New Advances Bring Fusion Closer to Reality

An anonymous reader writes "The Christian Science Monitor reports on new advances in nuclear fusion research. For years we've been waiting for the technical breakthroughs that would make cost-effective fusion energy a reality. Are we getting close, or are the problems insurmountable?"

Comments

Years away

[Nuskrad]

"Nuclear Fusion has always been 15 years away, and always will be"

Re:Years away

[Eric_Cartman_South_P]

"Nuclear Fusion has always been 15 years away, and always will be"

I think you mis-spelled "Duke Nukem Forever".

Re:Years away

[Anonymous Coward]

Nuclear Fusion is about 8 minutes away, and will always be*

* At least until the sun finishes its main phase

Re:Years away

[sillybilly]

You know what bugs me? The world is squabbling over where to build the 6 billion dollar ITER (international thermonuclear reactor.) See http://fire.pppl.gov/ They've been negotiating over locations between France and Japan, neither party willing to yield, for over a year now. 6 billion dollars? Screw it, build two of them, one in Japan, one in France, but that's not the point. They don't want to build it, because if anyone can make cheap energy out of rainwater, then how do you control them? The powers that be actually like the setup where they can fight and take over any limited resources, then have people come beg them for a piece of the pie. It doesn't matter to them if billions of people die, as long as they are not one of them. But civil war and social chaos is not picky.

Re:Years away

[Decaff]

"Nuclear Fusion has always been 15 years away, and always will be"

This glib statement seriously underestimates the achievements in this area in the past few years. We have gone from doubts as to whether controlled fusion could ever be achieved to a point where we are working on stabilising the reaction to the level where it produces commercial results.

And by the way, the classic quote was '50' years, not 15!

Re:Years away

[Binestar]

Given the challenges facing today's nuclear reactors, they have long dreamed of harnessing the same energy source that powers the sun.

Uh...Solar power anyone?

The sun powers solar power, Fusion powers the sun.

Re:Years away

[ejort79]

'First rule in government spending: Why build one when you can have two at twice the price?'

Re:Years away

[anorlunda]

Not to reveal my age, but when I was an engineering student in the early 60s the big science news was that flat screen TV was only 2 years away, and that CRTs would be rendered obsolete. Flat screen TV was perpetually 2 years away in the future for most of my life, but it finally did arrive.

Our goal should be to have commercially useful fusion energy in operation by the end of the 21st century. It's vital, but not easy, for the public to support such long-term goals. That's particularly true when we can't visualize the links in the chain that will connect now with then.

The actual breakthroughs that make energy power cheap and safe are likely to come closer to the end of the century, and we can't imagine what they might be. Still, we must support constant inquiry and scientific research to create the fertile conditions for breakthrough discoveries.

The only reservation I have about supporting big science is a serious one. Money should go for science, not to feed the egos of the pricipals. The bigger the project, the harder it is to assure that.

Re:Years away

[ssj_195]

Well, AI with Turing machines has allegedly been proven mathematically impossible.

I think you've been misinformed - I'm willing to bet you're talking about Godel's Theorem or the Halting Problem...?

Re:Years away

[HMA2000]

Even with fusion power "too cheap to meter" there will still be limited resources. Trust me, there is no government of a developed nation on earth that doesn't want the incredible economic boost free power will have.

I will never understand where this hyper cynicism comes from. On one hand our "evil rulers" will do anything to make a buck. On the other hand they will not do something that will save trillions of bucks because they don't want to lose influnence and power.

It's a stupid way to go through life and precludes rational analysis of real political actions and motives.

Re:Years away

[homer_ca]

Even with fusion power "too cheap to meter" there will still be limited resources. Trust me, there is no government of a developed nation on earth that doesn't want the incredible economic boost free power will have.

Exactly right. As another poster said, fusion scales up not down. To be cost-effective, a fusion plant using currently known science needs to be huge. That implies huge levels of investment, labor and organizational structure. Think Hoover Dam, not rooftop solar. Not something a small country with no technological infrastructure can throw together. There are other low-tech energy sources that could democratize energy (I'm thinking algae ponds for biodiesel), but they can't match the energy density of fusion or even fossils.

Re:Years away

[Rei]

CSM is actually a surprisingly good paper. Don't denigrate it because of the name.

Re:Years away

[Rei]

Does personal electric rail really require new power sources? I can't see how transmission losses would lower power plant efficiency down below the inefficiency of current gasoline engines (perhaps down below diesel efficiencies...)

The reason we don't have personal electric rail is largely due to the infrastructure problem. We have a staggering amoung of infrastructure geared towards our problem-laden traction-propelled human-guided noncooperative road system. The real needed factor is not cheaper power (although that would help!), because cheaper power will also transfer to fuel costs (cheaper to make ethanol, cheaper to charge electric cars or produce hydrogen, etc).

What is needed is for people to see the scale of the benefits - almost no weather/visibility related problems, full freedom of destinations apart from "offroading", travel times that beat airlines for all but the longest trips, almost eliminated traffic, almost nonexistant vehicle accidents (the leading cause of death for a sizable age range in the US), no traffic violations, no needing to drive, the ability to deliver things and have them delivered to you fior incredibly cheaply (Want groceries? Just send your vehicle to the grocery store with a list for their stockers to load up), a cheap, individualized public transit "taxi" system that goes right to your door, the possible ability to turn a profit with your vehicle by having it be a "taxi" when you're not there, reduced need for parking at busy areas by having vehicles automatically drive to more remote parking areas (or even back to your home) and return when you need them, the freeing up of the large space needed for roads because of the much smaller profile of elevated tracks, simpler (and thus cheaper and lower maintainance) vehicles... etc. The benefits go on and on. The problem is that it has huge upfront costs involving the replacment of our entire road system with a track system.

Of course, cheap power wouldn't hurt ;)

If only they'd listen

[Anonymous Coward]

I built a cold fusion device that uses heavy water as its fuel, but my work is being supressed by the hot fusion cabal at Princeton.

One day I'll be famous.

Of course we will!

[Anonymous Coward]

Are we getting close, or are the problems insurmountable?

According to this documentary, we'll have fusion powering our homes and cars within 10 years.

Re:Of course we will!

[Daniel Dvorkin]

I'd say Back to the Future is about as reliable as the Christian Science Monitor for finding science facts.

The CSM is actually a very respectable news source, and not especially influenced by CS ideology. It's no more about CS than The Economist is strictly about economics, or the New York Times is just about things that happen in New York.

