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Is It Time For the US Government To Back Fusion At NIF Over ITER?

ananyo writes "Laser beams at the National Ignition Facility have fired a record 1.875 megajoule shot into its target chamber, surpassing their design specification. The achievement is a milepost on the way to ignition — the 'break-even' point at which the facility will finally be able to release more energy than goes into the laser shot by imploding a target pellet of hydrogen isotopes. NIF's managers think the end of their two-year campaign for break-even energy is in sight and say they should achieve ignition before the end of 2012. However, with scientists at NIF saying that a $4 billion pilot plant could be putting hundreds of megawatts into the grid by the early 2020s, some question whether the Department of Energy is backing the wrong horse with ITER — a $21-billion international fusion experiment under construction at St-Paul-lez-Durance, France. Is it time for the DoE to switch priorities and back NIF's proposals?" Perhaps a better idea, given the potential benefits of fusion research, would be for the DoE to throw their weight behind multiple projects, rather than sacrificing some to support others.

13 of 308 comments (clear)

  1. Re:well, i dunno by baudilus · · Score: 5, Insightful

    The two are not mutually exclusive. Just think of the internet you're using to post your comments for an example.

  2. Capture the Energy Produced? by earls · · Score: 5, Insightful

    I'm vaguely familiar with the NIF and their "how it works" section breaks down in great detail everything involved in generating the beam, amplifying the beam, targeting the beam, and imploding the target, but how do they capture the energy produced by the target?

    1. Re:Capture the Energy Produced? by Rei · · Score: 5, Informative

      They don't.

      Next question?

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    2. Re:Capture the Energy Produced? by opinionbot · · Score: 5, Informative
      Actually the front-end optics in NIF are usually replaced after each shot using modular Final Optics Assemblies, because debris from the exploding pellet and hohlraum is deposited onto surfaces. In a fusion reactor the optics would also need to withstand the flux of 14 MeV neutrons, without degrading excessively. Besides this there are several major hurdles to overcome in turning NIF's (impressive) performance into a source of power:
      1. The definition of "ignition" here means laser energy onto target vs. fusion power out. Current laser technology is not efficient enough at the high powers needed for ICF. It's still meaningful because in laser fusion the target physics is largely separated from the lasers so once the principles work an improved laser can be developed.
      2. The glass lasers used in NIF need to cool down for several hours between firings, whereas in a power plant the lasers need to fire at 10-15 Hz. High-power solid state lasers need development.
      3. The indirect drive scheme used in NIF is too inefficient to be used in a power plant. NIF uses a hohlraum to create a uniform implosion, but the conversion of laser energy to x-rays on the target is only a few percent.

      I've been around NIF and it is an amazing machine. It's also designed (and funded) to study warm dense matter physics like equations of state at high density for nukes, not fusion. Use of NIF for fusion is a great side-benefit and hopefully they can get useful data from it.

      The HiPER project to design a fusion reactor based on fast ignition has been though an initial concept design phase, but is now waiting further development. There is still a lot of research which needs to be done in target physics, lasers, and materials before ICF is ready to build an ITER-like machine

      The physics behind the ITER tokamak on the other hand is quite well understood at this point. Sure there are outstanding issues which are still being worked on (ELMS, divertor detachment, RWM control spring to mind) but we're pretty confident it will work. The design of ITER started in 88, and before that the INTOR project in '78, but it has taken a long time for politicians actually put some serious resources behind it. Hopefully it won't take that long for ICF projects like HiPER to be taken seriously and funded at a level which will make them happen

  3. Re:well, i dunno by Rei · · Score: 5, Informative

    NIF itself isn't really the answer, though. It's great for super-dense matter studies and gathering information of use for nuclear bomb detonations, but if the goal is sustainable fusion, NIF's approach is too expensive and inefficient. Rather, you need to go with a variant like HiPER. NIF relies solely on a compression pulse. HiPER uses a compression pulse plus a heating pulse. This allows the compression pulse to be much smaller and easier to achieve.

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  4. Hard problems haven't been tackled yet by Anonymous Coward · · Score: 5, Insightful

    Well, good luck with getting power into the grid by 2020.

    The reason why I'm saying this, is that it's an incredibly bold goal to turn the technology they've already got into a working prototype, incorporating everything learnt elsewhere, into a next-generation scientific experiment, let alone a power plant, by 2020. Hell, even HIPER won't break ground before 2020.

    Besides, the REAL fun stuff, is things like advanced materials for the combustion chamber, and a working blanket, which NOBODY has yet demonstrated, not JET, not ITER, not NIF -- nobody.

    Worse yet, we don't know what problems we'll run into once we achieve ignition in NIF, or the burning plasmas regime in ITER.

    To the genius who suggested that ITER is a political waste of time is obviously unfamiliar with the science. Even if ITER achieves its low-balled goals, it'll be a massive step towards a working plant. And they plan to actually test working power-generating, and tritium-breeding blankets as well, although that won't start until quite late in the project (the D-T phase of the project).

    The 'patriotic' Americans slagging ITER on /. should be quiet, as the US is, true to form, turning its back on the rest of the world, starving the US Domestic Agency of funding, and doing what it wants anyway.

  5. Re:And this is better than thorium because....? by gestalt_n_pepper · · Score: 5, Insightful

    Thanks, but I'm aware of the "new technology will solve the energy crisis" meme. The deal is this. We do need a new source of electricity as hydrocarbon depletion, or more importantly, hydrocarbon's ever shrinking energy return, starts to bite in a big way. We don't have many affordable options that scale. Nuclear has a chance of that, but conventional plants are dangerous and uranium isn't an infinite resource either. We have much more thorium than uranium, and while the plants are technologically challenging, we've already built them. It's not a matter of "trying to break even." We've broken even. It's a matter of building enough of the things safely and economically. That take incremental development, not some major breakthrough. It seems to me that pursing thorium is an easier and more economic solution than continuing to futz with fusion.

