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a discussion forum for Polywell fusion
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Helius
Joined: 21 Oct 2007
Posts: 400
Location: Syracuse, New York
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 Posted: Fri Nov 13, 2009 10:17 pm Post subject: |
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| MSimon wrote: | | Quote: | | New technologies only need to be a higher threshold of difficulty in making nuclear weapons, over the tried and true methods already established. |
There has been considerable discussion of this topic here during the 2+ (is that all?) years this board has been here.
The general thought is that a BFR would make proliferation some easier. Building a BFR (once it is known to work) will be easier and less hazardous than building a fission nuke. And it turns on and turns off at the flick of a switch. So unlike a nuke you don't have to plan for continuous neutron flux while loading and unloading starting material. And 3 days (Xe poisoning) between restarts. And you don't have to worry about criticality accidents. |
Of course 2 available methods is never more secure than 1. A state that wants a nuclear warhead, however would be foolish to vie for a new method. Polywell is proliferating, however, given a state with the technology to build Fusion Reactors and wants a substantial nuclear arsenal. It is comical to parlay that into "lets be dumb.... for our own security!"... then pretend our rejecting useful technologies adds to our security. The Al Gore method of security, is similar to the ostrich method.
"I want 500 nuclear warheads dang it, or heads will roll. Where's that Polywell salesman?" |
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MSimon
Joined: 16 Jul 2007
Posts: 8780
Location: Rockford, Illinois
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| Posted: Fri Nov 13, 2009 10:35 pm Post subject: |
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| Helius wrote: | | MSimon wrote: | | Quote: | | New technologies only need to be a higher threshold of difficulty in making nuclear weapons, over the tried and true methods already established. |
There has been considerable discussion of this topic here during the 2+ (is that all?) years this board has been here.
The general thought is that a BFR would make proliferation some easier. Building a BFR (once it is known to work) will be easier and less hazardous than building a fission nuke. And it turns on and turns off at the flick of a switch. So unlike a nuke you don't have to plan for continuous neutron flux while loading and unloading starting material. And 3 days (Xe poisoning) between restarts. And you don't have to worry about criticality accidents. |
Of course 2 available methods is never more secure than 1. A state that wants a nuclear warhead, however would be foolish to vie for a new method. Polywell is proliferating, however, given a state with the technology to build Fusion Reactors and wants a substantial nuclear arsenal. It is comical to parlay that into "lets be dumb.... for our own security!"... then pretend our rejecting useful technologies adds to our security. The Al Gore method of security, is similar to the ostrich method.
"I want 500 nuclear warheads dang it, or heads will roll. Where's that Polywell salesman?" |
It may be because I am shy 5 cups of coffee but I didn't understand your point.
_________________
Engineering is the art of making what you want from what you can get at a profit. |
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Helius
Joined: 21 Oct 2007
Posts: 400
Location: Syracuse, New York
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| Posted: Sat Nov 14, 2009 12:21 am Post subject: |
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| MSimon wrote: | | Helius wrote: | | MSimon wrote: | | Quote: | | New technologies only need to be a higher threshold of difficulty in making nuclear weapons, over the tried and true methods already established. |
There has been considerable discussion of this topic here during the 2+ (is that all?) years this board has been here.
The general thought is that a BFR would make proliferation some easier. Building a BFR (once it is known to work) will be easier and less hazardous than building a fission nuke. And it turns on and turns off at the flick of a switch. So unlike a nuke you don't have to plan for continuous neutron flux while loading and unloading starting material. And 3 days (Xe poisoning) between restarts. And you don't have to worry about criticality accidents. |
Of course 2 available methods is never more secure than 1. A state that wants a nuclear warhead, however would be foolish to vie for a new method. Polywell is proliferating, however, given a state with the technology to build Fusion Reactors and wants a substantial nuclear arsenal. It is comical to parlay that into "lets be dumb.... for our own security!"... then pretend our rejecting useful technologies adds to our security. The Al Gore method of security, is similar to the ostrich method.
