Slashdot Mirror
UK Joins Laser Nuclear Fusion Project
arisvega writes with this quote from the BBC:
"The UK company AWE and the Rutherford Appleton Laboratory have now joined with [the National Ignition Facility in the U.S.] to help make laser fusion a viable commercial energy source. ... Part of the problem has been that the technical ability to reach 'breakeven' — the point at which more energy is produced than is consumed — has always seemed distant. Detractors of the idea have asserted that 'fusion energy is 50 years away, no matter what year you ask,' said David Willetts, the UK's science minister. 'I think that what's going on both in the UK and in the US shows that we are now making significant progress on this technology,' he said. 'It can't any longer be dismissed as something on the far distant horizon.'"
If someone asked that question 50 years ago, shouldn't we have it by now? Just because something is hard.
While "frickin" laser beams are awesome, especially ones that size, it is so much easier for a star with plenty of gravity that does all that particle squishing for free.
Sharks? Just saying...
Fusion is now no longer 50 years away. It is only 49 years away. We expect this distance to be reduced by another year in another 50 years.
The Tao of math: The numbers you can count are not the real numbers.
He says "'It can't any longer be dismissed as something on the far distant horizon.'".. ;)
I agree, it is more like 20 years away
"The UK company AWE and the Rutherford Appleton Laboratory have now joined with [the DOD funded National Ignition Facility in the U.S.] to help make laser fusion part of their nuclear weapons testing program as well.
Fixed!
http://en.wikipedia.org/wiki/National_Ignition_Facility
The reason its only ever 50 years away is because funding required to make it 0 years away is never accepted and projects are habitually underfunded and cut short before they reach their goals. Several scientific groups and individual scientists have said they'll bring it to us now if they get their X billion for funding. So far no government or company has had the good faith to grant the amount needed. There are prototypes from the 1950's which might have worked, but at the time cost'd some enormous amount. The deal is the science behind it is sound, but the investment sense is not for anyone with the ability to start it up. Its a little like building solar arrays in space, it will pay off, but in like 200 years.
Unlike many technologies, fusion power requires a certain technological threshold to achieve, where various different technologies (possibly in the order of hundreds) finally reach the point where they are advanced enough to achieve breakeven or beyond. We need an electromagnetic containment system, a fuel-production system, monitoring and control, ignition (probably laser), even the materials the reactor is made of need to be of a certain kind. Many of these technologies we do not have, making fusion power more than simply requiring one specific breakthrough like many other technologies do.
It's a bit like how smartphones were developed. We needed not only better touchscreens, but better batteries, smaller computers, faster wireless systems, and more compact storage. Once a certain threshold was achieved, it became possible to build the modern smartphone. Before, things like them were possible, but a certain level of many technologies was required before it could really become practical.
The additional problem with fusion is not only to achieve breakeven, but to do so competitively versus other sources of power (specifically, coal). Coal is pretty cheap in terms of raw cost (the long-term consequences are much more expensive, but the investors can safely ignore most of those.) This is why fusion has been perpetually 50 years in the future: because so many things need to come together to make it practical that one single breakthrough, even if it is massive, simply won't be enough to make it practical. It is a technology we should pursue with tremendous effort, and which should one day pay off in one form or another, but it isn't a magic bullet and won't be for some time.
"None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
I remember reading the predictions decade after decade since the 1950's. The ones I've read always said 20 years in the future. I guess maybe you have to be a detractor to say 50.
.
"The laser fusion idea uses pellets of fuel made of isotopes of hydrogen called deuterium and tritium. A number of lasers are fired at the pellets in order to compress the fuel to just hundredths of its starting size.
In the process, the hydrogen nuclei fuse to create helium and fast-moving subatomic particles called neutrons whose energy, in the form of heat, can be captured and used for the comparatively old-fashioned idea of driving a steam turbine."
That last line reads like the punchline of a (bad) joke. (It's also a testament to how useful water is.)
Anyway, there's huge potential revenues for solving this problem. I just hope a US company gets a share of the eventual windfall.
What makes this news worthy?