"Splitting atoms"

[Dancin_Santa]

While I believe that fusion will likely be the only sustainable energy source as our current supplies of oil and uranium eventually run out, nuclear fission is about the only 'safe' alternative in the meantime. Generating many orders of magnitude less radioactive waste than current fossil fuel plants, they are inherently better for the environment on a purely objective level.

What I object to, though, is the insinuation that we are the ones splitting the nuclei of the radioactive elements. These things are radioactive precisely because of their tendency to decay and in fact split themselves. They don't even split into other elements. You can't turn uranium into gold, for example, even though it ought to be a straightforward process of splitting off the required number of protons from each atom (if the "we're splitting atoms" camp claims are correct).

We use the heat generated by the decay of radioactive elements to fuel our generators. We do nothing like smashing atoms into smaller bits.

Just a pet peeve of mine whenever I see a nuclear power article.

Re:"Splitting atoms"

[Viol8]

"nuclear fission is about the only 'safe' alternative in the meantime. Generating many orders of magnitude less radioactive waste than current fossil fuel plants,"

I completely agree with you , but try telling that to the kneejerk reaction anti nuclear fanatics who can't see the wood for their own foolishly planted trees. Mind you, I've met some of these people and half of them couldn't even spell "radioactivity" never mind tell you what it was. They work purely on a fevered emotional level and no amount of rational discussion will convince them otherwise. They are the same sorts of people who dunked old women in ponds back in the 17th century because they talked to their cat and someone got ill in the village shortly afterwards.

Re:"Splitting atoms"

[Anonymous Coward]

They are the same sorts of people who dunked old women in ponds back in the 17th century because they talked to their cat

...or committed the heinous crime of weighing less than a duck!

Re:"Splitting atoms"

[kfg]

...or committed the heinous crime of weighing less than a duck!

Hey, now that one's a fair cop.

KFG

Re:"Splitting atoms"

[Anonymous Coward]

My favourite peice of braindead kneejerk quasi-science claptrap has been the reaction to mobile phone cell masts here in the UK. I've seen masts which have been graffited with an "Ionising Radiation" warning sign, neatly confirming what I had suspected for some time; The people who scream the loudest are usually the most clueless.

Re:"Splitting atoms"

[StrawberryFrog]

I object to the insinuation that we are the ones splitting the nuclei of the radioactive elements

Well, fine. But you can say that by refining the uranium, and bringing sub-critical amounts of together in a pile, or supercritical amount together in a bomb, we are utilising the nucleus's innate tendency to split, and to thereby trigger a chain reaction in nearby uranium nuclei, in order to generate a self-sustaining level of radioactivity that would not have otherwise occured.

You could also say when making tea that we are not the ones boiling water, we are merely allowing electricity to flow through a restisting metal rod, which generates heat which when transfered to the water causes a rise in temperatre to boiling point that would not have otherwise occured. But that would be very, very pedantic.

Re:"Splitting atoms"

[starman97]

Decay?
You mean all those extra neutrons flying about dont have anything to do with it? Those neutrons traveling at carefully determined energies intended to impact the nucleus of the U238 atoms and cause it to become unstable and break apart into two smaller ones that are usually highly radioactive?
As opposed to the normal decay which merely sheds a single alpha, beta or gamma ray, leaving the original nucleus largely intact. This results in less radioactivity, not more.

Re:"Splitting atoms"

[curmudgeous]

"... They don't even split into other elements." Uhhh, wrong. My physics was a bit rusty, so I did a google on the fission process and found this on world-nuclear.org: "The number of neutrons and the specific fission products from any fission event are governed by statistical probability, in that the precise break up of a single nucleus cannot be predicted. However, conservation laws require the total number of nucleons and the total energy to be conserved. The fission reaction in U-235 produces fission products such as Ba, Kr, Sr, Cs, I and Xe with atomic masses distributed around 95 and 135. Examples may be given of typical reaction products, such as: U-235 + n ===> Ba-144 + Kr-90 + 2n + energy U-235 + n ===> Ba-141 + Kr-92 + 3n + 170 MeV U-235 + n ===> Zr-94 + La-139 + 3n + 197 MeV " So you can see that U-235 is indeed split into other elements. The full articles can be found at: http://www.world-nuclear.org/education/phys.htm

Re:"Splitting atoms"

[calibanDNS]

try telling that to the kneejerk reaction anti nuclear fanatics who can't see the wood for their own foolishly planted trees

I was having a discussion with my wife and several friends a few nights ago, and the topic turned to energy concerns. I was amazed to find that I was the only person in the room who wasn't opposed to nuclear power plants, but then I remembered that I was the only person in the room with an engineering background and anything more than a high school physics class under my belt. I showed them all this Wired article and it actually seems to have helped their understanding of how nuclear power can be safe. That's a hard concept to sell to almost anyone who's spent years being convinced, or convincing themselves, that nuclear power cannot be safe, but I've found that it is possible to convince some. I'm also very proud of my wife, who has abandoned her "They can build it, just not near our house" attitude.

Re:"Splitting atoms"

[Enigma_Man]

since when does a fossil fuel power plant produce radioactive waste? :)

Take a look at some of the research and data on how much naturally radioactive particles are released into the atmosphere through burning of fossil fuels, you'll probably be surprised. I believe it's a few orders of magnitude more than the amount generated in current fission plants.

-Jesse

Re:"Splitting atoms"

[Anonymous Coward]

Why are you proud of her for abandoning that idea? That attitude is pretty damn good, actually.

To have any sort of industrial area near your house lowers the property value significantly. Even if there were no pollution, you'd have to make the concession of having a big, honking nuclear power plant right next door with its hundreds of employees showing up every morning in their cars or on the bus and generally crowding the roadways in your area.

No, keep the power plants somewhere else far away from the livable areas. The reason for NIMBY is not always irrational fear of nukular power. Sometimes it's a result of just not wanting to have an eyesore as a neighbor. You talked to your neighbors lately?

Re:"Splitting atoms"

[ohsoot]

since when does a fossil fuel power plant produce radioactive waste? :)

heh heh. Actually coal plants do produce radioactive waste. Instead of putting it in a container and storing it, they disperse it in the atmosphere.

Look at this link

Notice that you get more than 3 times more dose if you live near a coal plant than if you live near a nuclear plant. (If you live within 50 miles of a nuke plant you get 0.009 mrem as opposed to 0.03 mrem if you live within 50 miles of a coal plant.)

Re:"Splitting atoms"

[Anonymous Coward]

People who are gravely skeptical about nuclear power are not all kneejerk ignorant reactionaries. I understand how nuclear power works. I also understand that even ordinary rocks and concrete walls are radioactive, or that burning fossil fuels introduces some radioactive material into the atmosphere. Hell, even the potassium in our bones is a source of significant exposure, as is flying at high altitudes in a plane. And I understand that we are slowly being backed into a corner when it comes to conventional fossil fuel supplies, and therefore must consider new energy sources or expansion of known ones.

