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

nytimes.com

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

#111

Post by neltnerb »

7373737373 wrote: post #83
zachrose wrote: post #78

Earlier quoted context omitted.

I’m also a layperson and also a fan of the 7-X, almost on purely aesthetic grounds. The plasma shape is a beautiful twisted loop, the magnets resemble a French crueler, and with the shielding and instrumentation it has all the charm of a steampunk time machine

As a layperson, this design seems far too complex to be useful for fast iterative research and ultimately, economic replication. It reminds me of the principle that one shouldn't start a space travel project that is estimated to take more than x years to complete, because by that time, technological progress will have surpassed its speed and capabilities, and would physically overtake it (the 'wait calculation').

Yeah, fusion is not fast to research though, ITER isn't even built yet.

They're all extremely complicated, and while this one is harder to fabricate than a tokamak, fabricating arbitrary geometries is also something we've gotten a lot better at. If this is as complicated as it has to be in order to work as required... well, that's just physics right?

The problem is unnecessary complexity, but whether that's the case here or not is still unclear.

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

#112

Post by simonh »

Florin_Andrei wrote: post #40
mdorazio wrote: post #16

Here's the actual summary: "Although many significant challenges remain, the company said construction would be followed by testing and, if successful, building of a power plant that could use fusion energy to generate electricity, beginning in the next decade." In other words, "very likely" in this case means "if several roadblocks are overcome, it might be a net-positive power generator in a decade". Even so, this…

> this is still exciting given how anemic advancement in the fusion space has been for 50+ years At the top of my list for when I'll be king for a day is - massive, national-scale investments (think: reaching towards one percent of GDP) in fusion research. This is a major roadblock, but things look awesome on the other side. We just need to get our stuff together to hop over this fence somehow.

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 might even have reached break-even on power generation, but in the longer term would now be just as redundant and superseded by this new approach.

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

#113

Post by pfdietz »

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…

Also note from this paper:

The power density of the reactor is 0.5 MW/m^3, which is 1/40th the power density of a commercial PWR primary reactor vessel.

The reactor (a single one!) uses something like 40% of the world's current annual production of beryllium. If all the world's estimated resource of Be is used to make these reactors, it would be enough for reactors producing just 1% of world primary energy demand.

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

#114

Post by 08-15 »

splitrocket wrote: post #80

Fusion, always, always 5 years away for the past 20 years.

Yeah, but before that, it was 20 years away for about 50 years, so there is some progress after all!

Seriously though, the article reads like "Remember SPARC? We're still trying to build it." I wish them luck, but if past experience with fusion can be extrapolated, they will run into some unexpected, crippling problems.

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

#115

Post by pfdietz »

Florin_Andrei wrote: post #44

> Sparc would be far smaller than ITER — about the size of a tennis court, compared with a soccer field If we could make efficient fusion reactors the size of a truck, the solar system will become our backyard.

DT fusion would be quite useless in space. The reactors are necessarily much larger than fission reactors, especially space reactors that can use highly enriched materials. And like fission it produces its energy as heat (from the neutrons.) Why use a large, complex heat source, when one can use a small, simple heat source?

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

#117

Post by [deleted] »

Florin_Andrei wrote: post #40
mdorazio wrote: post #16

Here's the actual summary: "Although many significant challenges remain, the company said construction would be followed by testing and, if successful, building of a power plant that could use fusion energy to generate electricity, beginning in the next decade." In other words, "very likely" in this case means "if several roadblocks are overcome, it might be a net-positive power generator in a decade". Even so, this…

> this is still exciting given how anemic advancement in the fusion space has been for 50+ years At the top of my list for when I'll be king for a day is - massive, national-scale investments (think: reaching towards one percent of GDP) in fusion research. This is a major roadblock, but things look awesome on the other side. We just need to get our stuff together to hop over this fence somehow.

[deleted]

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

#118

Post by criddell »

DataDaoDe wrote: post #48
Florin_Andrei wrote: post #40

Earlier quoted context omitted.

> this is still exciting given how anemic advancement in the fusion space has been for 50+ years At the top of my list for when I'll be king for a day is - massive, national-scale investments (think: reaching towards one percent of GDP) in fusion research. This is a major roadblock, but things look awesome on the other side. We just need to get our stuff together to hop over this fence somehow.

I couldn't agree more. Once you realize that energy is the fundamental unit which powers everything else in the economy, not only from every movement of ourselves to those of our machines as well, you realize the more we advance in our ability to produce more and more energy at cheaper and cheaper costs in increasingly reliable ways, the more we can accelerate, without exception, every other industry.

Can you make enough energy that you could satisfy the demands of bitcoin miners and still have enough left over for productive uses?

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

#119

Post by tim333 »

_kst_ wrote: post #67
pklausler wrote: post #46

Earlier quoted context omitted.

Speaking pedantically, the next decade actually starts 1-Jan-2021.

Speaking even more pedantically, a new decade is starting right now ... and here comes another one. The 2020s start 2020-01-01 (just as the century called "the 1900s" started 1900-01-01). The 21st century started 2001-01-01. The 203rd decade starts 2021-01-01 -- but nobody talks about the "203rd decade". That's the difference in terminology between decades and centuries; we don't refer to decades by their ordinal num…

Continuing the pedantalization escalation the 21st century started 2001-01-01 if you follow the Gregorian calendar "named after Pope Gregory XIII, who introduced it in October 1582"

However if you are not fussed about pope Greg and then and go with ISO 8601 or common usage it started 2000-01-01.

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

#120

Post by MauranKilom »

7373737373 wrote: post #96
Tade0 wrote: post #84

Earlier quoted context omitted.

To me it looks like alien technology. Such an organic shape. So many valves an openings. What is their purpose? How deliberate is their placement? Awe-inspiring.

Very negative take here: To me it looks like premature optimization, some politicians, mathematicians or engineers wet dream, a design that by today is probably known to be suboptimal, that probably caused millions if not billions of euros of unexpected costs, and tens of thousands of hours of migraine for the people who actually have to run and maintain the thing

This design overcomes one of the fundamental problems with the Tokamak style fusion reactors. It's like choosing quick sort over bubble sort. And yes, the difference here matters.
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