"We've done fusion at fairly high levels already. Even on Sunday night, we did the highest fusion yield that has ever been done."
"Dr Moses said that a single shot from the Nif's laser - the largest in the world - released a million billion neutrons and produced for a tiny fraction of a second more power than the world was consuming."
PS: I don't reply to ACs.
The phrase I heard before was "Fusion power is twenty years away and always will be."
The Moore-Murphy Law: The number of things that will go wrong will double every 2 years.
Part of the problem has been that the technical ability to reach 'breakeven' — the point at which the same amount of energy is produced as is consumed
There. I fixed that for you.
There are now multiple different approaches to fusion research. Laser fusion looks promising although we don't have a really good understanding of how to efficiently extract energy from laser fusion. Magnetic containment fusion in the form of tokamaks is also still ongoing. There is an international group working now to build ITER which will be a very large tokamak which will be in France. http://en.wikipedia.org/wiki/ITER. There are other ideas out there but unfortunately many of the more interesting ones are not receiving much funding. Laser fusion confines the plasma and crushes it with brief intense laser pulses while tokamaks confine the plasma using a torus of electromagnets. However, stellarators use a different form of magnetic confinement and might end up working but they are getting almost no funding.http://en.wikipedia.org/wiki/Stellarator
The idea that we are always 50 years from fusion seems to be unfair. We've gotten much better at handling the basics. We can now consistently get fusion to occur with a variety of methods. The primary problems are doing so efficiently enough to get more energy out than we are putting in. We've made slow but steady progress at improving efficiency through a variety of methods. The development of so-called high temperature superconductors (that is able to superconduct a bit over the temperature at which nitrogen boils) in the 1970s has helped a lot. And the engineering issues really are immense. We've also sort of been spoiled by the previous success with fission power. The United States pored a massive amount of funding and resources into fission research from the beginning of the Manhattan project until a bit after World War 2. If fusion power was treated the same way we might be able to develop it quickly also.
There's another aspect about this sort of thing that is good news. The United States is steadily eroding its scientific and exploratory capability. We've retired the shuttle with no replacement. In the 1990s we canceled the Superconducting Super Collider. As a result when the LHC came online the US lost a lot of particle physicists who went over to Europe. The US particle physics has been in a state of decline since then. Most recently, the US is closing down the Tevatron, http://www.sciencenews.org/view/generic/id/68988/title/Tevatron_to_shut_down_in_September which is the star US particle accelerator. While the energy levels of the Tevatron are less than the LHC the types and variety of collisions it does are sufficiently different such that having both of them is very much not redundant. And, the James Webb Telescope might be getting canceled, so it looks like cutting edge astronomy is another area the US is giving up on. If I had just been told that there was a Slashdot headline about laser fusion in the US I would have guessed that it would have been funding cuts for the NIR. The fact that organizations from elsewhere are actually joining suggests that the decline in US science might not be as bad as a pessimist might think. It might be reversible.
They keep adding new methods to the ones they want to try out. That's great, but when you have X amount of money divided by Y projects, you really want Y to be smaller rather than bigger.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
It's remotely plausible that this could eventually lead to commercial power generation, but still far less likely than even magnetic confinement fusion, which will be difficult enough to achieve as it is. Laser fusion projects get tons of funding for the simple reason that it allows us to recreate the conditions of a hydrogen bomb in the laboratory for the first time. Hence why anyone who works on NIF needs a Q clearance. I work in magnetic confinement fusion, and even when people from NIF give scientific talks on it, it's quite clear that the goal isn't commercial power generation. But, it is remotely possible, and hence the government can claim they're spending money on "energy research" when it's effectively just defense spending.
Fusion is probably going to take huge expensive and sophisticated facilities to produce an economically viable power reactor. To some point (not completely though) I think much of this has been just government works projects. On the other hand thorium nuclear reactors could be exploited for far less money and much quicker. Thorium is a fairly abundant element that does not have many of the negative properties which a plutonium or uranium based react would have. We have to do something to beef up the electrical grid. I read an article that said if 10% of the cars in the USA switched to electric, it would collapse the capacity of the grid. Besides, most electricity here is now generated by coal. Please look into the more promising technology of the liquid fluoride thorium reactor (LFTR). http://en.wikipedia.org/wiki/LFTR http://www.youtube.com/watch?v=AZR0UKxNPh8 I'm not saying we should stop research on fusion, but we have to have a quickly viable alternative.
