I recall in the movie "Blown Away" http://www.imdb.com/title/tt0109303/ a robot which several of the supporting cast held an affection for. Until it blew up. Al Gore's roommate is a jerk.
But you know, I've always wondered why they don't use big air-cooled heat engines instead of a cooling tower. It adds complexity, but they get to extract energy from the hot water that would have otherwise just been blown off anyways.
The above links, read in order, should step through nicely outlining the fusion process, and some of the major challanges that are to be overcome in making it a viable power source for use on Earth.
Today, I will have understanding of fusion. Tommorrow I will understand Subscriber trunk dialing, and then, computers. Once I have an understanding of computers, I will rule the world!
Now, realize that the containment structure and underlying tech is providing all of the force to maintain the conditions for the fusion to take place. The power goes out, and fusion stops. You are left with a reactor full of hot gas, that just... cools down. There might be some materials damage, but because of neutron flux issues, we are expecting materials damage anyways. Relative to the rest of the challanges surrounding hot fusion, this is a non-issue.
I would highly suggest you try out Trend Micro. Centrally managed scans and updates, installs across a web-browser, and it works. They sell by block, so if you need 60 licenses you get each license for cheaper than if you needed 50 or less. It also keeps a good watch on spyware.
CANDU reactors are available for sale pending approval from AECL (Atomic Energy of Canada Limited), they can use natural, unenriched uranium, and make extremely efficient use of the fuel burned. They also generate tritium and can be used to breed uranium from thorium. Given the difficulty in mastering the timing required for implosion fission (a requirement of which is also plutonium), proliferation concerns from the creation of uranium would be mostly focused on preventing gun-type (damned simple, monkey-with-a-hammer) bombs from being built, or dirty bombs.
Now, this is not to say that concern and forethought should not be invested in the fusion-proliferation problem, but fusion is hard. It's going to be hard 10 years from now, and when they get it working it's still going to be hard. Right now, we have the next most viable step looking to be the ITER, which is (supposed to be) a joint international effort. The ITER is not going to be run by one country, and I personally doubt that countries like North Korea (current mindset) will ever muster the resources to build viable fusion reactors. I doubt they will ever muster the resources, with or without the Americans opposition.
Commercial fusion power will be like any other tool of useful potency: It will be harness-able for constructive or destructive purposes. And considering how much simpler it is to buy or build a fission reactor today than it is to even plan what the next "leap" in fusion technology advancement will be, I do not currently view proliferation as my top-most concern regarding fusion.
You're welcome. The potential for these engine designs is enough to make me wish I had taken the path of a materials engineer. I hope your dad enjoys reading them too.
I. What sort of fusion reactor is the sun?
Fortunately for life on earth, the sun is an aneutronic fusion
reactor, and we are not continually bombarded by fusion neutrons.
Unfortunately, the aneutronic process which the sun uses is
extremely slow and harder to do on earth than any of the reactions
mentioned above. The sun long ago burned up the "easy" deuterium
fuel, and is now mostly ordinary hydrogen. Now hydrogen has a
mass of one (it's a single proton) and helium has a mass of four
(two protons and two neutrons), so it's not hard to imagine sticking
four hydrogens together to make a helium. There are two major
problems here: the first is getting four hydrogens to collide
simultaneously, and the second is converting two of the four protons
into neutrons.
Regarding D + He3 aneutronic fusion:
If the reactor is optmized (run in a He3 rich mode) the number
of neutrons can be minimized. The neutron power can be as low as about 5% of the total. However, in a 1000 megawatt reactor, 5% is 50 MW of neutron power. That is [still] a lot of neutron irradiation. This lower neutron level helps in designing structural elements to withstand neutron bombardment, but it still has radiation consequences.
I apologize for the rather simplistic answers provided by the article, but it does a nice job of summarizing where I would tend to ramble on.
