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Revamped German stellarator should run longer, hotter and compete with tokamaks

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Re: Revamped German stellarator should run longer, hotter and compete with tokamaks

#91

Post by GordonS »

pfdietz wrote: post #53
GordonS wrote: post #29

Earlier quoted context omitted.

I agree. If we were able to eventually miniaturise fusion reactors, they would be incredible for space flight. Back on Earth, if they could be made safe enough, maybe we could even use them to run container ships?

DT fusion would be just ridiculous for space flight. Anything a DT reactor could do a fission reactor could do much better -- much smaller, much higher power density, much less complexity. And similarly for use in ships down here on Earth. In practice, synfuels would be better than either for ships on Earth.

I don't understand this; if fission reactors were "better", we wouldn't be pouring so much into fusion?

Also, if it makes a difference, I didn't mean we'd be bolting a first gen tokamak to a container ship; I meant, much later down the line, if we were able to miniaturise (similar to how we have nuclear powered subs and ice breakers).

Re: Revamped German stellarator should run longer, hotter and compete with tokamaks

#92

Post by GordonS »

sidkshatriya wrote: post #79
ClumsyPilot wrote: post #47

Earlier quoted context omitted.

what kindof disaster could be relevant in this context? If the ship sinks, the minor radioctivity of a shutdown reactor will not be relevany Technically, container ships are enormous and can use ballast water for shielding. I can't judge the ecobomics ofcourse

Well fusion reactors are likely to cost a huge amount of money when they do become operational. No point having them sinking in a storm. Probably just safer to charge a huge battery and put it on a ship (if you don’t want to use fossil fuels). Avoids a lot of unfoseen commercial risk. Even though you could use water for shielding, the metal container and other things that hold the reactor would be highly radioactive…

> Probably just safer to charge a huge battery and put it on a ship

Large container ships burn through 16 tons of bunker oil per hour, and each journey can last up to 3 weeks - any idea what size of battery such a ship would need? I have no clue how to calculate that), but I'm guessing it would be completely impractical, even if we made huge strides in battery energy density.

Re: Revamped German stellarator should run longer, hotter and compete with tokamaks

#93

Post by tsimionescu »

okasaki wrote: post #48
moogly wrote: post #41

Earlier quoted context omitted.

> We’re still a few years away from having them in actual power plants I admire your optimism. I'd say half a century, if things go well, but I'm not convinced fusion will ever be economically feasible.

The UK government plans to have a fusion power plant on the grid by 2040 https://assets.publishing.service.gov.uk/government/uploads/...

They can also plan to bring world peace and end world hunger by this winter. Doesn't mean it will happen.

Re: Revamped German stellarator should run longer, hotter and compete with tokamaks

#94

Post by dabber21 »

NKosmatos wrote: post #28

Just like COVID helped the mRNA/CRISPR technology evolve and come faster and closer to us, with the potential for many more usages in various diseases, I hope that the ongoing/coming energy crisis will help all nuclear fusion technologies tokamak/stellarator become real. We’re still a few years away from having them in actual power plants and a few decades away from solving our energy problems for every, but I hope w…

In an interview about this project with the recent changes, they said its investment in future energy production in 2050

Re: Revamped German stellarator should run longer, hotter and compete with tokamaks

#95

Post by 7thaccount »

ForHackernews wrote: post #71
pfdietz wrote: post #59

Earlier quoted context omitted.

We've already given it more than 50 years.

Solving hard engineering problems is expensive. You have to put lots of money into it. Say, 30% of the funds invested by VCs in jitney cabs and collectable JPEGs.

It is so sad how much money and talent goes into getting people to click on more ads.

Re: Revamped German stellarator should run longer, hotter and compete with tokamaks

#96

Post by mpweiher »

dleslie wrote: post #6

Forgive my ignorance; what with all the effort made to isolate the exceedingly hot plasma from connecting with any surface, what are the plans to extract the heat in order to generate power?

From the fine article: "Over the past 3 years, W7-X’s creators stripped it down and replaced all the interior walls and fittings with water-cooled versions, ..."