Oh, yeah! Wise guy, huh? Woob woob woob woob! Nyuk! Nyuk!
Both Hiper and Life, a similar effort at Nif, estimate that a functioning laser power plant would need to cycle through more than 10 fuel pellets each second - a million each day.
Out of curiosity do we have any plans on how to precisely feed and align a pellet into an, I assume submerged, reaction chamber to heat water/steam?
That seems like an engineering challenge on the same order of difficult as the laser etc.
Would it be like belt fed? I assume it would need to position and clear the firing target in about 10ms.
That also seems like a recipe for a maintenance nightmare. Are there any similar machines in other industries?
Put a whole bunch of smart and dedicated people together on the same project and they will work their ass off to solve that project. Along the way, they will develop (or spin off for development) a slew of other fantastic ideas.
Support the creative stew!
Nuclear Fusion is now only twenty years away!!
The US doesn't do atmospheric or underground nuclear weapons tests anymore, but there is a lot of research that needs to be done in the realm of "stockpile stewardship" that can be done with a system like NIF. LIFE is a nice PR fluff-piece so that we can all talk about fusion energy... but make no mistake: NIF was conceived as a project for the US weapons community, by the US weapons community, and employs a large segment of the US weapons community. The British AWE (Atomic Weapons Establishment) has some very smart people with similar interests to the folks at LLNL... but they put their interests right in their organization's name.
I see what you did there
There is no right to feel safe thru security vaudeville at the expense of everyone's freedom, privacy and tax money.
The science is sound but the engineering isn't. The kind of problems that just the materials engineers have to cope with are stupendous for tokamak style high temp large scale reactors. The neutron bombardment of the structure holding the magnets makes it hard to figure out what material could stand up to the task. There are no known materials, last I checked in on this, that can do the job. So even if they get an energy sustaining reaction, they still have a bunch of engineering issues to solve which are very hard, if they want to build a commercial reactor that doesn't dissolve into dust after 5 years of operation. Much harder than the problems we solved for fission reactors..
I am sure there is a good reason, but why are we always fusing hydrogen? Why not heavier, easier to grab - move - focus elements? Like fusing Iron or something, it'll turn into something higher up the elements ladder. Because we can shuffle iron about with magnets quite easily, compared to hydrogen that isn't magnetic. Just some very fine iron dust into the big magnet thingy and hit it with all that pressure. Or if not Iron, something else.. Why always hydrogen?
AWE is the Atomic Weopons Establishment. They're interested in fusion all right.
But maybe not the kind you want in your neighborhood.
Hey, NIF fanboys - it's a military project. They want make BIG BOOM not nice electricity.
Watch this Heartland Institute video
While more money might help, there is no amount that could bring certain success in a short few years. I've seen several otherwise great scientists say their project would make a commercial fusion reactor in 5-10 years if they just had enough money to build one some several times larger. This is a result of excess enthusiasm from seeing evidence that scaling up the design would make it run better, but often it turns out a larger machine will show some other effects kicking in that cause new problems not seen with the smaller design. I've seen talks about some of the designs that look really promising and as if money is the only hurdle left. But then someone will ask, "Several other designs encountered problem X when they got bigger, how do you plan to deal with X or do you have any reason to think it is not applicable to your design?" The answer is too often, "I haven't even thought about that, but don't expect it to be a problem" ...
I've worked on some of those fusion projects that try to look for a way other than tokamaks or inertial confinement for fusion, and while they have potential, they have a long ways to go. Quite a few show that scaling evidence, that they could get better if built bigger, but what they need is incremental increases to show that trend continues before dumping billions into a commercial plant sized version. Right now, with US funding at least, there is the question of putting money into alternative designs versus trying harder with a small number of designs, and it can be difficult to figure out which alternative designs should get limited funding. But some projects are being funded, even by private companies like Tri-Alpha and General Fusion.
