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ZunarJ5
2012-May-28, 01:15 PM
In a previous thread I proposed fusion power as a possible alternative to nuclear powered space-craft of the future and as a solution to powering vehicles that would leave our solar system. The response I received made me question whether fusion power will ever be a likely reality, or whether I will ever see it at all (assuming I'm alive 50 years from now).

http://www.ccfe.ac.uk/index.aspx

The above link seems to be a fairly legitimate authority on fusion power... unless I've been taken in, which is entirely possible.

I'm never without a critical eye, I always question my sources of information... but of course I do this in degrees. So, just how skeptical should I be of the information on that website?

What are your best guesses on the fusion time line? What are the best sources of information that you have found on the subject?

Ara Pacis
2012-May-28, 04:40 PM
Fusion is nuclear power.

ZunarJ5
2012-May-28, 04:49 PM
Fusion is nuclear power.

Sorry, by nuclear I meant fission, as in the form of nuclear power available to us today. Thank you for the constructive reply.

ZunarJ5
2012-May-28, 04:54 PM
With the impending power crisis this planet is facing I would think there would be more interest in fusion power. It seems like the one true "out" we have from this approaching disaster.

Is there reason to think that fusion power is a dead end?

Or is it the inevitable next step in energy generation?

noncryptic
2012-May-28, 06:51 PM
With the impending power crisis this planet is facing I would think there would be more interest in fusion power. It seems like the one true "out" we have from this approaching disaster.

Since we don't yet have fusion power, it's primarily a research interest.
Other alternatives are already available and are being implemented.


Is there reason to think that fusion power is a dead end?

Given the research in fusion that's going on, more than a few scientists seem to think it's not a dead end.


Or is it the inevitable next step in energy generation?

Maybe, but with the (ongoing) global power crisis, we can't afford to wait for fusion.

mutleyeng
2012-May-28, 07:11 PM
there was a wonderfull bbc horizon documentary back in 2009, called "can we make a star on earth".
The tentative conclusion was that the experiments and trials going on at that time should at least show whether it will be possible (practically viable) or not within the next 4 years -- not long to go now then

Swift
2012-May-28, 07:15 PM
Is there reason to think that fusion power is a dead end?

Or is it the inevitable next step in energy generation?
I claim no expertise on this topic, but it seems to me the reality is somewhere between those two positions. The running "joke" for the last 50 years is that practical fusion power is 50 years in the future, and it still seems to be true. I think fusion has turned out to be a lot harder than anyone ever thought. I think it probable that the technology will eventually be made to work, but I don't think it will be any time soon, nor may it be as much the magic solution people imagined it would be.

But I also don't think it is the "one true 'out'" we have from "this approaching disaster".

Jens
2012-May-29, 12:03 AM
Fusion is a funny thing, because we know it works. But it's just very hard to achieve technically. Even the sun is from what I understand not very efficient at it at all. But there are lots of people who believe it is achievable, and there are many well funded projects that are trying to achieve commercially viable fusion, so I'm cautiously optimistic.

mutleyeng
2012-May-29, 02:00 AM
But I also don't think it is the "one true 'out'" we have from "this approaching disaster".

It would change everything though.
I think the moment the research demonstates its viable, things will move very quickly.
We will all move over to hydrogen ecconomies .. and maybe i can have my 100w light bulbs back

Swift
2012-May-29, 02:06 AM
It would change everything though.
I think the moment the research demonstates its viable, things will move very quickly.
We will all move over to hydrogen ecconomies .. and maybe i can have my 100w light bulbs back
Maybe, but I'm not convinced of that. Depending on how complex or dirty the technology turns out to be, it might be extremely expensive for example. If can only use deuterium or tritium, you are going to have to separate those out from hydrogen.

Ara Pacis
2012-May-29, 04:08 AM
It might be useful to point out that we do have fusion. It's done all the time. It can even be commercialized as a novelty, if we wanted to do it. However, it's not useful for electrical power generation because it takes more electricity to make than it produces. And then there's that whole radioactivity thing. Doing aneutronic fusion is even harder than doing regular fusion. If people weren't worried about radioactivity, then maybe we'd have a lot of breeder fission reactors by now.

HenrikOlsen
2012-May-29, 08:08 AM
It would change everything though.
I think the moment the research demonstates its viable, things will move very quickly.
We will all move over to hydrogen ecconomies .. and maybe i can have my 100w light bulbs back
It's been demonstrated with positive energy output decades ago.
It wasn't in a sustained reaction though and it wasn't in a power plant, to it's been demonstrated to be theoretically viable rather than practically viable.

That "change everything", "too cheap to meter" stuff was exactly what was claimed of fission before it was realized how large installations are needed to do it effectively, and how many extra costs environmental hysteric can pile on top of things.

mutleyeng
2012-May-29, 10:51 AM
[QUOTE=HenrikOlsen;2022366]It's been demonstrated with positive energy output decades ago.
It wasn't in a sustained reaction though and it wasn't in a power plant, to it's been demonstrated to be theoretically viable rather than practically viable.

I know, that was the context of what i meant by viable.


