China’s ‘Artificial Sun’ achieves fusion breakthrough • Hacker News Board

Re: China’s ‘Artificial Sun’ achieves fusion breakthrough

#211

Post by Jedd » Fri, Nov 11, 2016, 10:13 PM UTC

kmicklas wrote: post #209

Jedd wrote: post #120

Earlier quoted context omitted.

> The only up side is that the decay products have a shorter half life. So the waste will only be a problem for a century or so, instead of for millennia. This sounds like a tremendous underestimation of the problem - handling waste. We have people who live 'for a century or so' but we don't even have languages (now!) that have lasted a millenia.

> we don't even have languages (now!) that have lasted a millenia. Wut?

Okay, point taken - we certainly do have some languages still in use that that have lasted more than a millennia.

I'd posit that storage is not a solved problem, and a big part of that is a lack of confidence that we can reliably communicate with the people who will have to deal with this waste in the distant future.

There's also the inherent disdain involved in passing on massive costs and risks to future generations to solve a comparatively short-term problem of ours.

Re: China’s ‘Artificial Sun’ achieves fusion breakthrough

#212

Post by hx87 » Fri, Nov 11, 2016, 10:22 PM UTC

TheSpiceIsLife wrote: post #198

hx87 wrote: post #177

Earlier quoted context omitted.

Fusion-heated gas turbines are certainly possible, so we may see combined cycle fusion power plants.

What is a fusion-heated gas turbines . Combined-cycle gas turbines work by burning gas to spin a turbine and using the waste heat to create steam. Where does the fusion heat come in to that cycle?

Gas turbines don't need to burn anything to work--any sufficiently high temperature source of heat can be used. Fusion can be the source of that heat.

Re: China’s ‘Artificial Sun’ achieves fusion breakthrough

#213

Post by loup-vaillant » Fri, Nov 11, 2016, 10:26 PM UTC

marcosdumay wrote: post #165

loup-vaillant wrote: post #161

Earlier quoted context omitted.

I'll wager this was mostly because of the lack of funding. Those reactors were not as thoroughly researched as the light water ones. In a sense, they're still stuck in the 60's. (Really, putting molten salt reactors in the "new generation" bucket is a bit of a joke. It's old stuff that was shut down mostly for military and economic reasons, and only recently got more traction.) Another possible cause is path dependen…

I was serious when I said I was sure some extra R&D would solve those problems. It may not be just lack of founding. Materials science has advanced a lot since then, and those problems look solvable now, but I'm not sure they could be solved by the 60's.

Crap, I had an axe to grind, and didn't read your comment properly. Sorry.

Re: China’s ‘Artificial Sun’ achieves fusion breakthrough

#214

Post by loup-vaillant » Fri, Nov 11, 2016, 10:38 PM UTC

philipkglass wrote: post #202

loup-vaillant wrote: post #129

Earlier quoted context omitted.

Much of the nasty stuff comes from the fact that current (light water) reactors were actually meant to produce military plutonium. Bombs first. Energy was a by-product, and a very nice way to sell nuke-making to the civilians. There is another way of doing fission, that was demonstrated (working prototype and all) in the 60's: molten salt. You basically dissolve the fissile matter in molten salt, provide initial heat…

I don't know who in the thorium boosters' club started the "light water reactors were meant for weapons plutonium" meme but it's nonsense. To quote "Technologies Underlying Weapons of Mass Destruction", Reactor-grade plutonium recovered from civilian reactors differs from weapon-grade plutonium in the relative proportions of various plutonium isotopes. Reactor-grade plutonium has a higher rate of spontaneous fission…

I'm inclined to believe modern civilian reactors are terrible at producing bomb worthy plutonium. Indeed, the main goals quickly became energy and safety.

However, this was probably not the case for the first reactors. If I recall my documentary properly "la face gâchée du nucléaire" (French and German only I'm afraid), the technology was initially chosen because it could produce plutonium. Therefore it got lots of research, and naturally ended up working best.

Submarines were of course responsible for much of the continued funding. Molten salt got cut off in no small part because the very idea of a nuclear plane was not very good.

That said, I'll need to study this subject more closely before I consider myself properly informed.

Re: China’s ‘Artificial Sun’ achieves fusion breakthrough

#215

Post by philipkglass » Fri, Nov 11, 2016, 11:09 PM UTC

loup-vaillant wrote: post #214

philipkglass wrote: post #202

Earlier quoted context omitted.

I don't know who in the thorium boosters' club started the "light water reactors were meant for weapons plutonium" meme but it's nonsense. To quote "Technologies Underlying Weapons of Mass Destruction", Reactor-grade plutonium recovered from civilian reactors differs from weapon-grade plutonium in the relative proportions of various plutonium isotopes. Reactor-grade plutonium has a higher rate of spontaneous fission…

I'm inclined to believe modern civilian reactors are terrible at producing bomb worthy plutonium. Indeed, the main goals quickly became energy and safety. However, this was probably not the case for the first reactors. If I recall my documentary properly "la face gâchée du nucléaire" (French and German only I'm afraid), the technology was initially chosen because it could produce plutonium. Therefore it got lots of r…

It is not surprising that a pro-thorium documentary includes the same misstatements about uranium fueled light water reactors that have spread in writing.

The very first reactors were indeed built for plutonium production. Those 1940s reactors built in Hanford, WA, USA used unenriched natural uranium for fissile material, used purified graphite as their neutron moderator, and did not generate any useful energy. In fact they were net energy consumers because they needed an external power source to move water through to keep them cooled.

