13 ms·

All systems go for UK’s £55M fusion energy experiment

261 points by danboarder 6y ago

danboarder 6y ago
Awesome to see that this project has achieved first plasma on their MAST Upgrade tokamak, see a video of this at the end the article.
ggm 6y ago
"extracting the excess heat" is nice. Unless there is some other path to conversion of the fusion energy to "useful" energy, this heat is the primary mechanism: you drive a heat exchanger, to drive a turbine, to make electricity. This is what we want: excess heat, to drive a turbine. Clearly, this tokomak isn't going to make net positive contribution to energy delivery. Some future (30 years?) tokomak is meant to do it. I do get that for an experiment, "extracting" the heat is what its all about. (Happy to be put right by wiser heads, if there is some other path to useful energy out from fusion)
- ggm 6y ago
  I read up, the two other choices are fusion-fission driving: use the neutrons to activate fissionable materials and then put them into a classic fission reactor as food (not what we want really) and direct electic extraction of surplus charge, which is at 48% efficiency according to the wiki. So yes: surplus heat is likely to be one of the useful products but not the only one, and if 48% efficiency is acceptable, it might be better to do direct charge take-off and process the heat as a problem as a much as the solution to a problem. Once the heat isn't a problem, its useful. You can have a hot bath. Or feed tomato roots in a greenhouse. Or I guess, run a turbine...
  - j9461701 6y ago
    Achieving fusion would be a god-send, but aneutronic fusion - which is generally considered 'the next step' - would be utterly spectacular. First, it would save you having to build very expense and complex steam turbines. Like Chernobyl had 4 nuclear reactors powering 1 steam turbine, because the engineering required to build a high quality high capacity one is super expensive. With aneutronic fusion you could just use the energy from the generated charged particles and directly turn that into juice. The huge, huge, huge thing though would be no more neutron radiation. It would vastly simplify reactor construction, reactor cleanup, biological shielding, etc. etc. Aneutronic fusion would also us to just spam power plants, safely and cheaply, in a way that's difficult for modern society to even understand. Assuming the aneutronic reactor itself isn't mega expense of course.
    - arethuza 6y ago
      I'm pretty sure the Chernobyl plant had 4 separate "blocks" each with one reactor and two turbo generators? No.4 was the one that exploded but the other three kept on producing power for years after. https://en.wikipedia.org/wiki/Chernobyl_Nuclear_Power_Plant https://en.wikipedia.org/wiki/Chernobyl_Nuclear_Power_Plant
      - j9461701 6y ago
        You're totally correct. It was 4 reactor buildings feeding one turbine house, but the house contained two turbo generators. Thanks for the correction!
    - gameshot911 6y ago
      Aneurotnic fusion sounds like exciting stuff. Are there any pilots in development? Is it realistically achievable at the moment (well, as realistic as any fusion efforts), or still in the realm of room-temperature superconductors?
  - raducu 6y ago
    Why do you need to put those neutrons in a fission reactor? Neutrons would still be absorbed and produce heat. Is it because those neutrons damage the reactor structure?
    - ggm 6y ago
      yes. aneutreonic, a reaction with "less" neutrons would be cleaner. either you have less/no neutrons, or you absorb the neutrons you have. they make the structure radioactive and/or change it chemically (embrittlement) or, you absorb them into other things to make them radioactive, and useful. https://en.wikipedia.org/wiki/Neutron_embrittlement https://en.wikipedia.org/wiki/Neutron_embrittlement
andyjohnson0 6y ago
Meanwhile the consortium running ITER [1] is spending €22 billion but the UK is no longer a member because we left the EU. For engineering at this scale, cooperation is going to get results - not small projects like this.
- Retric 6y ago
  Those are very different projects with very different goals. ITER is designed conservatively to produce 10x fusion energy output vs electrical energy input. As in you out 1 MW of electricity in and get 1 + 10 = 11MW of heat output. While not designed to be an economic fusion system it would unequivocally demonstrate a working design and a provide a test bed for experiments relating to reactor materials and full scale operations. This however is aimed to explore novel geometries which may aid in future designs. However, the net efficiency at this scale would be vastly lower. It’s still a useful project, but it’s just one of many possible designs.
  - raducu 6y ago
    Why would it not be economic? After the first reactor, do we expect building a replica, without all the R&D costs would be significantly more expensive than a standard nuclear reactor? To me, 10x the energy sounds really good.
    - sandworm101 6y ago
      10x energy doesnt mean 10x electricity. How one captures that energy and converts it effectively remains an open question. Can all those particles be turned into heat? Will those particles degrade the reactor so fast that it is no longer economically viable?
      - arethuza 6y ago
        ITER seems to be addressing the "capture the energy" part? https://www.iter.org/sci/MakingitWork https://www.iter.org/sci/MakingitWork "The neutrons will be absorbed by the surrounding walls of the tokamak, where their kinetic energy will be transferred to the walls as heat. In ITER, this heat will be captured by cooling water circulating in the vessel walls and eventually dispersed through cooling towers. In the type of fusion power plant envisaged for the second half of this century, the heat will be used to produce steam and—by way of turbines and alternators—electricity."
zeristor 6y ago
The Royal Society has held a couple of talks on Fusion, there’s audio from the talks, but no YouTube video alas: [0] https://royalsociety.org/science-events-and-lectures/2020/03/inertial-fusion-energy/ https://royalsociety.org/science-events-and-lectures/2020/03... [1] https://royalsociety.org/science-events-and-lectures/2018/03/tokamak-development/ https://royalsociety.org/science-events-and-lectures/2018/03... I attended the second day of the 2018 talk [0], the talks are free and it was extremely interesting.
ncmncm 6y ago
There will be no earthbound, commercial Tokamak fusion power in the lifetime of anyone reading this. For reasons. The energy density of the plasma is necessarily so low that a useful power plant would be absolutely monstrous. Then, it would destroy itself with neutron flux in short order, leaving thousands of tons of radioactive scrap. There is no possibility of such a plant being competitive with solar and wind at current prices, and they are still on their way down. The prospect of commercial power generation is not the driver of fusion research. Rather, it is a jobs program for high neutron flux physicists, to maintain a population available to draw upon for weapons work. So, expect it to continue burning $billions indefinitely, with no deliverable.
- Godel_unicode 6y ago
  The numbers I've seen thrown around for the flux expected out of ITER are containable with existing material science, and it's a very conservative design which is modeled to generate 10x the input power. I'd call that a deliverable.
  - Jabbles 6y ago
    Note that ITER's output is heat, rather than electricity. Maybe the heat will be useful, but it's an important distinction.
  - pfdietz 6y ago
    ITER's volumetric thermal power density (volume of reactor + plasma) will be 50 kW/m^3, some 400x worse than the volumetric power density of a commercial PWR (reactor vessel + core). ITER also use a CuZr alloy backing up its first wall materials. This material is unsuitable for long neutron exposure. DEMO would have to use RAFM steel instead there, with an order of magnitude lower thermal conductivity. As a result, the power/area at the surface of the first wall in DEMO may be even lower than in ITER.
    - willis936 6y ago
      The first wall has an 8 mm layer of Be facing the plasma.
deleted 6y ago
[deleted]
hikerclimb 6y ago
Hopefully this doesn’t work

