Giant International Fusion Reactor Draws Nearer 967
nnnneedles writes "BBC is reporting that scientists are deciding on where to build the world's first big fusion reactor. The international effort is described as the boldest nuclear initiative since the Manhattan Project, and holds promise for future unlimited, clean energy. The choice on where to build the reactor currently stands between Japan and France, but apparantly, the U.S. is opposing a french site because France opposed the war in Iraq." There's also an AP story.
Why is this About US Opposing French Site ? (Score:4, Informative)
The site selection has nothing to do with anyone's position on Iraq or else France would have the support of the other countries as well. As it stands, they only have the support of the EU for typical reasons.
This is relying on the obsolete Tokamak design... (Score:5, Informative)
Re:Cart Before The Horse? (Score:2, Informative)
"Its goal will be to produce 500 megawatts of fusion power for 500 seconds or longer during each individual fusion experiment and, in doing so, demonstrate essential technologies for a commercial reactor."
It's only a demo. Fusion won't be practival for some time to come, if ever.
Re:Assuming it works... (Score:5, Informative)
It's not. This is apparently an experimental reactor. We haven't made this work yet; this reactor is being built so we CAN make it work through experimentation. After that, I would imagine all the countries will simply build their own reactors to supply their countries (and neighbors who wish to purchase energy and/or share in the construction costs) with energy.
What did you think, we'd build one reactor and supply the whole world with energy? Please. At the very least each country will want their own simply so their energy source simple to guarantee the existance of their own energy in case of war or natural disaster.
If this technology WORKED, you think the US in particular wouldn't drop $10bil on it in a heartbeat to build it ourselves? It doesn't work yet, and that's why we all want to build this experimental reactor.
Re:Japan is the obvious choice! (Score:5, Informative)
Sorry, I took a Natural Disasters class last semester and it was awesome. You can get back to your topic now.
Re:Why is this About US Opposing French Site ? (Score:5, Informative)
It SPECIFICALLY says this (after saying that Canada et al. support the Japan site):
Re:This is relying on the obsolete Tokamak design. (Score:5, Informative)
Re:Cart Before The Horse? (Score:3, Informative)
Indeed, but this project is explicitly designed to be the next "scale up" towards that goal. A design goal of 500MW of fusion power output is nothing to sneeze at....
On the other than, practical fusion is much further away than is advertised, since it requires fusing helium 3, which doesn't produce neutrons, but is a lot harder to fuse. Otherwise your reactor's atoms are slowly transmuted into other (frequently radioactive) elements as it runs. We also have to get a good source of helium 3 ("They're going to strip mine the moon!" the enviros are already whining).
As far as site selection, why not go with the Japanese? After all, back in 1979 Tomino did the first Gundam anime series, and part of its background was small fusion reactors running on helium 3, allowing for a) lots of power, b) big explosions if one can't shut down properly (this is explicit from the beginning), and c) a Jupiter Energy Fleet for the helium 3 (modeled on the petro-rich Arabs --- remember that Japan has to import all of its oil, and I think most of that comes from the Middle East) which is always behind each war, pulling the strings (with the exception of Zeta Gundam where one of them actually showed up; get it when it comes out next year in the US, it's very good)).
Re:This is relying on the obsolete Tokamak design. (Score:4, Informative)
Re:Japan is the obvious choice! (Score:2, Informative)
Re:Why is this About US Opposing French Site ? (Score:2, Informative)
Here is what the great, impartial BBC SPECIFICALLY says:
But BBC News Online science editor Dr David Whitehouse says the decision is highly political, involving huge amounts of horse-trading behind the scenes
That's some fantastic reporting there. Or is conjecture? That's what seems to pass editorial muster at the BBC these days.
The US is allegedly politicizing this issue and the other nations that alligned with France aren't supporting them. Somehow, it doesn't add up.
Not quite (Score:5, Informative)
The best fuel for igniting fusion is a tritium/deuterium mix because it fuses at a lower temperature. Tritium is a radioactive form of hydrogen with 2 additional neutrons. It is "bred" from lithium, but it's still a very radioactive substance. Technically speaking, fusion reactions do use radioactive material as fuel. DD reactions are possible, but they require higher temperatures and are less likely to be viable.
Secondly, the DT reaction emits neutrons. It's a simple matter of math - you have a deuterium and tritium nucleus which collide and produce helium. There's a neutron left over, with high amount energy and no electric charge. It will "ping" right out of the magnetically confined plasma. Most such neutrons will be absorbed by the lithium shielding (creating more tritium) but some will fuse with other parts of the reactor, creating, you guessed it, radioactive waste.
