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U.S. physicists rally around plan to build fusion power plant

sciencemag.org

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Re: U.S. physicists rally around plan to build fusion power plant

#211

Post by pontifier »

UnchartedSystem wrote: post #94
pontifier wrote: post #69

Ok, say I've got a new design for a fusion reactor, but it takes me 5 years to convince anyone that it's worth investigating. Fusion power has been set back 5 years. Someone please help me evaluate my design. Please! http://www.DDPROfusion.com

I've been helping with messaging for somebody looking for demonstration funding for an experimentally proven clean oil recovery technology and it makes me feel hopeless seeing there are so many people struggling to demonstrate potentially game changing technologies, often because people investing or allocating money have little technical competence. for those curious: http://www.envirotechdme.com If I could offer you…

Thank you for your advice. Communicating a new idea effectively is quite difficult. I have been thinking about doing some explainer videos.

I took a look at your site and had some thoughts I wanted to share with you.

Re: U.S. physicists rally around plan to build fusion power plant

#212

Post by to11mtm »

elihu wrote: post #11
est31 wrote: post #5

Earlier quoted context omitted.

Won't batteries run into the Lithium problem? I heard somewhere that the global Lithium reserves allow us to convert the entire car fleet of humanity to electric, but not anything beyond that, certainly not allowing large scale battery deployments that would make a dent.

I think at the moment cobalt is more of a constraining resource (though not all rechargeable battery chemistries require cobalt).

The 'best' ones currently do, which is the challenge. To wit; LiFePO4 (I don't know how to do subscript on HN, sorry) chemistries aren't exotic, and tend to be more 'stable'. But, you lose about 14% capacity per volume. [0]

[0] - https://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery...

Re: U.S. physicists rally around plan to build fusion power plant

#213

Post by pfdietz »

deweller wrote: post #116
olau wrote: post #110

Earlier quoted context omitted.

Fusion is not going to solve the sea level rise problem. You can see this by comparing it to fission. Fission fuels is not expensive on a kWh base, so cheaper fuel is not really a big advantage. Fusion plants produce radioactive waste too (perhaps less?), so you don't save yourself from that headache. Which isn't actually that big of a problem either, even if the costs are probably underestimated for fission plants.…

Fusion does not create any long-lived radioactive waste.

Fusion will likely produce a larger volume of waste contaminated enough to prevent easy disposal. That could very well make the waste more expensive to deal with.

Re: U.S. physicists rally around plan to build fusion power plant

#214

Post by pfdietz »

Gwypaas wrote: post #131
olau wrote: post #110

Earlier quoted context omitted.

Fusion is not going to solve the sea level rise problem. You can see this by comparing it to fission. Fission fuels is not expensive on a kWh base, so cheaper fuel is not really a big advantage. Fusion plants produce radioactive waste too (perhaps less?), so you don't save yourself from that headache. Which isn't actually that big of a problem either, even if the costs are probably underestimated for fission plants.…

Wouldn't the major differentiator be the safety standards? You can't have a runaway reaction, because you need energy input to the magnet field to get more energy out. Instead of creating the right environment to get a chain reaction started if your control rods end up in the wrong place. Drop the magnet field and it all collapses. Even if you lose control of it with the magnet field on the quantity is limited, tokam…

Fusion will still require a containment building because of tritium and because of the pressure from volatilized cryogenic coolants. The building will also require very strict control of tritium escape in normal operation. Remember, a 1 DW(e) DT reactor will burn enough tritium in one year to contaminate 2 months total flow of the Mississippi river above the legal limit for drinking water.

Fusion will also require highly reliable equipement, just like fission. Not because of safety, but because the fusion reactor will be complicated and very difficult to repair. The reactor itself, even the magnets, will be irradiated and activated beyond the point where hands on maintenance could be performed.

Re: U.S. physicists rally around plan to build fusion power plant

#215

Post by jl6 »

pontifier wrote: post #210
jl6 wrote: post #198

Earlier quoted context omitted.

This answer explains nicely why the “editorial we” is OK in papers...: https://academia.stackexchange.com/questions/2945/choice-of-... Short version: because it can be read as “we, the author and the reader”. But the site above uses phrases like “we have been granted a patent”, which come across as somewhat dishonest, making it appear on first glance as though this is the work of a team, corporate body, or at least t…

I've had several mentors and advisors and am doing everything I can to be inclusive without giving away equity. There was a legal entity created, and I have applied for several grants. Each time, I have put together a team or had lined up collaborators who could help if the grant had been awarded. I'm working with suppliers, and discussing the concept openly with everyone who is interested. Most of the time however,…

Are you trying to start a business or do scientific research? I think you’ll struggle to get investors interested in an idea that hasn’t been validated, and you’ll struggle to get academics interested in helping a money-making venture.

You might need to make a tough call to do one or the other.

Re: U.S. physicists rally around plan to build fusion power plant

#216

Post by pfdietz »

joncrane wrote: post #142
willis936 wrote: post #134

Earlier quoted context omitted.

