Fusion energy


mikbone
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23 minutes ago, mikbone said:

Still betting we will have a viable fusion reactor creating reasonable amounts of energy before civilians are jetting around in flying cars that can be parked in the garage.

Or the USA win the world cup.

Well, yeah.

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57 minutes ago, Carborendum said:

This right here is a big clue that this process is massively inefficient.

Excellent point! I should have thought of that. Do you think a battery of lasers delivering 2.05 MW could possibly be more than 50% efficient? I'm thinking a lot less than 50%. That means you double the energy in, meaning that you don't even break even in raw energy production any more, much less in usable energy.

It's a scam, I'm telling you. Don't buy into the claims.

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4 hours ago, Vort said:
4 hours ago, LDSGator said:

From what I’ve read (and I am no expert, so again @Vort call me out if I’m wrong) nuclear is actually much cleaner than most all other power sources we have now! 

Ftfy.

FTR, snarky though my answer was, it is true. If we're talking about molten salt reactors (which don't exist today in a usable commercial form), the proposition is so obviously true it needs no defending.

But even if we're talking about modern light-water reactors using uranium ceramic fuel pellets (but not Chernobyl-style or even Fukushima-style reactors, worthless, corrupt designs overseen by a corrupt administration using feudal-period regulatory practices; think more like modern French reactors, or standard US reactors), the assertion still holds up. Solar power and wind power are the two biggies for the "no-impact" movement. Yet even if we ignore the rare-earth problems each of these technologies inevitably encounter, we still have to realize that the ROI is simply vastly lower for solar or wind than for fission. Like, orders of magnitude lower.

Consider also the footprint problem. Solar cells take up a lot of space to generate electricity. If the space is "wasted", e.g. a rooftop, then that's perfect. But have you driven by any so-called solar farms? That's a whoooole lot of acreage taken up by solar panels. What of the grass, trees, etc. that will not be growing on that land because there are solar panels there? Windmills amount to much the same thing. And while the bird-blender thing is greatly overstated, windmills are so capricious that they cannot be considered a dependable energy source, certainly never a primary source for the public grid.

All of these problems produce some kind of "waste", usually physical but also just problematic issues that complicate things and decrease reliability. Fission produces shockingly little waste, can be made to produce a great deal less waste than it currently does (especially using molten salt reactors--anyone sensing a theme?), and is rock-solid reliable as long as you have several plants on-grid.

Edited by Vort
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4 minutes ago, mikbone said:

How’s about some lukewarm fusion?

I'm still secretly hoping that cold fusion wasn't just a hoax or a misreading, but actually represents a real fusion process. Unlikely? Well...yes. But there is some intriguing evidence that Pons and Fleischmann might have been on to something.

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1 hour ago, Vort said:

FTR, snarky though my answer was, it is true. If we're talking about molten salt reactors (which don't exist today in a usable commercial form), the proposition is so obviously true it needs no defending.

But even if we're talking about modern light-water reactors using uranium ceramic fuel pellets (but not Chernobyl-style or even Fukushima-style reactors, worthless, corrupt designs overseen by a corrupt administration using feudal-period regulatory practices; think more like modern French reactors, or standard US reactors), the assertion still holds up. Solar power and wind power are the two biggies for the "no-impact" movement. Yet even if we ignore the rare-earth problems each of these technologies inevitably encounter, we still have to realize that the ROI is simply vastly lower for solar or wind than for fission. Like, orders of magnitude lower.

Consider also the footprint problem. Solar cells take up a lot of space to generate electricity. If the space is "wasted", e.g. a rooftop, then that's perfect. But have you driven by any so-called solar farms? That's a whoooole lot of acreage taken up by solar panels. What of the grass, trees, etc. that will not be growing on that land because there are solar panels there? Windmills amount to much the same thing. And while the bird-blender thing is greatly overstated, windmills are so capricious that they cannot be considered a dependable energy source, certainly never a primary source for the public grid.

All of these problems produce some kind of "waste", usually physical but also just problematic issues that complicate things and decrease reliability. Fission produces shockingly little waste, can be made to produce a great deal less waste than it currently does (especially using molten salt reactors--anyone sensing a theme?), and is rock-solid reliable as long as you have several plants on-grid.

Are you optimistic more communities will switch to nuclear in the future? 

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3 hours ago, Vort said:

Excellent point! I should have thought of that. Do you think a battery of lasers delivering 2.05 MW could possibly be more than 50% efficient?

Standard lasers only reach efficiencies of about 10% at best.  Diode lasers have been known to be as high as 60% or so.  HOWEVER, diodes are limited in their application.  Today's diodes can only be used in low power applications. 

