Environmental impact of p-B11 fusion?

[JoeStrout]

Oh and here is a document on the effects on highly energetic neutrons (from D-T).

Where?

While the document uses Tokamaks, it may be applicable to Polywell to some degree.

Not to much degree, though, if (as Dr. Bussard seems certain) a Polywell machine can burn p-B11 instead.

[Zixinus]

Where?

Sorry, I'm very absent-minded today. Here:

http://www.acamedia.info/sciences/J_G/fusion.html

Not to much degree, though, if (as Dr. Bussard seems certain) a Polywell machine can burn p-B11 instead.

The first machines will definitely burn D-T, and it is very likely that the first power plants will do so as well. P-b11 is the future's song. D-T is much easier to do, and going straight for p-B11 is rather foolish.

[JoeStrout]

The first machines will definitely burn D-T, and it is very likely that the first power plants will do so as well. P-b11 is the future's song. D-T is much easier to do, and going straight for p-B11 is rather foolish.

Well, sez you, but Dr. Buzzard sez differently, and I think I understand why. In a Polywell machine, the ion velocity is a function of the well depth, which in turn is a (very steep) function of the machine size. So if a machine of a certain size can't do it, you make it a bit bigger, and it will.

Moreover, extracting the energy from a D-T reaction is very very hard because it's mostly in the form of neutron radiation. It requires lithium blankets and a heat cycle and all sorts of other nonsense, which makes it both expensive and difficult. It also has nasty side-effects like rapidly making your equipment (e.g. the coils in this case) radioactive. In comparison, p-B11 produces mostly charged particles which can be very easily converted to DC current. Very simple and easy in comparison.

So, I hereby officially bet you a pizza that the first fusion power plants will burn p-B11, not D-T.

[Zixinus]

So, I hereby officially bet you a pizza that the first fusion power plants will burn p-B11, not D-T.

You're on.

Oh, and I recall various papers and the video talking about putting Polywell in various coal or even fission power plants, in place of the heat source. The reason for this is that you can save mayor costs when building a power plant, as you already have a power plant.

Oh, as for what the Doc said, look at 59:33 of the google video.

[MSimon]

Bombs don't use tritium directly. These use lithium. Tritium is a bitch to store, and there is the problem of purity. He3, its end-product, is a neutron killer.
Instead they use lithium deuteride, which is solid but the neutrons from a fission bomb make lithium produce tritium.
To trigger a Teller-Ulam, you still need to do a fission bomb.

That depends on the kind of bomb I think. One of the very rare source of He3 on Earth is desintegration of tritium used in some nuclear weapons... And tritium is used in neutron bombs.

But anyway, I think that the main problem to consider is the production of plutonium. Maybe it's not a real problem, if the reprocessing necessary to isolate the right isotopes is a complex operation.
I just say that all those potential proliferation problems should be carefully evaluated if a low cost massive source of neutrons becomes available, as it might possible with a high gain IEC device.

Plutonium worries me too. Burning D-D should be no problem in a Polywell.

It looks like we are going to have two or three near term choices.

1. Coal
2. Fission nukes - plutonium guaranteed
3. Fusion nukes - plutonium optional

I like option 3.

Any extraction of Pu from irradiated U is going to be radiation intensive. So the source of Pu - fusion blanket or fission leftovers will not make a big difference in processing. The main difference would likely be the thickness of the shields not the requirement for shields.

Simon

[Zixinus]

2. Fission nukes - plutonium guaranteed

Not necessarily. Future fission fuel may not be plutonium at all; instead uranium-233 would be used, created by neutron bombardment of thorium, a much more abundant element then uranium. And according to nuclear weapons archive:

With deliberately denatured grades of U-233 produced by a thorium fuel cycle (0.5 - 1.0% U-232), very high gamma exposures would result. A 10 kg sphere of this material could be expected to reach 11 rem/hr at 1 meter after 1 month, 110 rem/hr after 1 year, and 200 rem/hr after 2 years. Handling and fabrication of such material would have to done remotely (this also true of fuel element fabrication) In an assembled weapon, even if a factor of 1000 attenuation is assumed, close contact of no more than 25 hours/year with such a weapon would be possible and remain within safety standards. This makes the diversion of such material for weapons use extremely undesirable.