Even so, I deeply question the need for additional nuclear power as the solution to our ills when I know that the products are both toxic and radioactive for at least thousands of years, when the load of radioactive materials in the atmosphere and the rest of the environment continues to rise, and when we have no permanent storage solution. By contrast, at least fossil fuel products are largely recycled in the natural environment, and what radioactivity they introduce isn't much different from what is already there naturally (compare: radioactive cesium and iodine).

By going nuclear we will solve our present energy problems by foisting new ones on the next generation, and for a great many after that. This is a decision that must be made cautiously, if it is acceptable at all. What's more, there are obvious alternatives, such as wind, solar, and simply conservation. Yes, they cost more money. Yes, they would mean many societal changes to accomodate. Yes, we might not be economically as competitive with countries that don't care about being messy (but recall the costs of having a contaminated environment). Yes, we can't solve some problems with them (e.g., flying commercial planes with solar isn't an option!). But is cheap and messy nuclear really the right choice to make if we care about the future, and not merely ourselves?

This view has nothing to do with superstitions and ignorance. Just the opposite.

I'm not kneejerk opposed to nuclear power. I think it *might* be a viable option. But I think it should be approached very, very, very carefully, and not with the attitude of "build more plants, otherwise business as usual". This is the opportunity to weigh *all* of the options. Even nuclear power has its limits in terms of non-renewable resources, so we're going to be facing the same sort of problems eventually in the slightly more distant future. I think it would be one of the greatest technical achievements of this generation if we manage to solve the problem more permanently rather than passing it on a generation or two.

Re:"Splitting atoms"

[rotty]

Well, it might be that state-of-the art reactors are quite safe, but that still leaves the problem of handling the resulting nuclear waste. It is a fact, that however safe a reactor might be, it produces very long lasting nuclear waste; there are no satisfying solutions on how to deal with that waste IMO/AFAIK.

Re:"Splitting atoms"

[Viol8]

"By contrast, at least fossil fuel products are largely recycled in the natural environment, and what radioactivity they introduce isn't much different from what is already there naturally (compare: radioactive cesium and iodine)."

Yes , all that CO2 is being recycled and isn't really building up in the atmosphere. As from the radioactivity not being different, well outside of a partical accelerator ALL radioactivity is natural - uranium ore is extracted from the ground just like coal, oil gas. I'm not sure what you're point is. And you're forgetting about the huge slag heaps that a lot of fossil fuel stations (mainly coal) produce which just get dumped or used in building material.

"But is cheap and messy nuclear really the right choice to make if we care about the future, and not merely ourselves?"

Frankly , who cares about what happens in 100,000 years time? Either our technology will be so advanced that nuclear waste be a non issue or we'll have gone back to the stone age in which case a bit of radioactivity will make little odds as there won't be many people about anyway. Besides which , right now short term solutions are better than maintaining the status que vis-a-vis fossil fuels given the state of the climate!

Re:"Splitting atoms"

[Junior J. Junior III]

The amount of radiation *generated* by burning coal and oil may indeed be less than the amount *generated* by nuclear fission, for the same amount of energy produced. But, ALL of the fossil fuel radiation is *released* into the atmosphere, whereas the nuclear fission radiation is *contained* unless containment is breached in an accident. Therefore, as long as containment holds, nuclear fission is cleaner and safer than fossil fuels.

Re:"Splitting atoms"

[swillden]

there are no satisfying solutions on how to deal with that waste IMO/AFAIK.

Put it in torpedos that bury themselves in the edge of the deepest part of the Marianas Trench. The trench is the meeting point of the Pacific and Phillipine tectonic plates, and subduction would pull the waste under the Pacific plate and into the mantle.

Actually, various forms of deep ocean disposal, whether at plate edges or, perhaps better, in the center of geologically inert areas, are an excellent option. Wastes buried a few meters deep in the soft, inert and lifeless sediments in the deeps would ensure that the waste will not migrate into the biosphere before it decays to a safe level and would make recovery by anyone nearly impossible, which means that the wastes would be safe from terrorists wanting to make dirty bombs.

The only obstacle, really, is an international treaty, the London Convention, which is just an agreement and could be modified through an appropriate political process.

Re:"Splitting atoms"

[Mt._Honkey]

What I object to, though, is the insinuation that we are the ones splitting the nuclei of the radioactive elements. These things are radioactive precisely because of their tendency to decay and in fact split themselves. They don't even split into other elements. You can't turn uranium into gold, for example, even though it ought to be a straightforward process of splitting off the required number of protons from each atom (if the "we're splitting atoms" camp claims are correct).
We use the heat generated by the decay of radioactive elements to fuel our generators. We do nothing like smashing atoms into smaller bits.
Just a pet peeve of mine whenever I see a nuclear power article.

And a pet peeve of mine is people posting on slashdot in an authoritative fashion when they know nothing about what they're saying.

It is true that Uranium does decay naturally and emit radiation. This decay, however, is the emission of one or very few particles, rather than splitting the nucleus into two large pieces:
U-235 -> U*236 -> Th-231 + alpha
U-238 -> U*236 -> Th-234 + alpha


In nuclear reactors used for power production on Earth, we use the neutrons emitted in radioactive decay to split nuclei of Uranium-235. These two new nuclei are indeed new atoms. A couple common fission processes are:
n + U-235 -> Xe-140 + Sr-94 + 2n
n + U-235 -> La-139 + Mo-95 + 2n

The masses of the two nuclei that come off tend to be between 72 and 160 AMU. Gold is not typically produced, as it's atomic mass is 197 AMU--too heavy to be made in the usual U-235 fission. I think that spontaneus fission might occur, but if it does it is at a much lower rate than is useful.

Energy derived solely from radioactive decay without any fission is sometimes used, but to my knowledge only on deep-space probes such as Voyager and Cassini. IIRC they use the natural heat decay of Plutonium, which is produced from U-238 in reactors.

Re:"Splitting atoms"

[mikerich]

since when does a fossil fuel power plant produce radioactive waste? :)

Since the day someone first burned coal. Coal has a uranium content of around 1ppm which is concentrated in the ashy residue after burning. It also contains measurable quantities of thorium, radon and radium. Coal ash can be as radioactive as an average granite (about 10-30 ppm uranium). If the powerplant doesn't have highly efficient filters then these tiny particles go up the smoke stack where they can be breathed in. Someone living downwind of a coal-fired power station accumulates about an additional 1% radiation exposure.