That "change everything", "too cheap to meter" stuff was exactly what was claimed of fission before it was realized how large installations are needed to do it effectively, and how many extra costs environmental hysteric can pile on top of things.

no claims of too cheap to meter, i wouldnt assume it would be any cheaper at the meter.
The rest comes under viable.
If it turns out that the cost to build the plants is on a par with fission, then it will be of limited help.
I dont quite see why it would when the major cost of fission is as you say safety related. I dont see anything like the scale of that problem with fusion, but i admit im not much of an expert on the subject.
We already know we couldnt build the numbers of fission reactors needed even if we had a mind to.
The point really being, it is the only solution i know of that has the potential to satisfy our current demand, provide the exta to facilitate moving to hydrogen ecconomies, and allow for the developing world to have access to the same energy levels as the developed world. But i do stress, potential

HenrikOlsen
2012-May-29, 11:13 AM
It it's going to allow the developing world to have access to the same energy levels as the developed world, it really does need to be "too cheap to meter" otherwise they wouldn't be able to afford it.

mutleyeng
2012-May-29, 11:23 AM
i dont think thats the point, they will build up their ecconomy the same as we did, gradually over time in various way (as they are in india and china right now). The point is that we have to allow for them doing that and demanding the energy that goes with it, as in generating capacity

John Mendenhall
2012-May-29, 12:11 PM
I find the link in the OP to be much too optimistic. The Wiki article is much more realistic, and is here:

http://en.wikipedia.org/wiki/Fusion_power

Regards, John M.

kzb
2012-May-29, 12:18 PM
Apparently, ITER will eventually work up to a positive energy balance, in other words there is more energy released in the fusion reaction than was put in to make it happen. This is being built now. It won't produce a commercially viable energy source though, because you need to produce several times the energy input as useful energy output before it is viable. The machine to do that will be the generation after ITER.

So you can imagine what kind of time line we are on before it could become commercially viable. I won't see it in my lifetime. It also seems to be the case that a fusion reactor along the lines of these machines would be described by the term power amplifier. They need a huge energy input, exceeding the capacity of the national grid, to deliver a fusion pulse.

In the meantime, fission technology, in the guise of a fast breeder and reprocessing fuel cycle, is a proven technology and could supply power for centuries to come.

cjameshuff
2012-May-29, 01:09 PM
It would change everything though.
I think the moment the research demonstates its viable, things will move very quickly.

It's been demonstrated to be physically possible, with several reactors demonstrating the needed plasma containment. ITER is expected to eventually produce 500 MW of thermal power, and is under construction now...and yet, all the international partners together are only spending ~$13 billion on it, spread over ten years.

Funding of fusion research has been pathetic. If we were seriously interested in an alternative to fossil fuels and fission, the US alone would already be running multiple ITER-scale projects in parallel on accelerated timetables, and not constantly cutting and canceling much-smaller research projects. (Instead, the closest thing we've got is NIF, which is more about nuclear weapons research than power production.)



We will all move over to hydrogen ecconomies .. and maybe i can have my 100w light bulbs back

If the only thing needed for a "hydrogen economy" was energy sources, we could have it now with nuclear power. The truth is that hydrogen's just a rather poor way to store or transport energy.

Swift
2012-May-29, 01:09 PM
<snip>
... and how many extra costs environmental hysteric can pile on top of things.
Not to mention, legitimate environmental concerns.

mutleyeng
2012-May-29, 01:13 PM
i would be really interested to see what the american multi laser approach manages to achieve when they finally fire it at a fuel pellet.
192 laser beams producing 400 trillion watts for 23 nanoseconds aimed at a 1mm target.
what could possibly go wrong

mutleyeng
2012-May-29, 02:02 PM
Funding of fusion research has been pathetic. If we were seriously interested in an alternative to fossil fuels and fission, the US alone would already be running multiple ITER-scale projects in parallel on accelerated timetables, and not constantly cutting and canceling much-smaller research projects. (Instead, the closest thing we've got is NIF, which is more about nuclear weapons research than power production.)

If the only thing needed for a "hydrogen economy" was energy sources, we could have it now with nuclear power. The truth is that hydrogen's just a rather poor way to store or transport energy.

I dont know what US funding is like, but by european standards the funding it gets seem to suggest they at least do take it seriously, which is quite significant for a technology that at best is still a long way from generating power into peoples houses.
I agree there are problems to be solved with hydrogen storage and transportaion.

Grashtel
2012-May-29, 02:24 PM
i would be really interested to see what the american multi laser approach manages to achieve when they finally fire it at a fuel pellet.
192 laser beams producing 400 trillion watts for 23 nanoseconds aimed at a 1mm target.
what could possibly go wrong
It failing and breaking the experimental equipment is really the worst plausible outcome. 400 trillion watts sounds like a lot of energy but if you actually work it out the fact that it is applied for only 23 nanoseconds means that its really not that much, a few tens of megajoules at most (for comparison a litre of gasoline contains 35 megajoules). If the fusion reaction succeeds really well then I could just about see it managing to blow up the lab, but I doubt that even if fully fused the fuel pellets would contain enough energy for that and would think its likely that the test chamber is going to be designed to survive even the largest possible energy release from one.

mutleyeng
2012-May-29, 02:34 PM
i meant to have a successful test, and was a back handed compliment at the technolgy they are using ( i think its kinda impressive thing they got going there)
dont worry, i didnt think it would create a black hole over California or anything.

Grashtel
2012-May-29, 09:03 PM
i meant to have a successful test, and was a back handed compliment at the technolgy they are using ( i think its kinda impressive thing they got going there)
dont worry, i didnt think it would create a black hole over California or anything.
Ah cool. Text isn't good for transmitting tone so I had misinterpreted what you said. Glad to see that you aren't one of the alarmist types who freaks out about big numbers without realizing what they mean

whimsyfree
2012-May-29, 11:19 PM
It's been demonstrated to be physically possible, with several reactors demonstrating the needed plasma containment.

