Why 10-25 times net power?

[djmelfi]

So here is where I am currently at: to equate to the 1400MW 2.4 Billion Nuclear project which is a real one being built.

1.5 meter 100mw scales 1:7



for 1400MW output we need a

1) 4 - 5 meter reactor (depending on capture efficiency)
2) built for $2.4 billion.
3) Boron Fuel costs per year would be $4,200,000. 840,000grams.
4) Possibly both Direct capture and steam tubines maximize capture.


The point here is rather than 40,000 page proposal, the Nuclear model can be trusted (Somewhat) as a commercially viable project and it is a small reach to use their model as a foil for ours. All of the enumerated costs ocassionaly thown out, transpotation, financing, property taxes, etc can be assumed to be folded into the 2.4billion Nuclear plant, and ours as well. Our 1400MW is equal to their 1400MW thus able to cover the associated overheads and produce a profit.

[alexjrgreen]

You have an equal opportunity to be right, but not an equal probability.

Another factless, personalised comment

Chris,

Argument from authority is invalid. Just because Bussard said it doesn't make it so.

Argument from experience, in contrast, is valid. MSimon has actual experience of running a Navy reactor. Rick Nebel has actual experience of running WB7.

Is argument from experience unassailable? No, they could be mistaken; but someone arguing from experience has slightly better odds of being right than someone who isn't.

Best regards,

Alex

[MSimon]

dj,

m = milli 1E-3
M = mega 1E+6

[chrismb]

Argument from authority is invalid. ...

Argument from experience, in contrast, is valid.

Exactly my bloomin' point!
Look at what I wrote:
"I have never tried to do it, which is about as many times as Bussard tried, so I guess that makes us equals in this regard." which IS an argument wrt experience and, thus, is valid by your OWN criteria.

at which point I was picked up by you with

"You have an equal opportunity to be right, but not an equal probability."

Which sounds very much to me like the sentiments of an argument based on authority! How is that an argument from experience, on the subject of direct energy conversion? Just give me the FACTS!!! If Bussard did the experiment, just tell me about it. Else by your own statement you have no argument against my own analysis based on *experience* to bring to the table when claiming what he may or may not have said about it.

You can say what his claims were, sure. And we can pick over those and you will persuade me if the evidence is there. But, please, these one-liners that seek to undermine me, personally, will get the discussion into trouble if the intent is to maintain a degree of scientific objectivity.

[MSimon]

This begins to approach the 200million proposed for BFR 100mw reactor.

The $200 million is the cost of a Program to produce a 100 MW net power reactor. Note that an actual "deliver to the grid power" unit will take more effort possibly as much as several billion more. This all assumes a "normal" development path. An accelerated path could cost 2X to 5X as much.

Actual reactor and power converter costs in production could be as little as $10 million and as much as $100 million with $50 million being my best estimate for early production units. i.e 50 cents a watt which is in line with simple gas turbine units. Provided direct conversion is possible.

$5 per gram of B11 is probably high due to the fact that five or six nines purity is not required. Two to four nines purity is probably adequate with my best guess being three nines.

In addition the time to build a BFR with direct conversion would be considerably less that the time to build a nuke. One year vs. five.

The economics of a pBj BFR are highly favorable IF it works.

[alexjrgreen]

"I have never tried to do it, which is about as many times as Bussard tried, so I guess that makes us equals in this regard." which IS an argument wrt experience and, thus, is valid by your OWN criteria.

Only if you artificially ignore the rest of Bussard's experience, some of which is relevant.

[chrismb]

Only if you artificially ignore the rest of Bussard's experience, some of which is relevant.

I would be interest to hear what relevant experience he had with energy recovery from ion beams. I am not aware of any.

[alexjrgreen]

Only if you artificially ignore the rest of Bussard's experience, some of which is relevant.

I would be interest to hear what relevant experience he had with energy recovery from ion beams. I am not aware of any.

Start here:
http://www.askmar.com/Fusion_files/EMC2 ... plants.pdf

then here:
http://yarchive.net/space/exotic/bussard_ramjet.html

[chrismb]

From:

http://www.askmar.com/Fusion_files/EMC2 ... plants.pdf

"Note that nearly all of the energy of the alpha particles
produced in p11B fusion can be converted with a modest
2 MeV convertor that may be only 0.4!1.6 meters or so
in width. This is because these alphas are at xed and
predictable energies, none exceeds 4 MeV, and their
charge state is always Z = 2."

This is wrong. They come in two wide distributions of alphas and can come at up to 10MeV. see "Observation of neutronless fusion reactions in picosecond laser plasmas V. S. Belyaev, A. P. Matafonov, and V. I. Vinogradov". I've quoted them in another post. This is *experimental* material, that means they are results *taken from an experiment*.

