Doesn't nuclear bombs prove that its possible to get free energy?

[Vmedvil]

1 hour ago, mistermack said:

That's been true up to now, but it's not the whole story. The ITER reactor being built at the moment is designed to produce more than it uses by a large factor of about 10. And in any case, the energy that you put in doesn't have to go to waste. 

Say you put in X amount of energy, and it produces 0.5X of extra energy, then you finish up with 1.5X of energy, for each X of input. If you can make the most of that 1.5X of energy, then it's not so bad. The problem is, you put in expensive energy like electricity, and get out lower grade energy like heat. That's why you need a good ratio of power out to power in.

But if you could use nearly all of the heat produced for productive projects, after it has generated electrical power, then the economics would be far more favourable. Low grade heat could be used in greenhouses in cold countries, and to heat cities. Maybe they could use it in hot countries to purify water.

Anyway, it will come, it's just annoying that it's taking so long.

Yes, but the Europeans had to build it larger to do that I know but it has not been built yet, when it finally comes online you may find "Technical Difficulties" that were unexpected you know how that goes.

Edited November 25, 2017 by Vmedvil

[Sensei]

26 minutes ago, swansont said:

He-3 fusing with what?

With itself.

He-3 + He-3 -> He-4 + p+ + p+ + 12.86 MeV

But it requires higher temperature to ionize gas (larger energy needed to eject electrons than with Hydrogen,Deuterium,Tritium).

And then larger temperature and larger energy needed to pass through Coulomb's barrier.

 

 

[Vmedvil]

8 minutes ago, Sensei said:

With itself.

He-3 + He-3 -> He-4 + p+ + p+ + 12.86 MeV

But it requires higher temperature to ionize gas (larger energy needed to eject electrons than with Hydrogen,Deuterium,Tritium).

And then larger temperature and larger energy needed to pass through Coulomb's barrier.

 

 

Yes, but with a different size which even applies the same shape everything will be slightly different which will take time to get correct magnetic field strength and such real life isn't always as pretty as theoretical values and models, it is always more variable, why because of the planck constant being so small and actions of length and time being the same way.

Edited November 25, 2017 by Vmedvil

[Moontanman]

5 hours ago, swansont said:

He-3 fusing with what?

 

Helium Three fusing with Helium Three amongst other things. 

 

"Aneutronic fusion"

Quote

Candidate reactions[edit]

Multiple fusion reactions have no neutrons as products on any of their branches. Those with the largest cross sections are these:

High nuclear cross section aneutronic reactions[2]

IsotopesReaction

Deuterium–helium-32D+3He→ 4He+1p+ 18.3 MeV

Deuterium–lithium-62D+6Li→24He  + 22.4 MeV

Proton–lithium-61p+6Li→4He+3He+ 4.0 MeV

Helium-3–lithium-63He+6Li→24He+1p+ 16.9 MeV

Helium-3-helium-33He+3He→ 4He+2 1p+ 12.86 MeV

Proton–lithium-71p+7Li→24He  + 17.2 MeV

Proton–boron1p+11B→34He  + 8.7 MeV

Proton–nitrogen1p+15N→ 12C+4He+ 5.0 MeV

 

[mistermack]

From what I've seen, helium3 would require far higher energies to fuse. As controlling a plasma is currently only possible for a few seconds, and projected for the ITER reactor for runs of only 15 to 20 minutes, at far far lower energy levels, there isn't a lot of point in going down the helium3 route any time soon. The technology just isn't there, and it doesn't look like it will be there for a very long time, if ever.

The molten salt reactor is  bit of a mystery. I've not read of any serious problems with the concept, and don't really understand why it hasn't been developed to commercial levels. It seems to have a long list of advantages, and very short list of snags.  Anybody know more about it?

[Moontanman]

3 hours ago, mistermack said:

From what I've seen, helium3 would require far higher energies to fuse. As controlling a plasma is currently only possible for a few seconds, and projected for the ITER reactor for runs of only 15 to 20 minutes, at far far lower energy levels, there isn't a lot of point in going down the helium3 route any time soon. The technology just isn't there, and it doesn't look like it will be there for a very long time, if ever.

The molten salt reactor is  bit of a mystery. I've not read of any serious problems with the concept, and don't really understand why it hasn't been developed to commercial levels. It seems to have a long list of advantages, and very short list of snags.  Anybody know more about it?

 

 

The main reason it wasn't pursued had to do with nuclear weapons production. Molten salt reactors aren't as conducive to making things like plutonium or Uranium 235. 

Several relevant U tube videos  are available... 

[Strange]

19 minutes ago, Moontanman said:

Several relevant U tube videos  are available... 

U₂₃₅ Tube ?

[swansont]

4 hours ago, mistermack said:

 The molten salt reactor is  bit of a mystery. I've not read of any serious problems with the concept, and don't really understand why it hasn't been developed to commercial levels. It seems to have a long list of advantages, and very short list of snags.  Anybody know more about it?

Coolant leaks become the equivalent of core breaches when the fuel and fission products are all dissoved in the salt. Your entire primary system has a bunch of radioactive material in it, even after you've shut down. And there's lots of nasty chemistry going on in the coolant.

[Moontanman]

9 hours ago, swansont said:

Coolant leaks become the equivalent of core breaches when the fuel and fission products are all dissoved in the salt. Your entire primary system has a bunch of radioactive material in it, even after you've shut down. And there's lots of nasty chemistry going on in the coolant.