That's great! how many years have they kept it contained?


If the only thing needed for a "hydrogen economy" was energy sources, we could have it now with nuclear power. The truth is that hydrogen's just a rather poor way to store or transport energy.

Gee it only seems like yesterday that Very Important People were making Serious Announcements (http://georgewbush-whitehouse.archives.gov/news/releases/2003/06/20030625-6.html) about the "hydrogen economy" being the solution to the world's problems (at least so far as energy and climate change are concerned). The idea was, for the reason you give, obviously naive and irrelevant to the problems it was supposed to solve. It made me wonder about the quality of advice our VIPs get from the highly respected (and paid) Distinguished Scientists who advise them on such matters. Or do they just ignore them?

John Mendenhall
2012-May-30, 12:29 AM
i would be really interested to see what the american multi laser approach manages to achieve when they finally fire it at a fuel pellet.
192 laser beams producing 400 trillion watts for 23 nanoseconds aimed at a 1mm target.
what could possibly go wrong

Don't worry. The designers say the ship is unsinkable.

cjameshuff
2012-May-30, 12:39 AM
That's great! how many years have they kept it contained?

Assuming you mean "how many years have they had the ability", JT-60 was able to contain a deuterium plasma (as a plasma research system, they don't actually run it with anything it can fuse) under conditions that would produce a power gain of 1.25 in D-T plasma back in 1998. Fusion benefits from large scales, but we haven't been funding new large scale devices...JT-60 was built in 1985, and is still one of the largest (and used resistive magnets, though it's being upgraded to use superconducting ones). ITER is to be about twice as large, with superconducting magnets, and to achieve peak gains of 10 with steady state operation at a gain of 5.

If you mean actual containment time, why would you require years of containment? Apart from that not being anything close to a requirement for fusion power, when and why would an experimental device have had time set aside for doing this? And why would funds be spent on equipping it with the cooling and other equipment needed for such a stunt, and the power needed to run it? It's just not a reasonable expectation, for anything up to and probably including a fully operational fusion power plant.

cjameshuff
2012-May-30, 12:52 AM
It failing and breaking the experimental equipment is really the worst plausible outcome. 400 trillion watts sounds like a lot of energy but if you actually work it out the fact that it is applied for only 23 nanoseconds means that its really not that much, a few tens of megajoules at most (for comparison a litre of gasoline contains 35 megajoules). If the fusion reaction succeeds really well then I could just about see it managing to blow up the lab, but I doubt that even if fully fused the fuel pellets would contain enough energy for that and would think its likely that the test chamber is going to be designed to survive even the largest possible energy release from one.

Vastly more energy goes into the equipment that produces the pulse. Producing precise, ultra-short pulses of high quality laser radiation is not an efficient process, and produces far more heat than it does laser radiation. They start off with 422 MJ of electrical energy and end up with about 1.8 MJ delivered to the target. The NIF is trying to get the cooldown period short enough to do multiple shots a day. A cooling failure following a shot could lead to thermal damage to quite a bit of equipment that's not normally exposed to the waste heat. We're probably talking "slowly melting plastic bits", though, not a spectacular explosion.

whimsyfree
2012-May-30, 03:29 AM
ITER is to be about twice as large, with superconducting magnets, and to achieve peak gains of 10 with steady state operation at a gain of 5.

If you mean actual containment time, why would you require years of containment? Apart from that not being anything close to a requirement for fusion power,


I may be confused and have not understood the terminology. I'm confused by some of your statememts. How can a fusion reactor be "steady-state" if it only operates for a few seconds at a time? I don't know much about containment times, so I defer to ITER partner General Atomics. According to their website (https://fusion.gat.com/iter/iter-ga/confinement_transport.html) the goal is 4s confinement and the best achieved is about 0.8s. I also checked out the ITER website (http://www.iter.org/). Seems they're just coming to the end of the digging big holes in the ground phase. The new headquarters building (http://www.iter.org/img/sq-640-85/all/content/com/img_galleries/p1240368.jpg) looks nice though. SciAm has a distinctly downbeat assessmemt (http://www.scientificamerican.com/article.cfm?id=fusions-missing-pieces-iter-problems) of the project.

cjameshuff
2012-May-30, 04:43 AM
I may be confused and have not understood the terminology. I'm confused by some of your statememts. How can a fusion reactor be "steady-state" if it only operates for a few seconds at a time?

It's just what it says, if the state's not changing, it's in steady state. Some processes take place in constantly changing events where such a condition is never reached, others go through a startup transient and reach a region of stable operation, which can be maintained as long as you maintain the conditions that produced it.



I don't know much about containment times, so I defer to ITER partner General Atomics. According to their website (https://fusion.gat.com/iter/iter-ga/confinement_transport.html) the goal is 4s confinement and the best achieved is about 0.8s.

Energy confinement time. They're not talking about how long the reactor can maintain a plasma, they're talking about how fast heat is lost to the reactor walls, which determines things like how hot the plasma gets and how much fusion occurs, and particularly whether ignition occurs (heat being generated fast enough to maintain fusion on its own).



I also checked out the ITER website (http://www.iter.org/). Seems they're just coming to the end of the digging big holes in the ground phase. The new headquarters building (http://www.iter.org/img/sq-640-85/all/content/com/img_galleries/p1240368.jpg) looks nice though. SciAm has a distinctly downbeat assessmemt (http://www.scientificamerican.com/article.cfm?id=fusions-missing-pieces-iter-problems) of the project.