Source: http://nuclearweaponarchive.org/Nwfaq/N ... ml#nfaq6.2

[MSimon]

2. Fission nukes - plutonium guaranteed

Not necessarily. Future fission fuel may not be plutonium at all; instead uranium-233 would be used, created by neutron bombardment of thorium, a much more abundant element then uranium. And according to nuclear weapons archive:

With deliberately denatured grades of U-233 produced by a thorium fuel cycle (0.5 - 1.0% U-232), very high gamma exposures would result. A 10 kg sphere of this material could be expected to reach 11 rem/hr at 1 meter after 1 month, 110 rem/hr after 1 year, and 200 rem/hr after 2 years. Handling and fabrication of such material would have to done remotely (this also true of fuel element fabrication) In an assembled weapon, even if a factor of 1000 attenuation is assumed, close contact of no more than 25 hours/year with such a weapon would be possible and remain within safety standards. This makes the diversion of such material for weapons use extremely undesirable.

Source: http://nuclearweaponarchive.org/Nwfaq/N ... ml#nfaq6.2

What is the chemical extraction process for separating U233 from Th-232? Are there fission products in the mix?

[Zixinus]

What is the chemical extraction process for separating U233 from Th-232? Are there fission products in the mix?

None. U233 is breeded from Th-232 by neutron bombardment. U232 is also produced, which is not a problem with power plants, but a problem for weapons.

The reactions are:
Th-232 + n -> Th-233
Th-233 -> (22.2 min, beta) -> Pa-233
Pa-233 -> (27.0 day, beta) -> U-233

[Isochroma]

Question: because the Polywell design uses Boron for fuel and outputs non-radioactive Helium, does this mean that it won't fall under US nuclear regulatory commission rules?

I mean, anyone with enough money could start operating one of these units because fuel would be available for purchase on the unregulated market (Borax), they could conceivably run it without detection or legal issues.

The reason I ask is that the NRC may become a major stumbling block because it is likely dominated by those who are invested in current nuclear plans (fission, ITER, etc.) [not to mention the Mob]. Being able to bypass them would be very valuable.

So the real question is can the NRC regulate something that neither takes nor produces radioactives?

[drmike]

All governments pretty much do as they please, and when it comes to power, they like it under their own control. It may not be the NRC, but you can bet it will be tightly controlled.

Now, if we can build 100kW power plants that fit in cars and replace hydrocarbon engines, the regulations won't be so stringent and life could get very interesting. But when you look at GW level plants, you can bet anything it will be hard to do in your back yard.

[scareduck]

Now, if we can build 100kW power plants that fit in cars and replace hydrocarbon engines, the regulations won't be so stringent and life could get very interesting.

I think those have been effectively ruled out just by the shielding requirements for p-11B.

But when you look at GW level plants, you can bet anything it will be hard to do in your back yard.

The cost alone would be prohibitive.

[MSimon]

Floating cities disguised as ships.

[seedload]

It doesn't make sense to take an intermediate step using any other reaction other than pB11 for break even power production if WB7/WB8 shows good results and suggests Bussard's predicted scaling is correct.

Be bold. Make the right machine. Don't make a machine that has flaws and can be associated with radiation in any way! Make a clean fusion machine. Leap over the competition by light years. Take no prisoners. Leave room for no political objections.

pB11 sells! This is all a heck of a lot easier if there can be no detractors.

[MSimon]

It doesn't make sense to take an intermediate step using any other reaction other than pB11 for break even power production if WB7/WB8 shows good results and suggests Bussard's predicted scaling is correct.

Be bold. Make the right machine. Don't make a machine that has flaws and can be associated with radiation in any way! Make a clean fusion machine. Leap over the competition by light years. Take no prisoners. Leave room for no political objections.

pB11 sells! This is all a heck of a lot easier if there can be no detractors.

I would run all test machines on D-D. Neutrons are really helpful in proof of concept tests. They are definitive.

There are also a couple of definitive problems to solve with B11. Like how to feed the B11 into the reaction space.

I would avoid D-T altogether. D-T is for wimps with wimpy machines.

[scareduck]

I would avoid D-T altogether. D-T is for wimps with wimpy machines.

No girly-men here!