Slashdot Mirror
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.
The two are not mutually exclusive. Just think of the internet you're using to post your comments for an example.
Seems like thorium reactors, which we've already built, and gotten working, are a much more tractable problem.
Please do not read this sig. Thank you.
Basically, this should be a 'hero' project. Like a moon shot. Lets face it, we need to transit off of fossil fuels to a large degree sometime down the line. Not tomorrow. Not next year, but certainly in the next decade or so. Nuclear fission is an option - but as we've seen, not a terribly good one. Solar / wind / hydro / ponies and pixie dust / conservation will also help but we still need a backbone capable of powering modern civilization unless we want to devolve into something less pleasant. And that backbone has to put a lot of gigajoules into the system on a 24/7/365 basis.
So we need to put our money where our collective mouths are and work on something capable of bringing up the entire world to first world standards.
Or fight the war to see who's standing over the oil fields.
Faster! Faster! Faster would be better!
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?
[NIF's managers] say they should achieve ignition before the end of 2012.
I'm guessing their target date is December 21.
Is $4B really that hard to come up with for this project? That sounds a lot cheaper than the constant state of war we find ourselves in today in the Middle East to keep the oil supply flowing.
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.
Teach me to love you, you squishy poet from beyond the stars!
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.
well then Thorium nuclear reactors would seem to be a better bet.
Service guarantees Citizenship! Questions Guarantee GITMO.... Amerika Uber Alles!
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...
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!
... still waiting for this free-as-in-beer free beer I keep hearing about.
Sugar cane also works for Brazil because they don't have nearly as many cars on the road in the first place. There's also the very serious hazard of using arable land to grow fuel rather then food, and the follow on effects that can have on global food prices.
Biofuels are really a non-starter - it's inefficient solar power, with all sorts of limitations and where and how much of it you can use. It also is only an answer for transportation fuel at that. There's no possible way we could satiate our electricity demands using biofuels (when you need 60% of the arable land in the US to manage the oil needs of transportation alone - optimistically).
Fusion research has to be done, no matter the cost, until we either definitely establish it can't be done, or we succeed. Given the positive results that we have that, it seems likely we can succeed - but nothing that complex is ever easy or quick.
I love how projected "breakeven" and "ignition" in 2012 has suddenly been extrapolated to MW powerplants on the grid within a decade.
Nevermind that we don't capture the energy yet, which might give us best-case 50% efficiency. Nevermind we need 3x breakeven the breakeven energy for converting heat into steam to power a turbine. Nevermind just about every factor of 2-3 efficiency loss out there. I'm going to post one goddamn link that was true when I interned there, and is still consistent today and then I want to see what the "scientists" who projected this commercial powerplant planned to do about this minor detail:
http://www.ieer.org/reports/fusion/chap3.html
By contrast, a large commercial power plant using ICF will require around five shots per second. Laser drivers also have low efficiencies, currently around 1% for solid-state lasers such as those to be used in NIF.
99% efficiency loss right off the bat. What's left for these people to even argue about?
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.
Service guarantees Citizenship! Questions Guarantee GITMO.... Amerika Uber Alles!
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.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
How do you generate hydrogen in a molten salt reactor? What's the source?
The Fukushima reactors generated it because the water was boiling to steam and reacting with the zirconium-cladded fuel canisters. There are no such canisters in a molten salt reactor, and there is also no water and no pressurisation of the containment structure (what's the vapour pressure of Lithium Fluoride anyway? ;) ).
The danger of overheating is also removed - the fuel is already molten *by design*, and is contained in the system by a plug of solid fuel that is kept below the melting point by active cooling. Should the power fail (or the temperature of the fuel go too high for the cooling if the plug to cope), the plug of fuel melts and the whole primary loop drains off and settles in a non-critical arrangement run off area. It will then either solidify, or remain as a liquid if the temperature is high.