261 points by danboarder 6y ago

Awesome to see that this project has achieved first plasma on their MAST Upgrade tokamak, see a video of this at the end the article.

ggm 6y ago

"extracting the excess heat" is nice. Unless there is some other path to conversion of the fusion energy to "useful" energy, this heat is the primary mechanism: you drive a heat exchanger, to drive a turbine, to make electricity. This is what we want: excess heat, to drive a turbine. Clearly, this tokomak isn't going to make net positive contribution to energy delivery. Some future (30 years?) tokomak is meant to do it. I do get that for an experiment, "extracting" the heat is what its all about. (Happy to be put right by wiser heads, if there is some other path to useful energy out from fusion)

ggm 6y ago
I read up, the two other choices are fusion-fission driving: use the neutrons to activate fissionable materials and then put them into a classic fission reactor as food (not what we want really) and direct electic extraction of surplus charge, which is at 48% efficiency according to the wiki. So yes: surplus heat is likely to be one of the useful products but not the only one, and if 48% efficiency is acceptable, it might be better to do direct charge take-off and process the heat as a problem as a much as the solution to a problem. Once the heat isn't a problem, its useful. You can have a hot bath. Or feed tomato roots in a greenhouse. Or I guess, run a turbine...
- j9461701 6y ago
  Achieving fusion would be a god-send, but aneutronic fusion - which is generally considered 'the next step' - would be utterly spectacular. First, it would save you having to build very expense and complex steam turbines. Like Chernobyl had 4 nuclear reactors powering 1 steam turbine, because the engineering required to build a high quality high capacity one is super expensive. With aneutronic fusion you could just use the energy from the generated charged particles and directly turn that into juice. The huge, huge, huge thing though would be no more neutron radiation. It would vastly simplify reactor construction, reactor cleanup, biological shielding, etc. etc. Aneutronic fusion would also us to just spam power plants, safely and cheaply, in a way that's difficult for modern society to even understand. Assuming the aneutronic reactor itself isn't mega expense of course.
  - arethuza 6y ago
    I'm pretty sure the Chernobyl plant had 4 separate "blocks" each with one reactor and two turbo generators? No.4 was the one that exploded but the other three kept on producing power for years after. https://en.wikipedia.org/wiki/Chernobyl_Nuclear_Power_Plant https://en.wikipedia.org/wiki/Chernobyl_Nuclear_Power_Plant
    - j9461701 6y ago
      You're totally correct. It was 4 reactor buildings feeding one turbine house, but the house contained two turbo generators. Thanks for the correction!
  - gameshot911 6y ago
    Aneurotnic fusion sounds like exciting stuff. Are there any pilots in development? Is it realistically achievable at the moment (well, as realistic as any fusion efforts), or still in the realm of room-temperature superconductors?
- raducu 6y ago
  Why do you need to put those neutrons in a fission reactor? Neutrons would still be absorbed and produce heat. Is it because those neutrons damage the reactor structure?
  - ggm 6y ago
    yes. aneutreonic, a reaction with "less" neutrons would be cleaner. either you have less/no neutrons, or you absorb the neutrons you have. they make the structure radioactive and/or change it chemically (embrittlement) or, you absorb them into other things to make them radioactive, and useful. https://en.wikipedia.org/wiki/Neutron_embrittlement https://en.wikipedia.org/wiki/Neutron_embrittlement

