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ITER: World's largest nuclear fusion project begins assembly

bbc.co.uk

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

#451

Post by nucpal »

irthomasthomas wrote: post #418
nucpal wrote: post #337

Earlier quoted context omitted.

You're confusing the strong and weak nuclear forces from particle physics with the fission and fusion nuclear reactions. The (residual) strong force underpins the energy release in both fission and fusion reactions. You've also linked to the debunked pseudoscience of 'cold fusion', (dressed up as low energy nuclear reactions...) from Pons and Fleischman. Plenty of work is being done in the field of handling radioacti…

From the first link: " It was only in 2006, with the publication of a landmark paper in the European Journal of Physics C, that neutron-induced transmutations, as something distinct from cold fusion, began to emerge as a viable theory. The paper predicts that electrons on a metal surface coated with hydrogen, deuterium, or tritium atoms can behave collectively (as Einstein had predicted) when driven by an oscillating…

Landmark paper is a strong term for something that has been repeatedly debunked and then ignored by the nuclear physics community (all its citations are cold fusion journals...)

The theory Widom and Larsen propose violates the laws of physics and has no experimental evidence.

Put simply, the weak reaction needs an enormous amount of energy to happen. The difference between a neutron and a proton is 1MeV, more than the mass of the electron. The electric field at the surface of the metal is of the order of eV and does not account for this. So where are these massive electrons magically getting their energy from?

Or if you're comfortable with theoretical physics, a better critique can be found here: https://coldfusionblog.net/category/widom-larsen/

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

#452

Post by nucpal »

rini17 wrote: post #344
nucpal wrote: post #341

Earlier quoted context omitted.

That article is quite outdated, JET has 2020 D-T campaign. More importantly, fusion is a thousand times better than fission with respect to waste. No one is claiming there is no waste at all, but tritium has a half-life of 12.5 years so most of the waste will be safe within a few decades. The rest will largely be neutron embrittled steels/materials (classified as low level nuclear waste) that is easily stored. Compar…

So the waste output/power output is 1000 times better? Any sources pls? And this "Neutron embrittlement" does not create any dangerous long-lived isotopes? Like, we just wait few years and then normally landfill the concrete or how should I imagine the process?

Fission creates neutron embrittled materials and steels as well. And yes we tend to store them until they can be safely disposed.

Again, the main difference is the fuel. Tritium is safe in a few decades, spent uranium is safe in a few hundred thousand years.

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

#453

Post by willis936 »

pfdietz wrote: post #439
willis936 wrote: post #433

Earlier quoted context omitted.

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.

You write with a healthy amount of bias. Are there some stakes you should disclose?

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

#454

Post by korantu »

lmm wrote: post #443
korantu wrote: post #431

Earlier quoted context omitted.

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…

> 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. Entirely true. But unfortunately there are a lot of nuclear plants not getting built at the moment. Tragic as it is, developing working fusion is probably an easier way to change that than political persuasion.

I guess we can agree to disagree here. What will probably happen is that Russia and China continue to build up nuclear, and export it to whoever will take it.

even the most active proponents of solar/wind will continue to lag way behind in decarbonisation, as the bigger percentage of renuables on the grid the more difficult it is to manage.

at some point optics of the situation will catch up, and political persuasion will happen this way.. in my opinion it will happen much faster than cheap fusion

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

#455

Post by eclat »

pfdietz wrote: post #378
lorenzhs wrote: post #376

Earlier quoted context omitted.

Hydrogen is really hard to store, though. EDIT: should have qualified my statement with "in man-made objects"

No, actually it's pretty easy, in underground caverns (cheapest is solution mined cavities in salt; cost per kWh of capacity about 1/200th the per-energy cost of batteries.)

Interesting

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

#456

Post by pfdietz »

willis936 wrote: post #453
pfdietz wrote: post #439

Earlier quoted context omitted.

> 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.

You write with a healthy amount of bias. Are there some stakes you should disclose?

No stakes that I'm aware of.

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

#457

Post by aspenmayer »

worik wrote: post #426
aspenmayer wrote: post #230

Earlier quoted context omitted.

I have seen Aoraki with my own eyes, and I understand what you seek to protect.

For the locals Aoraki is a literal ancestor. So it is not my job, it is taken care of.

I suppose I was unclear. Please forgive me. We need to protect the idea of preservation in culture and society, so that future people also hold these ideals of caretaking and awareness of our ancestors, including the planet and life itself, to be true.

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

#458

Post by pezezin »

the8472 wrote: post #450
pezezin wrote: post #441

Earlier quoted context omitted.

I'm currently working for IFMIF (sister project of ITER), and I know some people who work or worked for ITER, and yes, the bureaucracy is an absolute nightmare. Coordinating so many countries with so many different working cultures is really difficult. On the other hand, we DO build incrementally larger versions. The machine is built and tested in stages, it would be impossible to build such complex machines in just…

> On the other hand, we DO build incrementally larger versions. You're referring to JET? Does ITER benefit from production facilities that were used for it?

First of all, I'm just a computer guy who joined this field two years ago. I still don't know much, so please excuse my ignorance.

Regarding JET and ITER, according to what I heard from my coworkers, all the knowledge that was gained at JET is being used for ITER. I guess many of the productions facilities are being reused too, but I would need to ask them.

Regarding our project (IFMIF), we are building a linear accelerator to simulate the neutron flux inside a fusion reactor and study the behavior of different materials. The accelerator is composed of an injector, several acceleration stages, and a beam dump. First the injector and the beam dump were installed and tested, and then all the other stages are being installed and tested incrementally. But a linear accelerator is a very different machine from a tokamak.

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

#459

Post by pl-94 »

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 :)

OK but some models of gen iv of nuclear power plants can pretty much do the same. It sounds pretty dumb to me that journalists are super enthusiast about fusion but much less about gen iv (which is way more mature)

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

#460

Post by the8472 »

pezezin wrote: post #458
the8472 wrote: post #450

Earlier quoted context omitted.

> On the other hand, we DO build incrementally larger versions. You're referring to JET? Does ITER benefit from production facilities that were used for it?

First of all, I'm just a computer guy who joined this field two years ago. I still don't know much, so please excuse my ignorance. Regarding JET and ITER, according to what I heard from my coworkers, all the knowledge that was gained at JET is being used for ITER. I guess many of the productions facilities are being reused too, but I would need to ask them. Regarding our project (IFMIF), we are building a linear acce…

I'm asking because afaik (and that's fairly superficial knowledge) is that JET is mostly a european project while ITER is built internationally and the production is intentionally assigned fairly (to spread experience to contributors) rather than with a focus on efficiency. So that implies to me that there would be many new manufacturing places all over the globe. In other words it's made from scratch, more or less.
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