ITER's an international project with rather too many parties involved. Its resulting problems are not unique to fusion power. That article has no specific technical criticisms as far as I can tell, just vague doom and gloom and a rather ignorant claim that ITER is taking money from wind and solar power...which will never be able to handle the base load power supply that fusion power is intended to provide.

aquitaine
2012-May-30, 05:58 AM
Not to mention, legitimate environmental concerns.


Not as many as one might think. While there are some definate risks, many of them have been way over blown. (http://www.newscientist.com/article/mg20928050.200-risk-expert-why-radiation-fears-are-often-exaggerated.html) Still, much better than shivering in small, dark, freezing solar powered huts or choking on coal dust.



Gee it only seems like yesterday that Very Important People were making Serious Announcements about the "hydrogen economy" being the solution to the world's problems (at least so far as energy and climate change are concerned). The idea was, for the reason you give, obviously naive and irrelevant to the problems it was supposed to solve. It made me wonder about the quality of advice our VIPs get from the highly respected (and paid) Distinguished Scientists who advise them on such matters. Or do they just ignore them?


Given how dangerously unstable hydrogen is, why people would want to put the equivelent of a small bomb in their trunk is a mystery to me. Natural gas and gasoline are bad enough, but this thing is the widow maker for sure. (http://pesn.com/2011/08/11/9501892_Alternative-Fuel_Business_Explosion_in_Sylma-LA/)


EDIT: OT, provided things go well at ITER I'm pretty confident we'll see fusion ready for commercialization in the second half of this century. There's no fundemental reason for it not to work, it's just a matter of overcoming the massing engineering challenges.

HenrikOlsen
2012-May-30, 06:27 AM
Given how dangerously unstable hydrogen is, why people would want to put the equivelent of a small bomb in their trunk is a mystery to me. Natural gas and gasoline are bad enough, but this thing is the widow maker for sure. (http://pesn.com/2011/08/11/9501892_Alternative-Fuel_Business_Explosion_in_Sylma-LA/)
That's not a good example of hydrogen based energy transport though.
That was someone working on Stehl's magic water power, under conditions that had him up against the local OSHA for taking shortcuts that shouldn't be taken, basically it's someone who doesn't know what he's doing and has already killed one son doing it.

cjameshuff
2012-May-30, 11:14 AM
Given how dangerously unstable hydrogen is, why people would want to put the equivelent of a small bomb in their trunk is a mystery to me. Natural gas and gasoline are bad enough, but this thing is the widow maker for sure. (http://pesn.com/2011/08/11/9501892_Alternative-Fuel_Business_Explosion_in_Sylma-LA/)

That's a bit worse than plain hydrogen, it's another example of HHO free energy crankery...that is, they were messing with a stoichiometric mixture of hydrogen and oxygen in a perpetual motion scheme. However, you can look at Fukushima as a recent example of what small amounts of leaking hydrogen in the wrong place can do...

Hydrogen (with adequate ventilation) could be a useful intermediate step in synthesis of hydrocarbons. High temperature electrolysis can more efficiently use the energy of fission and perhaps fusion power to produce hydrogen, and hydrocarbon synthesis was demonstrated to be economical on large scales in WWII, it's just not very competitive with fossil fuels at the moment. Our production of ammonia demonstrates that we can handle large scale industrial processes using hydrogen with only occasional explosions. But hydrogen gas itself as a means of storing and transporting energy?



EDIT: OT, provided things go well at ITER I'm pretty confident we'll see fusion ready for commercialization in the second half of this century. There's no fundemental reason for it not to work, it's just a matter of overcoming the massing engineering challenges.

Indeed. The ITER approach may not even be the cheapest or best way to do fusion power (there's a whole zoo of other magnetic confinement approaches, and other approaches like Polywell that have not gotten the attention they deserved), but it'll work. If people will just stop mocking fusion power for its lack of results, look at what's been achieved, and actually fund the research needed to produce more results...

headrush
2012-May-30, 04:45 PM
We already know we couldnt build the numbers of fission reactors needed even if we had a mind to.
The point really being, it is the only solution i know of that has the potential to satisfy our current demand, provide the exta to facilitate moving to hydrogen ecconomies, and allow for the developing world to have access to the same energy levels as the developed world. But i do stress, potential


It it's going to allow the developing world to have access to the same energy levels as the developed world, it really does need to be "too cheap to meter" otherwise they wouldn't be able to afford it.


i dont think thats the point, they will build up their ecconomy the same as we did, gradually over time in various way (as they are in india and china right now). The point is that we have to allow for them doing that and demanding the energy that goes with it, as in generating capacity

With respect to all concerned, I think that when we figure out fusion or some other relatively cheap power source, we ought to be giving the technology to the developing world at no more than cost price.

Considering how many of their resources we have used getting ourselves up the ladder, it would not be right to let them struggle and besides which, we also don't want any more uncontrolled emissions.

IMHO as always...

Alan

Ara Pacis
2012-May-30, 06:34 PM
With respect to all concerned, I think that when we figure out fusion or some other relatively cheap power source, we ought to be giving the technology to the developing world at no more than cost price.

Considering how many of their resources we have used getting ourselves up the ladder, it would not be right to let them struggle and besides which, we also don't want any more uncontrolled emissions.

IMHO as always...

