Could This Lump Power the Planet?

[Skeptic Ginger]

OK, so this is in Newsweek, it is the Lawrence Livermore Lab and I don't have a clue if this is good science or woo other than viable power from nuclear fusion has kind of been in the woo category up to this point.

So I am calling on the knowledgeable skeptics here to weigh in. (My apologies if this is a duplicate thread.)

Newsweek: Scientists at Lawrence Livermore National Lab are betting $3.5 billion in taxpayer money on a tiny pellet that could produce an endless supply of safe, (http://www.newsweek.com/id/222792)

[ben m]

There's nothing "woo" about it; this is respectable, mainstream, evidence-driven science and engineering.

It's fair to ask questions like, "will the resulting power be competitive with fission/solar/?" and so on. But those aren't generic "skeptic" questions, like the questions you ask of homeopaths or Steorn or whatever. They're serious engineering questions.

[lionking]

The most significant statement in the article is this one:


fusion energy is only 40 years away, and will always be only 40 years away


I sincerely hope this is wrong.

[MRC_Hans]

Of course it is wrong. We know what to do, we almost know how to do it, we're just not able to build the machine to do it yet. However, the obstackles are in the areas of high power lasers, supermagnets, high-power physics, high-power computers. What has happened in the last 40 years in those areas? What can be expected to happen in the next?

Hans

[McHrozni]

I sincerely hope this is wrong.

To put it into proper context, the actual statement is:
The joke is that fusion energy is only 40 years away, and will always be only 40 years away.

I sincerely hope he this is right and it is indeed just a joke. ;)

McHrozni

[Jack by the hedge]

It's a joke all right, but unfortunately it's only funny because it has a kernel of truth: I think I first heard it over 30 years ago and, now as then, people are still saying 40 years away sounds reasonable.

Edit to add: Does anyone know just how old the joke is? I wonder when it was first put into print.

[macdoc]

Post 1905 for a certainty ;)

••••

To answer the OP - laserfusion is very much real. Energy has already been released....it's just not self sustaining.

I don't know if you completed the article but I have no idea what would lead you to think that engineering and science on this scale

http://www.newsweek.com/id/222792/page/2

would

a) not have an immensely strong theoretical base
b) lead up experiments demonstrating proof of concept.

It has both....that said - there may be other barriers unanticipated....that's why the money is being spent on a potentially commercial scale unit.

There is another being built in Europe approaching it from the traditional standpoint of magnetic confinement

http://www.iter.org/default.aspx?id=2152

http://news.bbc.co.uk/2/hi/science/nature/7972865.stm

This is big time science and engineering but in the backdrop of a seemingly forever receding horizon :(

Still the idea is commercial energy by 2030
http://nextbigfuture.com/2008/12/proposed-laser-ignition-fusionfission.html

One can hope _ do like this laser ignition fusion/fission hybrid as it may have a shorter timeline.

[MRC_Hans]

It's a joke all right, but unfortunately it's only funny because it has a kernel of truth: I think I first heard it over 30 years ago and, now as then, people are still saying 40 years away sounds reasonable.

Edit to add: Does anyone know just how old the joke is? I wonder when it was first put into print.Off topic, I have my own version of that joke. When I, as a very young fellow, set off on a carreer in electronics, people told me: "You must realize that in another 15 years, you will be too old to follow the developement". They still do. (I'm 60 now :p).

Hans

[macdoc]

Heh I get the same thing from my clients - they all think I'm 20 years younger than my 62 ( baby face helps ) cuz I run a tech company....:con2:

[Peter i]

The goal of ITER is to sustain a fusion reaction for eight minutes. This should pave the way for building a first powerplant ( DEMO ) hopefully producing power in 2050 (yup, that's 40 years from now)

[Cainkane1]

Heh I get the same thing from my clients - they all think I'm 20 years younger than my 62 ( baby face helps ) cuz I run a tech company....:con2:
Nobody believes I'm 62 either. I only have gravity wrinkles.

[Cainkane1]

OK, so this is in Newsweek, it is the Lawrence Livermore Lab and I don't have a clue if this is good science or woo other than viable power from nuclear fusion has kind of been in the woo category up to this point.

