Casting doubt on fusion power

2009-11-19

in Geek stuff, Science, The environment

Metal fence in front of electrical station

Looking at a diagram of a proposed fusion reactor, it is easy to get the false sense that such technologies will provide clean and inexpensive power within a few decades: fusing tritium and deuterium to produce heat, while generating new fuel from lithium using the neutrons produced.

A post on The Oil Drum enumerates the many technical challenges associated with achieving that aim, going so far as to say that dreams about fusion power should be ‘ended’ as a consequence. Written by Dr. Michael Dittmar, a researcher with the Institute of Particle Physics of ETH Zurich, the article enumerates a number of significant problems:

  • Large amounts of tritium are required and various problems exist with it as a material and a fuel.
  • Materials from which reactor walls can be made are unavailable, and far beyond anything that is available.
  • Many obstacles exist to breeding tritium from Lithium-6.
  • Similarly, obstacles exist to extracting tritium from the lithium blanket and delivering it in a pure form into the chamber where fusion is occurring.
  • Reactors may not be able to breed enough tritium to keep themselves going, much less provide excess tritium for new facilities.

While this may not be cause for declaring fusion a complete non-starter, it is at least a useful way to temper the assumption that fusion power will emerge any decade now, providing a pain-free solution to the problems of climate change and fossil fuel depletion.

The article also lists problems with fission reactors that breed plutonium or use thorium as fuel: both options mooted in response to concerns about limited availability of uranium for use in conventional reactors. All this is a reminder that – while renewables may be costly and have intermittency problems to manage – there is every reason to believe they can be practically deployed starting immediately.

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{ 22 comments… read them below or add one }

R.K. November 19, 2009 at 10:54 am

I was promised that amazing future technologies would solve all our problems and make the world wonderful. Is this not so?

Milan November 19, 2009 at 3:39 pm

It would be nice, wouldn’t it?

Anon November 19, 2009 at 5:21 pm

Would fusion using plain old hydrogen gas be much more difficult than using tritium?

M. Simon November 19, 2009 at 9:00 pm

Evidently you gentlemen are unfamiliar with the Polywell Fusion Reactor.

It avoids all the negatives you mentioned (and I agree that they are killers for a tokamak based design).

The US Navy is funding the experiments.

We Will Know In Two Years

James Makepeace November 20, 2009 at 4:01 am

There are challenges for fusion energy, but they are not insurmountable, even for the hugely difficult tokamak approach. What must be avoided however is the blind assumption that the solutions will be either quick, easy or cheap.
It seems extremely unlikely that s0-called “Polywell Fusion” will provide an answer on the industrial scale needed for the future but, if we really will know in just 2 years, they might as well get on with finding out.
Renewables are important and must be developed, but there are huge problems over efficiency and sustained capacity, so it would be foolish to assume that these will ever meet much more than 10% of man’s insatiable energy demands. It’s unfortunate, but a hard fact, so should not be ignored.
“Plain old hydrogen gas” is not an option for fusion. Deuterium and Tritium are the most likely two isotopes to achieve a fusion burn with net energy gain (which is the “holy grail” we are all talking about). … and the comment about problems with the quantitiy of Tritium needed seem to apply to the tokamak approach, but not so to the other approach, which is advancing very quickly now. The “new kid on the block” is inertial fusion energy, using very large lasers to achieve fusion burn. The laser has a very interesting capacity to concentrate energy, not only in space (as in a huge shot of energy onto a spot a tenth the thickness of a human hair) but in TIME too (as in concentrating that energy from a longer pulse into a trillionth of a second). That unlocks the possibilities which seem set to give us “Proof of Principle” for laser fusion in the next couple of years. Of course The Oildrum will keep on banging away about the drawbacks of fusion energy. Fusion won’t be mastered for a while yet, but it represents “the end of the game” for the fat cats of Big Oil, who have enjoyed an easy life for the past century, polluting our planet almost beyond recognition in the process. The hard reality is that we need another generation of fission reactors to keep the lights burning until fusion is conquered, but knocking fusion and stopping the research is an act of madness, given the mess we are in for energy supplies into the future and the timescale we need to fix the problem.