AlanWhat's a guy in a hut or a woman in a treehouse gonna do with electricity and nothing to use it with? We'd have to give them a lot more than just electricity.

headrush
2012-May-30, 06:52 PM
What's a guy in a hut or a woman in a treehouse gonna do with electricity and nothing to use it with? We'd have to give them a lot more than just electricity.

That's how you see the developing world ?
People in huts and treehouses ?

Oh dear, perhaps you haven't noticed the Indian sub-continent, or the rapid growth of Chinese industry using dirty fuels ?
And the west complains when they (developing nations) need an opt out for emissions just to catch up with us industrially and in their standards of living.

Or maybe you meant something else ?

Swift
2012-May-30, 07:23 PM
I think we need to avoid a discussion of technology transfer between the developed and developing world, as such policy issues get into politics, and that is not allowed on BAUT.

Let's stick with fusion.

Thanks,

aquitaine
2012-May-30, 11:25 PM
That's not a good example of hydrogen based energy transport though.
That was someone working on Stehl's magic water power, under conditions that had him up against the local OSHA for taking shortcuts that shouldn't be taken, basically it's someone who doesn't know what he's doing and has already killed one son doing it.


Ok, bad example. How about this one? (http://www.autoblog.com/2010/08/27/report-ny-hydrogen-station-used-by-gm-explodes-closes-airport/)



Hydrogen (with adequate ventilation) could be a useful intermediate step in synthesis of hydrocarbons. High temperature electrolysis can more efficiently use the energy of fission and perhaps fusion power to produce hydrogen, and hydrocarbon synthesis was demonstrated to be economical on large scales in WWII, it's just not very competitive with fossil fuels at the moment. Our production of ammonia demonstrates that we can handle large scale industrial processes using hydrogen with only occasional explosions. But hydrogen gas itself as a means of storing and transporting energy?


Given that in a highly controlled industrial setting there still are "occational" explosions, in an uncontrolled setting like a private automobile the risks of a random explosion dramatically increase. All it would take is one leak from the container and boom! Perhaps not even that.

whimsyfree
2012-May-31, 02:23 AM
Ok, bad example. How about this one? (http://www.autoblog.com/2010/08/27/report-ny-hydrogen-station-used-by-gm-explodes-closes-airport/)

Given that in a highly controlled industrial setting there still are "occational" explosions, in an uncontrolled setting like a private automobile the risks of a random explosion dramatically increase. All it would take is one leak from the container and boom! Perhaps not even that.

Hydrogen is very prone to leaking because of its small molecular size. It's low density so it needs to be very compressed or chemically combined as metal hydrides that are probably more dangerous than hydrogen itself. Ammonia is another hydrogen provider. It is relatively easy to store and transport but unpleasant if it leaks.

cjameshuff
2012-May-31, 03:26 AM
Hydrogen is very prone to leaking because of its small molecular size. It's low density so it needs to be very compressed or chemically combined as metal hydrides that are probably more dangerous than hydrogen itself. Ammonia is another hydrogen provider. It is relatively easy to store and transport but unpleasant if it leaks.

Which is why I was talking about hydrocarbons. Which do still occasionally produce fires and explosions, but anything with the needed energy density and ability for rapid release will have some similar hazard, and we already deal with hydrocarbons. Use biomass as a carbon source (carbon, not as the main energy source as with biofuels) and it's carbon-neutral or carbon-negative. As I said, the process was proven effective on a large industrial scale in WWII, and there's even a few operations running today, though using fossil fuels.

transreality
2012-May-31, 03:52 AM
there was a wonderfull bbc horizon documentary back in 2009, called "can we make a star on earth".
The tentative conclusion was that the experiments and trials going on at that time should at least show whether it will be possible (practically viable) or not within the next 4 years -- not long to go now then

At the end of the documentary mentioned above all the individual researchers and experts who were interviewed for the show each held up a sign with their best guess for the year in which sustainable fusion is commenced. Now I haven't done the exercise, but there was possibly large enough sample for the law of large numbers to be used, to expect an average of all those guesses to be quite accurate. I suspect they would point to around 2035.

IsaacKuo
2012-May-31, 04:14 PM
Maybe, but I'm not convinced of that. Depending on how complex or dirty the technology turns out to be, it might be extremely expensive for example. If can only use deuterium or tritium, you are going to have to separate those out from hydrogen.
There is no tritium to separate out from natural hydrogen. It decays into Helium-3 within decades. Tritium would be produced by lining reactors with lithium.

As for the original question--I wouldn't bank on fusion power. My attitude might be more optimistic if the fusion research community could shake off the de facto taboo against lithium deuteride fuel. It really is the perfect fusion fuel, being relatively cheap, stable, and dense (solid at room temperature). It also has an extremely favorable mix of reactions going on.

Given the wonderful properties of lithium deuteride, it's no surprise that practical fusion devices use lithium deuteride. The problem? They're nuclear bombs.

See, there are two types of fusion scientist. Ones who have been slapped with national security NDAs and ones who fear being slapped with national security NDAs. Ultimately, a scientist makes a living on publishing papers. No publishing? No livelyhood. A national security NDA is as good as excommunication from the scientific community.

This is why fusion research has concentrated on fuels which can't (easily) be used in nuclear bombs. This is why fusion research has shied away from the perfect fusion fuel. Oh well...

cjameshuff
2012-May-31, 04:36 PM
As for the original question--I wouldn't bank on fusion power. My attitude might be more optimistic if the fusion research community could shake off the de facto taboo against lithium deuteride fuel. It really is the perfect fusion fuel, being relatively cheap, stable, and dense (solid at room temperature). It also has an extremely favorable mix of reactions going on.