So I am calling on the knowledgeable skeptics here to weigh in. (My apologies if this is a duplicate thread.)

Newsweek: Scientists at Lawrence Livermore National Lab are betting $3.5 billion in taxpayer money on a tiny pellet that could produce an endless supply of safe, (http://www.newsweek.com/id/222792)
Sounds too good to be true. When it sunds like this it usually is too good to be true.

[SonOfLaertes]

OK, so this is in Newsweek, it is the Lawrence Livermore Lab and I don't have a clue if this is good science or woo other than viable power from nuclear fusion has kind of been in the woo category up to this point.

So I am calling on the knowledgeable skeptics here to weigh in. (My apologies if this is a duplicate thread.)

Newsweek: Scientists at Lawrence Livermore National Lab are betting $3.5 billion in taxpayer money on a tiny pellet that could produce an endless supply of safe, (http://www.newsweek.com/id/222792)

I wonder at the tone of the "sceptics" (scientists themselves) in the article. If this project is indeed based on real science, and has produced some incremental breakthroughs in laser technology, then why the vehement language, such as "snake-oil salesman"? Is it just professional jealousy ( my project and idea are better than his, why am I not getting this funding?") or is the approach this team is using fatally flawed?

I would think that the scientific community would welcome any well funded, reality-based project; these projects tend to produce unexpected ancillary benefits, employ talented people who later move on to bigger ideas (think NASA), and have that chance of actually accomplishing their goal.

So why the nasty tone of the naysayers in the article? Did they simply interview the wrong people to get an opposing viewpoint?

I, like most sane people, would welcome a hint of a true possibility of such a breakthrough. If commercial fusion reactors firing up in 30 years were to suddenly become a possibility, hope for our ongoing prosperity would flower immediately. Psychologically, this would be huge.

[macdoc]

Why do you think sudden prosperity...they will be expensive like current nukes.

What we need NOW is a few hundred more current and 3rd Gen nukes to dump coal.

Nuclear power over time is cheap.

[Cuddles]

We know what to do, we almost know how to do it, we're just not able to build the machine to do it yet.

I'd make a slight correction to that. It's not that we're not able to build the machine, it's just that we haven't built it yet. We're pretty sure we know what to do and how to do it, but we haven't finished building the machine to do it so we're not entirely sure.

I wonder at the tone of the "sceptics" (scientists themselves) in the article. If this project is indeed based on real science, and has produced some incremental breakthroughs in laser technology, then why the vehement language, such as "snake-oil salesman"? Is it just professional jealousy ( my project and idea are better than his, why am I not getting this funding?") or is the approach this team is using fatally flawed?

Well, firstly it's worth noting that only one person quoted could really be described as "vehement", the other expressing skepticism about it was simply saying that he doesn't think it's there yet and bigger lasers are needed. It's hard to say why anyone would describe this as snake-oil, but it may be worth noting that the National Resources Defence Council that he is a member of is an environmental charity and lobby group, and not actually anything to do with nuclear research. From what I can tell from their website, it appears his concerns, which may well be justified, are to do with the politics and funding behind the establishment of NIF, and nothing to do with the actual science. I doubt he would have anything bad to say about the science itself, but he believes that the case for NIF was not adequately made and that it was pushed through due to political and financial interests despite not actually being capable of producing sustainable fusion.

There does tend to be some rivalry between researchers in inertial confinement fusion, which is what is discussed here, and magnetic confinement, which is what ITER will test. So far magnetic confinement is ahead, having achieved break-even (the point where you generate as much power as you put in). However, the rivalry mostly consists of saying things along the lines of "Their approach might work, but we're going to get there first.", rather than anything particularly nasty. However, I don't think that's really what influenced the comments here.

I would think that the scientific community would welcome any well funded, reality-based project; these projects tend to produce unexpected ancillary benefits, employ talented people who later move on to bigger ideas (think NASA), and have that chance of actually accomplishing their goal.

Ah, if only scientists weren't human.;)

So why the nasty tone of the naysayers in the article? Did they simply interview the wrong people to get an opposing viewpoint?