Where is the experimental content regarding energy recovery in this paper you reference, and how does it demonstrate "experience". The author of this paper merely has experience of waffling on about something with erroneous facts.


http://yarchive.net/space/exotic/bussard_ramjet.html

No idea what that's got to do with recovering ion energies. What part of this did you want me to look at?

If you are trying to argue effectively against my posit that energy recovery is fantasy, you will need to provide some more specific references. You can't just point me to 'wikipedia' or whatever generalised text you want to claim makes a point and then claim you've proved some point that the text doesn't cover!!

[TallDave]

There was an article recently (on DailyKos IIRC) that took the number 1.2 from Wikipedia (the ratio of bremsstrahlung to fusion power for a thermalized p-11B plasma) and somehow managed to misinterpret it as the target gain for a p-11B BFR.

Heh, I noticed that too. Didn't go to the trouble of registering to correct it though.

If it works at all, power and gain will both almost certainly scale much faster than capital cost. Barring scale-dependent confinement phenomena, gain should go as the fifth power of the radius, and power as the seventh. Unless capital cost manages to scale faster than linear with power output, which I doubt, it should be quite reasonable to expect a profitable plant somewhere on the curve, and 100 MW is looking pretty comfortable.

Yep. M Simon did some calculations a while demonstrating the limiting factor is probably the ability of Magrid materials to withstand the fusion energies. At that point, we'll only be able to increase power at the rate of the radiative square law, which means costs may rise faster than energy (costs tending to rise as radius cubed). Still, there should be a sizable sweet spot, and materials may get a lot better if this creates a big market for them.

They come in two wide distributions of alphas and can come at up to 10MeV.

Efficiency might be a problem, but alpha conversion is hardly new or radical.

Total efficiency by this calc = 45%

Yes, but remember: that's only the efficiently captured portion of the energy. The rest becomes heat, which is captured in the normal inefficient manner.

So we actually have 33% vs (45 +55/3) = 63%

Even with all the issues it seems likely you still come out way ahead of D-D/D-T, plus you don't have to deal with neutrons.

[djmelfi]

Normal plants convert one energy source to another. Fussion Reactors can be self breeding and convert a realtively cheap feed stock (Boron) to energy. You do not have the continuing cost of energy input in this scenario so it would seem that operational costs would be competitive.

Well yes you do. It is called accelerating the ions.

Thats done from energy from the reactor, hence no "NEW" fuel, we need new energy not new fuel, the Boron forms a catalyst of sorts and is our only NEW fuel and we divert energy from generated output. Assuming a net gain greater than 100%, this seems plausible. I DO GET THE BASICS.

REGARDS THE PHILOSOPHY OF ARGUMENT (HOPE A EUPHENISM FOR DISCUSSION)

Seems to me the source of the argument (experience or authority or other) has little or no pertinernce, it is the destination of the process/argument/exercize that makes the difference. If that is a honest exchange for knowledge and understanding, the source of the argument is irrelevant, the issue is the advancement of the model and/or the understanding of one or more of the participants. The participants have the repsonsibility to sort out the arguments to their own ability, and thus within their own ability they advance their understanding of a theoretical model. One tries to gain support for the model thru a consensus, or modifies the model to encompass valid input.

Any sense of understanding is subjective and personal to each individual, only the final plan and execution and physical model results in certainty.

I am probably more out of my home waters here than any of the participants and the source of all my arguments may be suspect, but I would propose I have benefited the most. For that I thank everyone.

This concept of model building is not outside my experience as I am a retired Software Architect having practiced for 48 years. (Since Wired panels)

It is only when the destination of the argument brcomes twisted that the exercize fails, as it might if the participation was directed toward self-grandisement or egotistical displays.

As long as the focus is on improving the model, the exercize is valid.

I often use the INTEL experience as an example of the modeling exercize, it would seem curious in retrospect to some that INTEL advanced their processors in small increments for years, one would assume it would be more profiteble to skip some of the excrutiating mini steps. Truth is they just didn't know how. Many times the predicted threshold of silicon circuits was passed and exceeded. Without the input from building the next model, they couldn't gain the grounding to advance to the next step. Today computer simulations may approach that ability, but without physically building the current consensus model the NEXT STEP may never be achieved.

This exercize of slowly improving the model is evident in all of mankinds endeavors from Orvill's Popcorn, to Du Bai towers, to Pong and Mario Brothers there is a constant incremental advancement in model building.

[93143]

They come in two wide distributions of alphas and can come at up to 10MeV. see "Observation of neutronless fusion reactions in picosecond laser plasmas V. S. Belyaev, A. P. Matafonov, and V. I. Vinogradov".

I wouldn't exactly call those "wide". If we can handle magrid sputtering (a big if, admittedly), then we can handle high-side sputtering for both bands (or all bands, if you try to subdivide them). Unless, of course, sputtering increases dramatically as you go from 3 MeV to hundreds of keV, which I won't try to rule out (not being an expert in this field).