"I want 500 nuclear warheads dang it, or heads will roll. Where's that Polywell salesman?" |
It may be because I am shy 5 cups of coffee but I didn't understand your point. |
That's because you only read the last line, as usual.
Clearly 2 available methods always have more possibilities than 1. Think "or" gate. That being said, the establishment of new energy production methods must be made more difficult for Nuclear weapons development than existing methods for rogue states. It's better to leave North Korean weapons developers pushing uranium slugs through graphite blocks rather than some streamlined method with lower cost and low IAEA visibility to produce evermore nuclear weapons.
Polywell doesn't need to proliferate nuclear weapons, but as you've said, we've had that discussion before. |
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pfrit
Joined: 28 Aug 2008
Posts: 238
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| Posted: Sat Nov 14, 2009 5:03 am Post subject: |
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| Helius wrote: | | MSimon wrote: | | Helius wrote: | | MSimon wrote: | | Quote: | | New technologies only need to be a higher threshold of difficulty in making nuclear weapons, over the tried and true methods already established. |
There has been considerable discussion of this topic here during the 2+ (is that all?) years this board has been here.
The general thought is that a BFR would make proliferation some easier. Building a BFR (once it is known to work) will be easier and less hazardous than building a fission nuke. And it turns on and turns off at the flick of a switch. So unlike a nuke you don't have to plan for continuous neutron flux while loading and unloading starting material. And 3 days (Xe poisoning) between restarts. And you don't have to worry about criticality accidents. |
Of course 2 available methods is never more secure than 1. A state that wants a nuclear warhead, however would be foolish to vie for a new method. Polywell is proliferating, however, given a state with the technology to build Fusion Reactors and wants a substantial nuclear arsenal. It is comical to parlay that into "lets be dumb.... for our own security!"... then pretend our rejecting useful technologies adds to our security. The Al Gore method of security, is similar to the ostrich method.
"I want 500 nuclear warheads dang it, or heads will roll. Where's that Polywell salesman?" |
It may be because I am shy 5 cups of coffee but I didn't understand your point. |
That's because you only read the last line, as usual.
Clearly 2 available methods always have more possibilities than 1. Think "or" gate. That being said, the establishment of new energy production methods must be made more difficult for Nuclear weapons development than existing methods for rogue states. It's better to leave North Korean weapons developers pushing uranium slugs through graphite blocks rather than some streamlined method with lower cost and low IAEA visibility to produce evermore nuclear weapons.
Polywell doesn't need to proliferate nuclear weapons, but as you've said, we've had that discussion before. |
While I seriuosly doubt your point, it is moot. If there is ONE method that cannot be prevented and is easy, adding another does not make the situation worse. The horses are well and truly out of the barn. There is no way to prevent a state from developing nuclear weapons. It is easy. Unless you have a bright idea about how to prevent a rogue state from going nuclear now, arguing about whether a new method will make it easier to make nucs is silly. They can make them and we can't stop them.
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What is the difference between ignorance and apathy? I don't know and I don't care. |
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MSimon
Joined: 16 Jul 2007
Posts: 8780
Location: Rockford, Illinois
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| Posted: Sat Nov 14, 2009 5:18 am Post subject: |
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Actually my method when coming across something I don't understand is to reread it several times.
And my usual order is to read the first line or two and start firing. I rarely start with the last line.
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KitemanSA
Joined: 28 Sep 2008
Posts: 2428
Location: Northern VA
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| Posted: Sat Nov 14, 2009 12:28 pm Post subject: |
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MSimon.
Thank you!!
Thank you for ending the battle of the repeated quotes. Thank you for editing (or not quoting in the first place) what you responded to. Judicious editing is the most considerate process. Continued unedited quoting is annoying. Thank you. |
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MSimon
Joined: 16 Jul 2007
Posts: 8780
Location: Rockford, Illinois
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| Posted: Sat Nov 14, 2009 4:49 pm Post subject: |
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| KitemanSA wrote: | MSimon.