Well, as I say, I don't think there was actually much of a nasty tone. The only quote that could be viewed as nasty was the snake-oil comment, and it seems that was probably aimed more at the politicians and management involved than the actual science and scientists.

[ArcturusA]

I'm working on magnetic fusion confinement, but it means I rub shoulders with inertial confinement people too. I have to agree with everyone else here in saying that ICF is far from 'woo', being well tested and having a solid theoretical base.

There is a bit of a rivalry between ICF and MCF, but that just because the ICF people are bitter that we're backing the faster horse ;)

In all seriousness, though, I think ICF may overtake MCF soon. A new project, HiPER, is sort of their equivalent of ITER, being the last step before a demonstration plant. HiPER doesn't have funding yet as far as I'm aware, though it does have support from plenty of universities, and could be up and running around 2025.

The advantage HiPER holds over ITER is that HiPER (if its built) could be modified into a power plant itself, rather than requiring a new facility like DEMO for MCF. That means that, although MCF seems to be winning the race at the moment, ICF could make the sprint finish.

Time (and money) will tell!

[BenBurch]

EVEN if ITER is a stunning success, and its follow-on production plants operate reliably. we can build Thorium Energy Amplifiers at 10% the cost per MW generated.

And we could have the first one online in ten years, and build them quickly.

And we have a LOT of Thorium on the planet.

And I cannot for the life of me understand why we do not have a pilot plant being designed right now.

[Dave Rogers]

fusion energy is only 40 years away, and will always be only 40 years away

I sincerely hope this is wrong.

Actually, there's rather a lot of it eight minutes away, and it will be eight minutes away for a good few million years.

Dave

[ben m]

EVEN if ITER is a stunning success, and its follow-on production plants operate reliably. we can build Thorium Energy Amplifiers at 10% the cost per MW generated.

An old colleague pointed out to me once: one of the reasons it's hard to ramp up new nuclear fuel cycles is that we aren't training enough nuclear chemists. He had some incredibly grim numbers about the shrinking enrollments (often to zero) in nuclear-related Ph.D. programs across the country.

We have lots of skilled plasma-physics and laser-engineering research capacity---lots of top people, good institutions, etc. So if someone has an idea for improving ICF: bang, there's a letter-of-intent and a proposal and a flurry of activity out of Livermore, Rochester, Sandia, etc. New ideas in MCF? Princeton and MIT pounce on it, and they have the people and infrastructure to make it happen. That kind of excitement has a lot of pull on a funding agency. Remember, a lot of this research funding gets "pulled", not "pushed"---the DOE sits there with money and waits for proposals/arguments to come in; the proposals "pull" the money out. An incredibly good idea that nobody pushes the case for is unlikely to get very far.

So Rubbia (smart guy, but doesn't run a nuclear engineering lab) comes up with Accelerator Transmutation and it just sits there---there's no group of experts sitting around waiting to pounce on the next step. There's no big, diverse university lab writing grants to develop new actinide chemistry. There's not even a group that's quite qualified to make the case to the DOE that they should "push" resources in this direction: Rubbia's work stops at " ... but there are a bunch of unanswered questions about the fuel chemistry and we can't tell if it will ever work. Anyone else know? Anyone?" That's not the most forceful case. A forceful case is "If you give us $1B, then group X will answer this fuel-chemistry question and group Y will answer this blanket-materials question and group Z will do value engineering on the accelerator". That's the sort of proposal that the ICF and MCF people are capable of writing.

Anyway: my colleague said that France (for example) has a perfectly functional nuclear-chemistry training system, and much more capability to "push" research from the top. So all is not lost.

[Skeptic Ginger]

There's nothing "woo" about it; this is respectable, mainstream, evidence-driven science and engineering.

It's fair to ask questions like, "will the resulting power be competitive with fission/solar/?" and so on. But those aren't generic "skeptic" questions, like the questions you ask of homeopaths or Steorn or whatever. They're serious engineering questions.Don't misunderstand me, that wasn't my point.