>”Break-even" is nowhere near enough to get practical power out, because the energy extraction process must be so inefficient, with two stages of heat exchange before you get a working fluid you can run through your turbine. Correction: break-even is most of the way to a working plant. A “burning fusion plasma” is one that self heats. The plant requires very little power when the plasma is supplying most of its own h…

Liquid lithium wall blanket? I've heard the use of Lithium as a tritium breeder (which is important, assuming we're committed to duterium-tritium fusion), but never as a liquid. it makes sense though because in that case you don't have to completely disassemble the tokamak and replace the neutron blanket every few years(?). But again the technology to completely coat the inside of the tokamak in an even layer of liqu…

The Achilles Heel of fusion is low volumetric power density. This is because all the energy has to go through the first wall, which has limited area compared to the surfaces of fuel pins in a fission reactor.

So, there's been effort to try to maximize the power/area at the first wall. One part of that is the power that directly strikes the surface (ions, electrons, photons). The capacity to carry away this heat is limited by the strength of the wall material and its thermal conductivity, a fact that was pointed out by Pfirsch and Schmitter in the 1980s.

https://pure.mpg.de/rest/items/item_2131865_1/component/file... (see section 4.1.1)

One could raise this limit by doing away with a solid wall (with its limits on thermal conductivity and stress) and instead using a liquid wall. This would also address erosion of the wall by sputtering, and help reduce damage from plasma disruptions (which may well otherwise be a showstopper for tokamaks.)

Re: U.S. physicists rally around plan to build fusion power plant

#217

Post by pfdietz »

lambdatronics wrote: post #202
ncmncm wrote: post #130

Earlier quoted context omitted.

Yes, yes we are at an inflection point. But maybe not the kind you are thinking of. There will never be a commercial tokamak power plant. There has never, at any time, been any reasonable expectation of getting practical, commercial power from magnetic-confinement hot-neutron fusion. Renewables, with practical energy storage, will always be much, much cheaper than fusion could ever have been, even if it could be made…

>There has never, at any time, been any reasonable expectation of getting practical, commercial power from magnetic-confinement hot-neutron fusion. Not true. The existence of privately-funded fusion efforts implies that some people think there is a reasonable expectation, and are willing to put money behind it. This costing study suggests that $2-6/W could be achievable for some fusion concepts[0]. Using some rough c…

> Not true. The existence of privately-funded fusion efforts implies that some people think there is a reasonable expectation

Examine some of those efforts in detail and you will realize utterly bonkers nonsense can still get funding. One well known effort was told 20 years ago their scheme didn't work, but wishful thinking springs eternal.

Re: U.S. physicists rally around plan to build fusion power plant

#218

Post by Lammy »

jasonwatkinspdx wrote: post #206
Lammy wrote: post #101

Earlier quoted context omitted.

Yep, and it is not just feasible but easy to build fission plants right now and stop using greenhouse-gas emitters entirely, but we won't, because Reasons. Our collective focus is being distracted from that working, clean, but politically-disadvantageous tech to this non-functional speculative future-tech that the author simultaneously insults.

People love to post comments like this on every thread where nuclear comes up, but it really distorts the reality of the situation. Investment in nuclear has essentially evaporated. This is because fission plants take billions of dollars and around a decade to stand up. If you go through the numbers the ROI looks pretty ugly. Meanwhile you can look at the trend over time in levelized energy costs and storage costs, a…

> Even if you waved a magic wand and eliminated any form of political opposition, that doesn't change this less than favorable cost picture.

The cost is the manifestation of the political opposition.

Re: U.S. physicists rally around plan to build fusion power plant

#219

Post by pfdietz »

wiml wrote: post #68
garmaine wrote: post #33

Earlier quoted context omitted.

For most of my life fusion has been perpetually 30 years away. Now it is only perpetually 20 years away. That's progress!

This graph often gets mentioned in the context of "always 30 years away": https://imgur.com/3vYLQmm It's not on "schedule" because we aren't putting the resources towards it.

That graph was for a crash program under the assumption that tokamaks work better than it turns out they do.

So, if that money had been allocated, it would have been a failure. There was also not the appreciation then of the grave nature of the engineering challenges facing fusion, even if the plasma physics worked wonderfully.

The implication that we'd have had fusion if that money had been spent is not supported by the evidence.

Re: U.S. physicists rally around plan to build fusion power plant

#220

Post by pfdietz »

mchusma wrote: post #58
garmaine wrote: post #33

Earlier quoted context omitted.

For most of my life fusion has been perpetually 30 years away. Now it is only perpetually 20 years away. That's progress!

Both ITER is scheduled to be done and SPARC are trying to make net energy in 5 years. They probably won't hit those dates, but we aren't really talking about 20 years anymore. (I agree with several commenters on this thread that any project with a 20 years to completion timeline should be shelved for things with <10 year timelines).

ITER won't even start burning DT until 2035 or so (assuming they control disruptions enough to be allowed to introduce tritium.)
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