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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

#151

Post by tunesmith »

simonh wrote: post #112
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 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…

That's a version of "The Wait Calculation". For instance, it would be a waste of resources to build a starship right now to visit the closest other solar systems, because given our current maximum velocity and our rate of technological increase, it's a virtual certainty that in the future we would be able to build a second starship that would catch up and overtake it.

Eventually there is a break even point (for the closest solar systems, last I checked, it's around 400 years), but in order to know what it is you need to know the amount of time to reach the goal and your rate of increase. I don't know if there's a way to estimate that with fusion research.

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

#152

Post by toyg »

ElFitz wrote: post #137
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. "Nuclear fusion. 30 years away since 1950" Joking aside. I too am glad to see some progress of any kind, and new (seemingly credible) initiatives being funded and pursued

“The year of the nuclear desktop”!

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

#153

Post by jacquesm »

isoprophlex wrote: post #8

I never quite understood the math behind power densities in a fusion reactor. In the sun, isn't energy production occurring at something like 100-1000 W/m3? So, if you want to build a multiple MW fusion plant, shouldn't these plants be ridiculously huge compared to, say, a wind turbine rated at a couple of MW? Is the density of the plasma so much higher in a fusion reactor? Also, something else I never grokked, how d…

> In the sun, isn't energy production occurring at something like 100-1000 W/m3?

~250W/m3.

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

#154

Post by natch »

What are the decommissioning costs?

Who will pay for the cost overruns?

Just one of the big problems with nuclear is that it is very centralized and takes individual control away from the consumers, who foot the bill through increased taxes and fees, and who could otherwise be using their money to finance options that give them individual control over their energy costs.

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

#155

Post by lovegoblin »

pklausler wrote: post #46
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…

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

No one is interested in this pedantry. Save your time.

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

#156

Post by _kst_ »

tim333 wrote: post #119
_kst_ wrote: post #67

Earlier quoted context omitted.

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.

And the transition from Julian to Gregorian just changed the leap year rules. It didn't change the fact that there's no year 0. The 1st Century began in the year 1.

I don't believe anything in ISO 8601 refers to the century starting 2000-01-01 as "the 21st century" (though apparently it does, in some contexts, allow "20" to refer to the century that started on that date).

The century called "the 1900s" overlaps with the 20th century for 99 of 100 years.

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

#157

Post by devonkim »

ElFitz wrote: post #137
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. "Nuclear fusion. 30 years away since 1950" Joking aside. I too am glad to see some progress of any kind, and new (seemingly credible) initiatives being funded and pursued

Sounds about the same as generalized AI in time tables

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

#158

Post by [deleted] »

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…

[deleted]

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

#159

Post by ada1981 »

tunesmith wrote: post #151
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…

That's a version of "The Wait Calculation". For instance, it would be a waste of resources to build a starship right now to visit the closest other solar systems, because given our current maximum velocity and our rate of technological increase, it's a virtual certainty that in the future we would be able to build a second starship that would catch up and overtake it. Eventually there is a break even point (for the c…

This is a great mental model. I'm curious about applying this in areas of one's own life. Certain things that you'd actually accomplish faster, by starting later and leveraging the compounded time / resources that would have been spent pursuing it earlier.

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

#160

Post by DennisP »

Baeocystin wrote: post #123
pfdietz wrote: post #110

Earlier quoted context omitted.

80% of the energy from DT fusion comes out as neutrons, which enter a blanket and deposit energy there by collisions and nuclear interactions.

Thank you! Do you know how far along are we in understanding how to build an effective blanket that can withstand the neutron flux while maintaining its physical integrity?

SPARC's approach is for the blanket to be a molten salt, and also function as a coolant. That will surround an inner wall which gets replaced annually. They tested joints in the REBCO superconductors, so the reactor can be opened up on hinges.
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