Compact nuclear fusion reactor is 'very likely to work,' studies suggest • Hacker News Board

Re: Compact nuclear fusion reactor is 'very likely to work,' studies suggest

#211

Post by willis936 » Wed, Sep 30, 2020, 2:05 AM UTC

shellfishgene wrote: post #99

nielsbot wrote: post #68

My current favorite future fusion reactor project (I'm a layperson) is the Wendelstein 7-X: https://en.wikipedia.org/wiki/Wendelstein_7-X Seems like they're meeting all their planned milestones and it's going well! Excited for their next updates... More from their project page: https://www.ipp.mpg.de/w7x "Wendelstein 7-X is the world’s largest fusion device of the stellarator type."

For the German speakers, this podcast is a few years old but super interesting interview with scientist working on it: https://alternativlos.org/36/

Omega Tau has a few great (and long) episodes in English:

Episode 22 is an intro to fusion power research and tokamaks.

Episode 157 is an interview of a director at ITER.

Episode 304 interviews the author of the book you’re reading.

Episode 312 is a set of interviews with experimentalists and computational theorists at W7-X.

https://omegataupodcast.net/

Re: Compact nuclear fusion reactor is 'very likely to work,' studies suggest

#212

Post by hitekker » Wed, Sep 30, 2020, 2:08 AM UTC

Tossrock wrote: post #150

I wish these people the best, and I really hope they get a working fusion plant soon. That said, I can't resist sharing Admiral Rickover on academic reactors vs practical reactors: Important decisions about the future development of atomic power must frequently be made by people who do not necessarily have an intimate knowledge of the technical aspects of reactors. These people are, nonetheless, interested in what a…

A solid, reality check. Here is the source link: http://ecolo.org/documents/documents_in_english/Rickover.pdf

Re: Compact nuclear fusion reactor is 'very likely to work,' studies suggest

#213

Post by dougabug » Wed, Sep 30, 2020, 2:10 AM UTC

ClumsyPilot wrote: post #183

m0zg wrote: post #109

Earlier quoted context omitted.

Just the little bit responsible for Chernobyl and Fukushima is not a part of the design at all. No big deal. :-)

I am really tired of this line - the taunami killed 18,500 people. The reactor incident killed no-one through radiation and 32 people through physical injuries. One failure of Banqiao Dam killed an estimated 240,000 people. That's more than all people who have ever died from anything to do with nuclear, reactors and bombs combined. Air pollution kills about 2,000 people every single day. Reactor incidents are like pl…

But the tsunami didn’t render large areas of land uninhabitable, as in the case of Chernobyl and Fukushima.

Re: Compact nuclear fusion reactor is 'very likely to work,' studies suggest

#214

Post by maccam94 » Wed, Sep 30, 2020, 2:14 AM UTC

ivanb wrote: post #50

Basic thermodynamics. Particle energy grows as T (because energy = 3/2 kT). Thermal radiation energy grows as T^4. At fusion temperature up to 80% of energy is in radiation. Energy density of radiation in this case is close to energy density of metals. It's impossible to contain such radiation.

The SPARC design uses a combination of extremely high strength magnetic fields to contain charged particles inside the vacuum chamber and a molten-salt blanket (FLiBe) for neutron capture and cooling. They believe this will be a viable containment system.

Re: Compact nuclear fusion reactor is 'very likely to work,' studies suggest

#215

Post by sheeshkebab » Wed, Sep 30, 2020, 2:14 AM UTC

samatman wrote: post #167

Tossrock wrote: post #150

I wish these people the best, and I really hope they get a working fusion plant soon. That said, I can't resist sharing Admiral Rickover on academic reactors vs practical reactors: Important decisions about the future development of atomic power must frequently be made by people who do not necessarily have an intimate knowledge of the technical aspects of reactors. These people are, nonetheless, interested in what a…

It's a good contribution to the conversation, keeping in mind that Adm. Rickover wrote these words in 1953. Anyone could have said similar things about computers in 1953, and been just as correct. Are nuclear reactors computers? Of course not, and neither have practical reactors kept pace in development with practical computers. But neither is it inevitable that steady progress cannot grind down the latter set of cha…

I guess we can ask Huawei about how easy it is to build computers in 2020...

Re: Compact nuclear fusion reactor is 'very likely to work,' studies suggest

#216

Post by simonh » Wed, Sep 30, 2020, 2:29 AM UTC

xyzzyz wrote: post #124

simonh wrote: post #112

Earlier quoted context omitted.

I think it’s generally very hard to force technological progress along by just throwing money at it. Let’s suppose this proposal works out, ITER will become a very expensive boondoggle. A technological dead end. But if you’d taken the ‘Manhattan Project’ approach and thrown 10x as much money at fusion research 20 years ago we’d most likely have spent most of it on a super-ITER. It might be operational by now and migh…

Sure, but on the other hand, such a lucky break of this new approach might have had never happened. At the same time, if super-ITER approach was shown to work, by producing it en masse, it would likely be cheaper per installed MW than nuclear power, which would remove the need for solar panels and wind altogether. We'd have cheap power with no danger of nuclear pollution, no real nuclear waste problem, and no destroy…

Maybe, or maybe not, who knows? That’s the problem, your betting everything on your best guess what the optimum approach might be long before you have any idea what the odds are.