andyjohnson0 6y ago

Meanwhile the consortium running ITER [1] is spending €22 billion but the UK is no longer a member because we left the EU. For engineering at this scale, cooperation is going to get results - not small projects like this.

Retric 6y ago
Those are very different projects with very different goals. ITER is designed conservatively to produce 10x fusion energy output vs electrical energy input. As in you out 1 MW of electricity in and get 1 + 10 = 11MW of heat output. While not designed to be an economic fusion system it would unequivocally demonstrate a working design and a provide a test bed for experiments relating to reactor materials and full scale operations. This however is aimed to explore novel geometries which may aid in future designs. However, the net efficiency at this scale would be vastly lower. It’s still a useful project, but it’s just one of many possible designs.
- raducu 6y ago
  Why would it not be economic? After the first reactor, do we expect building a replica, without all the R&D costs would be significantly more expensive than a standard nuclear reactor? To me, 10x the energy sounds really good.
  - sandworm101 6y ago
    10x energy doesnt mean 10x electricity. How one captures that energy and converts it effectively remains an open question. Can all those particles be turned into heat? Will those particles degrade the reactor so fast that it is no longer economically viable?
    - arethuza 6y ago
      ITER seems to be addressing the "capture the energy" part? https://www.iter.org/sci/MakingitWork https://www.iter.org/sci/MakingitWork "The neutrons will be absorbed by the surrounding walls of the tokamak, where their kinetic energy will be transferred to the walls as heat. In ITER, this heat will be captured by cooling water circulating in the vessel walls and eventually dispersed through cooling towers. In the type of fusion power plant envisaged for the second half of this century, the heat will be used to produce steam and—by way of turbines and alternators—electricity."

zeristor 6y ago

The Royal Society has held a couple of talks on Fusion, there’s audio from the talks, but no YouTube video alas: [0] https://royalsociety.org/science-events-and-lectures/2020/03/inertial-fusion-energy/ https://royalsociety.org/science-events-and-lectures/2020/03... [1] https://royalsociety.org/science-events-and-lectures/2018/03/tokamak-development/ https://royalsociety.org/science-events-and-lectures/2018/03... I attended the second day of the 2018 talk [0], the talks are free and it was extremely interesting.

ncmncm 6y ago

There will be no earthbound, commercial Tokamak fusion power in the lifetime of anyone reading this. For reasons. The energy density of the plasma is necessarily so low that a useful power plant would be absolutely monstrous. Then, it would destroy itself with neutron flux in short order, leaving thousands of tons of radioactive scrap. There is no possibility of such a plant being competitive with solar and wind at current prices, and they are still on their way down. The prospect of commercial power generation is not the driver of fusion research. Rather, it is a jobs program for high neutron flux physicists, to maintain a population available to draw upon for weapons work. So, expect it to continue burning $billions indefinitely, with no deliverable.

Godel_unicode 6y ago
The numbers I've seen thrown around for the flux expected out of ITER are containable with existing material science, and it's a very conservative design which is modeled to generate 10x the input power. I'd call that a deliverable.
- Jabbles 6y ago
  Note that ITER's output is heat, rather than electricity. Maybe the heat will be useful, but it's an important distinction.
- pfdietz 6y ago
  ITER's volumetric thermal power density (volume of reactor + plasma) will be 50 kW/m^3, some 400x worse than the volumetric power density of a commercial PWR (reactor vessel + core). ITER also use a CuZr alloy backing up its first wall materials. This material is unsuitable for long neutron exposure. DEMO would have to use RAFM steel instead there, with an order of magnitude lower thermal conductivity. As a result, the power/area at the surface of the first wall in DEMO may be even lower than in ITER.
  - willis936 6y ago
    The first wall has an 8 mm layer of Be facing the plasma.

deleted 6y ago

[deleted]

hikerclimb 6y ago

Hopefully this doesn’t work