Tritium is a dangerous fuel. It's intensely radioactive and bodies absorb it readily. (The good news is that tritiium ingestion is *easy* to treat).
http://en.wikipedia.org/wiki/Tritium
I call FUD. It's radioactivity is beta rays, and weak ones at that. They put the stuff on keychains, in watches and gun sights. Your smoke detector is a bigger danger.
Well, it would wreck the plane, and depending on the containment structure around the guts of the thing, it might damage the plant into unusable status. The hot gas inside might escape and turn in to cool gas. Some people might lose their lights and their ice cream might melt. Mostly, it would wreck the plane.
I have to say, I am officially confused... Where did you see anything relating to a phrase "best that we can hope for without massive shielding"? I've gone back through the great-grand, grand, and parent posts to mine... Zip. Also nothing for the Aneutronic (neutron free) article I linked from Wikipedia. Please clarify this point.
My point with the linked article is to show, even with the current best-case theory for hot fusion, a significant neutron flux will be generated. With Deuterium + Tritium (D + T fusion, the easiest and most readily attainable), the flux level compared to a modern fission reactor of similar power is roughly 100 times greater. http://en.wikipedia.org/wiki/Fusion_power#The_D-T_ fuel_cycle The neutron flux level is in fact the driver of one of the critical areas of needed research into fusion power: materials engineering.
Furthermore, the entry used human survivability next to a small "clean" fusion reactor as an illustration of the flux level. In no way am I implying, or would I imply, that we need to build reactors that someone can stand directly next to them, unshielded, and survive the environment. As it stands, there is some incorrect information in posts above mine regarding flux levels, and the resultant radioactivity of reactor materials. They aren't long lived isotopes, but the radiation level of fusion needs to be understood.
The next most attainable reaction is D + D. Direct products from this reaction are tritium, a 2.45 MeV neutron, Helium 3, and a proton. The tritium produced will most likely go on to be further reacted in D + T fusion. The disadvantage of going this route is greatly increased difficulty in harnessing a useful amount of energy from the reaction (further delaying fusion's use as a power source).
It's not really a matter of needing to shield it, it's (for me) a matter of reminding folks that the thing will require shielding in the first place, and that it won't be a cakewalk to get rid of when we're done with it. Still beats oil or coal power.
I especially favor CANDU myself, between the use of unenriched uranium (or thorium), and that any significant deformation of the fuel geometry results in an inability to sustain a chain reaction... Well, it's a wonder we don't use more CANDU reactors. http://en.wikipedia.org/wiki/Anti-nuclear
For an industrial size (100 MW) reactor under the same assumptions, the dose rate would be thousands of times higher, and anyone standing nearby would receive a fatal dose in a fraction of a second. The neutrons would also activate the structure so that remote maintenance and radioactive waste disposal would be necessary. Of course, material damage and safety problems would be brought into an easily manageable range.
This is the from the article on aneutronic fusion, even. D + D fusion is much dirtier.
The L4 project, and the Wikipedia article on the L4 Microkernel, are both important to mention in a discussion of a modern Microkernel. It has potential - and belongs alongside Mach in such a discussion.
The OP shows signs of having never been in an altercation of substantial seroiusness as anybody (including so-called "trained" martial artists) facing a knife should get the hell out of Dodge if possible. Couple that with the most popular martial art in the US (and maybe the world?) being Tae Kwon Do and you have a recipe for disaster. Even Brazillian jiu-jitsu folks have trouble when facing somebody with a knife. I think everybody gets this picture of somebody pulling it and executing an orderly thrust or some erratic pansy-assed slashes. We had a kid in high school (back in the 80's.. oh my) who pulled a Buck knife and when completely apeshit.. totally erratic. He was fast and not over-committing. There was no defense against that and they hauled the other kid out on a stretcher.