Commercially viable fusion reactors, if they ever exist, will almost certainly produce radioactive byproducts. It will be a great improvement on fission power, as there will be less waste in total with a shorter half-life, but radioactive waste is radioactive waste. Like fission waste, fusion waste will be expensive to deal with and be around for many generations.
For more info, here's a link to the Wikipedia entry [wikipedia.org].
Re:Hot fusion is not "clean" nuclear power. (Score:2, Informative)
Re:Childish behavior (Score:5, Informative)
Re:Assuming it works... (Score:3, Informative)
You seem to be reading even more into the BBC article than what wasn't there. It's bad enough that this formerly excellent news organization has become so biased in its "reporting", but even in their article it didn't say that the US was stating the reason was because they were mad at France - it's only the BBC saying that's why the US favors Japan. The article only casually mentions that all the other members of the group prefer Japan over France too.
Re:Hot fusion is not "clean" nuclear power. (Score:3, Informative)
Protons can be contained by magnetic fields, neutrons can't. That means less rad worries.
Re:Why is this About US Opposing French Site ? (Score:2, Informative)
What the US Wants... (Score:2, Informative)
Although fusion is relatively "clean", ITER is still a neutron heavy design (http://wsx.lanl.gov/Publications/neut-activate.p
Re:Why is this About US Opposing French Site ? (Score:1, Informative)
Re:Why? (Score:2, Informative)
ITER has only survived because of international funding. The US came late in the game.
If you come to the bar when the lights are just being turned on, you don't get to take anyone home.
Re:Why is this About US Opposing French Site ? (Score:2, Informative)
Both statements are in complete concord.
The US is specifically quoted for politicizing the decision, and the BBC science editor says that the decision is political.
nothing strange there... no conjectures, the US says straight out that it supports japan for political reasons.
Re:Practical pork-barrel politics (Score:1, Informative)
really neat idea, but wrong ^^
Re:Not quite (Score:5, Informative)
What ITER is about (Score:4, Informative)
EO = energy outflow (cooling of plasma)
EF = energy produced by fusion reaction
EI = energy input (external heating)
then the following equations can be set up:
1) EO 0, the above equations 1 & 2 are hard to maintain. Why? Because hot plasma is cooled down by the reactor walls (+ other kinds of cooling).
Simply put, EO (cooling) is an area dependent function.
EF (energy from fusion) is a volume dependent function.
Thus, if you just build a large enough reactor, you can increase the EF/EO rating as much as you wish. However, a larger reactor costs more.
If we build a big reactor (r=20m) it would produce net energy output. It would NOT be commersially usable.
The ITER or Not-ITER discussion is about whether a large expensive test reactor would be worth its investment, or if the money rather should be used for base reasearch and computer simualtions.
There are two fundamentally different fusion reactors, the "tokamak", and the "stellarator" (IIRC). You want a magnetic field inside the reactor that keeps the plasma away from the walls. In the conseptually easier tokamak, that magnetic field is caused by letting a large (Mega Amp) current flow through the plasma. This current is produced in the plasma using the same concept as a AC voltage-transformer (the plasma is considered one of the spools). However, this means that the current in the "other" spool needs to increase linearly in order to maintain constant plasma current. In reality, this limits the time the reactor can operate to a few seconds (then you lose the plasma and need to restart).
A stellarator uses a very complex set of spools around the reactor to create constant magnetic field inside the reactor. "Very complex" means "not yet practically solved". Actually, its primarily a computational task.
THE EQUATIONS (Score:3, Informative)
1) EO < EF + EI
2) EO < EF
1) means that we have a net energy output (assuming 100% efficiency)
2) means that we have a "lit", self sustataining reactor
Re:Even Donald Rumsfeld..... (Score:2, Informative)
Re:Okay! (Score:2, Informative)
Check your facts.... (Score:4, Informative)
If you read the Article... (Score:3, Informative)
Meanwhile, "Canada, China, Russia, South Korea, the United States and Tokyo itself are reported to be favouring Japan".
It seems like its the EU against the world on this one.
Re:Against the war? (Score:2, Informative)
Do some research: the original war with Iraq over the invasion of Kuwait never ended.
The UN agreed to enter into what became a 10+ year-long cease-fire with Iraq. The sole purpose for this cease fire was to (a) allow Iraq to preserve some sense of independence after the defeat in the Gulf war, and (b) allow the UN to verify the absence of WMD programs in Iraq.