Citation? the info I've seen, admittedly dumbed down, says there is no possibility of a core breach in the ways it currently occurs and such a breach would be a local non explosive event because of the low pressure environment of the reactor and the coolant. No mention of any bad chemistry going on in the coolant but the purveyors of this system would appear to be a little less than neutral IMHO.   

A new one... 

 

 

[Sensei]

53 minutes ago, Moontanman said:

No mention of any bad chemistry going on in the coolant but the purveyors of this system would appear to be a little less than neutral IMHO.   

Salt atom bombarded by free neutrons, produced during decay of U-235, can be captured, and changing atom to something else..

f.e. "Similarly, any lithium present in a salt mixture must be in the form of purified lithium-7, because lithium-6 effectively captures neutrons and produces tritium. Even if pure 7Li is used, salts containing lithium will cause significant tritium production, comparable with heavy water reactors."

https://en.wikipedia.org/wiki/Molten_salt_reactor

Edited November 29, 2017 by Sensei

[swansont]

8 hours ago, Moontanman said:

Citation? the info I've seen, admittedly dumbed down, says there is no possibility of a core breach in the ways it currently occurs and such a breach would be a local non explosive event because of the low pressure environment of the reactor and the coolant.

I thought this would be obvious. If you have a primary coolant leak, you have released fuel and fission products. They are not contained.

8 hours ago, Moontanman said:

No mention of any bad chemistry going on in the coolant but the purveyors of this system would appear to be a little less than neutral IMHO.   

The fuel, all of your fission products, plus the salt (which usually contains fluorine), and there's no bad chemistry? You've got half the periodic table involved. You'll have corrosion issues and metals plating out on the cooler surfaces (like the heat exchanger)

[Moontanman]

13 hours ago, Sensei said:

Salt atom bombarded by free neutrons, produced during decay of U-235, can be captured, and changing atom to something else..

f.e. "Similarly, any lithium present in a salt mixture must be in the form of purified lithium-7, because lithium-6 effectively captures neutrons and produces tritium. Even if pure 7Li is used, salts containing lithium will cause significant tritium production, comparable with heavy water reactors."

https://en.wikipedia.org/wiki/Molten_salt_reactor

The issue with the tritium is addressed in the video. I would love to discuss this in detail but as you know it is beyond me and all I can do is parrot what the experts say. Thanks for the link. 

https://en.wikipedia.org/wiki/Generation_IV_reactor

4 hours ago, swansont said:

I thought this would be obvious. If you have a primary coolant leak, you have released fuel and fission products. They are not contained.

The fuel, all of your fission products, plus the salt (which usually contains fluorine), and there's no bad chemistry? You've got half the periodic table involved. You'll have corrosion issues and metals plating out on the cooler surfaces (like the heat exchanger)

Not obvious, they would still be contained as they do not explode or operate under high pressure... Bad chemistry is a subjective term. Bad in comparison with what? 

[swansont]

1 hour ago, Moontanman said:

Not obvious, they would still be contained as they do not explode or operate under high pressure...

By definition if you have a leak, the material is not contained. I said nothing about an explosion.

Quote

Bad chemistry is a subjective term. Bad in comparison with what? 

In comparison to chemistry involving a much smaller subset of the elements.

[Moontanman]

38 minutes ago, swansont said:

By definition if you have a leak, the material is not contained. I said nothing about an explosion.

In comparison to chemistry involving a much smaller subset of the elements.

 Well you may be right! I may be crazy! (enough song lyrics...) Seriously, all I can do is parrot what experts in the field say, In many places I see the people who are supposed to know say that these things are not a big problem. Many of them are not explicitly or obviously defending a position emotionally or for financial gain. But I do enjoy taking in the information... 

[Sensei]

Quote

Bad chemistry is a subjective term. Bad in comparison with what? 

If some element changes to other element, as a result of bombarding it by free neutrons, then it's not chemistry, but physics. From initial state, when reactor is started with just some U-235, U-238, salt, there is created bunch of other elements that was not there before.. and scientists don't know what is there until checking it..

 

Edited November 29, 2017 by Sensei

[Moontanman]

1 hour ago, Sensei said:

If some element changes to other element, as a result of bombarding it by free neutrons, then it's not chemistry, but physics. From initial state, when reactor is started with just some U-235, U-238, salt, there is created bunch of other elements that was not there before.. and scientists don't know what is there until checking it..

 

I think the idea was to use thorium instead of uranium but point taken.. 

[swansont]

4 hours ago, Sensei said:

If some element changes to other element, as a result of bombarding it by free neutrons, then it's not chemistry, but physics. From initial state, when reactor is started with just some U-235, U-238, salt, there is created bunch of other elements that was not there before.. and scientists don't know what is there until checking it..

That's not what I was talking about. The chemistry happening is taking place in the system after the fission takes place.

[mistermack]

As far as leaks go, it's the likelihood of a leak to the environment that's important. If there is no prospect of a breach of the outer building, then it's not much of a risk. Compare it to the Japanese accident, or Chernobyl or Three Mile Island. At present, there is a theoretical risk of very nasty accidents at the standard fission power stations. But we take the risk, and manage it, and make it as small as possible. It looks to me like the basic risks are lower in a molten salt reactor, and can be designed to be much lower, with some designs. The worst that can happen is probably a big earthquake, or a direct bomb hit, and I think those things can be covered in the design.

I haven't read of any materials problems that are considered a stumbling block. I think the experimental reactor threw up very few serious problems in that regard. If you looked at modern nuclear power stations in terms of the problems and risks, you could produce a pretty formidable list, and a strong case for never going down that road. But once you've started, you can end up with a practical power station that has a place in modern generation.