To scale up to a practical power grid type scenario, we'd have to research new diode technology that can be used in high energy, large scale applications.  That puts the diodes at least 30 years into the future.  Then fusion another 25 years beyond that.

So, there has to be some sort of unanticipated breakthrough for fusion to be a reality.  All this talk of 25 years is just flapping our gums.

But it's worse than that.  The main reason why it will be impossible is the biggest model of a fusion reactor we have -- the sun.  OK, it's not just a model.  It's the real deal.  But think about this:

Quote

 Theoretical models of the Sun's interior indicate a maximum power density, or energy production, of approximately 276.5 watts per cubic metre at the center of the core, which is about the same power density inside a compost pile.

 -- https://en.wikipedia.org/wiki/Sun

That's not a huge energy rate for a given volume, especially when considering that the sun's core has a specific gravity of about 150.  Modern power plants are usually in the 100s of MW range.  How many m^3 of solar mass would we need?*

The sun requires no energy to fuse the atoms together.  It's all done by gravity.  And that is the rate of energy that is possible with that much mass.

  • So, were are we going to get that much mass?  
  • How are we going to fuse it together at a rate more efficient than gravity?
  • Where are we going to put a reactor large enough to process that much hydrogen at a rate sufficient to produce any useful amount of energy?

And that is just to produce the heat.  Then we have to change that heat into mechanical energy to generate electrical energy.

They're so busy trying to push the big picture that they forget that the little details already prohibit it.  

I'll start believing in it when they get a working power plant that doesn't blow up an area larger than Rhode Island.

Edited by Carborendum
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No one has mentioned how freakin cool the reactors are though.

Come-on it’s a Tokamak.

6368D7C4-9B4A-405C-8004-FD0590A0EEF1.thumb.webp.521efb9eeef84fc5c07212d45a2c5ec3.webp

Even if we don’t get reliable energy for 50-100 years we are gonna learn a crud ton of science.

Magnets, Plasma, freakin sharks with lasers.  

How can we not be hopeful.

Godspeed!

And here in California!

I was so hacked when they decided to stop the construction of the supercollider in Texas.

Now CERN is having all the fun.

Edited by mikbone
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Imagine what we could do if we didn’t have a $31T national debt.

Or if we took all the money spent on health care awareness or LGBTQ+ studies…

We would likely have a working Thorium reactor or ten by now.

Remember when we went to the moon in ‘69 with slide rules?

Edited by mikbone
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3 hours ago, Carborendum said:

Standard lasers only reach efficiencies of about 10% at best.  Diode lasers have been known to be as high as 60% or so.  HOWEVER, diodes are limited in their application.  Today's diodes can only be used in low power applications. 

To scale up to a practical power grid type scenario, we'd have to research new diode technology that can be used in high energy, large scale applications.  That puts the diodes at least 30 years into the future.  Then fusion another 25 years beyond that.

So, there has to be some sort of unanticipated breakthrough for fusion to be a reality.  All this talk of 25 years is just flapping our gums.

But it's worse than that.  The main reason why it will be impossible is the biggest model of a fusion reactor we have -- the sun.  OK, it's not just a model.  It's the real deal.  But think about this:

That's not a huge energy rate for a given volume, especially when considering that the sun's core has a specific gravity of about 150.  Modern power plants are usually in the 100s of MW range.  How many m^3 of solar mass would we need?*

The sun requires no energy to fuse the atoms together.  It's all done by gravity.  And that is the rate of energy that is possible with that much mass.

  • So, were are we going to get that much mass?  
  • How are we going to fuse it together at a rate more efficient than gravity?
  • Where are we going to put a reactor large enough to process that much hydrogen at a rate sufficient to produce any useful amount of energy?

And that is just to produce the heat.  Then we have to change that heat into mechanical energy to generate electrical energy.

They're so busy trying to push the big picture that they forget that the little details already prohibit it.  

I'll start believing in it when they get a working power plant that doesn't blow up an area larger than Rhode Island.

When I wrote that I wouldn't want to get into the technical details of why fusion "just like the sun!" is impossible, this is exactly what I had in mind. The sun produces energy at a volumetric rate roughly equal to that of the human body. Using fusion of the type [ 4 1H → 4He + 2ν (neutrinos) + γ rays ], like the sun does, would result in a local reactor of spherical shape about a mile across, or far bigger if it's not spherical and/or not over 100 meters or so in height. It's not merely an engineering impossibility, it's an engineering stupidity. No one could or would build that.

