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U.S. physicists rally around plan to build fusion power plant

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Re: U.S. physicists rally around plan to build fusion power plant

#131

Post by Gwypaas »

olau wrote: post #110
free_rms wrote: post #20

Earlier quoted context omitted.

God I wish we could Manhattan Project this shit. I'm a layman too but I get the impression that the theory is basically there and we just need to figure out the engineering. That's a solvable problem with lots of money and lots of teams. Are we going to wait until the sea level rises 20 feet and then say, geez, compared to the costs this imposed, fusion would have been easy?

Fusion is not going to solve the sea level rise problem. You can see this by comparing it to fission. Fission fuels is not expensive on a kWh base, so cheaper fuel is not really a big advantage. Fusion plants produce radioactive waste too (perhaps less?), so you don't save yourself from that headache. Which isn't actually that big of a problem either, even if the costs are probably underestimated for fission plants.…

Wouldn't the major differentiator be the safety standards?

You can't have a runaway reaction, because you need energy input to the magnet field to get more energy out. Instead of creating the right environment to get a chain reaction started if your control rods end up in the wrong place. Drop the magnet field and it all collapses.

Even if you lose control of it with the magnet field on the quantity is limited, tokamaks can only sustain bursts before going unstable. Wendelstein like designs would also be limited by the quantity contained.

If everything goes completely wrong you simply end up with a dirty bomb from the neutron bombarded core material and an initial burst of radiation. Sure not amazing but not a meltdown releasing vast quantities of heavy radioactive decay materials which can leach into the environment. Remember, fission is messy, it's not a chemical reaction where A+B = C. You get a spread of materials and energies, as seen by the Z number here. [0]

Essentially, you can at any point do an unsafe abort which might damage something or if everything aligns it's no more than a dirty bomb, but you will never lose control. Your Swiss cheese model needs to have far fewer and simpler layers compared to fission, vastly bringing at least those costs down.

I'm still betting on renewables for the near future, but my guess is at least harnessing fusion will have a place for projects with extremely specific goals in the 50-100 year timescale.

[0]: https://upload.wikimedia.org/wikipedia/commons/thumb/6/68/Th...

Re: U.S. physicists rally around plan to build fusion power plant

#132

Post by willis936 »

tyho wrote: post #117
deweller wrote: post #116

Earlier quoted context omitted.

Fusion does not create any long-lived radioactive waste.

No, but fast neutrons are created in some processes which induce long lived radiation in reactor materials though.

100 years is not “long lived” in the context of radioactive waste disposal.

http://www.acamedia.info/sciences/J_G/fusion.html

Re: U.S. physicists rally around plan to build fusion power plant

#133

Post by pasabagi »

kenneth wrote: post #108
SiempreViernes wrote: post #99

Earlier quoted context omitted.

Its amazing how cutting emission by regulation is completely left out of the list of options, somehow spending infinite money is seen as easier than getting congress to act... Anyway, I let Wellerstein reply to this: """The Manhattan Project was an unusual, somewhat dubious enterprise that had massive, world-affecting consequences. Ignoring that not only misunderstands the Manhattan Project, it misunderstands what ha…

It's widely believed that the use of the bombs in WWII as a practical demonstration of the technology is what lead to there not being a WWIII and generally a period of (granted, uneasy) world stability throughout the cold war. Thanks to the bomb's use at the end of an almost-finished conflict, everyone was too afraid of the destruction to turn the cold war hot. Without it, the cold war would have turned hot and a lot…

I think the USSR was typically very keen to avoid a war for obvious reasons: they had a much smaller economy, exhausted population, significantly smaller military and massively smaller industrial base than the West.

America was more keen, but the logistics of actually invading the USSR would make any war essentially unwinnable.

Maybe if the nukes didn't exist, the USSR would have annexed western Berlin, but I don't really know how they would have managed more than that, even if they had wanted to.

I also don't think nuclear weapons would have prevented a war if the USSR was more aggressive or more close to the USA in military power.

Re: U.S. physicists rally around plan to build fusion power plant

#134

Post by willis936 »

ncmncm wrote: post #130
divbzero wrote: post #78

Are at an inflection point for fusion power? With interest and funding for it finally gaining steam? I’ve noticed several announcements about independent efforts this past year [1–6] but not sure if (a) it’s always been this way or (b) my view is skewed by HN. [1]: https://news.ycombinator.com/item?id=21806334 "General Fusion" [2]: https://news.ycombinator.com/item?id=23979608 "ITER" [3]: https://news.ycombinator.com…

Yes, yes we are at an inflection point. But maybe not the kind you are thinking of. There will never be a commercial tokamak power plant. There has never, at any time, been any reasonable expectation of getting practical, commercial power from magnetic-confinement hot-neutron fusion. Renewables, with practical energy storage, will always be much, much cheaper than fusion could ever have been, even if it could be made…

>”Break-even" is nowhere near enough to get practical power out, because the energy extraction process must be so inefficient, with two stages of heat exchange before you get a working fluid you can run through your turbine.

Correction: break-even is most of the way to a working plant. A “burning fusion plasma” is one that self heats. The plant requires very little power when the plasma is supplying most of its own heating. Keep the confining coils cool, keep the control systems (correction coils and heaters) running, and watch as the heat comes in. Q = 1 is the balance point. The distance (in terms of lawson criterion) between Q = 0.5 and 1 is much larger than Q = 1 and infinity,

Also, two stages of heat exchange are not needed and not a killer for power generation regardless. A liquid lithium wall blanket operates as tritium breeder and coolant. Run the lithium through a heat exchanger to boil water. Watch as the turbine spins. Very similar to PWRs.