"Trained" martial artists will indeed be better equipped than your average couch potato in an unarmed altercation against a knife wielding assailant. "Posers", "wanna-bee's" and "trolls" will serve to discredit any amount or style of training. Furthermore, to pretend that a particular (well developed) style of martial art is inherently superior to another is, in my experience, another hallmark of the novice, or armchair enthusiast.
The above quote is exactly right in its last sentence. In no way does a trained individual enter a knife fight willingly. Self-defense is almost always at the disadvantage, as the assailant will always be in charge of picking the time, place, and circumstances of the situation. Get out with life intact, is what a reasonable person should learn from self-defense training in any martial art.
Proper training (which includes physical AND mental aspects) will ALWAYS increase the chances for survival for a given individual for a given situation.
In other words, why would you argue that, if a bully is expected to attack you (even, perhaps, with a knife) no matter your actions, then would you rather A) cower in fear and plead for mercy, or B) React in a manner appropriate with prior training, which has been given forethought and can be planned somewhat.
The best response for self defense is the response that has the best chances for survival for the victim(s). In the case of rape, this means FIGHT BACK and RUN as soon as possible. In the case of armed robbery, this means TOSS THE MONEY, it's not worth it, do what you have to to get out of there, and get to safety.
Self-defense isn't about winning a fight you didn't start. It's about preserving life and liberty for the one(s) being attacked. And the fellow who asked about outrunning bullets? I have a heck of a lot better chance against a gun, if I don't stand dead still and make myself a practice target. A person committed to shooting first in a fight, will have SHOT FIRST. Get the hell out of Dodge when you have a chance.
Slashdot Mirror
I recall in the movie "Blown Away" http://www.imdb.com/title/tt0109303/ a robot which several of the supporting cast held an affection for. Until it blew up. Al Gore's roommate is a jerk.
But you know, I've always wondered why they don't use big air-cooled heat engines instead of a cooling tower. It adds complexity, but they get to extract energy from the hot water that would have otherwise just been blown off anyways.
http://en.wikipedia.org/wiki/Stirling_engine
Doh! Oh well, I got to post the nice illustration on hydrogen 1 fusion. Too bad I look like a butt for doing so.
There is, in fact, a fusion reaction for hydrogen-1, but it is entirely impractical for terrestial power production. Feels good when sunbathing, though.c hain.html
http://csep10.phys.utk.edu/astr162/lect/energy/pp
http://en.wikipedia.org/wiki/Fusion_power
http://en.wikipedia.org/wiki/Aneutronic_fusion
http://en.wikipedia.org/wiki/Nuclear_fusion
http://en.wikipedia.org/wiki/Neutron_flux
http://en.wikipedia.org/wiki/Neutron_radiation
http://en.wikipedia.org/wiki/Proton-proton_chain
http://en.wikipedia.org/wiki/CNO_cycle
The above links, read in order, should step through nicely outlining the fusion process, and some of the major challanges that are to be overcome in making it a viable power source for use on Earth.
Today, I will have understanding of fusion. Tommorrow I will understand Subscriber trunk dialing, and then, computers. Once I have an understanding of computers, I will rule the world!
My apologies, Terry.
First off: The sun, on a gram for gram scale, releases energy SLOWLY. Please read
... cools down. There might be some materials damage, but because of neutron flux issues, we are expecting materials damage anyways. Relative to the rest of the challanges surrounding hot fusion, this is a non-issue.
http://en.wikipedia.org/wiki/Proton-proton_chain
Now, realize that the containment structure and underlying tech is providing all of the force to maintain the conditions for the fusion to take place. The power goes out, and fusion stops. You are left with a reactor full of hot gas, that just
I would highly suggest you try out Trend Micro. Centrally managed scans and updates, installs across a web-browser, and it works. They sell by block, so if you need 60 licenses you get each license for cheaper than if you needed 50 or less. It also keeps a good watch on spyware.