Milan November 20, 2009 at 8:44 am

Renewables are important and must be developed, but there are huge problems over efficiency and sustained capacity, so it would be foolish to assume that these will ever meet much more than 10% of man’s insatiable energy demands.

They already do in several places.

About 20% of Denmark’s electricity comes from wind. Canada gets around 60% of its energy from hydroelectricity.

I expect concentrating solar plants to become a key energy source in places like North Africa and the southern United States, as well.

With demand management, energy storage, and the balancing of different sorts of renewables against one another, there is good reason to think that the majority of electricity production globally could eventually come from renewables.

The “new kid on the block” is inertial fusion energy, using very large lasers to achieve fusion burn.

My sense is that experiments like the National Ignition Facility are more oriented towards military projects – like ‘improving’ hydrogen bombs – than towards learning ways of using fusion energy for civilian use.

Of course The Oildrum will keep on banging away about the drawbacks of fusion energy.

The Oil Drum doesn’t have a consistent editorial stance, and includes articles written by many people. If there is a consistent theme, it is the probability of peak oil and what humanity can and should do to anticipate and respond to it. If it were practical, fusion power would be a nice way to deal with part of the problem (though electricity isn’t an ideal fuel for most forms of transportation).

James Makepeace November 21, 2009 at 5:14 pm

In response to Milan…

Renewables … will never meet much more than 10% of man’s insatiable energy demands.

“They already do in several places. About 20% of Denmark’s electricity comes from wind. Canada gets around 60% of its energy from hydroelectricity.”.

But only in isolated areas where there is a huge energy surplus. On the wide scale they can’t meet the demand. Denmark is windy (with not too many people), and Canada is mountainous, has an extremely low population density and has a huge amount of water falling on it each year. Great places for renewables, but try doing it in Shanghai, Rio or Dallas!

” I expect concentrating solar plants to become a key energy source in places like North Africa and the southern United States, as well. With demand management, energy storage, and the balancing of different sorts of renewables against one another, there is good reason to think that the majority of electricity production globally could eventually come from renewables”.

Demand management sounds good, but it amounts to persuading millions of people not to burn nearly so much energy… no easy call when they’ve been used to it for generations ! Solar plants will be good, but only where there is high average sunshine. Long-range distribution remains a nightmare to solve !

” My sense is that experiments like the National Ignition Facility are more oriented towards military projects – like ‘improving’ hydrogen bombs – than towards learning ways of using fusion energy for civilian use”.

Your sense is only right in small part. Yes, NIF exists partly for nuclear stockpile stewardship, but it has a dual purpose (written into its original role) and the other function is fusion energy research… which is now becoming much more important to mankind than maintaining hydrogen bombs. Ironically, if man had not succeeded in creating the hydrogen bomb, we would not now have a potential solution to the energy crisis. This is the ultimate example of “swords beaten into ploughshares” ! It just needs to be understood by governments with the imagination to see past all the media furore generated by people who can’t understand more than the word “nuclear”. NIF is within a couple of years of the primary proof of principle for laser fusion… and that will far outweigh any contribuition it makes to ensuring a safe and reliable nuclear stockpile.

” If it were practical, fusion power would be a nice way to deal with part of the problem (though electricity isn’t an ideal fuel for most forms of transportation)”.

You speak of applying “demand management”… well certainly the gas-guzzling automobile won’t run too well on electricity ! What “demand management” really means to me is persuading a lot of people who have enjoyed the easy ride of cheap fossil fuel (petroleum & diesel) for a few decades, to shift to methods which use whatever energy IS abundant. If, through fusion, electricity becomes a best source in 20 or 30 years, people will adapt… because they will simply have to. That is how people operate… whether it means developing electric cars (better battery technology needed) or using electricity efficiently to crack water into hydrogen and oxygen (two perfect and portable fuel elements IF they can be made in sufficient quantities without consuming too much energy in the process).

