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AI for real-time fusion plasma behavior prediction and manipulation

control.princeton.edu

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Re: AI for real-time fusion plasma behavior prediction and manipulation

#81

Post by gauge_field »

chriskanan wrote: post #74

There is a lot of AI research in the nuclear fusion space. For inertial confinement fusion (a competing technology to magnetic confinement fusion, e.g., tokamaks) the National Ignition Facility (NIF) used it for their experiment that resulted in "ignition." My lab is collaborating with researchers at the Laboratory for Laser Energetics to use AI to improve inertial confinement fusion (ICF). We recently put out this p…

I got curious when you said " old Fortran code, are slow, and have a high error between their predictions " Do you have any online reference/docs that explain apis/software/source code related to projects in this area?

Re: AI for real-time fusion plasma behavior prediction and manipulation

#82

Post by gpm »

fkyoureadthedoc wrote: post #24
CtrlAltmanDel wrote: post #16

Earlier quoted context omitted.

"causes heat" Heat is the transfer of energy due to a temperature differential. I think you may want to review the highschool physics textbook.

I never took high school physics so I asked my best friend what you're talking about and he (ChatGPT) said > CtrlAltmanDel nitpicks anon291’s use of "causes heat," arguing that heat is energy transfer due to temperature differences. This critique feels overly pedantic, as "heat" is commonly used to describe energy released in fusion (even if "thermal energy" might be more precise). I don't know if I should trust the…

> I don't know if I should trust the machine god or the snarky commenter

Neither of these are worthy of your trust. Even if they had agreed.

Re: AI for real-time fusion plasma behavior prediction and manipulation

#83

Post by adrian_b »

cosmic_quanta wrote: post #33
atomic128 wrote: post #12

Neutrons make hardware radioactive. Many on Hacker News fantasize about fusion (not fission) reactors. These fusion reactors will be an intense source of fast neutrons. All the hardware in a fusion reactor will become radioactive. Not to mention the gamma rays. If you have to deal with radioactive materials, why not just use fission? After 70 years of working with fission reactors, we know how to build and operate th…

> Neutrons make hardware radioactive True, but two caveats: 1. Neutron bombardment due to fusion makes hardware radioactive for less than 10 years, which isn't great but does not compare to fission waste; 2. Some fusion processes don't emit neutrons (aneutronic fusion). As I understand it, these processes aren't as efficient, but there is the possibility of a tradeoff between generation of ratioactive waste vs. effic…

> Neutron bombardment due to fusion makes hardware radioactive for less than 10 years

Very false. The current design target for fusion reactors is that the materials taken out of the reactor should become "low-level radioactive waste" after being stored for one hundred years.

It is acknowledged however that it is likely that a small fraction of the materials will not satisfy the criteria for "low-level radioactive waste" even after one thousand years.

For example it is extremely difficult to avoid using carbon in the reactor. Besides various kinds of steels used in reactor components there are now some proposals to replace the tungsten used in the plasma-facing surface with some carbides, for increased endurance. Carbon 14 remains radioactive for thousands of years.

There are many commonly used materials for which substitutes must be developed, e.g. new alloys, because otherwise they would produce radioactive isotopes with lifetimes of tens of thousands of years, e.g. there are efforts to develop some stainless steels with chromium and tungsten as a replacement for the normally used steels with chromium and molybdenum, which would generate long-lived radioactive waste.

See e.g. the UK governmental report:

https://assets.publishing.service.gov.uk/media/61ae4caa8fa8f...

Re: AI for real-time fusion plasma behavior prediction and manipulation

#84

Post by anon291 »

B1FF_PSUVM wrote: post #66
anon291 wrote: post #8

Earlier quoted context omitted.

No this is actually using neural nets to predict and control plasma boundary disruptions, which is an intractible problem to solve numerically. I've been studying plasma physics and from what I understand perfect control isn't necessary as long as you can control it long enough to get useful power. If the plasma dissipates you just restart. But ideally it's controlled enough that while it is in there, it's producing…

> an intractible problem to solve numerically. Yeah, so we'll just get a reduced dimension model that we don't know how it works. Sounds good.

This is an engineering problem not a scientific one. We can wait for better analytic methods or we can use a technique that is mathematically proven to be able to approximate the exact solution if you throw enough compute at it to learn the functions

Re: AI for real-time fusion plasma behavior prediction and manipulation

#85

Post by meindnoch »

empath75 wrote: post #80
meindnoch wrote: post #67

Earlier quoted context omitted.

>And if the rocks get a liiiitle bit too close together, they might explode Impossible. Worst thing that can happen without carefully designed explosive lens is a nuclear fizzle.

There are lots of ways that nuclear plants can explode or fail in otherwise catastrophic ways, it doesn't need to be an atomic explosion.