I am asking sincerely if fusion has passed from the takes-more-energy-to-produce-than-you-get or whatever the barriers were into the reaching-feasibility phase? This is not my area of expertise and this is the first time I've seen news it might be on the horizon since the cold fusion claims from decades ago.

[Skeptic Ginger]

Post 1905 for a certainty ;)

••••

To answer the OP - laserfusion is very much real. Energy has already been released....it's just not self sustaining.

I don't know if you completed the article but I have no idea what would lead you to think that engineering and science on this scale

http://www.newsweek.com/id/222792/page/2

would

a) not have an immensely strong theoretical base
b) lead up experiments demonstrating proof of concept.

It has both....that said - there may be other barriers unanticipated....that's why the money is being spent on a potentially commercial scale unit.

There is another being built in Europe approaching it from the traditional standpoint of magnetic confinement

http://www.iter.org/default.aspx?id=2152

http://news.bbc.co.uk/2/hi/science/nature/7972865.stm

This is big time science and engineering but in the backdrop of a seemingly forever receding horizon :(

Still the idea is commercial energy by 2030
http://nextbigfuture.com/2008/12/proposed-laser-ignition-fusionfission.html

One can hope _ do like this laser ignition fusion/fission hybrid as it may have a shorter timeline.Oooh thanks, this is just what I was looking for.

[Skeptic Ginger]

Sounds too good to be true. When it sunds like this it usually is too good to be true.Well maybe the "safe" part of the claim anyway, just like nuclear power was touted as "pollution free" in its early days.

[ben m]

Don't misunderstand me, that wasn't my point.

I am asking sincerely if fusion has passed from the takes-more-energy-to-produce-than-you-get or whatever the barriers were into the reaching-feasibility phase? This is not my area of expertise and this is the first time I've seen news it might be on the horizon since the cold fusion claims from decades ago.

My impressions (from a ways outside):

ICF is pretty certain that they have solved all of the questions about how to achieve break-even. They just haven't built the device that implements all of those solutions.

MCF is building the device (ITER) that implements most of what they know about achieving break-even, but it's less clear that we understand enough to predict that it will work.

I would not be terribly surprised if ITER's main result is "we discovered a new plasma instability which makes break-even a bit more challenging than expected." I would be more surprised to hear something like this from the ICF community.

[Ziggurat]

Newsweek: Scientists at Lawrence Livermore National Lab are betting $3.5 billion in taxpayer money on a tiny pellet that could produce an endless supply of safe, (http://www.newsweek.com/id/222792)

Let me clarify something about the language used here. The tiny pellet in question is a deuterium-tritium capsule, the fuel for the fusion reactor. The phrasing of that title could be read to mean that one pellet could provide endless energy, but that's not the case. What's really meant is that we can make an (almost) endless supply of such pellets (deuterium and tritium can be extracted from ocean water), each of which would actually burn up quite quickly in such a reactor.

[BenBurch]

Tritium in ocean water is pretty scarce.

[Ziggurat]

Tritium in ocean water is pretty scarce.

And the ocean is pretty big. Getting tritium isn't the problem.

[Tubbythin]

And the ocean is pretty big. Getting tritium isn't the problem.

Don't they extract it from fission reactors?

[ben m]

You don't get tritium from the ocean, you get it by putting deuterium or lithium into a neutron source (either a fission or fusion reactor). That's one of the reasons that fusion people always talk about putting a lithium-rich blanket around their reaction area---the neutrons from the fusion reaction "breed" their own tritium fuel.

Deuterium you get from water. This is isotope separation, but compared to U235-U238 it's easy and inexpensive, mostly because the H-D mass difference is so large.

[Ziggurat]

Don't they extract it from fission reactors?

I was a little off in my previous statements. The typical production method is to use heavy water reactors (ie, deuterium). The deuterium, which is extracted from ordinary water, captures neutrons and converts into tritium. Plenty of deuterium in the ocean, so plenty of tritium available upon demand.

[Tubbythin]

I was a little off in my previous statements. The typical production method is to use heavy water reactors (ie, deuterium). The deuterium, which is extracted from ordinary water, captures neutrons and converts into tritium. Plenty of deuterium in the ocean, so plenty of tritium available upon demand.