The fact is that mankind has become entirely addicted to easy cheap energy and, however hard the “de-tox”, we must try to get “un-hooked” as much as possible… But try explaining that to the developing nations in the far east for example… or to a housewife in Frankfurt… or Washington !

We got ourselves into this mess by being clever, then failing to see the price we were starting to pay for that cleverness. Now we need to be much cleverer still … or we most certaqinly will pay the price, and it will be a very high one !

Milan November 21, 2009 at 6:33 pm

But only in isolated areas where there is a huge energy surplus. On the wide scale they can’t meet the demand.

A great comprehensive analysis of this is David MacKay’s Sustainable Energy Without the Hot Air. Desert solar with long distance high voltage direct current transmission is very promising.

It’s still exploiting nuclear fusion, really. We just leave it to the sun, without trying to build a little one of our own.

Demand management sounds good, but it amounts to persuading millions of people not to burn nearly so much energy… no easy call when they’ve been used to it for generations!

Just convincing people to spread energy use more evenly could have a big impact, by reducing the usage of inefficient peaker power plants. This could be done by using smart appliances and heating and cooling systems that automatically run themselves during times of low demand. Demand-based pricing would also help.

Solar plants will be good, but only where there is high average sunshine. Long-range distribution remains a nightmare to solve!

The DESERTEC solar plan envisages using HVDC connections to link energy from solar plants in North Africa to Europe. Something similar could be done using facilities in the southern US.

Ironically, if man had not succeeded in creating the hydrogen bomb, we would not now have a potential solution to the energy crisis.

The technologies are really awfully different. A Teller-Ulam configuration bomb only sustains fusion for a minute span of time, and actually generates most of its energy from fission. A fusion power plant would need to run for months or years. As such, bomb knowledge may not be too applicable.

You speak of applying “demand management”… well certainly the gas-guzzling automobile won’t run too well on electricity !

Not only do electric cars look more and more viable, they could eventually be a key source of energy storage: topping up the grid during times of high demand and charging at times when demand is scarce. Pumped hydroelectric storage is another viable option, along with tidal facilities with multiple sections.

If, through fusion, electricity becomes a best source in 20 or 30 years, people will adapt… because they will simply have to.

There is basically zero chance of this. ITER may not be running in 20 years, much less a demonstration plant that actually produces power, much less a commercial station. We need to accept the likelihood that fusion may be fifty years out or more. We will need to replace fossil fuels before then.

John Mashey November 22, 2009 at 9:45 pm

Burt Richter did a good talk a few years ago locally (including role for fusion (“Not for at least 50 years”) ), called Gambling with the Future: Energy, Environment, and Economics in the 21st Century. He also led the American Physical Society’s Energy = Future …Think Efficiency report.

Of course, he may or may not be right, but he is a Nobel physicist and member of the US National Academy of Sciences, among other things, so his opinion might be worth considering.

R.K. November 23, 2009 at 4:55 pm

The touchstone when it comes to nuclear fusion seems to be skepticism about undemonstrated claims. If you are wrong and someone really does come up with a technology that can be applied commercially soon, you can always eat your words when they have a full-scale demonstration plant running. At the same time, you will avoid getting suckered by the endless stream of people who can’t make it work.

Milan November 25, 2009 at 11:20 am

I basically agree: we cannot count on fusion energy emerging as a viable commercial option before we need to basically eliminate fossil fuel use to prevent climate change.

If fusion does emerge, it would be a nice suprise and good addition to the low-carbon energy mix. That being said, I think it would be very foolish to come up with a mitigation plan that depends on the kinks in fusion being worked out any time soon.

. November 25, 2009 at 11:47 am

Polywell
From Wikipedia, the free encyclopedia

The polywell is a plasma confinement concept that combines elements of inertial electrostatic confinement and magnetic confinement fusion, intended ultimately to produce fusion power. The name polywell is a portmanteau of “polyhedron” and “potential well.” The experimental fusors that employ this concept are called “Wiffle Balls”.

