ITER: World's largest nuclear fusion project begins assembly • Hacker News Board

Re: ITER: World's largest nuclear fusion project begins assembly

#431

Post by korantu » Thu, Jul 30, 2020, 12:58 AM UTC

lmm wrote: post #373

korantu wrote: post #293

Earlier quoted context omitted.

To add to your list of currently available proven approaches, would an approach that decarbonized France's energy in just 10 years should also be considered? It looks like proven track record of decarbonisation if there is one.

You're talking about fission? I think we should push it as far as it will go. At the same time I think there is some legitimacy to the waste and disaster concerns (even if mostly overblown) and so fusion offers enough potential advantages to still be worth pursuing.

I am all for pursuing fusion, for pushing borders of our knowledge.

At the same time, concerns are way overblown about fission. You know, it is regulated to 1/10000 amount of radioactive increase that is known to ever cause harm.

This is causes the designs to be order of magnitude more expensive then they could be. For example, for BWR, fukushima, there is no graphite inside, and reaction is going on only when water is present. There is no reason to have super expensive air-tight building around it.

Moreover, in fukushima case, the fact that it was airtight actually caused it to explode, as hydrogen formed inside it. Should there be ventilation, there would not be chance for it to explode and disperse material further than otherwise.

Secondly, unneeded evacuation actually caused ~1k deaths when they were removing patiends from life support equipment, for example.

As for the waste - it is again purely political problem, you can totally reprocess it, as they do in France and they end up with a few slabs of glass for 30 years of powering Paris. Even if you dont reprocess it first, it takes ridiculously little space, and never harmed anyone.

Compare coal - 14000 tons of coal daily. Just imagine that, and compare this to the fact that it is possible to store _all_ nuclear waste right _on site_, ready for politicians to come to their senses. :)

To look at it this way, most dangerous nuclear plant is the one that does not get built, as it will be for significant part will be replaced with something burining dinosurs.

Re: ITER: World's largest nuclear fusion project begins assembly

#432

Post by korantu » Thu, Jul 30, 2020, 1:06 AM UTC

ClumsyPilot wrote: post #345

korantu wrote: post #233

Earlier quoted context omitted.

Well, one example. I live in Singapore, and for it to become energy independent, it would need a square kilometer for a nuclear plant. To achieve the same with solar, you need to pave the whole country with solar panels. Besides, to make these solar panels you need to spend energy too. and EROI for advanced solar is about 20, where for nuclear it is 80+. I think people should stop using nature when they can get the s…

I view renewables as energy farming, and city-states like Singapoure, lixemburg, etc. Are not very suitable for either form of farming :) for most countries the calculus is very different. UK has been developing sea based wind turbines quite succesfully, thats something that could work for singapore. I view nuclear as a bit of a lost cause to be honest, they take long time to build, cost a lot upfront, you need a lot…

What I meant is ofcourse de-carbonise economy, Singapore can't be energy independent in meaningful sense as it does not have fuel sources of any kind. And solar/wind do not count as there could totally be still nights.

I frankly dont understand how an energy source that can shift from 100% to 5% capacity on its own whim, independent of its user's needs could get so much attention and considered viable replacement for something predictable..

There was not a single economy decarbonized on solar\wind, even for those that tried really, really hard (see Germany). And we have example where it worked, in short 10 years.

There are countries still that can build nuclear on time and on budget - see South korea for example. Wonder why they don't get all the orders for urgent decarbonisation needs.

Re: ITER: World's largest nuclear fusion project begins assembly

#433

Post by willis936 » Thu, Jul 30, 2020, 1:22 AM UTC

pfdietz wrote: post #430

willis936 wrote: post #370

Earlier quoted context omitted.

Indeed you are allowed to come to your own conclusions. I object to this statement. >Fusion is an example of sunk cost thinking. The only reason we're working on it is because we had been. This is putting forward the opinions of others. The premise is the people who stay in the field lacked some form of awareness of your arguments. They are aware and they disagree. You can’t assume your argument is accepted in the ar…

No, I'm sure the people in the field are, at some level, well aware of the arguments. They're not new, after all -- look at Lidsky from 1983. But the human power of rationalization is very powerful when your career depends on it. They get a comforting assurance that the argument was wrong, and they don't look too closely to see if the refutation was actually correct. What did Upton Sinclair say? "It is difficult to g…

If the arguments are old, how is that a point in favor of people in the field being unaware of them? There has been 50 years of people arguing against the use of resources in pursuit of this field. You still think people in a field of physics have somehow sheltered themselves from these arguments? You have had a conversation with a physicist, yes? They will shred someone making dubious claims.

Further, if you think plasma physicists would go hungry if fusion research ceased, you’re simply wrong. Nobody researches fusion for the paycheck. An industry paycheck for the equivalent quality of work is double.

Re: ITER: World's largest nuclear fusion project begins assembly

#434

Post by lambdatronics » Thu, Jul 30, 2020, 2:20 AM UTC

ratdragon wrote: post #298

What does HN crowd think of companies like hb11 or lppfusion which try to construct much smaller but still powerful (lpp plans for 5MW, relatively small, reactor. They also want to use a different fuel that produces very little neutrons, thus very low radiocativity. And moreover they do not need thermal part as electricity is generated by directly collecting alpha particles (and some Xrays IIRC). It _feels_ to me lik…

Fusion scientist here. Hydrogen-boron is 500x harder than deuterium-tritium to ignite, roughly speaking. NIF couldn't even do that. I don't believe that these two groups have hit on the solution. Yes, it would be nice to have aneutronic fusion, but right now we're struggling to get deuterium-tritium to work. One step at a time.