It's not a major problem (not compared to the acid and mercury thrown out by coal-fired plants), but fly ash from coal-fired power stations is widely used to improve concrete which may then get used in housing and offices. There people could be exposed to much larger amounts of radiation - particularly from the constant release of gaseous radon into their environment.

Best wishes,
Mike.

Re:"Splitting atoms"

[swillden]

I for one, wouldn't make any guarantees that the nuclear waste is safe down there for an practically unlimited amount of time.

These sediments haven't moved in hundreds of millions of years, and nothing is going to disturb them for similar periods of time into the future. This is a disposal method which promises to hold the materials safely out of the way for millions of times longer than the materials will be at all dangerous to anyone.

I think its just plain irresponsible behaviour to produce something that imposes such a long-lived danger.

That is a statement of opinion, built on a set of invalid assumptions. Open your mind and educate yourself on the issues, and you'll see things differently. Particularly when you compare fission to the available alternatives.

Conclusion: Say no to fission energy, however safe reactors may be.

That's not your conclusion, that's your starting point.

Re:"Splitting atoms"

[tootlemonde]

Take a look at some of the research and data on how much naturally radioactive particles are released into the atmosphere through burning of fossil fuels...

According to this Report to Congress on Wastes from the Combustion of Fossil Fuels, radioactivty in fossil fuels is not a problem.

The report says (page 44) that because the radioactive elements are not burned, they concentrate in the ash instead of spreading in atmosphere.

As for the danger of the ash, the report says:

EPA has reviewed radionuclide concentrations in coal and ash in connection with other regulatory programs (EPA 1989a, 1989b, 1995c). One of these studies examined potential exposures of worker and nearby resident to radioactivity from ash released from coal pile through wind and runoff erosion. Exposure from direct contact, inhalation, and ingestion were estimated to fall below natural background radiation exposure levels even for a worker standing on the ash pile.

The report concludes that the risks from non-radioactive elements in coal (selenium, arsenic, aluminum, and boron) are of much more concern.

Re:"Splitting atoms"

[sjames]

it produces very long lasting nuclear waste;

The longevity of some waste is important to consider, but there are three important mitigating factors that are usually overlooked in discussion.

First, longevity and intensity of nuclear waste are inversely related. The really nasty stuff has halflives of hours to days. The mid level stuff on the order of months. It's actually the low level waste that can last such a long time.

Secondly, reprocessing of the low level waste would extract useful plutonium that can be used as fuel again and will further reduce the volume of waste to store. It may even be possible to reduce the volume yet again by irradiating the low level waste to force it to decay faster.

Finally, coal burning releases a great deal of thorium and other radioactives. If coal plants were held to the same standards for release of radioactive waste products as nuclear plants are, each one would produce many tons of low level radioactive waste a year. That waste would also have to be stored for thousands of years.

Perhaps we should measure low-level waste in the unit "hours of coal", that is, in terms of the released radioactive waste per hour from an average coal fired power plant.

The real problem with nuclear power in the U.S. is lack of standardization in plant design and waste management. With standard design, we could build a body of practical operational and engineering knowledge that would apply to every plant. That in turn would allow increased safety.

HUrray!

[jim_v2000]

Does this mean I'll finally be getting a Mr. Fusion to put on my Delorean?

Re:Christian?

[jim_v2000]

It's not a theological magazine, it's an actual newspaper. The have World/US/Science/etc news.

http://www.csmonitor.com/aboutus/about_the_monitor .html

Re:Cheap? Clean? when will we learn

[0123456]

"What will happen to the material that stops all those neutrons?"

Assuming you don't use aneutronic fusion, it will get mildly radioactive. So bury it in the middle of nowhere... who cares? We're not talking about 'hot' fission fuel here.

"What is the failure mode for a collapsed fusuion capable magnetic field?"

The confinement vessel warms up by about two degrees C, you fix the problem and restart it. You've been watching too many SF movies if you think that a confinement failure will cause a nuclear explosion.

"Fusuion power will NEVER be safe"

Fusion is extremely safe compared to fission: you appear to be just a typical ill-informed knee-jerk anti-nukleah.

Re:Cheap? Clean? when will we learn

[Viol8]

"What is the failure mode for a collapsed fusuion capable magnetic field?"

The plasma disperses and the fusion stops. What do you think happens when they shut the field down now after their tests?

"Wow, these are bad, very very very bad also."

Really? Why?

"The folks that came to our little burg for a 'rah rah' meeting claimed that power would be so cheap, it wouldn't be metered."

And it would have been had the anti-nuclear nutters who stopped the whole thing in its tracks. Yes 3 mile island happened and then chernobyl. So what? When an airliner crashes 400 people die. Do we stop all flight? Tens of thousands of people die in car crashes every year. Do we ban cars? No.

"The situation with nuclear power has not changed just becuase we are looking at 'new and improved' fusion"

If the halfwitted political loudmouths of society can be convinced this new form is "better" than the old form (whether it is or not) then we may get somewhere with it. If it ever works that is.

Why don't you read up...

[cnelzie]

...on the history of the Christian Science Monitor.

My understanding is that it is one of the oldest and longest running *actual* news sources that has remained rather committed to the *actual* scientific truth, not the false truth pushed by Born Again Christian Fundamentalists.

Dumbed down

[Anonymous Coward]

The article was so dumbed down it was actually harder to work out what it was saying, but I think it goes like this:

"We still intend to use a donut-shaped plasma contained in a magnetic field. But now we've got better scopes and the latest release of 'budget fluid-model XP' for our souped-up research PCs"

Perhaps the real point of the article is to announce that Christian HQ has finally decided that nuclear fusion isn't blasphemous (and God has presumably decided not to enforce her patents on the sun).

The problems aren't insurmountable

[Rik Sweeney]

Just because we can't do it right now doesn't mean we never will.

100 years ago we would never have dreamed space exploration would be possible. Why's this so different?

Re:The problems aren't insurmountable

[AbbyNormal]

True, but without any other market incentive does it ever go anywhere? Look where space exploration is now...35 years since we've landed on the moon.

Re:The problems aren't insurmountable

[CrimsonAvenger]

100 years ago we would never have dreamed space exploration would be possible. Why's this so different?

I refer you to "Exploration of Space by Means of Reactive Apparatus" by Konstantin Eduardovich Tsiolkovsky, written in 1896. That was 108 years ago...

Ask Slashdot?

[anum]

Is this an Ask Slashdot?

If so then my answer is yes! I mean no! err..What was the question again?