= 639856
http://www.cdw.com/shop/products/default.aspx?EDC
CANDU reactors are available for sale pending approval from AECL (Atomic Energy of Canada Limited), they can use natural, unenriched uranium, and make extremely efficient use of the fuel burned. They also generate tritium and can be used to breed uranium from thorium. Given the difficulty in mastering the timing required for implosion fission (a requirement of which is also plutonium), proliferation concerns from the creation of uranium would be mostly focused on preventing gun-type (damned simple, monkey-with-a-hammer) bombs from being built, or dirty bombs.
Now, this is not to say that concern and forethought should not be invested in the fusion-proliferation problem, but fusion is hard. It's going to be hard 10 years from now, and when they get it working it's still going to be hard. Right now, we have the next most viable step looking to be the ITER, which is (supposed to be) a joint international effort. The ITER is not going to be run by one country, and I personally doubt that countries like North Korea (current mindset) will ever muster the resources to build viable fusion reactors. I doubt they will ever muster the resources, with or without the Americans opposition.
Commercial fusion power will be like any other tool of useful potency: It will be harness-able for constructive or destructive purposes. And considering how much simpler it is to buy or build a fission reactor today than it is to even plan what the next "leap" in fusion technology advancement will be, I do not currently view proliferation as my top-most concern regarding fusion.
You're welcome. The potential for these engine designs is enough to make me wish I had taken the path of a materials engineer. I hope your dad enjoys reading them too.
http://fusedweb.pppl.gov/FAQ/section1-physics.txt
Regarding D + He3 aneutronic fusion: I apologize for the rather simplistic answers provided by the article, but it does a nice job of summarizing where I would tend to ramble on.
I call FUD. It's radioactivity is beta rays, and weak ones at that. They put the stuff on keychains, in watches and gun sights. Your smoke detector is a bigger danger.
Well, it would wreck the plane, and depending on the containment structure around the guts of the thing, it might damage the plant into unusable status. The hot gas inside might escape and turn in to cool gas. Some people might lose their lights and their ice cream might melt. Mostly, it would wreck the plane.
http://gprime.net/video.php/planevsconcretewall
I have to say, I am officially confused ... Where did you see anything relating to a phrase "best that we can hope for without massive shielding"? I've gone back through the great-grand, grand, and parent posts to mine ... Zip. Also nothing for the Aneutronic (neutron free) article I linked from Wikipedia. Please clarify this point.
_ fuel_cycle The neutron flux level is in fact the driver of one of the critical areas of needed research into fusion power: materials engineering.
My point with the linked article is to show, even with the current best-case theory for hot fusion, a significant neutron flux will be generated. With Deuterium + Tritium (D + T fusion, the easiest and most readily attainable), the flux level compared to a modern fission reactor of similar power is roughly 100 times greater. http://en.wikipedia.org/wiki/Fusion_power#The_D-T
Furthermore, the entry used human survivability next to a small "clean" fusion reactor as an illustration of the flux level. In no way am I implying, or would I imply, that we need to build reactors that someone can stand directly next to them, unshielded, and survive the environment. As it stands, there is some incorrect information in posts above mine regarding flux levels, and the resultant radioactivity of reactor materials. They aren't long lived isotopes, but the radiation level of fusion needs to be understood.
The next most attainable reaction is D + D. Direct products from this reaction are tritium, a 2.45 MeV neutron, Helium 3, and a proton. The tritium produced will most likely go on to be further reacted in D + T fusion. The disadvantage of going this route is greatly increased difficulty in harnessing a useful amount of energy from the reaction (further delaying fusion's use as a power source).
It's not really a matter of needing to shield it, it's (for me) a matter of reminding folks that the thing will require shielding in the first place, and that it won't be a cakewalk to get rid of when we're done with it. Still beats oil or coal power.