Thank you!!
Thank you for ending the battle of the repeated quotes. Thank you for editing (or not quoting in the first place) what you responded to. Judicious editing is the most considerate process. Continued unedited quoting is annoying. Thank you. |
There is no style sheet around here. But you are welcome to make your preferences known. ;-)
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Engineering is the art of making what you want from what you can get at a profit. |
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KitemanSA
Joined: 28 Sep 2008
Posts: 2428
Location: Northern VA
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| Posted: Sun Nov 15, 2009 1:43 am Post subject: |
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| Just tried. D'ya think it might do some good? |
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MSimon
Joined: 16 Jul 2007
Posts: 8780
Location: Rockford, Illinois
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| Posted: Sun Nov 15, 2009 8:57 am Post subject: |
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| KitemanSA wrote: | | Just tried. D'ya think it might do some good? |
Doubtful.
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randomly
Joined: 10 Nov 2009
Posts: 11
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| Posted: Sun Nov 15, 2009 11:55 pm Post subject: |
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| scareduck wrote: |
Nonsense. There's the issue of fuel availability (FAR more boron and deuterium in the world than fissible uranium-235), which you keep glossing over. |
Your comment got me curious about what the real abundance of Boron, Thorium, and Uranium is . Boron is actually fairly scarce. In fact there is less Boron than Thorium. Boron is roughly 20 times less dense but yields about 20 times less energy than a fission of U233 bred from Thorium. Thorium is about 1.5 times more abundant (~15 ppm in the earths crust) so there is actually more energy potential available in Thorium than in Boron. |
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scareduck
Joined: 17 Oct 2007
Posts: 552
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| Posted: Mon Nov 16, 2009 4:00 am Post subject: |
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| randomly wrote: | | scareduck wrote: |
Nonsense. There's the issue of fuel availability (FAR more boron and deuterium in the world than fissible uranium-235), which you keep glossing over. |
Your comment got me curious about what the real abundance of Boron, Thorium, and Uranium is . Boron is actually fairly scarce. In fact there is less Boron than Thorium. Boron is roughly 20 times less dense but yields about 20 times less energy than a fission of U233 bred from Thorium. Thorium is about 1.5 times more abundant (~15 ppm in the earths crust) so there is actually more energy potential available in Thorium than in Boron. |
You got me on boron. But not deuterium. |
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MSimon
Joined: 16 Jul 2007
Posts: 8780
Location: Rockford, Illinois
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| Posted: Mon Nov 16, 2009 5:32 am Post subject: |
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| randomly wrote: | | scareduck wrote: |
Nonsense. There's the issue of fuel availability (FAR more boron and deuterium in the world than fissible uranium-235), which you keep glossing over. |
Your comment got me curious about what the real abundance of Boron, Thorium, and Uranium is . Boron is actually fairly scarce. In fact there is less Boron than Thorium. Boron is roughly 20 times less dense but yields about 20 times less energy than a fission of U233 bred from Thorium. Thorium is about 1.5 times more abundant (~15 ppm in the earths crust) so there is actually more energy potential available in Thorium than in Boron. |
Boron is concentrated (mostly) in two places. Turkey has about 70% of the world's mineable supplies. The USA about 25%. IIRC. There is enough boron in mines for about 20,000 to 50,000 years of Earth's electrical supply. Plenty of time to figure out what is next. Or begin ocean extraction.