It's not readily fused at room temperature, and under the conditions where fusion occurs, not notably easier to handle. D-Li6 is about as difficult as p-B11, but produces neutrons. So what makes it "the perfect fusion fuel"?

IsaacKuo
2012-May-31, 04:49 PM
It's not readily fused at room temperature, and under the conditions where fusion occurs, not notably easier to handle.
Irrelevant to ICF, which is how practical fusion devices work.

D-Li6 is about as difficult as p-B11, but produces neutrons. So what makes it "the perfect fusion fuel"?
It produces neutrons like crazy, which is great for how its mix of reactions work. Also, the fast neutrons fission cheap U238, greatly boosting yields.

[edit added]
Oh, I forgot to mention. Lithium deuteride is a heck of a lot easier than p-B. It's essentially the same difficulty as D-T to start, although a bit easier since it starts off with a better density. The mix of fusion and fission reactions gives it a far better yield than D-T, though.

HenrikOlsen
2012-May-31, 05:47 PM
And how is this any good in power production?

IsaacKuo
2012-May-31, 06:30 PM
And how is this any good in power production?
Lithium deuteride pellets with small amounts of tritium could be good for an ICF fusion reactor, or more accurately a hybrid fission/fusion reactor. Unlike D-T ICF fusion, this would keep the same fuel that has already been used successfully.

NEOWatcher
2012-May-31, 07:34 PM
At the end of the documentary mentioned above all the individual researchers and experts who were interviewed for the show each held up a sign with their best guess for the year in which sustainable fusion is commenced. Now I haven't done the exercise, but there was possibly large enough sample for the law of large numbers to be used, to expect an average of all those guesses to be quite accurate. I suspect they would point to around 2035.
I wonder how they interpreted "sustainable fusion is commenced" and would be curious if they where asked "sustainable fusion is commercially viable".
Although; I'm not sure if they would have a grasp of how long it would take to commercialize it.

mutleyeng
2012-May-31, 07:46 PM
been a while sinse i watched it, but i thought the question was when will we have it, as in when will in be sending power to peoples houses.
I think they were generally working on the assumption that we, the world, had decided we wanted it, and the required investment was forthcoming - i recall that was quite heavily stressed in the program

whimsyfree
2012-May-31, 11:32 PM
Which is why I was talking about hydrocarbons. Which do still occasionally produce fires and explosions, but anything with the needed energy density and ability for rapid release will have some similar hazard, and we already deal with hydrocarbons.


Well, obviously... but hydroCARBONs are bad, mmm'kay? Synthetic hydrocarbons lack the mass green appeal of hydrogen and windmills and birkenstocks.


Use biomass as a carbon source (carbon, not as the main energy source as with biofuels) and it's carbon-neutral or carbon-negative.

That's still a large drawdown on biomass. Has the feasibility been demonstrated?

Jens
2012-Jun-01, 12:04 AM
This is why fusion research has concentrated on fuels which can't (easily) be used in nuclear bombs. This is why fusion research has shied away from the perfect fusion fuel. Oh well...

It sounds like you're disappointed about this. If it is easy to use in nuclear bombs, isn't that a valid reason to shy away from it?

cjameshuff
2012-Jun-01, 03:36 AM
Lithium deuteride pellets with small amounts of tritium could be good for an ICF fusion reactor, or more accurately a hybrid fission/fusion reactor. Unlike D-T ICF fusion, this would keep the same fuel that has already been used successfully.

That sounds almost completely unsuited for power production. Hybrid systems are worthless for power generation, there's nothing to gain by involving fusion and huge arrays of delicate laser optics if you're doing fission. The most complicated and expensive pure fission plants would be cheaper to build and operate, and would likely be vastly more efficient due to not burning huge amounts of power generating laser pulses. And if you go pure fusion, if you can do deuterium-lithium you can do proton-boron fusion and not have to deal with neutrons. (And either option leaves you with the little problem of pulling that reaction off when ICF has largely failed even with the much easier D-T fusion.)



Well, obviously... but hydroCARBONs are bad, mmm'kay? Synthetic hydrocarbons lack the mass green appeal of hydrogen and windmills and birkenstocks.

They provide high density energy storage in a form easily handled at atmospheric pressure and ambient temperature with little environmental impact, given a closed carbon cycle. They are essentially the only common, low-toxicity compound that does so and can be synthesized at large scales. And it's not just a fuel, we have a vast chemical industry geared to using hydrocarbons as raw materials.



That's still a large drawdown on biomass. Has the feasibility been demonstrated?

We're not talking about throwing away the bulk of the plant and using part of the stored chemical energy in the remainder to convert an even smaller portion into a usable fuel...most of the dry mass of a plant is carbon. We produce vast amounts of carbon-rich waste that could be used. It needn't be energy-rich, the energy comes from elsewhere. If you still end up carbon-starved, you could even reduce carbon from other industrial processes that produce CO2, like cement production. However, I would be very surprised if it's not energy production that's the bottleneck.

It probably won't reach both the cost and volume of oil (unless energy becomes really cheap), but be realistic, none of the alternatives have the capability to do better.

aquitaine
2012-Jun-01, 06:01 AM
This is why fusion research has concentrated on fuels which can't (easily) be used in nuclear bombs. This is why fusion research has shied away from the perfect fusion fuel. Oh well...