The problem is (1) the earlier you spend big the greater the chance you’ll pick wrong because you have less information to base a decision on and (2) Spending big doesn’t actually improve the odds that the approach you pick will end up being the right one. It just means you find out sooner.

Re: Compact nuclear fusion reactor is 'very likely to work,' studies suggest

#217

Post by Stevvo » Wed, Sep 30, 2020, 2:45 AM UTC

pdonis wrote: post #13

Someone wrote: post #4

“Sparc takes advantage of a newer electromagnet technology that uses so-called high temperature superconductors that can produce a much higher magnetic field, Dr. Greenwald said. As a result, the plasma is much smaller.” So, is this ‘just’ a matter of ITER being obsoleted by improvements in magnet tech before it is completed, or is there more in this design than scaling down ITER?

The arxiv paper describing the design concept is here: https://arxiv.org/abs/1409.3540 Some additional features (besides the magnets) that jump out at me: The reactor vessel has joints to allow it to open up for maintenance access (previous tokamak designs have a reactor vessel that cannot be opened up once constructed, so maintenance inside has to be done through small access ports using remote manipulators). The ex…

You would still want to use remote manipulators even if you can open the reactor. The problem is not "small ports", it's that parts of the reactor vessel itself become irradiated. People can and have easily fit through the ports on JET, and will be able to on ITER.

The remote manipulators are an amazing piece of technology; having the movements of your arms and hands replicated exactly by a robot is mind-blowing.

Re: Compact nuclear fusion reactor is 'very likely to work,' studies suggest

#218

Post by latch » Wed, Sep 30, 2020, 2:47 AM UTC

tootie wrote: post #203

Tossrock wrote: post #150

I wish these people the best, and I really hope they get a working fusion plant soon. That said, I can't resist sharing Admiral Rickover on academic reactors vs practical reactors: Important decisions about the future development of atomic power must frequently be made by people who do not necessarily have an intimate knowledge of the technical aspects of reactors. These people are, nonetheless, interested in what a…

This isn't an academic reactor. MIT is involved because they did the theory work, but it's venture funded with a plan to build a working reactor in a few years.

How isn't this an academic paper as defined by Admiral Rickover? It meets a lot of his criteria: small, cheap, built quickly and, probably most importantly, it's not being built now.

Re: Compact nuclear fusion reactor is 'very likely to work,' studies suggest

#219

Post by taneq » Wed, Sep 30, 2020, 2:47 AM UTC

samatman wrote: post #167

Tossrock wrote: post #150

I wish these people the best, and I really hope they get a working fusion plant soon. That said, I can't resist sharing Admiral Rickover on academic reactors vs practical reactors: Important decisions about the future development of atomic power must frequently be made by people who do not necessarily have an intimate knowledge of the technical aspects of reactors. These people are, nonetheless, interested in what a…

It's a good contribution to the conversation, keeping in mind that Adm. Rickover wrote these words in 1953. Anyone could have said similar things about computers in 1953, and been just as correct. Are nuclear reactors computers? Of course not, and neither have practical reactors kept pace in development with practical computers. But neither is it inevitable that steady progress cannot grind down the latter set of cha…

Ah, back in 1953, when they were only 20 years away from practical nuclear fusion.

Re: Compact nuclear fusion reactor is 'very likely to work,' studies suggest

#220

Post by Maursault » Wed, Sep 30, 2020, 2:49 AM UTC

ClumsyPilot wrote: post #173

Maursault wrote: post #166

Earlier quoted context omitted.

That just isn't the case. Nuclear (fission) has always been the single most expensive way to generate electricity, and the expense has only increased. Uranium is crazy expensive. Security is very expensive. Spent fuel storage effectively never stops costing, and it isn't ever cheap. If nuclear was simply expensive because of regulations, investors would find a way, and you could not beat them away from building nucle…

Thats not accurate at all, Uranium itself is much cheaper than coal / any fuel per unit energy. Some contries have permanent, final storage for nuclear waste, it does not cost any more once created. Furthermore, not only was solar power borderline non existent when those reactors were built, it is also still intermittent. You are just glossing over the biggest challenge of energy - balancing the powe grid. No-one nee…

I'll respond to your straw man. It isn't about the energy within the thing, the exorbitant cost of Uranium is in mining and refining. No one said anything about coal, but it doesn't need refined, and is cheaply mined... but you've also made a false equivalency, because coal isn't the only competition to nuclear. The sun just shines, wind just blows, water just flows, and the geothermals just produce heat, without any investment or refinement.

If just 10% of the resources poured into nuclear development, which is a cost no one that is pro nuclear wants to tally into the bill, were instead invested into solar energy, nuclear power would not have been able to compete with solar power by 1980.

Nuclear power isn't cheap, unless you ignore the insane R&D that was paid for by tax payers by government mandate and never paid back, unless you ignore the massive cost of construction long before one watt of power is produced, and unless you ignore the massive cost of decommissioning, and unless you ignore the never ending cost of spent fuel storage. It is entirely absurd that you believe once a spent fuel storage facility is built, the costs just disappear. The costs never go away. Maintenance. Security. Testing. It isn't free and it isn't cheap.