Again, modern technology should be considered before weighing the "risk of meltdown".
http://en.wikipedia.org/wiki/Pebble-bed_reactor
http://en.wikipedia.org/wiki/CANDU_reactor
I especially favor CANDU myself, between the use of unenriched uranium (or thorium), and that any significant deformation of the fuel geometry results in an inability to sustain a chain reaction
http://en.wikipedia.org/wiki/Aneutronic_fusion
I will quote one of the most relevant parts:
This is the from the article on aneutronic fusion, even. D + D fusion is much dirtier.
Steve, you might enjoy these two links as well.
http://auto.howstuffworks.com/quasiturbine.htm
http://en.wikipedia.org/wiki/Quasiturbine
The L4 project, and the Wikipedia article on the L4 Microkernel, are both important to mention in a discussion of a modern Microkernel. It has potential - and belongs alongside Mach in such a discussion.
http://en.wikipedia.org/wiki/L4_kernel
http://www.l4hq.org/
"Trained" martial artists will indeed be better equipped than your average couch potato in an unarmed altercation against a knife wielding assailant. "Posers", "wanna-bee's" and "trolls" will serve to discredit any amount or style of training. Furthermore, to pretend that a particular (well developed) style of martial art is inherently superior to another is, in my experience, another hallmark of the novice, or armchair enthusiast.
The above quote is exactly right in its last sentence. In no way does a trained individual enter a knife fight willingly. Self-defense is almost always at the disadvantage, as the assailant will always be in charge of picking the time, place, and circumstances of the situation. Get out with life intact, is what a reasonable person should learn from self-defense training in any martial art.
When is ignorance a good self-defense?
Proper training (which includes physical AND mental aspects) will ALWAYS increase the chances for survival for a given individual for a given situation.
In other words, why would you argue that, if a bully is expected to attack you (even, perhaps, with a knife) no matter your actions, then would you rather A) cower in fear and plead for mercy, or B) React in a manner appropriate with prior training, which has been given forethought and can be planned somewhat.
The best response for self defense is the response that has the best chances for survival for the victim(s). In the case of rape, this means FIGHT BACK and RUN as soon as possible. In the case of armed robbery, this means TOSS THE MONEY, it's not worth it, do what you have to to get out of there, and get to safety.
Self-defense isn't about winning a fight you didn't start. It's about preserving life and liberty for the one(s) being attacked. And the fellow who asked about outrunning bullets? I have a heck of a lot better chance against a gun, if I don't stand dead still and make myself a practice target. A person committed to shooting first in a fight, will have SHOT FIRST. Get the hell out of Dodge when you have a chance.
If we use our heads, there is much better than a 50 year supply.
h e_Thorium_fuel_cycle
http://www.world-nuclear.org/sym/1999/adamov.htm
http://canteach.candu.org/library/20054702.pdf - PDF Warning!
http://en.wikipedia.org/wiki/Thorium_fuel_cycle#T
http://en.wikipedia.org/wiki/Thorium_fuel_cycle#Th e_Thorium_fuel_cycle
For the moment, I don't think we should let the lack of an absolutely permanent solution stop us from migrating away from coal. Vitrification or Synroc for now. There is plenty of fuel in the world. And (hot)fusion produces a significant amount of waste on its own.
http://en.wikipedia.org/wiki/Fusion_power
http://en.wikipedia.org/wiki/Nuclear_fusion
http://en.wikipedia.org/wiki/Aneutronic_fusion
Wikipedia on pebble beds:
http://en.wikipedia.org/wiki/Pebble_bed_reactor
Other useful stuff:
http://en.wikipedia.org/wiki/Synroc
http://en.wikipedia.org/wiki/Vitrification
http://en.wikipedia.org/wiki/Nuclear_waste
http://en.wikipedia.org/wiki/Aneutronic_fusion
Suffice to say, these articles cover alot of ground.
Perhaps you would like to do some reading:_ fuel_cycle
http://en.wikipedia.org/wiki/Fusion_power#The_D-D
http://en.wikipedia.org/wiki/Carl_Schurz
http://www.bartleby.com/73/1641.html