As far as nuclear bombmaking goes even the "perfect" fusion fuel you talk about would be completely worthless without the runaway fission reaction to start the runaway fusion reaction. The chokepoint for terrorists building nuclear bombs is highly enriched uranium. The fact that we haven't seen any mushroom clouds over any western cities seems to indicate this is a very difficult problem for a clandestine individual or terrorist organization to overcome. I doubt concerns over proliferation was the reason that research path hasn't gotten as much attention.

Van Rijn
2012-Jun-01, 09:25 AM
[edit added]
Oh, I forgot to mention. Lithium deuteride is a heck of a lot easier than p-B. It's essentially the same difficulty as D-T to start, although a bit easier since it starts off with a better density. The mix of fusion and fission reactions gives it a far better yield than D-T, though.

I'm going off publicly available data, but as I understand it, in a bomb, the key advantage of lithium deuteride is that it's a cheap and compact way to store deuterium. The lithium itself isn't as important as the deuterium (which fuses and produces a lot of tritium which fuses very rapidly). When neutrons hit the lithium, some tritium is produced, but it isn't the primary tritium source in this case. There's also some energy produced when neutrons hit Li7. That was very embarrassing in one early test (Castle Bravo), when the yield was rather greater than predicted.

Anyway, it isn't clear to me how lithium deuteride would do better for ICF, and for magnetic confinement I don't see how it would be used. I think the lithium blanket idea (to capture the neutrons thereby producing tritium and where most of the energy would be gotten from the power plants, using pipes running through the liquid lithium, cooling it) is probably the most practical way to make this a lithium-deuterium fueled reactor.

kzb
2012-Jun-01, 11:40 AM
Whatever the fuel is, there is a LONG way to go before fusion reactors can be competitive in the commercial world. You have a giant torus with myriads of connections to it, and it has to be under very high vacuum to work. One tiny vacuum leak and it won't go. Internal faults have to be fixed by remote operations, because the thing gets neutron-activated.

http://www.ccfe.ac.uk/images_detail.aspx?id=5

cjameshuff
2012-Jun-01, 01:18 PM
Whatever the fuel is, there is a LONG way to go before fusion reactors can be competitive in the commercial world. You have a giant torus with myriads of connections to it, and it has to be under very high vacuum to work. One tiny vacuum leak and it won't go. Internal faults have to be fixed by remote operations, because the thing gets neutron-activated.

The most common types of fission reactors have been operated for decades with pressure vessels exposed to much higher pressure differentials, and they share the issue with repair of internal faults.

Ara Pacis
2012-Jun-02, 12:26 AM
I wonder if there is a way to use a magnetic confinement plus some sort of moving ramjet-like object to create increased density, heat or neutron activity that moves inside the torus. This might be coupled to its own dynamo as well as creating heat for steam turbines warmed by pipes in the periphery of the torus.

whimsyfree
2012-Jun-02, 02:13 AM
When neutrons hit the lithium, some tritium is produced, but it isn't the primary tritium source in this case. There's also some energy produced when neutrons hit Li7. That was very embarrassing in one early test (Castle Bravo), when the yield was rather greater than predicted.

I don't think that can be right. The yield of CB was about three times expected. AFAIK the contribution to the energy output of neutrons hitting Li7 is negligible; the contribution of the Li7 is more tritium and more neutrons.

HenrikOlsen
2012-Jun-04, 01:43 PM
The most common types of fission reactors have been operated for decades with pressure vessels exposed to much higher pressure differentials, and they share the issue with repair of internal faults.
Yep, it's one of the common mistakes of thinking, that very high vacuum means substantially larger pressure differential that low vacuum, with people forgetting that the pressure differential won't get above 1 atmosphere of pressure no matter how much is sucked from the vessel.

quotation
2012-Jun-26, 01:44 PM
It would appear that if you are a fusion research scientist or engineer, you'd better learn Mandarin:
http://www.washingtonpost.com/national/health-science/budget-cuts-threaten-pursuit-of-nuclear-fusion-as-a-clean-energy-source/2012/06/25/gJQAKlpS2V_story.html
Budget cuts threaten pursuit of nuclear fusion as a clean energy source

President Obama’s budget request for next year cuts domestic fusion research by 16 percent, to $248 million. It would shutter a fusion lab at MIT, one of four funded by the Department of Energy. It would slash 50 to 100 jobs from the 450 at the Princeton lab

This would be “devastating” to the community of several hundred U.S. scientists working on fusion energy, said Stewart Prager, the physicist who heads the Princeton lab

In February, the nation’s top fusion scientists met at an Energy Department advisory committee meeting. For hours they wrangled with the “doom and gloom” of the budget proposal, said Martin Greenwald, an MIT plasma physicist and head of the committee.

Then the leader of China’s fusion program, Jiangang Li, addressed the group. He said that China is committed to producing 2,000 new fusion scientists and that fusion research enjoys strong political and financial support from “the top leaders all the way up to the president,” according to minutes from the meeting. He described a billion-dollar plasma experiment now underway and plans for bigger experiments.

Said Greenwald : “[Li] basically said, ‘Thanks for 60 years of research; we’ll take it from here.’ ”

cjameshuff
2012-Jun-26, 05:17 PM
That's us...we'll spend billions of dollars on sports stadiums, but a long-term, sustainable, scalable power source? We grudgingly allocate a couple hundred million a year, spread across the entire field, and gripe about the lack of progress as under-funded fusion experiments are canceled one after another.