If you're talking about the Fusor, there are papers that indicate it can't get net positive energy. The prototypes DO work; the fusor is used commercially for neutron production. They just don't get net energy, and there's reason to believe they can't.
Equally, just because some group says they can do it in 0 years (er, can we make it 5?) with X billion, doesn't mean they in fact can.
You're a hair's width from saying the technology works and is being suppressed :)
Aneutronic fusion reactor is much better in terms of technical design. http://www.crossfirefusion.com/nuclear-fusion-reactor/overview.html
Absolutely right. We should be concentrating on LFTRs for a short to medium term solution.
Why? Well how about replacing those dirty coal fired power stations and also providing a MUCH safer nuclear reactor to those which should be decommissioned soon. It fixes your pesky CO2 problem (be you for or against AGW), has a greater abundance of fuel compared to Uranium (and Plutonium) fueled reactors. It's harder to make weapons grade nuclear material from than current designs (that's where they came from), and is far more efficient in its use of the fuel. Imagine being able to solve the Iranian nuclear problem by giving them LFTR, rather than a 30 year old Russian Uranium reactor design.
TFA is about laser fusion, not high-temperature plasma fusion as in a tokamak design. At least read the friendly summary, or if that's too much the friendly headline before commenting, if TFA is too much to ask.
Scientific American examined the argument a year or so ago. It is an engineering challenge even worse than magnetic containment in a Tokamak-style approach.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
until we get some sharks involved.
I am sure there is a good reason, but why are we always fusing hydrogen? Why not heavier, easier to grab - move - focus elements? Like fusing Iron or something, it'll turn into something higher up the elements ladder. Because we can shuffle iron about with magnets quite easily, compared to hydrogen that isn't magnetic. Just some very fine iron dust into the big magnet thingy and hit it with all that pressure. Or if not Iron, something else.. Why always hydrogen?
Fusing the deteurium and tritium isotopes of hydroden is the easiest form there is. Next is deuterium-deuterium which has the advantage that of being naturally available. But, if you're having trouble getting DT fusion going, you will never get DD. Proton fusion, which is what the Sun mostly uses even harder and impractically slow. But that's why the Sun continues to shine. If it were made entirely of deterium and tritium, there would have been just one big bang and that would be it.
Other elements have been proposed. Helium3 fusion has the advantage of not producing neutrons but it is much more difficult (requires more extreme heat and pressure) than DT and there is also the problem that there is negligable He3 on Earth. Boron-proton fusion is also aneurtonic and Boron is at least available but is wishful thinking to try when we still haven't managed to produce energy from DT.
As the elements get heavier, it requires more and more extreme conditions to get the nuclei to fuse and you get less and less energy out. Iron is a dead end. Fusion takes more energy than it gives. So does fision.
"I read an article that said if 10% of the cars in the USA switched to electric, it would collapse the capacity of the grid. "
Read something else...
"Since utilities have built enough power plants to provide electricity when people are operating their air conditioners at full blast, they have excess generating capacity during off-peak hours. As a result, according to an upcoming report from the Pacific Northwestern National Laboratory (PNNL), a Department of Energy lab, there is enough excess generating capacity during the night and morning to allow more than 80 percent of today's vehicles to make the average daily commute solely using this electricity. If plug-in-hybrid or all-electric-car owners charge their vehicles at these times, the power needed for about 180 million cars could be provided simply by running these plants at full capacity."
http://www.evpowersystems.com/PHEVs%20Save%20Grid.htm [evpowersystems.com]
"A new study for the Department of Energy finds that "off-peak" electricity production and transmission capacity could fuel 84 percent of these 198 million vehicles if they were plug-in hybrid electrics. ... Researchers found, in the Midwest and East, there is sufficient off-peak generation, transmission and distribution capacity to provide for ALL of today's vehicles if they ran on batteries."
http://www.pnl.gov/news/release.asp?id=204 [pnl.gov]
Any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so.