13 years after the Hanford reactors started, Shippingport became the first civil power reactor in the US: https://en.wikipedia.org/wiki/Shippingport_Atomic_Power_Stat...

Shippingport literally started with a surplus naval reactor from a cancelled aircraft carrier project. It was a pressurized light water reactor requiring enriched fuel like most reactors now operating commercially. Everything about it was different from the early plutonium reactors: the fuel, the moderator, the heat exchange... by a funny coincidence, Shippingport was also the only commercial reactor in the US to use the thorium fuel cycle, from 1977 to 1982.

Re: China’s ‘Artificial Sun’ achieves fusion breakthrough

#216

Post by Hydraulix989 » Fri, Nov 11, 2016, 11:10 PM UTC

Confirmed?

Re: China’s ‘Artificial Sun’ achieves fusion breakthrough

#217

Post by motoboi » Fri, Nov 11, 2016, 11:15 PM UTC

londons_explore wrote: post #196

cc438 wrote: post #191

Earlier quoted context omitted.

Land utilization is the issue. The largest solar farms in the US requires an order of magnitude more land to produce the same amount of power as a relatively average nuclear plant. The largest solar farm in the US, the Topaz Solar Farm in California, covers 25sq/km has a peak generation capacity of 550MW. The source uses the median of the 59 nuclear plants in the US to arrive at its 3.36sq/km (1.3sq/mile) per 1,000MW…

More importantly, with fusion, energy could become significantly cheaper allowing us to do things which weren't economically viable. Make everything out of environmentally friendly, lighter and long lasting aluminium rather than steel + concrete. Have street lighting that is as bright as sunlight over entire cities, allowing us to no longer be dependant on time of day. Growing food crops indoors with artificial light…

I made me curious about something.

Will the heat from all that electricity generation affect the environment in significant ways?

At which energy usage scale humanity will be restricted by the planet environment capacity to deal with the generated heat?

Re: China’s ‘Artificial Sun’ achieves fusion breakthrough

#218

Post by Grishnakh » Fri, Nov 11, 2016, 11:18 PM UTC

nnq wrote: post #122

sonium wrote: post #92

Earlier quoted context omitted.

This might sound a bit like a buzz-kill, but I don't think fusion power is necessarily competitively cheap. I think it will be comparable to nuclear power with a ~ 10 times higher capital investment to build a fusion-plant. Already now solar is said to be cheaper then nuclear. But nevertheless humanity should explore fusion since it is more or less the only significant power source not (indrectly) depending on the su…

NO... humanity should explore fusion because we might desperately need it to survive . To what amount can you scale up solar in a particular region?! Yeah, I know, we're into low-power everything nowadays... but let's say that you end up with a desperate need for smth like 1 TW of power for something like a sea-water desalination plant, massive irrigation needs because climate change fucked you up, or building a huge…

There's other reasons you might want fusion power: any place you need a large source of power, but siphoning off ambient energy (i.e. wind, solar) isn't feasible or sufficient, fusion is the way to go or else you have to use fission or fossil fuels.

This applies to things like ships and submarines, and to spacecraft.

So yeah, solar/etc. sounds great in an ideal scenario in a perfect world, but what if you're not on this world? Solar power isn't sufficient to do serious mining operations in the asteroid belt or to redirect a large asteroid threatening to impact the Earth. It also won't power your aircraft carrier or cruise ship. A clean source of nuclear power would be ideal for all these things, if we can figure out how to make such a thing work.

Re: China’s ‘Artificial Sun’ achieves fusion breakthrough

#219

Post by ww520 » Sat, Nov 12, 2016, 12:41 AM UTC

Godel_unicode wrote: post #79

ww520 wrote: post #77

Earlier quoted context omitted.

Isn't that the premise of the whole thread? Lumping all the reporting by its organization.

That's not what I've read above. It seems to me that some on this thread are saying they distrust science (and therefore science reporting) out of China because of the low quality of historical science and science journalism from China. See the difference?

Kadin's comment, which I replied to, never mentioned anything about science or science reporting. He only talked about press in general and made the point that since the news organization is not trustworthy, any news out of it can't be trusted. You were the only one talking about science reporting out of all the comments in the whole thread. That's kind of irrelevant to the specific discussion.

Edit: Or are you saying the science news reporting from People.cn are separated from the political reporting and thus can be trusted? You were making the point that science reporting and political reporting are different.

Re: China’s ‘Artificial Sun’ achieves fusion breakthrough

#220

Post by wallace_f » Sat, Nov 12, 2016, 1:04 AM UTC

varjag wrote: post #142

jimmaswell wrote: post #66

Earlier quoted context omitted.

Its byproducts, spent material, can be safely stored indefinitely in appropriate facilities. Running nuclear plants doesn't pollute the environment. How is it not clean?

Much of the actual, exiting waste however is not stored safely. And the two INES scale 1 incidents we had did pollute the environment pretty badly. So yes it is pretty dirty so far. You don't get very far in life relying on best-case scenario planning.

Yea, and even best case scenario is an indefinite nuclear waste facility somewhere inside Yucca mountain for the world to worry about for thousands of years to come.

It's interesting that it may be cleaner than traditional fossil fuels, but suggesting nuclear waste does not pose any environmental risk because it can be safely stored is exactly as you say: it's like saying anything does not pose risk because it can be safely averted. I could use the same logic to argue cars do not pose any safety risk because we can safely avert accidents. It's just wishful thinking to say we are capable to not make mistakes, and it's not logical to say there is no risk when there is.