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Fusion News Ignites Optimism

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Re: Fusion News Ignites Optimism

#21

Post by motoboi »

dabeeeenster wrote: post #11
BrianOnHN wrote: post #10

Earlier quoted context omitted.

I'm trying to ELI5 here, so, "keep dropping heavy-water pellets and pulsing laser beams."

That doesnt sound simple to me. But maybe it is?

A single pellet contains a lot of atoms. The current process is able to fuse some of those but soon the plasma cools down.

The goal is to start fusion by compressing the pellet using lasers and then use magnets to keep the plasma (charged, very hot gas/thing) confined to a small volume and hot enough so fusion becomes a chain reaction until all atoms of the pellet becomes a heavier element, when fusion stops (because a much higher temperature and pressure is required to fuse those).

This will generate a lot of energy which you car harness capturing the heat (by stoping the neutrons it emits or other method).

Use that heat to vaporize water to very high temperatures and use the high pressure to squeeze it through a pipe and then to push a generator.

So, this is a pulse thing. Pellet, laser, fusion, discard. Repeat.

Re: Fusion News Ignites Optimism

#22

Post by wnkrshm »

danpalmer wrote: post #4

While I'm excited for this, I'm also cynical about the public reaction to fusion power as it gets closer to success and eventual general availability. These past 2 years have highlighted to many how a combination of poor critical thinking and politicisation of so many aspects of our lives can lead to literal catastrophes. Will the public see Fusion as the wonderful advancement for humanity that it will likely be, or…

Use of fusion as an energy source removes a lot of threats our civilizations are facing but it also comes with some caveats rooted in human behavior.

Human energy consumption has always gone up when the supply got more efficient, from coal to oil to fission. While here, the power generation itself won't have such a drastic impact (unless humanity overdoes it, though, we seem to always do that) but maybe more power means more consumption and demand for other goods that get used up while using things that consume power. And with enough power you can think about making things that consume more or even build more things that consume more power. Lots of processes that were considered too wasteful suddenly become feasible.

Just like with digital documents, when people predicted that paper wouldn't be needed in the modern economy and the demand for paper would decline, it has actually skyrocketed - because a paper document isn't important anymore. You throw it away and print a new one when it has a crease.

Historically, we've been very bad at predicting such side effects. So I won't buy in a 'fusion solves everything' mindset. Fusion power can be a boon for humanity on a global scale but it could also make some problems worse.

Re: Fusion News Ignites Optimism

#23

Post by tsimionescu »

xupybd wrote: post #7
danpalmer wrote: post #4

While I'm excited for this, I'm also cynical about the public reaction to fusion power as it gets closer to success and eventual general availability. These past 2 years have highlighted to many how a combination of poor critical thinking and politicisation of so many aspects of our lives can lead to literal catastrophes. Will the public see Fusion as the wonderful advancement for humanity that it will likely be, or…

I don't think it will as it should be radically cheaper. It should come with an economic improvement.

Given the current trends, it seems very unlikely that fusion will be even close to competitive with solar or wind by the time it arrives (which is still probably more than 20 years away as a commercial endeavor).

Fusion, in any of its forms, requires some of the highest technology ever produced by mankind. It then exposes these ultra-high-tech wonders to extreme temperatures, and extreme temperature differences, and large amounts of extreme radiation (neutron bombardment), plus corrosion from the extremely fine hydrogen gas. Initial fusion power plants will operate at a very small energy efficiency, and they will need constant maintenance via high-tech robots capable of withstanding the radioactive environment that the neutron bombardment will create all around the reactor. Most pieces of the reactor will probably not last for more than a few months or at best years, due to all of the pressures described before.

Not to mention, the potential for catastrophic failure, though much less than with fission, is still enough to completely destroy the reactor and a good chunk of the plant, if the plasma containment fails. While of course incomparably safer than a fission reactor meltdown, it would still be a massive economic issue.

So commercial fusion, when it does finally arrive (or if), will be extremely expensive, with its only plausible use case as a somewhat reliable base load. Cheap fusion, if it is even possible, is much further away into the future than that - I would confidently bet that cheap fusion will not exist this century, even if ITER or others reach all of their milestones as planned.

Re: Fusion News Ignites Optimism

#24

Post by myrmidon »

danpalmer wrote: post #4

While I'm excited for this, I'm also cynical about the public reaction to fusion power as it gets closer to success and eventual general availability. These past 2 years have highlighted to many how a combination of poor critical thinking and politicisation of so many aspects of our lives can lead to literal catastrophes. Will the public see Fusion as the wonderful advancement for humanity that it will likely be, or…

> fusion power as it gets closer to success and eventual general availability

IMO it is not clear that fusion will ever be useable for power plants: Depending on costs (construction/maintenance/decomissioning), it might never be competitive with (battery backed) photovoltaics (or wind), no matter how much progress we make.

Personally I believe that fusion research is worthwile no matter the outcome, but calling it a "purely academic waste of ressources without positive environmental/economical ROI" might turn out to be correct (playing devils advocate here but this is important to consider, no matter how much pro-nuclear you are).

Re: Fusion News Ignites Optimism

#25

Post by tsimionescu »

motoboi wrote: post #21
dabeeeenster wrote: post #11

Earlier quoted context omitted.

That doesnt sound simple to me. But maybe it is?