IANANE (I am not a nuclear engineer) but if I read that article correctly then it seems some of the many problems have theoretical solutions. In other words, it worked in the simulation. We need to get this thing built and do real tests before we can even think about being "close" to having fusion plants.

They can't even decide where to build it! Why can't I vote to spend my (US) tax money on putting one of these over here. Even as a test bed it will give the contry it's in some home field advantage.
You can use my back yard if you want! Don't listen to my whiney neighbors, they don't know what's good for them!

Re:Ask Slashdot?

[d_strand]

They can't even decide where to build it! Why can't I vote to spend my (US) tax money on putting one of these over here. Even as a test bed it will give the contry it's in some home field advantage.

That isn't a problem any more. The EU decided a few weeks ago to build ITER in france by themselves and inviting the Japanese to join if they like (dont know what's happening with the US participation, but considering that they didn't join until a short while ago and wasn't paying much anyway it hardly matters)

Re:Ask Slashdot?

[nizo]

The problem is that there are two countries who want to have it: France and Japan.

As a typical American, I would like to recommend that they simply build it on their shared border. Problem solved!

Reason for Low Funding

[Mr_Blank]

Whenever fusion comes up I gotta refer to this Economist article:

SOME say that a dollar spent on nuclear fusion is a dollar wasted. And many, many dollars have been spent on it, as physicists try to duplicate, in a controlled setting, the process by which the sun shines. Since 1951, America alone has devoted more than $17 billion (see chart) to working out how to fuse atomic nuclei so as to generate an inexhaustible supply of clean, safe power.

The claim that this money is wholly wasted may not be entirely fair, though. Fusion science has made a big return on this investment in the form of a new universal constant. This constant is the number 30, a figure that has for the past half-century or so been cited almost religiously by researchers as the number of years that it will take before fusion power becomes a commercial reality. ...[continues]

With observations like that in reputable news sources like the Economist it is no wonder that investment in fusion waxes and wanes. People want a return on investment before the next election, not 30 years from now.

Re:Reason for Low Funding

[R.Caley]

People want a return on investment before the next election, not 30 years from now.

I think you are missing the point the writer was making. The 30 is a constant, ie we are always 30 years from fussion. This is not a return in 30 years, but a return an infinite amount of time in the future.

Now, I think the fusion experiments are worth funding because they are fun. I think it's a shame that the political environment is such that the scientists need to pretend there is gold at the end of the rainbow, when the rainbow is so beautiful itself.

We aren't talking big money here in government terms. Eg IIRC the proposed ITER budget is 10 billion Euro over 30 years. The EU pours approximately 100 billion into the common agrecultural policy every year and I presume the USA is operating on basicly the same level, just to prop up buisinesses who produce food no one wants to eat.

Biodiesel is better fusion power

[ScrewTivo]

use the suns fusion to grow biodiesel. A lot cheaper and it will clean the atmosphere. My understanding is that all carbon in plant is extracted from the atmosphere. Extracting the oil leaves carbon waste, so even dirty engines cannot put more carbon back into air then was extracted.
Although we may end up with oxygen pollution :)
biodiesel home page

Re:Biodiesel is better fusion power

[henrygb]

First you have to ensure that all the inputs come from biodiesel and are not just some energy intensive subsidy to farmers.

UK duty on ordinary diesel 47.1 p/litre
duty on biodiesel 27.1 p/litre
duty on ordinary diesel paid by farmers 5.22 p/litre

Re:Cheap? Clean? when will we learn

[Qzukk]

What is the failure mode for a collapsed fusuion capable magnetic field?

The reaction stops. No, seriously, current fusion reactor designs require the magentic field to cause the fusion to happen. Thats why its currently so expensive, most of the time it takes more electricity to power the magnet than you can get from the fusion.

Current nuclear reactors have a GREAT track record, by any other industry standard. However, those who worked on the years of clean up at three mile island

Guess what, the reactor there wasn't a current design. In fact, I believe none of the reactors in operation in the US is a current design, since instead of replacing them with better designs that have been in use for almost a decade now, little "know it alls" like you complain and prevent new plants from being built to replace the old.

The situation with nuclear power has not changed just becuase we are looking at 'new and improved' fusion.

The situation with nuclear power changed decades ago with the invention of reactors that could burn fuel that would have otherwise been considered "spent", reducing the need for disposal. It changed years ago with the invention of better fission reactors that are resistant to meltdown in emergency situations, and it will change yet again with the invention of fusion reactors that operate by converting small atoms (Helium) into slightly larger ones, rather than using heavy metals like uranium and plutonium.

Re:Cheap? Clean? when will we learn

[beefo]

Yeah, I know I'm ill informed. It's true. I've never worked on a tokomak or any other nuclear facility. I do know that it takes more than two degree C from ambient to make fusion happen with known methods. And the product of twenty years of operation is not well understood, there is more than one person in the nuclear field (possibly informed, and/or just crazy) that wonders what happens to materials even if the neutrons are not 'hot'. The argument that nearby materials will not get dangerous appears to be based on statistics (of course because this is all you've got). So who is looking at real failure modes (versus the ones where things get two degrees out of wack and the confinement politly disipates into a safe cloud of well behaved plasma)? Take another look at the density goals for these operations, recalculate the energy moderation outside a confinement, then let me know if you still come up with only two degrees. (I'm also pretty bad at arithmetic, so I get exponents wrong all the time, just by one or two, but hey, a few degrees of magnitude make all the difference, don't they)

Re:Christian?

[Scarblac]

I'm sorry, we're looking at a theological magazine for technical articles?

I'm a total atheist, but the Christian Science Monitor is an extremely good publication, very independent.

It was apparently originally founded by a wealthy and religious woman about a century back. It is owned by a church, but you couldn't tell from the content. What you can tell is that it's not just another news organization for which profit is the all important thing.

Step one - increase the cost of alternatives

[coyote_oww]

I think we're getting closer to "cost-effective" fusion, if for no other reason than that the alternatives are getting more expensive. If the cost of fusion just stays constant, fusion will eventually win out. Other energy sources will simply become more expensive, leaving fusion the "bargain" energy source.

Re:Step one - increase the cost of alternatives

[Guppy06]

"If the cost of fusion just stays constant, fusion will eventually win out."

It doesn't work that way. Fusion electricity isn't competing with other sources of electricity, it is competing with the price of running the plant. As it stands now, a controlled fusion reaction generally requires more power than it produces, a net energy loss. Simply increasing the price of other forms of electricity doens't magically make the efficiency of a fusion reactor climb above 0.