They've had this technology at Global Dynamics for years.
If you do what you always did, you get what you always got.
funny other smarter countries in the U.S. are heavily investing and developing thorium (and other breeder technology) reactors. The first world will soon be those that have nuclear power, and the rest will be third world.
Laser fusion has been going in the direction of D-T fusion too, and will produce just as many neutrons as tokamak fusion for the same amount of fusion power. Different fusion concepts can reduce the amount of material and expensive equipment exposed to neutrons, or at least give more flexibility for what materials can be used. But they will still have to deal with some things being exposed to large neutron fluxes.
Most tech was either R&D'd directly by the US government itself (efficient) or tax breaks/incentives for inefficient corporations to do it. Good luck finding anything technical that you know and love (including medical) that actually was the result of anything resembling free market capitalism. As usual, risk is socialized and profits privatized, then it's called capitalism. Corporations constantly attack the government, but anybody who knows anything knows that corporations wouldn't have anything to sell without the gov't and nothing would get done without it. Capitalism works like an engine millions of people have to continuously manually crank so that a few people can ride around in comfort.
National Ignition Facility. I don't know what they do and I want to work there. Worth burning some Karma.
Unlike yourself, of course. All hail the conquering naysayer!
Paranoia is a Survival Trait!
Thorium has similar problems to ordinary U/Pu fission. You still have fission product waste and still have the potential for release of large amounts of hazardous radioisotopes. It is fission, after all. These problems may well be manageable but they're manageable in conventional fission power stations too.
*grin* It'd be interesting to see them refuse it.
Paranoia is a Survival Trait!
"We've also sort of been spoiled by the previous success with fission power. The United States pored a massive amount of funding and resources into fission research from the beginning of the Manhattan project until a bit after World War 2. If fusion power was treated the same way we might be able to develop it quickly also. "
Fission worked right away because neutrons are neutral electrically, but nuclei aren't. Fusion did work pretty soon too, but you can only do it with a fission weapon.
Fusion power is hard because there are many 'near-collisions' which do not release nuclear energy because the minimum radius was not small enough, however, these collisions do contribute to increasing entropy and reducing the proportion of fast-moving nuclei which could generate power. Fission doesn't have this problem: shine neutrons on uranium, and you'll get fission.
So in a tokamak there are N thousand near-collisions for each fusion reaction, so it is a great challenge to keep all the energy inside the nuclei from leaking (as it wants to at every opportunity) before fusing.
The difficulty of controlled fusion power is intrinsic in the physics. We have plenty enough of R&D to know this.
We should concentrate on better fission plants and actinide burners to reduce the long-term waste. Of course the fission disaster at Fukushima is prompting people to do precisely the wrong thing which is NOT to replace less safe nuclear reactors or invest in long-term reprocessing. If it were like cars, it would be finding a flaw which caused the accident, and then refusing to fix any car in the field and shutting down the parts factory.
While I understand your concerns about nuclear waste. The problems of thorium vs uranium reactor waste is substantially different. Much of the fuel in a uranium reactor leaves fissionable products that must be reprocessed into new fuel. This processing also allows for the production of weapons grade materials. If it is not processed, it remains hazardous for many thousands of years. This is not the case with a thorium LFTR reactor. As a matter of fact, an LFTR can actually utilize some of the waste left over from a uranium reactor and burn it up as fuel too. Yes, there will be some products left over from an LFTR that will be hazardous. But it is a tiny fraction of the waste from a uranium/plutonium reactor. The little that does remain from an LFTR would only be hazardous for a few centuries, not countless millenia.
Oh, yeah! Wise guy, huh? Woob woob woob woob! Nyuk! Nyuk!