Instead of complying with UN resolutions, Saddam Hussein and his government spent over a decade blustering, posturing and doing their best to draw out what could have, and should have, been a very quick conclusion to the Gulf war.
US and coalition forces did not act illegally. They simply cartried out the original mandate they were given by the UN. If that's a crime, then so was the Gulf war, and any other action sanctioned and supported by the UN.
Re:France (Score:5, Informative)
If it doesn't involve nonsense like orcs, mithril armor and little twerps playing 'witch' games, then no Slashdotter will read it.
I suggest Keegan's "The First World War" to dispell any Merikin foolishness about how cowardly the French are in wars. The US showed up in the Great War well after the shit went down. Also, according to cca 1941 GOP policy, WWII was "Roosevelt's War." Godless unpatriotic queers!
Re:good point...but (Score:2, Informative)
I don't think so. If you clicked on the link you would see that ignition in this context refers to the point at which the energy derived from the fusion reactions is enough to maintain the necessary plasma temperature to continue the reaction. Correct me if I'm wrong, but current reactors haven't even reached a breakeven. The energy output from the fusion reactions is less than the energy needed to heat the plasma.
Re:Check your facts.... (Score:1, Informative)
In the USA?
What are you smoking Jack?
The USA had a few large protests organised by International A.N.S.W.E.R an avowed Communist group that hates the US they were attended by a few thousand ignorant people nostalgic for the Vietnam War protests.
I think marseille is a good place to put it (Score:2, Informative)
I think the french spot is good because it is in europe with some quite strong economies that has been affected as badly by the US recession.
It is also quite close(4:00 hours by tgv ) to the high energy physics research center of CERN(http://www.cern.ch) and the nano tech in Grenoble(the reactor group http://isnwww.in2p3.fr/reacteurs-hybrides/reacteu
Re:waiting for Godot... (Score:5, Informative)
Building a stable, sustained, controllable fusion reaction is relatively easy. That isn't, and never has been, the problem. You contain the plasma in a magnetic field that has a single half-twist in it.
Building a stable, sustained, controllable fusion reaction is _incredibly_ difficult. Yes, plasma can be contained by a toroidal magnetic field, FSVO "contained." A nice, cold plasma, at a few tens of thousands of degrees? No problem. At higher temperatures, though, collisions knock lots and lots of ions and electrons off-axis and into the walls of the reactor. This is a major mode of energy loss in magnetic confinement fusion experiments. As you mentioned, instabilities are also a tremendous problem, and that problem has not been solved.
Once you ignite your super-cold plasma, the nuclei are already much closer together, and can't move apart (density too high, plus magnetic field containing the plasma). Your ideal starting material would be a Bose-Einstein Condensate. You cannot get a better density than that, using just conventional means.
This is why you'd need the stupendous magnetic fields. What I'm suggesting is not fusion of a low-density gas, but fusion of a pseudo-liquid or pseudo-solid. To retain that kind of density, when the material is undergoing fusion, would require fields vastly greater than those currently used in fusion research.
As far as Bose-Einstein Condensates go, BEC's occur at temperatures in the nanokelvin range -- that's a full, what, 12 or 13 orders of magnitude too low in thermal energy to overcome the Coulomb potential keeping the nuclei apart. BEC's are notoriously tricky to create; you need to go through several cooling stages involving precisely tuned ultrastable lasers, and at the end of all that work, you get a ball of maybe a few billion atoms. It is simply not feasible to produce BEC's at any larger scale, nor to keep them condensed at fusion temperatures.
And as stupendous magnetic fields go, well, the best anyone can do right now is a sustained field of about 25 Tesla. I don't know offhand what fields they use in Tokamak experiments, but I'm betting it's no more than 10 Tesla, nor less than 1. Either way, there is no way we know of to make steady-state magnetic fields "many orders of magnitude stronger."
It's late now, and I'm getting tired, but suffice it to say that there's a lot more to be done than just making everything bigger. The energy scales are enormous, nobody really knows how to keep a plasma hot and contained, and it's going to take a lot more R&D before we can get usable energy out of fusion.
Re:Why is this About US Opposing French Site ? (Score:3, Informative)
In this case, I don't think the majority of the people in the world had the guts to make a tough decision
Rubbish. The majority of the people in the world made the decision against it. We didn't cover our eyes from anything. It was the US that was scared here. A couple of buildings had been destroyed by terrorists a year or so previous, no real progress had been made in locating bin Laden,and U.S. officials felt they had to be seen to be doing something.