Agreed. Its something of a menace to the fission folk I think. So its really a win-win situation if they can do something useful with it.

[dogjones]

But next year Moses and his scientists will fire it up with a full load of deuterium-tritium fuel, and Moses feels confident it will achieve "ignition," meaning a controlled burn in which you get out more energy than you put in.

Can someone explain to me why/how this would not break the laws of thermodynamics?

[Tubbythin]

Can someone explain to me why/how this would not break the laws of thermodynamics?

The same way burning coal doesn't break the laws of thermodynamics.

But more specifically to this case. Tritium and deuterium fuse giving helium-4 and a neutron. Helium 4 plus a neutron has less mass than tritium plus deuterium combined. That mass difference is then released as energy (good old E=mc2).

[Ziggurat]

Can someone explain to me why/how this would not break the laws of thermodynamics?

They're not counting the potential energy of the fuel itself. If the "spark" takes more energy to strike than the "fire" produces, you can never extract energy from the process.

[Almo]

Of course it is wrong. We know what to do, we almost know how to do it, we're just not able to build the machine to do it yet. However, the obstackles are in the areas of high power lasers, supermagnets, high-power physics, high-power computers. What has happened in the last 40 years in those areas? What can be expected to happen in the next?

Hans

This joke comes from the details of what has happened in the history of plasma physics.

The fundamental issue is containing the plasma. My plasma professor showed us a bunch of the neat ways over the years how we've tried to contain it, and then how unforseen details of the physics meant the plasma would escape.

He finished the discussion by saying, "The bottom line is, whatever you do, the plasma will find a way to escape. That has been our experience thus far. Maybe we'll solve the problem, but it's a hard one."

So what's going on with attempts at making fusion plants is that we put in more energy to contain the plasma than we get back out.

[dogjones]

The same way burning coal doesn't break the laws of thermodynamics.

But more specifically to this case. Tritium and deuterium fuse giving helium-4 and a neutron. Helium 4 plus a neutron has less mass than tritium plus deuterium combined. That mass difference is then released as energy (good old E=mc2).


They're not counting the potential energy of the fuel itself. If the "spark" takes more energy to strike than the "fire" produces, you can never extract energy from the process.

Gotchya. Thanks.

[Cuddles]

My impressions (from a ways outside):

ICF is pretty certain that they have solved all of the questions about how to achieve break-even. They just haven't built the device that implements all of those solutions.

MCF is building the device (ITER) that implements most of what they know about achieving break-even, but it's less clear that we understand enough to predict that it will work.

Not quite. MCF is ahead because it has already achieved break-even. ITER is not about that, it is addressing the advances in science and engineering required to get from an experimental reactor to a commercial power plant. The problems ITER faces are not so much on the fusion side, since we already know we can do it, but are related to cycling fast enough to produce a sensible amount of power, removing waste, and things like that.

ICF, on the other hand, is pretty much as you say. It's achieved fusion before, but has never reached break-even. ICF has the advantage that it should be much easier to make into commercial power, since the problems noted above for ITER are generally easier in engineering terms than for MCF. However, it has the problem that it hasn't actually been shown to be physically possible to reach break-even yet.

I would not be terribly surprised if ITER's main result is "we discovered a new plasma instability which makes break-even a bit more challenging than expected."

They shouldn't have problems reaching break even. However, it's certainly possible that we may hear something along the lines of "we discovered a new plasma instability which makes keep the vessel intact a bit more challenging than expected". Given that the requirements are already at, or in some cases apparently just beyond, the cutting edge, that would be quite a big problem.

[rjh01]

I got confused because I did not understand the abbreviations used. However Wikipedia came to the rescue with good information.

MCF magnetic confinement fusion
ICF Inertial confinement fusion
Magnetized target fusion

[Dr Adequate]

EVEN if ITER is a stunning success, and its follow-on production plants operate reliably. we can build Thorium Energy Amplifiers at 10% the cost per MW generated.

And we could have the first one online in ten years, and build them quickly.

And we have a LOT of Thorium on the planet.

