology has already been well developed elsewhere, there is a guy at Los Alamos interviewed in this article who has been working it for decades, but it has not achieved critical density / temperature for fusion. By banging a few dozen hammers and focusing the shockwave inside the sphere with a fluid, spheromaks at the middle should go critical. Banging some hammers on a fluid filled sphere is not exactly new science- this is just a massively complicated engineering problem (mostly involving synchronizing the hammers). As the article says, shortly (within a year or so) they plan to have built enough hammers and a good enough synchronization system for a critical reactor that achieves break even.

    Then there are a couple of years for practical issues- their demonstrations so far have used water as the fluid and a tube through the water for the plasma which gets crushed by each shot. The plan is to use molten lead for the fluid to protect from the fusion neutrons, with molten lithium in the lead to breed tritium as a source for DT fusion, and spin up the molten lead lithium mixture to make an opening in the middle for the plasma like the opening in water as it spins around a sink before going down the drain. They also will need to build the rest of the 200 hammers the system needs for full operation, all synchronized to generate a shockwave in the middle on time-scales of 1-100 microseconds. These are engineering issues, no plasma research and nothing ‘scientific breakthrough’-ish about it.

    Once they get all this to work, they shoot it once a second, take heat out of the molten lead using a heat-exchanger / steam turbine combo, and they have a fusion reactor power generator. This is a big-ugly-absolutely no finesse way of getting MTF to work, not very attractive to your average fusion scientist, but the thing is it is just an expensive engineering problem. The Los Alamos MTF researcher says if they can solve their engineering issues to provide the needed shockwave, then it should generate the output energy they claim. The guy named Laberge who dreamed all this up was engineering parts for Kodak printers, but he actually got his doctorate in plasma physics when he was younger and was interested in fusion at the time, and he decided to go back to his roots and do something for the world. His company is getting the money it needs. A fund with Jeff Bezos, the founder of Amazon, just put in $20 million, and they already had millions.

    I think it is quite possible General Fusion will be selling reactors before there is a prototype DPF. And their reactors will be big, ugly, noisy, expensive, deal with bunches of radioactive material from the tritium and high energy neutrons, and not very reliable. Kind of like first generation analog cell phones, but radioactive. Did I mention expensive? Consider heat exchangers and steam turbines, interfacing with molten lead laced with radioactive tritium. However, for comparison current power reactors cost billions of dollars.

    tl;dr

    My point is their success could be a very good thing for the fusion field, and for LPPX in particular. How many billions of dollars every year are invested in cell phone technology these days? Would all that money be invested if passing the initial hurdle of demonstrating some type of cell phone had not occurred? Why does DPF need to be the first commercial fusion reactor? Once we get past investors thinking about fusion as something that will never actually happen, to investors thinking about the merits of various types of reactors, I expect DPF to take off. Especially considering the radioactive part.

    #10253
    Lerner
    Participant

    Tokamaks have been claimed to be basicaly an engineering project for 40 years. Ultimately, GF is also asking the plasma to sit still like a good dog while it is compresssed. Sounds good until you get instabilities.

    #10254
    TimS
    Participant

    Tokamaks were claimed to be an engineering project, but when I looked at what people have actually been doing in the tokamak field for the last decades they have been doing what looked an awful lot like plasma research. “Just need to figure out one last instability mode…” GF looks to be doing engineering. If the “good dog” gets too squirrely in the sub-millisecond of compression, or MTF fails in their reactor environment, then this just isn’t going to work. Not all engineering problems are solvable.

    #10255
    jamesr
    Participant

    The lead-lithium combination would likely be used in tokamak and inertial confinement schemes. So from this aspect it is the same as all the other big-ugly MCF & ICF designs

    The lead is not to protect from the neutrons, as a heavy element its pretty useless at that. It can protect against some gamma and hard x-rays that penetrate the first wall, and result from the various nuclear reactions with the lead itself and the lithium. Its primary use is to breed more neutrons.

    To make enough tritium to sustain your fuel supply you need to breed more neutrons to react with the lithium since you will never capture all the high energy neutrons from the D+T reaction. Some you can breed if you have a Beryillium wall, but not normally enough. When a neutron hits a lead nucleus it has a chance of knocking out some more neutrons.

    Molten lead makes a good coolant since it is liquid over a large temperature range and does not have to be at high pressure, unlike water used in PWR fission reactors.

    #10257
    Ivy Matt
    Participant

    Wow, how did I get promoted to admin? %-P

    #10258
    Rezwan
    Participant

    I have no idea. That’s weird. Message in to expression engine forums.

    #10268
    Ivy Matt
    Participant

    Oh, I just assumed somebody moved my thread and, in the process, became its owner. I’ve noticed recently that a number of older threads have been “updated” and appear as new forum posts on the front page.

    #10270
    Rezwan
    Participant

    Yes, I’ve noticed that too. I think that might have to do with the rearranging that I’ve been doing – moving forums about and switching categories.

    But this attribution switch from you to Admin is weird.

    #10278
    Rezwan
    Participant

    It appears to be a bug, not a hack.

    #10781
    Brian H
    Participant

    Lerner wrote: Tokamaks have been claimed to be basicaly an engineering project for 40 years. Ultimately, GF is also asking the plasma to sit still like a good dog while it is compresssed. Sounds good until you get instabilities.

    My non-technical generalization has been: Nature permits only Big and Tiny fusion. Star-sized, or microplasmoid sized. Both of those can suppress instabilities long enough for fusion temperatures to occur.

    Mid- and human-sized is “forbidden territory”. Plasma is too damn frisky for stable artificial containment.

    Am I being too simplistic?

    #10782
    Brian H
    Participant

    TimS;
    The success of General Fusion could be a very good thing. But its far more probable failure could/would/will further strengthen the eye-rolling reflex of the fusion doubters.

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