Most of the world (people, even if not governments) were quite happy to let inspectors do their job and due process to go ahead. There was NO immediate threat from Iraq. Meanwhile, Americans were getting jumpy and insecure. Joe and Jane Usian didn't want to fly anymore because they thought they might get hijacked, and confidence in the incumbant government was falling... So what to do? Launch an attack on a manufactured enemy, coerce the governments of other countries against the wishes of thier people, and follow it through until presidential ratings go up.
Fuck that. You say the rest of us don't have guts? It was fear that inspired this whole mess. Fear of losing power, and fear of not feeling safe in your own country. Guess what, the terrorists DID win this one. BTW, anyone who thinks Iraq is actually being liberated should know this: "Any demonstration against the government or coalition forces will be fired upon." [reuters.co.uk] Freedom my ass.
Re:What ITER is about (Score:3, Informative)
www.pppl.gov/ncsx/Scientificconf/ 2000_01_21_TOKI/Toki.pdf
(I was just googling on "stellarator design", try that, it will give you many matches).
But if you just want something world-related to play with, this mission is as follows (this will require some physics knowledge
The plasma consists of charged particles only. These particles are very hot. If the hit the wall of the reactor two bad things will happen:
1) the molecules in the wall will heat up and potentially leave the wall and go into the plasma. You definately do not want metal-ions in the plasma (as those generate extreme radiation when heated to plasma, they will chill the plasma and destroy it).
2) that part of the plasma, hitting the wall, will be lost.
Ions can be trapped within a magnetic field. Think about a pipe-like reactor with a homogenous magnetic field going parallell with the pipe. The plasma particles in the pipe can freely move from one end of the pipe to the other, but the magnetic field will stop the plasma from getting to the walls (the particles will move in small circles around the magnetic field lines). This was the ideal case - the particles close to the walls might actually get to the walls.
So, consider a cross section of the reactor pipe:
Reactor wall | Vacuum | Plasma | Vacuum | Reactor Wall
No plasma will hit the walls and we can have a nice encapsulated fusion going on.
Questions:
1) How do we produce such a magnetic field
2) What happens in the end of the pipe?
The answer to 1) is that you can put spools around the pipe generating a homogenous magnetic field in the pipes direction.
The answer to 2) is more tricky. The best thing anyone has come up with is "bend the pipe to a ring". Now comes a tricky physical implication (depending on your knowledge of physics). Bending the magnetic field to a ring will cause the magnetic "pressure" to be in-homogenous: stronger closer to the center of the ring (not the center of the pipe), and weaker far out from the center of the ring. Essentially this causes the plasma to "drift out" (and be destroyed in seconds).
In a tokamak you put a strong current in the plasma (the current parallell to the magnetic field). This current will cause a new magnetic field "twisting" the resulting magnetic field. So, a particle that finds itself far from the center of the reactor will follow its magnetic field line and after a while it will find itself close to the reactor center. Problem is - you cant sustain such a current for long time.
In a stellarator you design the spools to generate an inhomogenous twisting magnetic field in the first place. Then you need no current, and the reactor can burn for a long time
If you take a look on the pictures in the
The typical dimensions of a stellarator could be
R=4m
r=0.5m
current in spools=30kA
pressure inside reactor=1 Atmosphere
temperature inside reactor=10-100 MK
Point is, there are many physical phenomenas that complicate things...
Solving the plasma behaviour in a fusion reactor is much like doing a weather-simulation. You want to contruct the reactor in a way that the wind blows the same all the time
Taking a class or two in plasma physics should get you introduced
(I just studied a course in Fusion Physics with focus on environmental effects)
Re:Except that debt and your 35 hr week and... (Score:1, Informative)
Re:waiting for Godot... (Score:3, Informative)
jd, you are misinformed. Creating a stable plasma field is *very* hard indeed. This has been fusion power's greatest problem for several decades. The torus was a great way to confine the plasma, but we still have problems with instabilities.
Trying to store so much energy in such a small volume is like balancing an elephant on a needle. It is an unstable system. Any kirks or quirks in the plasma and the system crashes.
Another big problem is with neutron bombardment. Only charged particles are confined in the magnetic field. There's nothing to build the reactor of that can sustain this bombardment without becoming radioactive. All proposed materials are extremely poisonous and have a limited lifetime, and one of the reasons we wanted fusion power in the first place is environmental issues.
Re:good point...but (Score:3, Informative)
I still say that ignition has been reached and sustained for several minutes. Of course you're producing (gamma radiation+neutrons)-> heat and heat is termodinamically not very efficient to be converted in electricity.
So, what has not yet been reached is the energetic breakeven point inclusive of all the energy losses.