Re:Step one - increase the cost of alternatives

[Teancum]

It is interesting that you mention this fact. I just heard on a morning television program a discussion regarding Saudi Arabia and how they set their price for Crude Oil. Apparently one of the major factors they use to set the price is the idea that if they set the price too high, they will be sitting on a huge pile of oil that nobody will want to buy. The quote was "they are deliberately setting the price to discourage alternative energy sources including R&D". In other words, this is a deliberate policy of the Saudi government, and is done at least unofficially with the backing of the U.S. government. If another energy source becomes viable, OPEC will rip the "rug" from under it and lower oil costs to compete more effectively.

In other words, if you want to end dependancy on the Middle East oil reserves, drive your gas-guzzeling SUV and buy as much gasoline as possible so the oil stocks in the Middle East are used up. Kinda stupid, but it is reality.

Some countries who produce oil already realize that the end is in sight when oil will no longer be used as a primary energy source, and are selling oil at rate cheap enough to simply grab as much money as they can while the party lasts. If not fusion then solar or perhaps even effective fission reactors, which IMHO can be made safe but the $$$ are not there to make it happen.

In the case of fission research, we know we can get fission reactors to produce energy inexpensively. The problem is that to build a nuclear fission reactor that is also destroying the nuclear waste (in amounts of end products quite comparable to fusion reactors) they are also capable of producing large quantities of enriched nuclear-bomb grade fission materials. This is one aspect of the nuclear genie that has been "kept in the bottle" because of the potential to unleash cheap fission reactors that governments can't keep track of. Imagine if Bin Laden was able to afford a small breeder reactor for less than $100,000 and fill Northern Pakistan with them.

Let's hope that you can't make an effective weapon with fusion reactors. That will kill research into it (or perhaps that is the problem).

Re:Atheism isn't the same as secularism.

[NarrMaster]

Non-belief in a god != Belief God doesn't exist. Atheism is not the same as a religion. How many times must this fallacy be repeated? Not being a football player does not make me an athlete. Not collecting stamps does not make me a hobbiest. Not writing a book does not make me an author. Get it? Not believing in a god/God does not make me religious.

There is such a thing as non-religious. And it has nothing to do with faith. Its called atheism.

Re:Typical slashbot

[Cat_Byte]

I believe he said we didn't believe it would be possible...not just dreaming of it. Right now I think landing a human on Venus will never be possible just because of the environment. Maybe that will be proved wrong someday. Things are moving at an extremely rapid pace. The first jet engines used as a top secret venture during WW2 and seen over the skies of Germany was only about 60 years ago. Then..what...25-30 years later we land on the moon? That is impressive and I'm betting nobody would have dreamed we would have made leaps and bounds like that 100 years ago. I wanna see whats next!

Some useful links

[JaF893]

IANANP (I am not a nuclear physicist) but a lot of people don't seem to know much about fusion so here are some links which explain a bit more about it:

http://www.jet.efda.org/pages/content/fusion2.html
http://hyperphysics.phy-astr.gsu.edu/hbase/nucene/ fusion.html
http://en.wikipedia.org/wiki/Timeline_of_nuclear_f usion
http://www.fusion.org.uk/
http://www.iter.org/

It'll Never Happen

[occamboy]

Sorry to be a nathering nabob of negativism, but...

Practical nuclear fusion would be the best thing that ever happened to our planet: we'd lose our dependence on the Middle East for energy, and dramatically cut pollution. If it were up to me, I'd launch a nuclear fusion program on the scale of the Manhattan Project.

However, the Bush family and that crowd will never allow nuclear fusion to become a reality - they make too darned much money on oil, and cash is all they understand.

Silicone Carbide? Fusion in breast implants?

[jakedata]

I have a sneaking suspicion that the article meant to refer to SILICON carbide.

Silicon and Silicone are often confused.

OTOH, perhaps this will be the next big thing. Talk about too hot to handle...

-j

Yeah, tritium's too rare.

[MickLinux]

Yep, my father quoted that one on his PhD thesis.

Granted, they do have fusion -- but not practical fusion.

But to prove his statement, he pointed out how expensive it is to generate tritium for the DT reaction, and how little there is.

If we're ever going to have practical fusion, it's going to be cold fusion. Use a molecule with an explosive bond that shoves two other molecules on a predefined pathway into a range where you get a 1% chance of reaction between two hydrogen nuclei, by tunnelling, and you could do it.

But that would take a pretty complicated and well-designed molecule.

There may be some ways of doing it once we have better molecular manufacturing, but as for right now, cold fusion is also dead.

For that matter, unless we're using it in space, I hope they don't get cold fusion.

To quote Don Lancaster (www.tinaja.com), if anyone finds a free energy source and manufactures it without also providing a free energy sink, they'll be the worst criminal in human history. Oh, and our planet will glow like a star too.

I think the proper solution to our energy problems needs to be wind and wave. Those take care of the energy source/sink problem. Sorry, just my two cents.

Re:Yeah, tritium's too rare.

[kravlor]

Actually, in ITER, the reactor discussed in the article, tritium will be bred in the reactor vessel itself.

The first wall will contain lithium, which can transmute to T when bombarded by the fast neutrons generated by the fusion reactions. For more info, see Boeing's blurb on the shield/breeding blanket designs.

Of course, with improving technology, higher beta (a measure of fusion plasma confinement capability), and hotter plasmas, D-T can be forsaken for other reactions. :)

Re:Yeah, tritium's too rare.

[deglr6328]

"Use a molecule with an explosive bond that shoves two other molecules on a predefined pathway into a range where you get a 1% chance of reaction between two hydrogen nuclei, by tunnelling, and you could do it."

Um, what is an "explosive bond"? I'm sorry but this can never happen. First energy is released when bonds are FORMED, not broken. Second, any chemical reaction concievable can never initiate fusion of nuclei, the difference in energy scales (per atom) between chemical bonds (electromagnetic force) and nuclear bonds (strong force) is orders of magnitude. THAT is why cold fusion isn't real and never will be.

Re:Cheap? Clean? when will we learn

[Anonymous Coward]

The Joint European Torus (JET) fusion lab in Culham, Oxfordshire, UK 'jumped' a few years ago. The plasma touched the wall of the reactor vessel and dissipated. The entire reactor 'jumped', and the event is visible on seismograph traces. (The reactor, in total, was quite heavy)

This is not good for the retaining magnets - the magnetic field quenches, and the energy goes into heating up the magnets. Even the superconducting (and therefore cooled) ones warm up - boiling off a lot of refrigerant, and possibly/prbably distorting/damaging the coils..