I am making clear statements to try to elicit a factually based rebuttal of my rejection of the fantasy of direct energy recovery from p11B alphas.

True. But it is not fair to call it a fantasy considering that no one has yet tried to build such a system. (On the other hand, the reverse system is pretty standard; it's called a particle accelerator...) After reading your rather severe either-or statement of the problem, I begin to suspect you of a certain lack of imagination:

viewtopic.php?t=629

The idea presented in that thread has some holes in it as it stands, but I still think it's just a question of sufficient creativity and engineering ability being brought to bear on the problem. If the reactor chamber doesn't have to be super compact, we have more options for trying to herd the alphas around to where we want them. There will definitely be losses, but I think you're being unnecessarily pessimistic at this point.

Hmm... If a lot of collectors at closely-spaced potentials were used for one (or both) of the bands, the insulating spacers wouldn't have to be all that large. They'd rapidly become positive and deflect interband alphas back into the next lowest band at a relatively low residual kinetic energy. Maybe - it would need to be modeled...

Also, trap grid transparency is not an issue if there aren't magnetic coils inside; we should be able to get well above 90%, particularly if the grid doesn't use cylindrical members, and we may be able to hide the thing at least partially in the magrid shadow to further reduce the losses.

[alexjrgreen]

Where is the experimental content regarding energy recovery in this paper you reference, and how does it demonstrate "experience". The author of this paper merely has experience of waffling on about something with erroneous facts.

The paper demonstrates that Bussard was already considering the practical requirements of energy recovery.

Prior art by NASA in this area is here: http://ntrs.nasa.gov/archive/nasa/casi. ... 005651.pdf

http://yarchive.net/space/exotic/bussard_ramjet.html

No idea what that's got to do with recovering ion energies. What part of this did you want me to look at?

Try

Suppose instead we decelerate the incoming protons against an electric field.

Making a Bussard Ramjet work above 0.17c requires this technology, so he had been researching solutions in this field for years.

[djmelfi]

I would be interested in comments on possibility of both thermal conversion AND electron capture in a BORON BFR. I understand the issues of cost for thermal turbines etc, but that suits our 1400MW Nuclear Base comparison. I also understand that Boron plasma will require a much higher heat reaction than a Deutrium reactor.

TallDave Eastimates 63% by combining heat and electron capture, as long as the base arithmetic remains in MW then this makes sense, else if 30% thermal and 90$ electrons arnt MW then it dosnt relate to the model.

Which is why I proposed from the beginning that we try to estmate capture relative to gain vs orignal MW energy required, which is the only yardstick we can put a value on.

If for argument sake we said 1.5 meters has a 100MW gain do we mean from thermal or electron or combination thereof?

Then if we scale that to 3 meters we have 700MW gain, RIGHT?


and at 4.5 meters a 2450MW gain then at:

2450MW GAIN AT 50% capture = 1275MW at 50MW recycle = 1225MW to grid. Somewhat short of our 1400MW $2.4Billion base plant.

2450MW GAIN AT 70% capture = 1700MW at 100MW recycle = 1650MW to grid. Somewhat better than our 1400MW $2.4Billion base plant.

I think we need to do Boron without neutrons because we dont need another dirty Nuclear technology, without the clean incentive we might as well build Fission plants which are viable enough now.

[MSimon]

Normal plants convert one energy source to another. Fussion Reactors can be self breeding and convert a realtively cheap feed stock (Boron) to energy. You do not have the continuing cost of energy input in this scenario so it would seem that operational costs would be competitive.

Well yes you do. It is called accelerating the ions.

Thats done from energy from the reactor, hence no "NEW" fuel, we need new energy not new fuel, the Boron forms a catalyst of sorts and is our only NEW fuel and we divert energy from generated output. Assuming a net gain greater than 100%, this seems plausible.

dj,

It is not energy directly from the reactor as in a tokamak. The Reactor energy first has to be converted to electricity. There will be losses.

The ultimate gain of pB11 operated at about 50 KV well depth (around 65 KV drive voltage) is about 22 (fusion power out/electrical energy in) this does not count Bremss. or any other parasitic losses. Such as the losses from operating the reactor hydrogen rich to prevent excessive Bremss.

And the Boron is not a catalyst. It is one element of the fuel mixture. The other element is hydrogen.

Now as to your other points: It is a New Year and I'm in an unusually kind hearted mood (I blame the likker) so I'm not going to address them. Let me just say that further study on your part might prove advantageous in preventing future embarrassment.

Let me add that there is a huge amount of ground to cover to get into the technical stuff. Those of us who have been at it for two years or so have a huge advantage in having assimilated the stuff slowly over that time so we have had a considerable amount of time to think a lot of this stuff through.

We can help you through the difficult points and you may even come up with stuff that hasn't been properly addressed. But it is easier if you show a little humility (I know - it is hard - I don't do it well either).

Well any way. Have a Happy New Year. The regulars will do their best to bring you up to speed.