I am guessing that the water used to cool the interior walls will get hot in the process...

Re: Revamped German stellarator should run longer, hotter and compete with tokamaks

#97

Post by wongarsu »

pfdietz wrote: post #59
simonebrunozzi wrote: post #43

Earlier quoted context omitted.

I think that 50 years is a reasonable timeframe to give fusion the possibility of delivering results. But I agree with you, it's pretty much impossible that anything will come out of fusion in the coming 10-15 years, despite the publicity we keep hearing lately.

We've already given it more than 50 years.

But apart from the part that's useful for nuclear weapons research, we've barely given it any funding. The idea of "we could have useful fusion reactors in 30 years" always came with the sentence "if we get the funding to do it".

There's this [1] famous graph comparing US research spending into Fusion, compared to 1976 predictions how long it would take with different budgets. According to that, the US funded fusion below the "not enough to ever get it done" budget. With that in mind, we have come remarkably far.

1: https://upload.wikimedia.org/wikipedia/commons/a/ab/U.S._his...

Re: Revamped German stellarator should run longer, hotter and compete with tokamaks

#98

Post by Galaxeblaffer »

sidkshatriya wrote: post #24
pfdietz wrote: post #11

Earlier quoted context omitted.

This would be for DT fusion, so most of the energy would come out as neutrons. And it would face the same showstoppingly bad volumetric power density as tokamaks, because of limits on that energy flow through the surface of the reactor.

> And it would face the same showstoppingly bad volumetric power density as tokamaks, because of limits on that energy flow through the surface of the reactor. I do think it is worth persevering though. The future of energy is Solar/Wind but Fusion should not be ignored. It is one of Nature's fundamental processes. Mastering fusion could turn out to be useful in ways we cannot possibly fathom at the moment right now.

We already have the perfect way to create heat and the science around it has been long solved and understood. Solar and wind won't save us and fusion certainly won't. It amazes me how solar and wind dreamers all seem to like fusion but fission is just super evil.

Re: Revamped German stellarator should run longer, hotter and compete with tokamaks

#99

Post by stormbrew »

GordonS wrote: post #92
sidkshatriya wrote: post #79

Earlier quoted context omitted.

Well fusion reactors are likely to cost a huge amount of money when they do become operational. No point having them sinking in a storm. Probably just safer to charge a huge battery and put it on a ship (if you don’t want to use fossil fuels). Avoids a lot of unfoseen commercial risk. Even though you could use water for shielding, the metal container and other things that hold the reactor would be highly radioactive…

> Probably just safer to charge a huge battery and put it on a ship Large container ships burn through 16 tons of bunker oil per hour, and each journey can last up to 3 weeks - any idea what size of battery such a ship would need? I have no clue how to calculate that), but I'm guessing it would be completely impractical, even if we made huge strides in battery energy density.

There seem to be efforts towards battery powered container ships out there[1], independently of any speculated use of nuclear power to charge them. Most likely they'd be battery banks in containers that get swapped out and charged at port using the same equipment as is used to load and unload cargo I believe.

I remember reading that they would have more limited range and lower top speeds, but that this might not be as much of a problem as it seems because the current routes are built around large container + long haul but that's not necessarily required (for all shipping at least).

[1] eg. https://maritime-executive.com/editorials/could-battery-powe...

Re: Revamped German stellarator should run longer, hotter and compete with tokamaks

#100

Post by TedDoesntTalk »

kortex wrote: post #61
onlyrealcuzzo wrote: post #17

Earlier quoted context omitted.

I would imagine since, combined, we're spending tens of billions of dollars on Fusion research - someone must have some ideas for step 2, right?!

We have some ideas, of course. The rough idea is: surround the reactor with a lithium blanket. This gets bombarded with neutrons, breeding fuel and heating the lithium, which transfers its heat to coolant to spin turbines. The devil is in all the engineering details, like: how do we make alloys to deal with neutron bombardment/hydrogen embrittlement, what's the optimal geometry to capture flux while being serviceable…

What is done with the “spent” lithium blanket? Is it radioactive waste?
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