Edited by Vort
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3 hours ago, mikbone said:

Even if we don’t get reliable energy for 50-100 years we are gonna learn a crud ton of science.

Magnets, Plasma, freakin sharks with lasers.

I don't disagree, but it should not be couched in terms of liberating humanity from its energy dependency. That will not happen in my lifetime, not with fusion, and may pretty likely never happen. (Unless non-muon-catalyzed cold fusion is a thing, in which case all bets are off.)

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2 hours ago, mikbone said:

Imagine what we could do if we didn’t have a $31T national debt.

Or if we took all the money spent on health care awareness or LGBTQ+ studies…

We would likely have a working Thorium reactor or ten by now.

Remember when we went to the moon in ‘69 with slide rules?

2 hours ago, Carborendum said:

The only thing stopping us is the political will.  We have the technology.  We can build them.

bravo-applause.gif

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Fusion.thumb.JPG.9832b94b93947b1626923aacac1c9fb2.JPG

So, our good friend Kyle Hill (Because Science) shows exactly what I was talking about with lasers.  

No.  We have not created more energy than we started with.  The claim from the NIF was basically, we put 1.3 MJ into "the reaction" (i.e. the final few steps only) and got about 30 MJ out.  That ignores the fact that they started out with 400 MJ. 

But even Kyle doesn't take into account the steps before that.  We have to gather the deuterium.  That takes energy to separate from water.  Then there are maintenance costs of the actual facility being subject to such high temperatures...

Kyle points out that we're at step 2 of 4.  And, yes, we have done that.  Step 3 is another 50 to 100 years away, maybe longer (or impossible).

Step 4?  That will be REALLY far away.  But an interesting note is that step 4 will actually be a hybrid fission/fusion reactor -- not in the way that most people think.  So, if we need to utilize fission anyway, why are we not doing it now?

Edited by Carborendum
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On 12/13/2022 at 5:20 PM, Carborendum said:

Theoretical models of the Sun's interior indicate a maximum power density, or energy production, of approximately 276.5 watts per cubic metre at the center of the core, which is about the same power density inside a compost pile.

This seems misleading.

I have a hard time comparing the sun to a compost heap.

Sure the sun is huge and it takes an enormous mass to reach the heat and pressure to ignite fusion.  But only a very small percentage of the Hydrogen is converted to Helium.

No one would compare a nuclear warhead to a compost heap.

Although granted you could produce a compost heap large enough to make a star.  

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1 hour ago, mikbone said:

This seems misleading.

I have a hard time comparing the sun to a compost heap.

Sure the sun is huge and it takes an enormous mass to reach the heat and pressure to ignite fusion.  But only a very small percentage of the Hydrogen is converted to Helium.

No one would compare a nuclear warhead to a compost heap.

Although granted you could produce a compost heap large enough to make a star.  

I can see why you'd think that.  It really is a good argument.  But ironically, it is just the opposite.  

The primary point I was trying to make is that (after all things are considered) nature itself tends to have methods which will be the most efficient.  It is based on the proposition that we can work *with* entropy instead of struggling against it.  Gravity is an amazing force of entropy.  Yet stars use it for free to generate power.  It's how plants can use chlorophyll to convert light energy into chemical energy at a near 100% efficiency.  Nothing man has ever produced even comes close to that.

We understand this principle with natural selection, but it is just as true with planetary alignments, and fusion reactions within the cores of stars.  Heck, even the Constitution was based on an analogous principle. (No thread jack intended).

If we accept this philosophy (which I grant is not a hard-and-fast rule for 100% everything in nature) then man must pursue either of the two options:

A) Accept that the reasonable rate of energy produced through fusion will have an upper limit of what stars produce.

OR

B) Provide a clear and convincing reason why man's innovation has a chance of bettering nature.

I freely admit that man has been able to accomplish (B) in many instances throughout history.  But so far, we have not even come close to describing why or how we can do that when it comes to fusion.

So far, we've only been able to release tiny amounts of energy with a tiny amount of matter.  As we increase the energy requirement to power plant levels, we're talking about increasing the mass input.  As mass input goes through, we'll have lower rates of reaction.  This is true of all energy production.

It has taken over 100 years to get certain components into the 90% efficiency range.  And a LOT of what is under the hood is geared towards that.  But when all things are considered, that 90% goes down to about 25% (similar to the energy flow chart from Kyle Hill above).  That's 100 years of after reaching Stage 4.

I am guessing the world will fall apart a lot sooner than that.  And we'll be in the Millennium (or our children will).  Then angels can instruct us on how to do it right.

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