Re: ITER: World's largest nuclear fusion project begins assembly

#435

Post by lambdatronics » Thu, Jul 30, 2020, 2:29 AM UTC

nucpal wrote: post #346

pl-94 wrote: post #282

Can someone explain to me the advantages of fusion over fission? Except for the radioactive wastes and the enthusiasm of journalists I don't get it

It's mainly the waste. Nuclear fission is a stable source of energy that does not produce carbon emissions in production. It's pretty much the answer to the climate crisis except that it produces dangerous waste that is horrendous to store and manage. Fusion mainly avoids this :)

Also, the accident scenarios are not as bad -- there's less total radioactivity in the device, and there's no meltdown risk.

Re: ITER: World's largest nuclear fusion project begins assembly

#436

Post by lambdatronics » Thu, Jul 30, 2020, 3:06 AM UTC

pfdietz wrote: post #262

Looking at stories like this, you need to realize how far out of the running this technology is. The power density of ITER (gross fusion power of the reactor divided by the volume of the reactor, not just the volume of the plasma) is 50 kW/m^3. This is horribly low, about 1/400th the power density of a PWR reactor vessel. The power/$ is also horribly bad. The cost is going to have to come down by two orders of magnit…

Solar was 2 orders of magnitude out of the running around 1975 -- and now it's at grid parity. So maybe fusion is 45 years away? :P

You're right that the cost is going to have to come down, and the power density up, before fusion can compete. High-field superconductors are one obvious route, and using plasma configurations that make better use of the magnetic fields are another. Either one of those approaches could deliver about two orders of magnitude in power density -- and they could be combined.

>The only reason we're working on it is because we had been.

I think there's been an element of that in the way the federal program has been run, but claiming it's the only reason to pursue fusion is not defensible.

Re: ITER: World's largest nuclear fusion project begins assembly

#437

Post by lambdatronics » Thu, Jul 30, 2020, 3:09 AM UTC

ragebol wrote: post #355

What downsides are there to fusion power, assuming it's commercially viable in a couple of decades? What negative externalities are there that could make it prohibitive? Fossil fuel has pollution etc, solar takes up lots of space and is apparently also ugly, wind energy is ugly and makes noise (according to NIMBYs). What argument could a NIMBY person have against fusion power, besides the big building in their back y…

Radioactive leaks/accidents -- they will be orders of magnitude less of a problem than fission, in the worst case, but people are innumerate, so they'll still object.

Re: ITER: World's largest nuclear fusion project begins assembly

#438

Post by lambdatronics » Thu, Jul 30, 2020, 3:19 AM UTC

thechao wrote: post #22

gautamcgoel wrote: post #2

I think fusion is cool, but I also think it distracts from more important and promising approaches to clean power. No one has ever demonstrated a self-sustaining, net positive fusion reaction. It will probably take >30 years to make this technology cheap , safe and reliable and another >20 years to deploy it at scale. We don't have 50 years to wait on clean energy, we need it today. We should be focusing our attentio…

Net-positive was achieved in 2013. As far as I can remember, ITER is a test-bed for economical and scalable nuclear fusion. Also, the corporate world (at least here in Texas, of all places) is perfectly capable of rolling out state-scale renewable power (wind).

Nope. JET achieved Q~0.7 in 1997[1],and that hasn't been beat since. In 1998, JT-60 would have gotten Q~1.2, had they put deuterium-tritium fuel [2] (but it wasn't built for that).

You might be thinking of some news from NIF. In 2013, they sorta claimed to have reached ignition, but that was only by moving the goal-posts.[3]

ITER is not by any means a test of an economical or scalable reactor -- it's still at the stage of a science experiment.

[1]https://en.wikipedia.org/wiki/Joint_European_Torus [2]https://en.wikipedia.org/wiki/JT-60 [3]https://en.wikipedia.org/wiki/National_Ignition_Facility#Bre...

Re: ITER: World's largest nuclear fusion project begins assembly

#439

Post by pfdietz » Thu, Jul 30, 2020, 3:46 AM UTC

willis936 wrote: post #433

pfdietz wrote: post #430

Earlier quoted context omitted.

No, I'm sure the people in the field are, at some level, well aware of the arguments. They're not new, after all -- look at Lidsky from 1983. But the human power of rationalization is very powerful when your career depends on it. They get a comforting assurance that the argument was wrong, and they don't look too closely to see if the refutation was actually correct. What did Upton Sinclair say? "It is difficult to g…

If the arguments are old, how is that a point in favor of people in the field being unaware of them? There has been 50 years of people arguing against the use of resources in pursuit of this field. You still think people in a field of physics have somehow sheltered themselves from these arguments? You have had a conversation with a physicist, yes? They will shred someone making dubious claims. Further, if you think p…

> how is that a point in favor of people in the field being unaware of them?

Perhaps they are movtivated readers and deliberately don't read the argument for comprehension. Kind of like what you just did there.

Re: ITER: World's largest nuclear fusion project begins assembly

#440

Post by KingOfCoders » Thu, Jul 30, 2020, 3:53 AM UTC

cwhiz wrote: post #382

KingOfCoders wrote: post #277

Earlier quoted context omitted.

No I guess NYC needs to keep that nuclear power plant in Lower Manhattan then.

I know you’re saying this as if it should be something scary that I should oppose. But I am not even remotely concerned about nuclear safety. If noise and traffic were no concern I would live right next to a nuclear power plant.

No I say this because if someone says solar is impractical in NYC and but nuclear somewhere else is, the comparison does not make any sense.