Ara Pacis
2012-Jun-26, 05:52 PM
That's us...we'll spend billions of dollars on sports stadiums, but a long-term, sustainable, scalable power source? We grudgingly allocate a couple hundred million a year, spread across the entire field, and gripe about the lack of progress as under-funded fusion experiments are canceled one after another.I can live without fusion power, but I can't live without football. :)

NEOWatcher
2012-Jun-26, 06:11 PM
I can live without fusion power, but I can't live without football. :)
But then how do they play night games or broadcast it to your TV? ;)

SkepticJ
2012-Jun-26, 06:14 PM
Good on China.

If the West fails (and boy does it look like it lately), they'll carry on. Over two thousand years of unbroken civilization, they must be doing something right.

Ara Pacis
2012-Jun-26, 07:16 PM
But then how do they play night games or broadcast it to your TV? ;)GITD Football, of course. And who needs TV when it can be seen live? Just make bigger stadia.

Ara Pacis
2012-Jun-26, 07:17 PM
Good on China.

If the West fails (and boy does it look like it lately), they'll carry on. Over two thousand years of unbroken civilization, they must be doing something right."Unbroken"?

HenrikOlsen
2012-Jun-26, 08:59 PM
Good on China.

If the West fails (and boy does it look like it lately), they'll carry on. Over two thousand years of unbroken civilization, they must be doing something right.
I'd call the first half of the last century a breaking of civilization.

whimsyfree
2012-Jun-27, 01:27 AM
I'd call the first half of the last century a breaking of civilization.

AFAIK they (at least some of them) could still read, grow food and had a more or less functional waste disposal system, so I don't think a few decades of disorder counts as a break (i.e. absence of existence) in their civilization. By the same token Western civilization has been unbroken for well over 2,000 years too.

I am more sceptical of the common claim that China has existed as an independent nation for more than 2,000 years. There are many times over that period when the current territory of China was divided between multiple states, and times when most of it was controlled by people who were, at the time, regarded as foreigners. Chinese continuity is maintained retrospectively: when there were many Chinese states one particular Chinese state is picked out as the "real" one; and foreign dynasties such as the Mongol and Manchu are "promoted" to be Chinese.

cjameshuff
2012-Jun-27, 03:13 AM
AFAIK they (at least some of them) could still read, grow food and had a more or less functional waste disposal system, so I don't think a few decades of disorder counts as a break (i.e. absence of existence) in their civilization. By the same token Western civilization has been unbroken for well over 2,000 years too.

Um, they couldn't grow food...not nearly enough. Mao's policies leading up to the Great Leap Forward produced a famine that killed tens of millions of people, while systematically attempting to wipe out the existing social structures and traditions.

novaderrik
2012-Jun-27, 03:49 AM
i'm convinced that fusion power will always be 50 years away..

whimsyfree
2012-Jun-27, 05:20 AM
Um, they couldn't grow food...not nearly enough. Mao's policies leading up to the Great Leap Forward produced a famine that killed tens of millions of people, while systematically attempting to wipe out the existing social structures and traditions.

I have trouble placing the Great Leap Forward (1958 to 1961) in the "first half of the last century".

Jens
2012-Jun-27, 06:29 AM
Um, they couldn't grow food...not nearly enough. Mao's policies leading up to the Great Leap Forward produced a famine that killed tens of millions of people, while systematically attempting to wipe out the existing social structures and traditions.

HenrikOlsen specifically said the "first half" of the last century, so I assume he was referring to the collapse of the Manchu Dynasty, the republican revolution, and then the Sino-Japanese war. But maybe he meant the second half. The Great Leap Forward was like in 1956 or 1958?

ETA: Sorry for that duplicate. I guess I was typing and was outposted!

HenrikOlsen
2012-Jun-27, 07:53 AM
Change "first half" to "first 6 decades" if you want to be pedants.

Geez, I'd have thought this was a science board where people know what the error bars are on "half".

Jens
2012-Jun-27, 08:21 AM
Change "first half" to "first 6 decades" if you want to be pedants.


I wasn't trying to be pedantic. I assumed that you were talking about the downfall of the Manchus and the emergence of the KMT. Because if you were talking about Mao, I would have gone even further to like the 1960s and the cultural revolution. If you were talking about the PRC, that's fine, it's just that I didn't get that.

quotation
2012-Jun-27, 01:03 PM
Good on China.

If the West fails (and boy does it look like it lately), they'll carry on. Over two thousand years of unbroken civilization, they must be doing something right.
Ah yes, well, the proverbial passing of the torch, what? Perhaps we did get a bit hidebound over here. I'm reminded of the advice a good friend/coach/mentor once gave, "Whenever you're in a slump, go back to basics." Right, well, good luck China. Would write more, but am busy trying to pull a plasmoid out of the microwave oven. Right ho!

whimsyfree
2012-Jun-27, 01:04 PM
I wasn't trying to be pedantic. I assumed that you were talking about the downfall of the Manchus and the emergence of the KMT. Because if you were talking about Mao, I would have gone even further to like the 1960s and the cultural revolution. If you were talking about the PRC, that's fine, it's just that I didn't get that.

Ditto (collapse of ancien regime, KMT, warlords, jap invasion). Actually the first half was probably worse than the second. Sure the second half started disastrously but it ended on an upbeat note, whereas the first half was grim from fart to spinach. I don't think Chinese civilization was interrupted in either half, though. In fact I don't think China will ultimately be seen as having done that badly in c20. Despite all the talk of the terrible impositions of foreigners they came through it with their empire intact. They still have dominion over the Tibetans, eastern Turks, and the Mongol territories they held.