Afer this event, th reactor was shut down for a long period (I think months), while the coils were checked for damage and realigned.

As for the amount of energy in the plasma itself - it's relatively small. Although the temperature is high, the particle density is actually quite low, so the total energy contained is (relatively) small. It *won't* go up like a hydrogen bomb.

The core lining in JET was lithium. It gets mildly radioactive due to being bombarded by neutrons all the time, but this is not a big deal. The neutron activation of the concrete and steel rebar used in the construction of the core (it has to withstand high mechanical forces from the magnetic fields) is more of an issue.

The plasma isn't meant to touch the tokamak wall, as it causes long and expensive downtime, but it's not as catastophic as (say) setting light to an oil well.

Re:The Law of Thermodynamics

[Pd-D20]

I am a Nuclear Enginneer,and work in Britain on the Joint European Torus Fusion Device. Check it out... http://www.fusion.org.uk When we fuse together the hydrogen, the helium formed is more stable and highly energetic. The thing to consider here is potential energy too. Just as there is chemical potential energy in the gun powder of a bullet, which allows the weapon to be fully automatic, so there too is nuclear potential energy. For large enough plasmas it is possible to use the highly energetic helium to sustain the fusion reaction, in a process known as ignition, so more energy can be retrieved than was put in. If all energies are considered, no laws are violated. You are right about the electricity generating process. The use of steam pressure and turbines is limited by the laws of thermodynamics, namely the Carnot cycle, so can only ever be approximately 40% efficient. The next step is the International Thermonuclear Experimental Reactor (ITER). As the politicians couldn't decide whether to build it in Japan or France, Europe has declared its going to build it anyway, and we're now just waiting for people to take sides :)

science is as science does

[Doc Ruby]

Does anyone else find it dissonant that the Christian Science Monitor, generally a fine paper, is primarily a journal for a community of Americans who shun medicine in favor of faith healing, yet reports other miraculous science like fusion without complaint?

Re:science is as science does

[bhima]

Cherckout: http://csmonitor.com/aboutus/about_the_monitor.htm l

"It's a real newspaper published by a church -- The First Church of Christ, Scientist in Boston, Mass., USA.... let's be clear: The Christian Science church doesn't publish news to propagate denominational doctrine; it provides news purely as a public service. Here's why: If the basic theology of that church says that what reaches and affects thought shapes experience, it follows that a newspaper would have significant impact on the lives of those who read it.

A newspaper whose motive is "to injure no man, but to bless all mankind," as its founder charged, would have a "leavening" effect on society, as well as on individual lives -- to use a metaphor Eddy herself appreciated and used. The idea is that the unblemished truth is freeing (as a fundamental human right); with it, citizens can make informed decisions and take intelligent action, for themselves and for society."

On a side note, I've just read throught the comments and I'm amazed at the number people that have made comments showing that they know no science... did IQs suddenly drop while I was away?

Re:"Splitting atoms" - yes, we do (I'm a Nuke)

[syrynxx]

Nuclear fission does split nucleii into fragments. U-235 fission absorbs thermal neutrons (room-temperature kinetic energy) and splits in half, P-239 fission absorbs fast (high-energy) neutrons and splits in half. The resultant atoms form an assymetric distribution called the 'Mae West' curve because it forms two big peaks (mapped # vs Z) that look like mammaries to lonely nuclear engineers that don't see nekkid women that often.

While Uranium/Plutonium do decay naturally (stability of a nucleus is determined by the Nuclear Shell empirical formula, which is a rough analog of the electron shell theory - everybody wants to be Iron Fe/26, the most stable nucleus), there's another form of decay that's an outcome of genuine nucleus splitting. That's is the decay of of these usually-radioactive fragments. This decay is important to the operation of a fission reactor, but only in determining the criticality of a nuclear pile. 'Critical' == exactly as many neutrons are released in any time period as are absorbed, meaning steady power output. Basically, over 99% of the neutrons necessary to keep a steady level of fission events come from 'prompt' neutrons - neutrons that are freed in the splitting of an atomic nucleus. You get one small chunk (which could very well be gold), one big chunk, and a couple free/fast neutrons.

If these 'prompt' neutrons were enough to sustain criticality, then the number of fission events would increase geometrically. Since the time between generations is about a millionth of a section, this means that a reactor core that's 'prompt-critical' would quickly escalate in temperature until the structural integrity of the core failed, and you have a molten slag of Uranium - which is exactly what happened at Chernobyl.

So the way to avoid this, you have to put in neutron-absorbing control rods to keep the number of 'prompt' neutrons below the number necessary to sustain the next generation of fission events. If 'prompt' neutrons were the only neutron source, your nuclear reactor would quickly cool down. But the decay of the fragments (which are ususally radioactive isotopes of stable elements) release additional neutrons. The 'art' of tuning a nuclear reactor is to insert the control rods just enough so that the reactor isn't prompt-critical, but the decay neutrons are just barely enough to make the pile critical.

One of the biggest problems with fusion in general is fuel. The easiest fusion reaction is deuterium-tritium. Deuterium is plentiful - the ocean is full of 'heavy water' where one of the hydrogen atoms in a water molecule has a proton and a neutron. Tritium, however, is radioactive with a pretty short halflife. You have to make tritium by getting Lithium to absorb a neutron, then decay.

Last time I was up-to-date on fusion research, there was only an estimated 300 years of Lithium to sustain the predicted energy needs of the world. However, with fission fast-breeder reactors like they use in France, there would be 5000 estimated years of power. Fission fast-breeder reactors can be built today - it's just that to make them passively safe, you need to use a liquid metal coolant like sodium, and any disaster like Chernobyl (from terrorists, for example) would be catastrophic. Liquid sodium will explode if it gets wet, so it's a huge engineering challenge. Argonne Nat'l Labs has reactor designs like this, but the US population is scared of nuclear power plants (plus, the cost overruns at plants made them economically unfeasible).

[I am a published principal author and presentor of a fusion reactor design (presented at the 8th Topical Meeting on the Topic of Fusion Energy in Salt Lake City), so I have a tiny bit of credibility. I got out of the field specifically because of the 15-year carrot-on-a-stick paradox.]

Coal plants do release more radioactivity.

[Firethorn]

according to Alex Gabbard

For comparison, according to NCRP Reports No. 92 and No. 95, population exposure from operation of 1000-MWe nuclear and coal-fired power plants amounts to 490 person-rem/year for coal plants and 4.8 person-rem/year for nuclear plants. Thus, the population effective dose equivalent from coal plants is 100 times that from nuclear plants. For the complete nuclear fuel cycle, from mining to reactor operation to waste disposal, the radiation dose is cited as 136 person-rem/year; the equivalent dose for coal use, from mining to power plant operation to waste disposal, is not listed in this report and is probably unknown.