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  6. The Numbers by docilespelunker · · Score: 5, Insightful

    Really now, they've fired ~2MJ pulse. But what does that mean? 2MJ of laser light was present in their test chamber. This was fueled by 400MJ of electrical energy stored in capacitors. So we can now see that they have accomplished making a 0.5% efficient laser. This is nothing to write home about. Lets consider the actual fusion power output. The most they've had is about 1kJ of fusion energy output. This is not a lot. The balance between energy in and energy out is very poor. Getting 1kJ from 400MJ is about the best they can hope for. An overall efficiency of 0.00025%. Who here thinks that's good? JET, which is the smaller brother of ITER has achieved a 90% energy balance. Still not breaking even, but still 3600 times closer. ITER is designed to output 10 times more energy than is input. So it'll spank NIF. QED. That doesn't stop it being expensive though...

  7. Re:Of course by Kreigaffe · · Score: 5, Informative

    Not just Thorium, and there's probably better designs out by now anyway, but I for one was very pissed and still am that Clinton canceled America's Integral Fast Reactor project. Because ohhh scary nuclear. Except the IFRs produce less waste, safer waste, and can be fed just about anything, including most the crap that right now is considered waste.

    Bad project, Bill kill!

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  8. Re:Cheaper than War by vlm · · Score: 5, Interesting

    If we found a completely free source of electricity, that used a large building to produce, we wouldn't get rid of our oil demand.

    Not really. Given enough cheap energy, synthetic fuel is pretty trivial.

    The energy cost of ethanol distillation makes it a borderline negative source of energy... but if that energy is infinite and free, well then... Think about it... aluminum is essentially congealed electricity (look how its made). So you make aluminum greenhouses out of free electricity and dirt, then you string 24x7 ultra-high intensity lights using free electricity, the plants grow in water that was desalinated ocean water using free electricity, then you ferment the "stuff" and distill using free electricity... Given an infinite source of free electricity, pretty much, sea water comes in one pipe, and motor fuel ethanol comes out another pipe.

    You could condense carbon dioxide out of the air and strip the carbon off, condense water out of the air to strip the hydrogen off, mix together in a somewhat complicated o-chem lab, and make synth-gas. Air goes in one pipe, gasoline comes out the other pipe.

    Takes a heck of a lot of energy to pull that trick off, but it can be done.

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  9. Re:And this is better than thorium because....? by Chris+Burke · · Score: 5, Insightful

    It seems to me that pursing thorium is an easier and more economic solution than continuing to futz with fusion.

    Why treat these things like we have to only pick one? It's not like the money for R&D into fusion reactors and money for the construction of production fission reactors are coming from the same place. Even if they were, I'm sure we could find some third thing to de-prioritize instead.

    Thorium fission reactors have great potential for solving many current problems with fossil fuels. Thorium reactors could be running and solving our problem long before fusion reactors could.

    Fusion reactors have the potential to solve our energy problems for any forseeable future -- making energy so plentiful and cheap that we could use it to do things that would be completely insane now. Even in a future where we are using nuclear fission for all our power, the creation of working, production fusion reactors would be a revolutionary change.

    We want both. Let's not pit them against each other.

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  10. Re:Of course by isotope23 · · Score: 5, Informative

    Why the fuck do people keep on mentioning Thorium reactors? They still produce fission products. And fission products are the only thing that nuclear reactors need to protect against releasing to the public. Fission products are also statistically determined. You will always get short medium and long term radionuclides even if you burn up some.

    There are benefits to Thorium reactors, but in a major accident they will still release enough highly radioactive substances that will require evacuation and quarantine of the affected area for decades. Yes, a thorium reactor can still meltdown, it still has decay heat, and it would require complex engineered safeguards to protect it.

    You do realize that EXISTING thorium reactor designs -

    1. Do not need water as coolant (hence no high pressure evironment and much smaller)
    2. As designed will shutdown on their own with no outside intervention.
    3. As designed they can't "overheat".

    "Best results occur with molten salt reactors (MSRs), such as ORNL's liquid fluoride thorium reactor (LFTR), which have built-in negative-feedback reaction rates due to salt expansion and thus reactor throttling via load. This is a great safety advantage, since no emergency cooling system is needed, which is both expensive and adds thermal inefficiency. In fact, an MSR was chosen as the base design for the 1960s DoD nuclear aircraft largely because of its great safety advantages, even under aircraft maneuvering. In the basic design, an MSR generates heat at higher temperatures, continuously, and without refuelling shutdowns, so it can provide hot air to a more efficient (Brayton Cycle) turbine. An MSR run this way is about 30% better in thermal efficiency than common thermal plants, whether combustive or traditional solid-fuelled nuclear.[27]"

    http://en.wikipedia.org/wiki/Thorium#Commercial_nuclear_power_station

    4. The US has a metric fuckton of thorium in it's coal deposits.

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  11. Re:Try Liquid Fluoride Thorium Reactor first by AmiMoJo · · Score: 5, Insightful

    It only needs to be commercialized.

    You say it so casually, as if it wouldn't take billions of euros and decades of time... It isn't just the reactor that needs to be designed, proven and certified, it's the infrastructure to handle the fuel and decommission the thing after its working life.

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