Though I think fusion is not a short term viable option for commercial energy production. There is another way of doing this though. Fusion using helium 3 is most likely to produce a commercially viable reactor. But the problem is, there is hardly any helium 3 on the earth. We can produce it in another reactor, but the cost would be beyond commercial sustainability. However, there is theoretically a considerable source of helium 3 on the moon. Helium 3 is a product of solar wind that is mostly deflected by the earth's magnetic field. So it does not accumulate here. But the moon has no way of deflecting solar wind, so helium 3 can and does accumulate in the lunar regolith. This could actually make a return to the moon economically feasible. The most likely candidate for a commercially feasible fusion reactor would use helium3. It appears to be the most efficient means of creating distributable energy from a fusion based energy economy. But I still think thorium is a better and cheaper solution.
Oh, yeah! Wise guy, huh? Woob woob woob woob! Nyuk! Nyuk!
That's interesting, but after last night's cascading power outage that put millions in the dark, myself included, from one little glitch out in the middle of the Arizona desert, I say, get us off this grid.
I would like to see small, independent power stations installed with every home, about the size of an outdoor AC unit, that provides enough energy for that family, supplemented by additional stations installed next to every gas pump. This would eliminate the interdependent risk of the grid, and reduce the waste from power lost in today's long line transmission.
TFA is about laser fusion, not high-temperature plasma fusion as in a tokamak design. At least read the friendly summary, or if that's too much the friendly headline before commenting, if TFA is too much to ask.
Laser fusion is high-temperature. It just used laser to and inertia to confine the plasma not magnetic fields. It still have all the same problems as tokamaks first wall material, how you get the energy out, etc.
The problem with inertial confinement is you need to have the insert the fuel, fire the laser, remove the byproducts and energy, the repeat it ~10 times every second. NIF is lucky to get 1 shot every hour. Also it requires such precise alinement to actually make it work that there is a huge hill you have to climb to get to that repetition rate.
If you believe the folks at General Fusion
Some of you may remember the write-up they had in PopSci a few years ago. Basically this thing is a brute force steam punk style fusion generator. There is a several metre diameter sphere of molten lead and lithium that is spun up to create a vortex. Plasma is injected into the vortex cavity and them BLAM!!! a bunch of giant steam powered pistons bang on the outside of the sphere to create a compression shockwave. The shockwave compresses the D-T plasma, fast neutrons are captured by Li to make Be, which then decays to make more delicious tritium. Grab some energy from heat, then revortex, reinject, resmash, repeat. The great thing is the clanging sound lets you know it's working.
I've been fortunate to visit the facility a few times, and the progress they've made over the past few years is astounding. These guys are the real deal. Hopefully in just a few short years the reactor will be up and running and we can stop spending billions and billions on less practical reactor designs.
By your own link the National Ignition Facility does nuclear weapons maintenance, not nuclear weapons testing. Weapons maintenance has to do with ensuring that existing nuclear weapons don't leak, explode or otherwise freak out as the components age, and with more deeply understanding just how radioactive material behaves in situations like that of building and storing a bomb; it has little or nothing to do with making new weapons, at least not inherently. Not only is their research critically important to responsibly storing or (hopefully) disposing of our existing bombs, there are also scientifically useful radioisotopes that can be extracted from the warhead cores as the uranium or plutonium decays (though for the life of me I can't recall which ones; I just remember reading it in other slashdot comments). I do understand that part of the program goal involves keeping current on the technology and the staffing that could be used to make weapons, but I don't see any evidence that they are involved in weapons research at the moment.
I think you are confusing the NIF with the Stockpile Stewardship and Management Program, a DOE initiative designed to deal with the ramifications of the Comprehensive Test Ban Treaty. While the goals of the SSMP are broadly what you have outlined, the NIF was created by the SSMP to specifically come up with a way around the criticality ban in the CTBT, so that nuclear weapons design could continue without the need for explosive testing. The wiki on NIF is revealing.
A couple of things people seem to be getting wrong here.
1: We've already achieved "break-even" in tokamak reactors. However, in order for a power plant to be useful it must produce much more energy ( say 100 fold ) than you put in. Break even is not nearly enough.