For a large number of coal samples, according to Environmental Protection Agency figures released in 1984, average values of uranium and thorium content have been determined to be 1.3 ppm and 3.2 ppm, respectively

And a 1,000 megawatt plant uses 4 million tons of coal a year, resulting in the release of 5.2 tons of Uranium and 12.8 tones of thorium.

A 1000 megawatt light water nuclear plant of the type used in the USA uses about 25 tons of uranium a year.

If you're willing to use breeder reactors and their ilk, you can actually get more power out the the uranium in the ash than you got burning the coal!

Why the guvvies haven't gotten fusion to work

[randall_burns]

There have been no real incentives to make fusion work. Twelve years ago, these guys has a chance and they blue it. The lawyers in congress refused to create sane incentives-and now are risking their own lives due to that failure. The world would be a very different-and imho better-place if viable fusion now existed. The middle east would not be a hotspot like it is now for example. The problem is that the kinds of people that run congress love centralization of power-more than they love life itself. In their eyes, the only suitable role for technical people is as obediant servants that like doing what they are told. What the last 20 years has shown, you just can't run a technological society that way.

Re:Why the guvvies haven't gotten fusion to work

[Teancum]

Thanks for the link. I read that some time ago here on /. but forgot all about it, and it should have been brought up when people were moaning that "why don't other science diciplines besides aviation and rocketry have prizes?" i.e. the X-Prize and related groups.

Nuclear Physics is no longer the glamour major it was in the 1950's and 1960's, and while there are a few new minds going into the profession, there are many other more cool things to do now and are taking up the energies of young minds. Nuclear Engineering is in even worse shape, and in many ways resembles some of the worst examples of government research gone amuck. Big budgets and not much to show for it. In some ways even worse than NASA over the past five years with manned spaceflight.

There is private research that is occuring, but it tends to be cranks and folks doing stuff on cold fusion or Farnsworth fusors... mostly treated as cranks even if they have a PhD from a respectable university.

I will agree with you about the centralization of power issues as well. If it turns out that something like a powercell can generate a lifetime supply of power for a home without the need of overhead powerlines, it would destroy a balance of political power that has huge amounts of money and no real reason to allow it to occur...even if it meant a substantially better life for ordinary citizens.

Re:Why the guvvies haven't gotten fusion to work

[randall_burns]

Anybody who can become an investment banker, professional athlete or star attorney would have to be either foolish or extraordinarily dedicated to go into nuclear physics instead. The "goodies" that American society offers are largely bestowed own individuals who are at best useless-and at worse downright sociopathic. The existing social order in the US seems intent on self destruction.

lies, damn lies, etc...

[Doktor Memory]

(Grumbling at the Economist, not Mr. Blank...)

Since 1951, America alone has devoted more than $17 billion [on fusion]

Ah the wonders of a contextless statistic. Wow, America has spent more than $17 Billion on nuclear fusion in the last fifty years without producing a commercially viable reactor?! Damn those profligate scientists and their free-spending ways! We must put a stop to this before they bankrupt us!

Oh wait. $17 billion divided by 53 years is... $320 Million a year.

In Federal budgeting terms, $320,000,000 is LINE NOISE. It's more than the National Endowment for the Arts gets, but that's about the only thing I can think of that's smaller. In comparison, check out these fun numbers from Table S-3 of our current federal budget:

Department of Defense: $401,000,000,000 (that's FOUR HUNDRED BILLION, and please note that that specifically doesn't include any money we are spending in Iraq)

Department of Homeland Security: $68,200,000,000

Department of Housing and Urban Development: $31,000,000,000

Executive Office of the President: $300,000,000

Yeah, you read that right: the "keep the White House bathrooms stocked with toilet paper" budget is roughly the same as the fusion budget. Oh wait, maybe we haven't been breaking the bank on fusion research after all...

Build it here in the US

[Junior Samples]

The six-nation project - called the International Thermonuclear Experimental Reactor, or ITER - is caught in a big-money squabble over where to put the $5 billion reactor. Japan and France both want the privilege.

Why not develop and build the prototype here in the US?

We need a Home Grown "Killer Application" / National Project to jumpstart the US economy and help eliminate our dependence on foreign oil. The loss of jobs resulting from manufacturing and High Tech operations moving off-shore, and the outsourcing of both technical and non-technical services in recent years is killing the US economy. We need to get back on track and reverse this loss.

The whole project would probably cost less than 1 year of war with Iraq.

The most relevant reason why this is nonsense is..

[downhole]

Everyone (except the far-left, and the RIAA) knows that you'll make far more money by embracing and investing in new technology then by trying to suppress it.

Read the Post, Pinhead

[occamboy]

The parent post says nothing whatsoever about the Bush family being the root of all evil, nor does it say anything in regard to Clinton, etc.

It simply suggests that the Bush family and their buddies are in the oil business, are extraordinarily greedy, and play hardball. All of these things are perfectly consistent with history.

What we see in SnarfQuest's response is the typical fringe-right tactic of attempting to refute reality by somehow changing the topic to something that they can attack. How utterly unhelpful.

Re:fusion was there forever

[brsmith4]

That was probably the case years ago, but there have been significant advances in creating these reactions in a controlled environment. The problem now is not controllability, it has been sustainability. Super-heated plasma would be used to generate the heat necessary to start the reaction, but inconsistencies would arrise in the flow of this plasma. Eddies would form and "cold spots" would form making the reaction stop. Apparently, they have used simulations to determine the best way to control these eddies and the plasma flow, thus making the reaction sustainable. I'm sure we'll see a working plant within 10-15 years or whenever a country decides they actually want to have one on their soil.

Running out of uranium

[Phronesis]

In THREE HUNDRED YEARS if we still do not have a better energy plan than fission, then I say we use it, by then we will still have at least 4700 years of fission material left. In the mean time fusion is a greatly useful technology.

According to the Uranium Institute, known resources of economically recoverable U-235 are "enough to last for some 50 years" at today's rate of consumption. If prices go up significantly, we could mine other sources, but even so, "all conventional resources are considered - 14.4 million tonnes, ... is over 200 years' supply at today's rate of consumption"

Today, fission supplies 16% of the world's electricity. If we converted the world to using nuclear power for all our electricity, we would use up the uranium six times faster, so all known supplies would last somewhere around 35 years.

To go beyond this, we would need to resort to more exotic technology, such as breeder reactors or extracting uranium from seawater and phosphate deposits.