It was developed by Robert Bussard under a US Navy research contract as an improvement of the Farnsworth-Hirsch fusor.

Bussard believed that this device can run with net energy production on boron-11 and proton fuel. Todd Rider calculates that bremsstrahlung losses with this fuel relative to the fusion production will be 1.20:1.00. Bussard said that his calculation of the losses are about 5% of this, and therefore, greater gains than unity are possible.

According to Bussard the high speed and therefore low cross section for Coulomb collisions of the ions in the core makes thermalizing collisions very unlikely, while the low speed at the rim means that thermalization there has almost no impact on ion velocity in the core.

Another paper on the feasibility of IEC fusion, using the full bounce-averaged Fokker-Planck equation operator, concluded that IEC systems could produce large fusion energy gain factors (Q values). However, a deuterium-tritium reaction was necessary to minimize operating potential and Bremsstrahlung losses in order to reach large Q.

. January 29, 2010 at 12:19 pm

Laser fusion test results raise energy hopes
By Jason Palmer
Science and technology reporter, BBC News

A major hurdle to producing fusion energy using lasers has been swept aside, results in a new report show.

The controlled fusion of atoms – creating conditions like those in our Sun – has long been touted as a possible revolutionary energy source.

However, there have been doubts about the use of powerful lasers for fusion energy because the “plasma” they create could interrupt the fusion.

An article in Science showed the plasma is far less of a problem than expected.

The report is based on the first experiments from the National Ignition Facility (Nif) in the US that used all 192 of its laser beams.

Along the way, the experiments smashed the record for the highest energy from a laser – by a factor of 20.

. February 1, 2010 at 3:35 pm

“Scientists estimate that if they can get to the point where they can burn about five fuel pellets a second, a power plant could continuously generate up to a gigawatt of energy—about what the city of San Francisco is consuming at any given moment.

In addition to the considerable engineering challenges involved in ramping up the laser systems for wide-scale use, the cost of the fuel pellets will also have to come down, said Mauel, a Columbia University physicist.

Each one of these costs between ten [thousand] and a hundred thousand dollars,” Mauel said. To use the pellet method to generate nuclear fusion power, “they’ll have to cost less than ten cents a piece.””

Tristan February 20, 2010 at 4:10 pm

“Renewables are important and must be developed, but there are huge problems over efficiency and sustained capacity, so it would be foolish to assume that these will ever meet much more than 10% of man’s insatiable energy demands. ”

The thing about “demand” is that when demand outstrips supply, no amount of yelling actually gets you what you want. In the long run, if nuclear doesn’t pan out, the consumption will become basically equal to what renewables can produce.

Milan February 21, 2010 at 12:05 pm

Indeed, imagine how different energy demand would have been between 1750 and 2000 if the Earth wasn’t endowed with fossil fuels.

Sean March 2, 2010 at 10:08 pm

Mr. Makepiece doubts that Dr. Bussard’s Polywell IEC Fusion will work when four independent analyses after his death confirmed that the next generation WB-7 design seems totally viable? Such skepticism confirms Bussard’s (40+ years of fusion research and former assistant director of AEC) conclusion that most authorities favor big-money boondoggles like the ITEC and are hopelessly committed to one thing – jobs. Makepiece goes on to say we need years more of fission power – makes you wonder what projects or companies fund him. Others say we can’t wean ourselves off oil in the foreseeable future – wonder if they ever looked at RB’s Google lecture where mentions that IEC Fusion can be used to generate steam and 35 cent a gallon ethonol from swamp swill as bi-products (I believe Brazil was interested in funding him for that reason alone)! Yeah, keep on thinking inside the same old academic box you were litter trained in – if you really want the world to go to hell… but then why don’t you try banking, there’s far more short term profit in Wall Street speculation and join the inevitable abreaction to IECF by oil, coal, gas and all the similar lucrative tax-breaks given those funding alternatives such as oilman T. Bone Picken’s wind farm.

