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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

#331

Post by maccam94 »

fabian2k wrote: post #38
nharada wrote: post #20

Earlier quoted context omitted.

There's a good talk here about why ITER is so large: https://www.youtube.com/watch?v=L0KuAx1COEk The idea is essentially that to get the parameters needed to make net energy with tokamaks, you need either very strong magnets or a large device. At the time of ITER's design, they used the strongest magnets they could find and then made the thing big enough to get the energy gain they wanted. The speaker of this talk ar…

I wonder how much the possible magnet strength affects the design of a tokamak. There are very clear limits on the field strength you can achieve with classical superconductors, and I know e.g. in Nuclear Magnetic Resonance those limits had been almost hit maybe a decade ago or so. But very recently spectrometers based on new high-temperature superconductors have been delivered, so the technology seems to be far enou…

Cambridge Fusion Systems[1] is a private company spun out of MIT that is building a proof-of-concept reactor based on these new magnets within the next 5 years.

Breakthrough in Nuclear Fusion? - Prof. Dennis Whyte (2016) - https://www.youtube.com/watch?v=KkpqA8yG9T4

Timeline (in case you want to skip over some parts):

  00:01:00 - introducing Dennis Whyte, MIT department head for nuclear science
  00:04:24 - presentation starts
  00:06:00 - identifies breakthrough with REBCO magnets
  00:07:25 - explains deuterium-tritium fusion
  00:12:30 - basic metrics for reactor performance
  00:17:15 - energy output of other previous fusion experiments
  00:19:00 - examines ITER and the problems of its approach
  00:22:00 - problems solved by high energy magnetic fields
  00:28:15 - full scale reactor concept, teardown of REBCO magnets
  00:37:00 - design limits and margins
  00:39:00 - fixes plasma instabilities found in weaker magnetic chambers
  00:40:00 - maintainability, lifespan, component replacement
  00:45:00 - solution to neutron damage and energy capture
  00:50:30 - cost and profitability
  00:54:00 - full graph of field strength vs reactor scale (and thus funding requirements)
  01:01:50 - Q&A
  01:30:00 - question about the biggest risks
He gave another talk in 2019 with more numbers and even more confidence: https://www.youtube.com/watch?v=rY6U4wB-oYM

1: https://cfs.energy/technology

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

#332

Post by imtringued »

belorn wrote: post #160
jpdus wrote: post #105

Earlier quoted context omitted.

> Picture a few large cities with contractors running around every roof tending to solar panels and compare to a few experts at a single nuclear power plant. For the contractors-on-roofs, the slip & falls add up even though they'll never get an HBO mini-series. This is a very flawed and short-sighted argument. Averages don't matter when you are talking about fat-tailed/power law risk distributions. Nobody would be op…

Renewables are only safer and cheaper bet once the battery issue is solved and can be made equally green, safe and cheap. The primary reason why nuclear isn't commercial viable today is that combining natural gas and renewables makes for a very cheap energy grid.

There is no "battery issue". There are lots of energy storage mechanisms that work well in combination. [0]

What you said is a tautology and brought nothing new to the table. (non cheap) nuclear can't compete against cheap renewables. Everyone knows that but almost nobody knows why nuclear is so expensive today.

The reason why nuclear power is not commercially viable is that it doesn't benefit from economies of scale. If you build custom tailored humongous monolithic nuclear plants you're going to pay a huge amount of money. Just think about how expensive it would be to build one giant solar panel with a total area of 1 km² instead of a million 1m² panels. It's absolutely nonsensical yet it happens every single time a nuclear plant is being constructed. The few success stories like France simply standardized on a single design. General corruption and budget bloat probably did more to stop nuclear than all anti nuclear hipsters combined.

[0] https://cleantechnica.com/2020/02/09/correcting-anti-renewab...

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

#333

Post by belorn »

worik wrote: post #192
belorn wrote: post #160

Earlier quoted context omitted.

Renewables are only safer and cheaper bet once the battery issue is solved and can be made equally green, safe and cheap. The primary reason why nuclear isn't commercial viable today is that combining natural gas and renewables makes for a very cheap energy grid.

Nope. There are other alternatives, and grid scale batteries are viable now. Just cheaper to burn gas/coal and fsck the future! The obvious alternative is pumped hydro, that is well established. Another is demand management, unexplored because the greed heads in control do not believe that our society can work together for the common good. Coming from Aotearoa, as I do, I know that is a fat lie.

Currently there does not exist a commercial viable pumped hydro installation in the world that buy overcapacity renewable energy and later sells it at a profit. There are a few experimental and proof of concept installations that demonstrate the possibility of hydro as a battery, and at least one operate as an additional reservoir to a hydro dam, but the commercial viability of buying cheap renewable energy to pump water in order to generate electricity later when the price is high is not yet here.