And I cannot for the life of me understand why we do not have a pilot plant being designed right now. If by "we" you mean the US, then as I understand it it's because given the amount of uranium we have, the amount of thorium we have, and the infrastructure already in place, it'll be fifty years before it's economical.

India, on the other hand, has little uranium but one third of the world's thorium, and is developing thorium technology right now.

---

This overlooks the possibility of using a thorium system as an incinerator for nuclear waste ... I'm not sure whether it would justify the cost of building one, but it's worth thinking about.

[AgeGap]

Horizon programme-"Can We Make a Star on Earth?" Have a search on Youtube. I am in work at the moment so can't give you a link. Stick "Professor Brian Cox " in your search if nothing comes up. Even if it doesn't work it doesn't mean it is woo.:)

[AgeGap]

RQjjKVyjq1U
3:30 and onwards.

[ksbluesfan]

CNN has a new article about this here. (http://www.cnn.com/2010/TECH/science/04/28/laser.fusion.nif/)

"We have a very high confidence that we will be able to ignite the target within the next two years," thus proving that controlled fusion is possible, said Bruno Van Wonterghem, a manager of the project, which is called the National Ignition Facility.

That would put the lab a step closer to "our big dream," he said, which is "to solve the energy problems of the world."

[TjW]

Can someone explain to me why/how this would not break the laws of thermodynamics?

Because when you fuse two elements that are lighter than iron together, the resulting mass is slightly smaller than the mass you started with. The missing mass is released as energy per E=MC^2.

[Complexity]

Controlled fusion for power production will rock.

Naysayers are usually ignorant luddites or fundies (sorry for the redundancy - my fingers slipped).

[OnlyTellsTruths]

Hello all, I hope this isn't too much of a derail. :)

If nearly free energy ever does turn out to be a success, by what percentage would the normal cost of energy drop?

In other words, approximately what percentage of the cost of electricity is tied up in transfer, maintaining the transfer structures, etc. (everything that isn't the actual production cost)?

[ArmillarySphere]

There's still going to be operating costs associated with them - paying off the construction and research costs, running the deuterium-extraction plants, paying personnel etc. The main advantages of fusion is that the fuel source is much more abundant and radioactive waste is much lower (not zero, since the neutrons play havoc with surrounding materials). The construction costs may be higher or lower than fission plants - we don't know yet, so the final cost per kWh is uncertain.

There's also the added advantage that fusion plants don't suffer from the bad publicity that fission has had, so it'll be easier to sell to the voters. Given the outrageous amounts of renewable-energy power plants you'd have to build to replace even one fission power plant, fusion plants give us a better shot at becoming carbon-neutral.

[shadron]

It's a joke all right, but unfortunately it's only funny because it has a kernel of truth: I think I first heard it over 30 years ago and, now as then, people are still saying 40 years away sounds reasonable.

Edit to add: Does anyone know just how old the joke is? I wonder when it was first put into print.

I don't know about the joke, but I know that I was reading Scientific American articles about the Tokamak (MCF) and a design for laser bombarded pellets (ICF) for a fusion power plant in the late 60s. I would imagine the 40 year joke probably started in the 80s or 90s.

[Modified]

If nearly free energy ever does turn out to be a success, by what percentage would the normal cost of energy drop?

In other words, approximately what percentage of the cost of electricity is tied up in transfer, maintaining the transfer structures, etc. (everything that isn't the actual production cost)?

The only thing I could find with a quick web search claims that about 1/3 of cost is transmission and distribution.

[Cuddles]

If nearly free energy ever does turn out to be a success, by what percentage would the normal cost of energy drop?

The problem here is that the term "free" in "free energy" does not refer to cost. We already have various sources of free energy, such as wind and solar power, that are (currently at least) significantly more expensive than other power sources. If fusion power is shown to be a viable energy source, that does not necessarily mean it will be cheap. In fact, given that the technology required is actually a bit past the cutting edge, it's likely to be extremely expensive, at least to begin with. One of the big advantages of fusion power (the other being the pollution angle) is that fuel will not become scarce for at least millions of years, so costs will never rise. Compare that to fossil fuels, which are much more expensive than they used to be, and likely to become much more expensive again. Fusion's advantage isn't in being cheaper than everything else, it's in remaining at the same cost while everything else gets more and more expensive.