2: You don't need ignition in a power plant. Ignition refers to the condition where the energy in the helium nuclei formed is enough to keep the plasma burning without any heating. This is not necessary in a power plant. It is sufficient that the amount of energy emitted by the plasma ( in the form of neutrons x-rays etc... ) is much greater than the energy you use heating it. Ignition is important if you are building a nuclear warhead. It is completely unnecessary , and probably undesirable , in a power plant.
3: At the moment the major issue for a fusion plant is not getting the fusion reaction to occur. That this can be done has been demonstrated many times. The difficulty is to keep it running smoothly for long time periods and finding materials to make the reactor from. The latter is particularly challenging since the best materials for coping with the heat and neutron radiation tend to be made from heavy nuclei that will mess up the plasma if even microscopic amounts of them are released from the reactor wall.
4: Building a plant that can be used to generate a lot of electricity is not the same as commercial viability. The latter requires that the energy can be generated at a reasonable cost. Since fusion reactors are much more difficult to build and maintain than a fission reactor it is not obvious that they will ever be financially viable within our lifetime.
5: The reason the time-line for building a working fusion power plant keeps getting pushed further into the future is at least in part due to the funding for the projects constantly being cut. Despite this, it is now pretty much clear that a workable fusion plant can be built. The uncertainty is if it can be made economically viable. This uncertainty is in part due to the materials problems. If neutron damage forces you to replace the reactor wall too frequently, the whole scheme quickly becomes prohibitively expensive.
6: There is no such things as neutron-free fusion. While helium-3 fusion is in theory neutron free, the products of the reaction involve nuclei that will easily cause other fusion reactions in the plasma, and these release neutrons. In addition, for any reaction other than deuterium-tritium or deuterium-deuterium , the energy losses due to x-rays are likely to greatly exceed the fusion yield, meaning D-T or maybe D-D fusion are the only viable candidates. The sun manages with just protons because the gravity ensures a sufficient density in the core that much of the radiation is re-absorbed by the plasma. It's vast size also means that it can produce a lot of energy with very slow reactions, a luxury we don't have on earth. I should note that this assumes that the plasma is somewhat neutral ( i.e contains electrons ), since it is the electrons that give rise to the x-ray losses. The problem is that for a plasma that does not contain electrons, the large collection of positive charges will make it almost impossible to achieve a sufficient density and energy confinement. Even at record breaking magnetic field strengths the confinement time necessary would have to be on the order of magnitude of several days in order to maker up for the abyssal number density. Yes, I know about polywell, and it's a load of snakeoil.
7: Thorium reactors are always mentioned in nuclear discussions. What is usually not mentioned is that if they are to operate on a thermal spectrum ( as is usually assumed since they don't really have any advantages in a fast spectrum ), then their doubling time is so long that you would have to start them up using traditional fuel. In practice this would likely imply reprocessed plutonium and recycling of the other actinides. Now if you are going to use reprocessed plutonium from spent fuel, then you are going to need fast reac
That is, if you eliminate all inspection and maintenance windows. And no plants go down because of a fault. And there isn't unusualyl hot or cold weather causing HVAC systems to run longer and/or harder.
Seriously, every energy professional I've talked to doubles over in laughter at those studies because they presume absurdly high availability rates.
Fushion is the only technology that is always 20 years away.
The science is sound but the engineering isn't. The kind of problems that just the materials engineers have to cope with are stupendous for tokamak style high temp large scale reactors. The neutron bombardment of the structure holding the magnets makes it hard to figure out what material could stand up to the task. There are no known materials, last I checked in on this, that can do the job. So even if they get an energy sustaining reaction, they still have a bunch of engineering issues to solve which are very hard, if they want to build a commercial reactor that doesn't dissolve into dust after 5 years of operation. Much harder than the problems we solved for fission reactors..
Can't they just route the neutron pulse through the main deflector dish? And like, vent some drive plasma through the nacelles or something?
The world you experience is only a close approximation of reality.
If you give my 1billion dollars, i will give you fusion in 2 years.
Yep, that was real easy.
The Grey Goo disaster happened 3 billion years ago. This rock is covered in self replicating machines!
The point is that you could cut the numbers in half, and still be above the 10% mark quoted in the previous post.
Any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so.