A single pellet contains a lot of atoms. The current process is able to fuse some of those but soon the plasma cools down. The goal is to start fusion by compressing the pellet using lasers and then use magnets to keep the plasma (charged, very hot gas/thing) confined to a small volume and hot enough so fusion becomes a chain reaction until all atoms of the pellet becomes a heavier element, when fusion stops (because…

In this case, is the pellet the highly precise gold holhraum described in the article? If that is the case, then isn't this whole thing obviously doomed to failure, given that the entire advancement described consisted of even more sophisticated methods of producing that holhraum?

Re: Fusion News Ignites Optimism

#26

Post by myrmidon »

BrianOnHN wrote: post #5
dabeeeenster wrote: post #3

Can someone ELI5 to me how this design would be industrialised? How do you repeat this process day in day out? Whenever there are articles written about inertial confinement, they always describe the current process (which I understand at a layperson level) but never how this design could be implemented in a repeatable manner?

More energy output than input such that output powers the input and so is a firehose of free money until energy no longer has monetary value. The initial investment may be scary, but I think this is discounted per people's experience with Moore's law (whether right or wrong).

> until energy no longer has monetary value.

"Energy too cheap to meter" was already an obvious scam with nuclear power in 1954* (because plants obviously cost TONS of money to build/operate/decomission).

I don't see how fusion power is going to change that.

edit: * "Obvious scam" might be a bit harsh, but it was definitely naive overenthusiasm at the very least.

Re: Fusion News Ignites Optimism

#27

Post by phreeza »

aristophenes wrote: post #9

I don’t understand the appeal of this type of fusion (as opposed to the plasma reactor approach). We’ve known how to get positive energy out of fusion fuel since thermonuclear weapons in 1952. The really hard part would seem to be capturing that energy efficiently. This experiment is stuck at the ignition phase. When that’s positive energy they won’t be done, they’ll be able to start working on the practical problems…

There was a project to collect energy from thermonuclear bombs by blowing them up in an underground chamber cooled by a shower of molten salt. It was abandoned because the cost of making the bombs was too high, not the energy capture.

https://en.m.wikipedia.org/wiki/Project_PACER

Re: Fusion News Ignites Optimism

#28

Post by tsimionescu »

myrmidon wrote: post #24
danpalmer wrote: post #4

While I'm excited for this, I'm also cynical about the public reaction to fusion power as it gets closer to success and eventual general availability. These past 2 years have highlighted to many how a combination of poor critical thinking and politicisation of so many aspects of our lives can lead to literal catastrophes. Will the public see Fusion as the wonderful advancement for humanity that it will likely be, or…

> fusion power as it gets closer to success and eventual general availability IMO it is not clear that fusion will ever be useable for power plants: Depending on costs (construction/maintenance/decomissioning), it might never be competitive with (battery backed) photovoltaics (or wind), no matter how much progress we make. Personally I believe that fusion research is worthwile no matter the outcome, but calling it a…

> Personally I believe that fusion research is worthwile no matter the outcome, but calling it a "purely academic waste of ressources without positive environmental/economical ROI" might turn out to be correct (playing devils advocate here but this is important to consider, no matter how much pro-nuclear you are).

One thing to remember is that a major goal of fusion research is also weapons applications, those that is never publically admitted.

Re: Fusion News Ignites Optimism

#29

Post by blake1 »

wnkrshm wrote: post #22
danpalmer wrote: post #4

While I'm excited for this, I'm also cynical about the public reaction to fusion power as it gets closer to success and eventual general availability. These past 2 years have highlighted to many how a combination of poor critical thinking and politicisation of so many aspects of our lives can lead to literal catastrophes. Will the public see Fusion as the wonderful advancement for humanity that it will likely be, or…

Use of fusion as an energy source removes a lot of threats our civilizations are facing but it also comes with some caveats rooted in human behavior. Human energy consumption has always gone up when the supply got more efficient, from coal to oil to fission. While here, the power generation itself won't have such a drastic impact (unless humanity overdoes it, though, we seem to always do that) but maybe more power me…

Your first point is not supported by the data. The US Energy Information Agency keeps track of this[1], and the per capita energy use peaked around 2000.

And we are much better at running an energy-efficient economy: energy use/real $ GDP has halved in the last century.

The trend may not continue. People might start to do much more air travel (which would require massive runway building). Global warming might increase the need for AC. But my intuition is that there is some limit to the amount of energy one person can consume.

[1] https://www.eia.gov/totalenergy/data/annual/pdf/sec1_13.pdf

Re: Fusion News Ignites Optimism

#30

Post by danpalmer »

tsimionescu wrote: post #28
myrmidon wrote: post #24

Earlier quoted context omitted.

> fusion power as it gets closer to success and eventual general availability IMO it is not clear that fusion will ever be useable for power plants: Depending on costs (construction/maintenance/decomissioning), it might never be competitive with (battery backed) photovoltaics (or wind), no matter how much progress we make. Personally I believe that fusion research is worthwile no matter the outcome, but calling it a…

> Personally I believe that fusion research is worthwile no matter the outcome, but calling it a "purely academic waste of ressources without positive environmental/economical ROI" might turn out to be correct (playing devils advocate here but this is important to consider, no matter how much pro-nuclear you are). One thing to remember is that a major goal of fusion research is also weapons applications, those that i…

I have never heard of fusion weapons research, or what they would even be. My understanding is limited but where I can see fission leading to weapons, I can't see the same for fusion.

Could you give some more detail? What form would a fusion weapon take? Is it about the laser technology?

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