[macdoc]

I find this approach intriguing tho the whole "nuclear waste" thing is over blown since spent fuel rods from first gen reactors retain 90% recoverable energy..:rolleyes:


http://www.utexas.edu/graphics/transparent.gif Nuclear Fusion-Fission Hybrid Could Destroy Nuclear Waste And Contribute to Carbon-Free Energy Future

January 27, 2009

http://www.utexas.edu/news/2009/01/27/nuclear_hybrid/

[One Skunk Todd]

One thing I've never understood is how do you feed new pellets into the reaction?

[soylent]

What has happened in the last 40 years in those areas? What can be expected to happen in the next?

In the same timeframe the estimated laser energy required for ignition went from about 1 kJ in 1972(almost 40 years ago) to 1 MJ today. It wasn't merely a factor 1000 increase; todays lasers are much better in all sorts of other dimensions that have nothing to do with total energy(e.g. pulse shaping and short pulse-lengths).

Will it increase by another factor 1000 in the next 40 years?

[soylent]

I find this approach intriguing tho the whole "nuclear waste" thing is over blown since spent fuel rods from first gen reactors retain 90% recoverable energy..:rolleyes:

Oh, it's just a ploy; that's not why they want to make fission-fusion hybrids.

Destroying the slightly used nuclear fuel by fissioning the actinides is equivalent to recovering the energy that is left in the fuel! Almost any actinide has a reasonably large fission cross-section for very fast neutrons from deuterium-tritium fusion and each fission you cause generates ~10 times more energy than a D-T fusion and you get some more neutrons. The fission blanket "amplifies" the energy you produce, potentially allowing you to be much worse at fusion and still be able to make a viable powerplant. The extra neutrons from fission might improve the amount of tritium you can breed(you have to crunch the numbers on this one to see if it's a net gain or loss of neutrons as many fission products gobble neutrons, but usually not the fast ones).

Tritium-breeding is potentially quite problematic; if you can't make more of it than you consume from lithium it will delay commercialization of fusion until you can ignite tritium-lean targets. If you can ignite a tritium-lean target you get extra tritium from D-D fusion which produces either tritium and a proton or helium-3 and a neutron(~50% branch probability).

[soylent]

One thing I've never understood is how do you feed new pellets into the reaction?

With a glorified BB-gun(possibly electrostatically or mechanically operated rather than gas, if that gives better precision). It needs to fire at approximately the same rate as a sub-machine gun, injecting several targets per second. Each target needs to be tracked and precisely aimed at by lasers.

NIF forgoes all this nasty business by simply having one stationary target in a hohlraum; they only fire a few times a day on various custom targets.

The HYLIFE-II concepts invisions kind of oscillating jets of FLiBe(not some kind of crazy abbreviation, those are the elements fluorine, lithium and beryllium; it's a molten salt) that periodically form cavities. Each target is injected to coincide with a cavity formed between the jets of FLiBe, so that when the target is ignited most of the neutrons will be captured in by the FLiBe. You both want to protect the first wall from being degraded by neutrons and capture as many neutrons as you can to make tritium.

[One Skunk Todd]

With a glorified BB-gun(possibly electrostatically or mechanically operated rather than gas, if that gives better precision). It needs to fire at approximately the same rate as a sub-machine gun, injecting several targets per second. Each target needs to be tracked and precisely aimed at by lasers.

NIF forgoes all this nasty business by simply having one stationary target in a hohlraum; they only fire a few times a day on various custom targets.

The HYLIFE-II concepts invisions kind of oscillating jets of FLiBe(not some kind of crazy abbreviation, those are the elements fluorine, lithium and beryllium; it's a molten salt) that periodically form cavities. Each target is injected to coincide with a cavity formed between the jets of FLiBe, so that when the target is ignited most of the neutrons will be captured in by the FLiBe. You both want to protect the first wall from being degraded by neutrons and capture as many neutrons as you can to make tritium.

Cool! Thanks. So each... cycle? releases enough energy to spark the next cycle plus have some left over to put to other uses?

