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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

#141

Post by pfdietz »

beervirus wrote: post #139
pfdietz wrote: post #113

Earlier quoted context omitted.

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.

> 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. That's crazy. I guess if the design works out we can start casting about for a beryllium replacement.

Beryllium has long been known to be problematic for fusion reactor walls, to be used sparingly if at all. Even lead (!) may have resource issues for widespread use of fusion.

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

#142

Post by IBCNU »

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

`"Nuclear fusion. 30 years away since 1950"`

I feel like there should be bonus points for getting this quote to the top of every fusion article posted until there's an existing fusion reactor.

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

#143

Post by wmwmwm »

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…

I chuckled/was staggered when I heard that the power density in the Sun's core is approximately the same as a compost heap! (albeit a rather large one...)

https://en.wikipedia.org/wiki/Solar_core#Energy_conversion

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

#144

Post by Krasnol »

Related:

Cities Snub Plan to Save Nuclear Power With Mini Reactors:

https://www.bloomberg.com/news/articles/2020-09-28/cities-sn...

Kaysville withdraws from nuclear power project:

https://outline.com/LAfTYG

Small Modular Reactor Decision Made With Inadequate Information:

https://losalamosreporter.com/2020/09/14/small-modular-react...

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

#145

Post by ElFitz »

beervirus wrote: post #136
elil17 wrote: post #24

Earlier quoted context omitted.

You're correct, that's a good ballpark for the average heat generation rate in the sun. However, 99% of heat generation in the sun occurs in the core (approximately the center 25% by radius) and this area is much more energy dense. Further, fusion reactors could achieve an even higher volumetric heat generation rate then the sun's core does. To collect energy, heat would be transferred to a working fluid (e.g., molte…

There's something that feels so archaic about using a nuclear reactor to... boil water and spin a turbine. It's disappointing that we haven't figured out a better way to convert to electrical energy than what we were using in the 1800s.

You will love these four strips:

http://www.geeksworld.org/strip_981.html

http://www.geeksworld.org/strip_982.html

http://www.geeksworld.org/strip_983.html

http://www.geeksworld.org/strip_984.html

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

#146

Post by notJim »

dnautics wrote: post #127
xyzzyz wrote: post #124

Earlier quoted context omitted.

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…

You don't know that. What if you had spent 1000x the budget of the manhattan project on building an atom bomb in the year 1789? You would have gotten squat.

I don't think that's quite an apt comparison. The fundamental physics of an atomic bomb were not well known until the late 1800s. Apparently the Manhattan Project cost about $23 billion in 2007 dollars. ITER apparently had an initial budget of around $5 billion in 2005-6. By now, the construction cost is estimated to be at least $22 billion. It seems plausible that if we throw $15 or 20 billion at it in 2006, we could get bring forward the timeline by a handful of years. Or we might burn $20 billion on things like advanced construction and salaries for physicists and engineers, with relatively little to show for it.

The GDP of the EU is apparently $18 trillion, so $20 billion is about .1% of the GDP in a single year, and of course that $20 billion is spread over 1-2 decades. If anything, it seems like as a species, we should have more of these bets going. What if we spent 1% of our GDP on 10 long-shot, high-impact projects? Or hell, half a percent on 5 long-shot projects, and half a percent on solving the dozens of problems that we could solve simply by funding them.

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

#147

Post by bpodgursky »

woeirua wrote: post #90

After watching the video posted in the top comment, I have to wonder why we would keep dumping money and time into ITER. I know, don't put all your eggs in one basket, but if the ITER design is so out-of-date, why wouldn't we just scrap it in favor of something that we could build 10 years faster and for much less money? It seems that if we can't make fusion work for SPARC it won't likely work in ITER either since th…

Well, "we" is very precise -- it's an EU program, and this reactor is not.

As far as "why", you can take your pick of:

- ITER's design is older, and maybe could be considered "lower risk" (that it will work at all)

- Sunk cost

- Academic jobs program

- Money has already been allocated to member states, and none are happy to give that up

- Big changes take time

I'm not optimistic on stuff like this, so IMO it's another JWST, but it's not totally crazy to keep working on a plan (for a while) when new avenues of research arise.

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

#148

Post by sien »

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…

The Fusion Triple Product, which is the key determinant of whether there is a self-sustaining reaction, increased faster than Moore's law up until about 2005. Then all the money went into ITER.

https://physicsworld.com/wp-content/uploads/2004/01/pwhoa4_0...

From the article at :

https://physicsworld.com/a/controlled-fusion-the-next-step/

more information about the triple product and the Lawson Criterion.

https://en.wikipedia.org/wiki/Lawson_criterion

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

#150

Post by Tossrock »

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 reactor plant will do, how much it will cost, how long it will take to build and how long and how well it will operate. When they attempt to learn these things, they become aware of confusion existing in the reactor business. There appears to be unresolved conflict on almost every issue that arises.

I believe that this confusion stems from a failure to distinguish between the academic and the practical. These apparent conflicts can usually be explained only when the various aspects of the issue are resolved into their academic and practical components. To aid in this resolution, it is possible to define in a general way those characteristics which distinguish the one from the other.

An academic reactor or reactor plant almost always has the following basic characteristics: (1) It is simple. (2) It is small. (3) It is cheap. (4) It is light. (5) It can be built very quickly. (6) It is very flexible in purpose ("omnibus reactor"). (7) Very little development is required. It will use mostly “off-the-shelf” components. (8) The reactor is in the study phase. It is not being built now.

On the other hand, a practical reactor plant can be distinguished by the following characteristics: (1) It is being built now. (2) It is behind schedule. (3) It is requiring an immense amount of development on apparently trivial items. Corrosion, in particular, is a problem. (4) It is very expensive. (5) It takes a long time to build because of the engineering development problems. (6) It is large. (7) It is heavy. (8) It is complicated.

The tools of the academic-reactor designer are a piece of paper and a pencil with an eraser. If a mistake is made, it can always be erased and changed. If the practical-reactor designer errs, he wears the mistake around his neck; it cannot be erased. Everyone can see it.

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