Parent was alluding to a nuclear explosion, not a steam explosion or other type of explosion. Other kinds of explosions have nothing to do with the fissile material ("rocks" in their parlance) being "too close together". Steam explosions in particular are caused by boiling water, due to increased reactor power, or inadequate circulation of coolant. In a nuclear reactor, the fuel cells are held in a fixed matrix, and are not moving an inch closer to each other, whether the reactor is operating normally, or a steam explosion is imminent.

In general, nobody was disputing the possibility of steam explosions, or other type of failures at nuclear power plants, thus your comment is besides the point, and irrelevant to this subthread.

Re: AI for real-time fusion plasma behavior prediction and manipulation

#87

Post by rnhmjoj »

cosmic_quanta wrote: post #33
atomic128 wrote: post #12

Neutrons make hardware radioactive. Many on Hacker News fantasize about fusion (not fission) reactors. These fusion reactors will be an intense source of fast neutrons. All the hardware in a fusion reactor will become radioactive. Not to mention the gamma rays. If you have to deal with radioactive materials, why not just use fission? After 70 years of working with fission reactors, we know how to build and operate th…

> Neutrons make hardware radioactive True, but two caveats: 1. Neutron bombardment due to fusion makes hardware radioactive for less than 10 years, which isn't great but does not compare to fission waste; 2. Some fusion processes don't emit neutrons (aneutronic fusion). As I understand it, these processes aren't as efficient, but there is the possibility of a tradeoff between generation of ratioactive waste vs. effic…

Unfortunately is pretty far from "less than 10 years", which I guess you got from the half life of tritium. Tritrium radiocativity, in the form of tritium retained in the plasma facing materials, does contribute in that order of years if done properly, but neutron activation dominates and it's unavoidable. The actual numbers are in the order of hundres of years, still a lot less than fission high level waste, but let's not make unreasonable expectations around fusion, please.

You can find here a good comparison in terms of radiotoxicity vs years after plant shutdown for a few designs in this article [1].

[1]: https://doi.org/10.1016/j.fusengdes.2018.05.049

Re: AI for real-time fusion plasma behavior prediction and manipulation

#88

Post by rnhmjoj »

adrian_b wrote: post #65
jylam wrote: post #62

Earlier quoted context omitted.

I'm not a specialist but here is what I think I know (I'm talking with the point of view of a Frenchman, who consumes most of his electricity from (fission) nuclear power plants): 1/ Uranium is not a renewable (quite the opposite), needs to be mined and treated (which is expensive and very polluting), and not present at the required concentrations in most of the world (this creates geopolitical issues). 2/ Fission nu…

Deuterium is also not renewable, even if it is more abundant than uranium. The H1-B11 reaction would be a much better energy source than anything else, but for now nobody knows any method to do it. There is no chance to do it by heating, but only by accelerating ions, and it is not known how a high enough reaction rate could be obtained.

I'm curious, what are you considering for stating that deuterium is not renewable? AFAIK there's an essentially limitless supply in the form of HDO in the oceans[1] and there are cost effective methods[2] to isolate it.

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

[2]: https://en.wikipedia.org/wiki/Girdler_sulfide_process

Re: AI for real-time fusion plasma behavior prediction and manipulation

#89

Post by noobermin »

chriskanan wrote: post #74

There is a lot of AI research in the nuclear fusion space. For inertial confinement fusion (a competing technology to magnetic confinement fusion, e.g., tokamaks) the National Ignition Facility (NIF) used it for their experiment that resulted in "ignition." My lab is collaborating with researchers at the Laboratory for Laser Energetics to use AI to improve inertial confinement fusion (ICF). We recently put out this p…

Here we go with the CS people saying "the old fortran codes are terrible." Yeah, the "high error" between code predictions and laser shots is because LPI is inherently noisy and it's essentially impossible to fully control conditions. I would work on expensive sims for days to weeks and the experiments would see differences that would be off from that from an order or mag because their focal point is off by a micron. There's nothing wrong with the "old Fortran codes," they have the right physics, the problem is the initial conditions are just uncontrollable so that's why simulating these systems is hard.

Codes are not magic, they are physical codes, as in, they generally encode the physics as we understand it relevant to the experiment, so you might as well say our physical models are wrong, which is a much harder bar to clear, you'd have to invalid probably near 100 years of plasma physics. The problem likely is as I said, the experiments are just hard to control and we don't know the correct inputs. It's not like weather forecasting where we can have a weather balloons across the world, we're not able to probe every micron of the target at all times for a plasma temperature and density.

Re: AI for real-time fusion plasma behavior prediction and manipulation

#90

Post by UltraSane »

atomic128 wrote: post #12

Neutrons make hardware radioactive. Many on Hacker News fantasize about fusion (not fission) reactors. These fusion reactors will be an intense source of fast neutrons. All the hardware in a fusion reactor will become radioactive. Not to mention the gamma rays. If you have to deal with radioactive materials, why not just use fission? After 70 years of working with fission reactors, we know how to build and operate th…

Exactly. We should be working on making nuclear reactors cost $1/watt to construct. I can't see a technological reason why they couldn't be that cheap to build.
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