[shadron]

Too late, cock...too late...

[soylent]

Cool! Thanks. So each... cycle? releases enough energy to spark the next cycle plus have some left over to put to other uses?

You don't want any direct interference between each target and the next. There's no continous reaction of some kind. The idea is that you inject a target into the chamber, you fire lasers at it to compress and heat it to the right conditions; it goes poof and releases a bunch of energy; then you wait just long enough for debris to settle before you start all over again.

The engine analogy isn't too bad. You put a fuel-air mix(target) into the engine cylinder(reactor), compress it and ignite it with a spark(lasers). Some of the energy thereby produced goes into operating the spark-plug, lights and whatever else a car needs in future cycles. If you get much more power out of the engine than it takes to operate the necessities, you have a lot of energy left over with which to make the car go forward(feed electricity into the grid), then you're in business.

[TjW]

You don't want any direct interference between each target and the next. There's no continous reaction of some kind. The idea is that you inject a target into the chamber, you fire lasers at it to compress and heat it to the right conditions; it goes poof and releases a bunch of energy; then you wait just long enough for debris to settle before you start all over again.

The engine analogy isn't too bad. You put a fuel-air mix(target) into the engine cylinder(reactor), compress it and ignite it with a spark(lasers). Some of the energy thereby produced goes into operating the spark-plug, lights and whatever else a car needs in future cycles. If you get much more power out of the engine than it takes to operate the necessities, you have a lot of energy left over with which to make the car go forward(feed electricity into the grid), then you're in business.

In the control room there were whispered introductions: "Dr. Remington, Dr. Mitty. Dr. Pritchard-Mitford, Dr. Mitty."
"I've read your book on plasma feedback control systems," said Pritchard-Mitford, shaking hands. "A brilliant performance, sir."
"Thank you," said Walter Mitty.
"Didn't know you were in the States, Mitty," grumbled Remington. "Coals to Newcastle, bringing Mitford and me up here for a tertiary."
"You are very kind," said Mitty. The tokamak, visible through the control room window, began at this moment to go pocketa-pocketa-pocketa.
"The new feed system is out of sync!" shouted a technician. "There is no one in the East who knows how to fix it!"
"Quiet, man!" said Mitty, in a low, cool voice. He sprang to a terminal, as the tokamak began going pocketa-pocketa-queep-pocketa-queep . He began fingering delicately. Columns of twelve digit coefficients appeared on the screen. He glanced at them, paged down, glanced again.
The technician was no longer shouting, but stood tensely, leaning toward the exit.
"Give me the root password!" Mitty snapped, making a hasty edit. Someone set a card down by the keyboard. The short patch was sudo'd into place. "That should do for now," he said. "But tell them that control loop really needs a third order filter."
Another tech hurried over and whispered to Renshaw, and Mitty saw the man turn pale. "The decline in output has destabilized the grid," said Renshaw nervously. "If you would take over, Mitty?"
Mitty looked at him and at the craven figure of Benbow, who drank, and at the grave, uncertain faces of the two great specialists. "If you wish," he said.

[gabeygoat]

it seems doable to me, however, i don't see how it would work in a capitalist economy.

[Jack by the hedge]

it seems doable to me, however, i don't see how it would work in a capitalist economy.

Sounds like the 21st century belongs to China, then. :)

[Skeptic Ginger]

Hello all, I hope this isn't too much of a derail. :)

If nearly free energy ever does turn out to be a success, by what percentage would the normal cost of energy drop?

In other words, approximately what percentage of the cost of electricity is tied up in transfer, maintaining the transfer structures, etc. (everything that isn't the actual production cost)?As long as we're asking interesting questions, I have another one.

Is it possible to build enough windmills on the planet to begin affecting the jet stream and other natural air currents?

[Skeptic Ginger]

....
There's also the added advantage that fusion plants don't suffer from the bad publicity that fission has had, ....As far as we know. I recall when the benefits of nuclear energy were touted as, it was pollution free.

[Prometheus]

As far as we know. I recall when the benefits of nuclear energy were touted as, it was pollution free.

It is. Mostly.