Demand management is also a great idea in concept but the commercial viability is questionable as long as people can just turn on the cheap gas burners. Commercially, turning off production and keep the industry closed when renewable are not producing is much more expensive compared to just paying what ever price society currently demands when burning fossil fuels.

Remove fossil fuels from being viable choice in the energy grid and the economic viability would change dramatically for every other energy source, including hydro pumps and nuclear. Demand management might even become a possible strategy to a point where it can have an significant impact on the energy grid. For now most grids operates by combining cheap renewable with cheap fossil fuels, with the environment taking the real cost when the fossil fuels burns.

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

#334

Post by raducu »

sgift wrote: post #329
irthomasthomas wrote: post #304

I'm surprised that we're still chasing moon shots in strong force fusion, while weak fusion, which has actually been demonstrated already, gets little attention. Chemically assisted/low energy nuclear reactions have been proven to produce clean energy and useful transmutation. This process can be used to turn radioactive waste into inert material. For example, technetium-99 is a particularly pernicious by-product of…

If we stopped what we worked on every time some nice theory came around which could work "better" (for whatever definition of better) we would never get anything done. Scientists/companies working in these areas are free to produce results that make ITER obsolete. After they've done that we can discuss about abandoning the - from our current understanding of science - most likely path to (more or less) unlimited ener…

But is the consensus that ITER will be self-sustaining from an engineering perspective?

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

#335

Post by rini17 »

The elephant in the room: fusion is no better wrt radioactive waste than fission. ITER is projected to end up with 30000 tons of radioactive waste.

https://thebulletin.org/2018/02/iter-is-a-showcase-for-the-d...

"Surrounding the ITER tokamak, a monstrous concrete cylinder 3.5 meters thick, 30 meters in diameter and 30 meters tall called the bioshield will prevent X-rays, gamma rays and stray neutrons from reaching the outside world. "

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

#336

Post by Scarblac »

elihu wrote: post #161
Scarblac wrote: post #126

Earlier quoted context omitted.

It gains the space underneath. Flat roofs (of large commercial buildings, for instance) sound like a good place for them. I don't understand why they are put on the ground instead so often.

Most people live in cities where land is very expensive, but rural land is cheap. So, it makes sense to do large-scale solar projects that aren't near cities at ground level, and put solar panels on roofs in cities and towns where the power is being used on-site and land is expensive. If people are putting installing solar panels at ground level in expensive urban settings, then yeah I think that's pretty weird. (It…

In my country (the Netherlands), there are a lot of huge distribution centers, large warehouses with flat roofs. But instead of putting solar on the roofs of those, rural land is used, and we don't have so much of that. It's a shame.

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

#337

Post by nucpal »

irthomasthomas wrote: post #304

I'm surprised that we're still chasing moon shots in strong force fusion, while weak fusion, which has actually been demonstrated already, gets little attention. Chemically assisted/low energy nuclear reactions have been proven to produce clean energy and useful transmutation. This process can be used to turn radioactive waste into inert material. For example, technetium-99 is a particularly pernicious by-product of…

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 radioactive waste from nuclear fission. My field (decommissioning and waste management) is entirely dedicated to it.

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

#338

Post by Angostura »

irthomasthomas wrote: post #304

I'm surprised that we're still chasing moon shots in strong force fusion, while weak fusion, which has actually been demonstrated already, gets little attention. Chemically assisted/low energy nuclear reactions have been proven to produce clean energy and useful transmutation. This process can be used to turn radioactive waste into inert material. For example, technetium-99 is a particularly pernicious by-product of…

> which has actually been demonstrated

For certain values of "actually be demonstrated". I don't think it's been reliably shown to be a real phenomenon, has it?

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

#339

Post by _Microft »

irthomasthomas wrote: post #304

I'm surprised that we're still chasing moon shots in strong force fusion, while weak fusion, which has actually been demonstrated already, gets little attention. Chemically assisted/low energy nuclear reactions have been proven to produce clean energy and useful transmutation. This process can be used to turn radioactive waste into inert material. For example, technetium-99 is a particularly pernicious by-product of…

In case you missed it, they are basically talking about "cold fusion".

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

#340

Post by saberience »

Dumb question here, but how is the actual power transmitted to the grid? I get we are trying to have some sustained reaction with plasma inside a magnetic field... but that just makes heat, not electricity.

Other reactor types have water to heat up and make steam but where does this happen in a Fusion reactor? It seems as though there is no obvious "place" for there to be water to turn into steam.

Again, sorry for dumb question.

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