Sean March 2, 2010 at 10:37 pm

Oh yeah, IEC fuses minimum tritium, it uses mostly pB11 which fuses into an excited state of C12 that decays into helium and beryllium – no neutron radioactivity that causes all the denting inside a tomamak. Clean energy makes climate debate a trivial pursuit, besides there’s more to environmental degradation than climate, Mr. Gore (who caused more damage supporting the SUV craze when his shares of Occidental Oil was held in blind trust as VP!). Anyway, what happened to global systems analysis? – I suggest your site look into broader problems than climate per se.

Tristan March 2, 2010 at 11:55 pm

“Broader problems than climate per se”.

Part of me wants to ridicule this, because obviously climate is the most meta systems analysis we can think of.

However, I am amenable to the view that what we should really be concentrating on is the specific negative impacts climate will have on the lived world, and political ramifications, etc…

I’m not an expert, but there does seem to be a general sense that climate change will hurt the world’s poor fastest and hardest. Since leaders don’t care about the unwashed masses, we shouldn’t be surprised that this does not create an outcry, and a global consensus to stop emissions.

I would like to be able to say that we should expect the elites to limit global warming to the amount that will benefit them. The problem with this is, our political and economic systems reward short term gains – not long term planning. Politiciens with long term vision have to fight doubly hard, and usually fail.

Chomsky has a talk on what to do next – “When Elites fail”
http://www.youtube.com/watch?v=Z1Jk2kPwUj0
http://www.youtube.com/watch?v=LpGaEE5pOdA&feature=related

. June 14, 2010 at 2:22 pm

ITER Fusion Reactor Enters Existential Crisis

“The long beleaguered experimental magnetic confinement fusion reactor ITER is currently in what some are calling the worst crisis of its 25 year history. Still existing only on the paper of thousands of proposed design documents, the latest cost estimates for the superconducting behemoth are soaring to nearly 20 billion USD — roughly twice the estimates from as recently as a few years ago. Anti-nuclear environmentalist organizations have seized upon the moment as an opportunity to use the current global economic crisis as a means to push for permanently killing the project. If ITER is not built, the prospect of magnetic confinement fusion as a technique to reach thermonuclear breakeven and ignition in the laboratory would be in serious question. Meanwhile, the largest laser-driven inertial confinement fusion project, the National Ignition Facility, has demonstrated the ability to use self-generated plasma optical gratings to control capsule implosion symmetry with high finesse, and is on schedule to achieve ignition and potentially high gain before the end of the year.”

. August 2, 2014 at 2:17 pm

The polywell is a refinement of another device known as a fusor, perhaps the simplest of fusion reactor designs. A fusor has two usually spherical electrodes made of wire mesh, one inside the other. When the setup is placed in a vacuum chamber filled with fusion fuel and a large voltage is applied across the electrodes, the electric field accelerates ions inward, toward the inner mesh. In theory, the ions fly right through the holes and continue on to the center where they collide with other ions and fuse. The problem is that too many ions hit the inner electrode and are absorbed, cutting the device’s efficiency and putting ignition out of reach.

Bussard’s idea was to replace the inner electrode with something that was harder to hit: a virtual electrode. The polywell is made up of a number of ring-shaped electro-magnets, usually arranged to form a cube. When current is passed through the magnets, they create a field that has a null point in the center of the cube, which traps any charged particles. An electron gun fires electrons through the middle of the rings and they become trapped by the field. Once enough are in place, the electrons act as an electrode, exerting a strong pull on positive ions. Atoms of fuel are puffed in at the corners, become ionized, accelerate into the center, and, with luck, collide with other ions and fuse.

. August 2, 2014 at 2:19 pm

The polywell’s big problem is confinement: Particles leak out through gaps in the magnetic field. In experiments carried out last October, EMC2 used improved electron guns to build up a high pressure of electrons in the center and showed that confinement was significantly improved.

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