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kurt9
Joined: 15 Oct 2007
Posts: 296
Location: Portland, Oregon, USA
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| Posted: Mon Nov 16, 2009 6:57 am Post subject: |
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| MSimon wrote: | | randomly wrote: | | scareduck wrote: |
Nonsense. There's the issue of fuel availability (FAR more boron and deuterium in the world than fissible uranium-235), which you keep glossing over. |
Your comment got me curious about what the real abundance of Boron, Thorium, and Uranium is . Boron is actually fairly scarce. In fact there is less Boron than Thorium. Boron is roughly 20 times less dense but yields about 20 times less energy than a fission of U233 bred from Thorium. Thorium is about 1.5 times more abundant (~15 ppm in the earths crust) so there is actually more energy potential available in Thorium than in Boron. |
Boron is concentrated (mostly) in two places. Turkey has about 70% of the world's mineable supplies. The USA about 25%. IIRC. There is enough boron in mines for about 20,000 to 50,000 years of Earth's electrical supply. Plenty of time to figure out what is next. Or begin ocean extraction. |
Or space. Boron-based fusion will certain get us into space. |
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Axil
Joined: 02 Jan 2009
Posts: 103
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| Posted: Wed Nov 25, 2009 12:16 am Post subject: |
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| Kert9 wrote: | | Why not use them for something? I would think that such a hybrid plant would produce 2-3 times the energy of the fusion-only plant. |
For a thorium hybrid plant it is more like 10,000 times.
I will address the thorium fuel cycle since it is highly proliferation resistant (I think proliferation proof) when coupled with fusion in preference to the uranium fuel cycle and its plutonium (a proliferation risk) byproduct.
An aneutronic boron reaction nets about 8 MeV of power and that’s it. On the other hand a d-d fusion reaction that breeds thorium nets about 200 MeV per initial thorium fission and that in turn will breed with 3 other secondary thorium atoms to net 800 MeV per each fusion/fission reaction.
In other words, each D-D fusion produces one neutron that breeds 4 U233 atoms.
An ideal thorium breeder reactor design will have a breeding ratio of 1.07. But due to neutron losses from the accumulation of isotopes of various kinds that poison the fission reaction, a thorium breeder will be lucky to break even. Let us assume a real world worse case breeding ratio in the range between .95 and .99.
So in round numbers, for every fusion neutron produced, about 400 thorium fissions can result. At 200MEv per fission that is (200Mev) (400) = 80000MeV per fusion neutron; as opposed to just 8Mev for boron fusion. That is an increased energy density factor of 10,000.
However, if not supplied with a small number of supplemental fusion produced neutrons, the thorium breeding nuclear reaction will eventually stop because the thorium breeding ratio is just a little less than one.
Without an occasional dose of fusion neutrons, the thorium fuel cycle will wind down to a stop.
It is not an overstatement to say that for the lack of an occasional neutron, the thorium fuel cycle is lost.
Those occasional neutrons can come from U235 and even Pu239 but fusion neutrons are clean and pure. It enables a pure thorium fuel cycle that leaves no long-lived nuclear wastes about. |
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D Tibbets
Joined: 26 Jun 2008
Posts: 969
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| Posted: Wed Nov 25, 2009 8:45 am Post subject: |
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Well, if Axil's estimates are possible in a real system, even a wimpy excess neutron producer like a D-T fueled Tokamac might work.
The non scientific issue though is the economics of the system- essentially two interlinked complex (?) reactors with the output of say a single uranium 235 reactor.
If your desperate for the power (Uranium reserves depleted), it makes sense, otherwise the cost is prohibitive.
I'm sceptical of the nonproliferation potential of thorium breeders. The Uranium 233 produced is not ideal for bombs, but I understand it might actually be easier to build. The Uranium 233 halflife limits the shelf life of the bomb- use it or lose it. And it fissions too easily. I understand only a few percent of the isotope would fission before the bomb blew itself apart- a fizzle, but that only means that a bomb hidden in a truck might only blow up a small city instead of a large city. It would also serve as a good trigger for a dirty bomb. A rogue nation or organization would have little concern for the technicions killed off in processing and assembling the bomb. The only saving grace may be that it would be more difficult to hide from radiation moniters.
Dan Tibbets
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