Slashdot Mirror
Thermonuclear Reactor To Use Coconut Shells
destinyland writes "A key component of a $10 billion nuclear fusion plant is vintage 2002 Indonesian coconut-shell charcoal. After a 20-year search, German researchers discovered that the coconut-shell charcoal is the best medium for 'adsorbing' waste byproducts sucked out of the thermonuclear reactor's vacuum chamber. In what will be the first fusion power facility that's commercially viable, magnetic fields will heat hydrogen isotopes to over 150 million degrees Centigrade. (Essentially, the super-hot plasma creates artificial stars.) As the article points out, 'It's not quite a Starship warp drive, but it does harness the power of the sun.'"
The head of the project, a former professor, was heard mumbling "Gilligan won't mess it up this time."
Quidquid latine dictum sit, altum sonatur.
I remember this one. The professor made the Thermonuclear reactor with a bunch of coconuts, financed, of course, by the Howell's... but then Gilligan saw Ginger...got all flustered and tripped over the whole thing causing a meltdown and the Skipper's hair to glow... yeah, that's a classic episode indeed
Karma: Excellent. 15 moderator points expire sometime.
It's a fusion reaction. Just say that. No stars here, no power from the sun. Nuclear fusion.
Floating face-down in a river of regret...and thoughts of you...
That's not the power of the sun, you're just bangin' two coconuts together!
Fixed that for ya
My vintage Casio calculator harnessed the power of the sun. This, not so much.
Any editor discussing technology who still feels the need to put the word adsorb into quotes, as though it's not a legitimate English term, should be fired. If you're afraid your audience won't understand, then insert a sidebar on the mechanics of adsorption; don't act as though it's a term out of sci-fi.
Fusion reactor? You've got two empty halves of a coconut and you're bangin' em together!
The 'containment shell' you are speaking of is called the thermal shield, and it is 10 inches of solid carbon steel (usually A36). First, the inside few inches may undergo embrittlement over the course of decades. There is still plenty of ductile material left to hold things together. Second, there will be literally no mechanical stresses in the thermal shield other than gravity... seems like 10 inches of steel ought to be able to hold itself up. It will see thermal stresses, but it is designed with expansion joints so that these to not convert into mechanical stresses. Finally, if these reactors follow any sort of conventional fission reactor design (they will), there will then be 6 feet of steel reinforced high density concrete surrounding the entire reaction chamber, called the 'bioshield'.
There is a lot of information on reactor design out there if you just look and educate yourself instead of reading an editorial and jumping to conclusions. the DOE's websites have a lot of non-classified documents out for public use.
How do you think stars are formed? Do giant space storks bring them?
Here's the executive summary -- Without fusion stars are just really big clouds of hydrogen gas. Gravitational collapse of gas clouds leads to internal heating and eventually drives the temperature at the core of the new star up high enough to start hydrogen fusion. Even before stellar ignition occurs these gravitationally powered stars can glow as brightly as their older, hydrogen burning main sequence cousins.
So unless your god damn heart is glowing like a blackbody at two thousand kelvin, with strong absorption in the Lyman Alpha line, then stars without fusion are certainly not any blacker than it.
To learn more about stellar evolution, T-Tauri stars, the Hertzsprung-Russell diagram, nuclear fusion and spectroscopy, why not go to your local library or take an astrophysicist out to a karaoke bar? Either way you'll hear a lot that you may not be able to understand.
BTW I love coconut.
:-(
Incidentally, coconut fibre (which I suspect might be what TFA might be referring to, rather than the shell) is a truly excellent material for producing an incredibly fine and pure charcoal (i.e. carbon) powder. The particles are so fine that they readily form nearly indelible stains on anything with which they come into contact. Especially on clothing.
The thing I love about Slashdot is that, apparently, no one actually reads the articles. TFA said that the carbon is being used as part of a PUMP to evacuate the waste helium (and some hydrogen, as well as dust created from the walls of the chamber gradually deteriorating from neutron bombardment) from the chamber and maintain vaccuum. They didn't say they were using this as shielding.
Well, at least TSA isn't letting you carry it through security anymore...
MCSE? No, sir...I don't do Windows. Yes, I am an idealist. What's your point?
Here's a quote from the article, where they discuss this.
In a bit more detail:
They need to remove the Helium because it gets in the way of the reactants. They also need to be able to filter out whatever small amounts of waste that are generated by the plasma brushing the wall. Presumably reactions between the plasma and the walls would produce metallic hydrides, which are toxic, and in some cases potentially explosive. Not only that, but after a while, the entire inside of the reactor will be radioactive, from neutron activation. Again, this is small amounts of material, but they can't just spew it out into the air. Besides, they'll want to analyze it and see what's in it, since no one has ever run one of these for an extended period of time before.