Re: U.S. physicists rally around plan to build fusion power plant

#135

Post by willis936 »

yread wrote: post #109
raziel2701 wrote: post #84

Earlier quoted context omitted.

I can only speak about NIF but they're under stress right now as their funding agency, the NNSA, is reviewing the progress of NIF as questions about its efficacy at achieving fusion become stronger after several failed campaigns. NIF needs to put up a pretty face so the press releases might be part of a combined effort to spin a positive picture of their progress, plus it serves as a recruitment tool since the lab is…

I always thought NIF is just a facade for weapons research, that there is no way to make it energy positive

It is. Their fusion power research program is essentially retired and it operates as a nuclear stockpile steward research facility.

Re: U.S. physicists rally around plan to build fusion power plant

#136

Post by DennisP »

nine_k wrote: post #72
orthecreedence wrote: post #29

Earlier quoted context omitted.

Yes, I've been saying it over and over: raise the price of oil until gasoline et al are $20+/gallon. Then nuclear will be cheap . Why are we letting a silly thing like scarcity, supply, and demand dictate whether we self-destruct?

Most fossil-based electric generation is not oil; it's either natural gas (reasonably clean, though it does produce a lot of CO₂), or coal (terrible on many counts). I'd say that killing coal would have a large effect. It would also put entire town populations out of work — a really hard problem, read about how UK tackled it in 1970s and 1980s, it was painful and ugly.

At the end of 2016 there were 50,000 coal miners in the US.[1] Their average annual pay is $29K.[2] We could give each of them one million dollars, invested and paying out 3% annually, and the $50B it costs would be a drop in the bucket compared to the economic benefit of eliminating those carbon emissions.

In fact, it would even be cheaper than the healthcare costs of pollution from coal plants, which amounts to $187 billion in the U.S.[3] And in Appalachia, healthcare costs from coal production are $75B annually, so we'd come out ahead there too, which would be a double benefit for the miners since they'd be both richer and healthier.

[1] https://en.wikipedia.org/wiki/Coal_mining_in_the_United_Stat...

[2] https://www.glassdoor.com/Salaries/coal-miner-salary-SRCH_KO...

[3] https://e360.yale.edu/digest/coal-costs-us-half-trillion-ann...

Re: U.S. physicists rally around plan to build fusion power plant

#137

Post by willis936 »

Animats wrote: post #6

This is more like "Fusion physicists rally around plan to improve message asking for more money". It's not like there's a serious plan to build a power plant. Except at Lockheed's Skunk Works, which is quietly plugging away on their own.

The skunkworks program has no published details and what has been published has been put in the “been-there, tried that” category by physicists. The slunkworks program is little more than a way to funnel money.

Re: U.S. physicists rally around plan to build fusion power plant

#138

Post by voodootrucker »

IanCal wrote: post #128
logicchains wrote: post #60

Earlier quoted context omitted.

>God I wish we could Manhattan Project this shit. Interesting point of reference: the Manhattan project cost around around $25 billion in today's dollars. The US government spent at least $6 trillion on the coronavirus response, which could buy 200 Manhattan Projects. Coronavirus will kill around a million people this year at most; air pollution kills around five million per year (and sea level rises could kill a lot…

The US medical system wastes enough each year ($950B) to start an LHC sized project (~$10B), fully funded, in each US state every year and have enough left over to fully fund three new Apollo scale set of missions ($150B). You can't recover all that, but still, it's hard to picture just how big some of these figures are until you compare to other large costs.

That number is shocking. I'd love to know details. Can you provide a source please?

Re: U.S. physicists rally around plan to build fusion power plant

#139

Post by Hammershaft »

trhway wrote: post #95
gpm wrote: post #53

Earlier quoted context omitted.

Fission seems like the better option for mars. The technology is ready now, and no one cares about a bit of nuclear waste on mars anyways.

yes, technically the next generation of Starships flying to Mars would be fission powered. Unfortunately the regulatory regime makes any fission related development close to impossible. Add to that practical unavailability of fission fuel - even NASA has issues getting those mere kilograms of plutonium, and even Musk wouldn't be able to get nor breeder reactor, nor enrichment plant (here on Earth i mean). As a result…

the physics of Fission work better (or work at all, really) at scale. Fitting the weight and size of a fusion reactor on a rocket ship strikes me as impossible for the forseeable future.

Re: U.S. physicists rally around plan to build fusion power plant

#140

Post by api »

hunter-gatherer wrote: post #125
kortilla wrote: post #25

Earlier quoted context omitted.

Fission is a solved engineering and science problem though and we’re still blocking it to let the sea levels rise. Point being, nobody actually cares about climate change enough to make hard decisions so a Manhattan style project is highly unlikely.

A month or so ago I was listening to an NPR interview about insects. The interviewee said that the insect population in Germany has declined something like 75% in 25 years. He noted that people don't tend to notice big changes over the span of a couple decades, which is a good point, and helps explain why climate change will probably never be seriously tackled. Edit- link to article: https://www.theguardian.com/envir…

It will be tackled through adaptation. Some coastal cities may die. Others may have to spend a ton on remediation. More people will migrate inland, and farming centers will shift.

It’s far too late to stop it with prevention, though there is still value in trying to cut CO2 when possible to blunt it a bit.

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