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Without any of the meltdown concerns a fusion powerplant is a lot simpler to actually build than a fission plant. It has a small fraction of the security, relia

by gpm 2y ago

Without any of the meltdown concerns a fusion powerplant is a lot simpler to actually build than a fission plant. It has a small fraction of the security, reliability, regulatory, etc concerns (not none, just way way less). Unless it's so marginal that it's barely producing electricity I'd be pretty surprised to find out we had Q>1 fusion and yet it couldn't out compete fission anywhere fission is practical.

beeflet 2y ago
I think that it will depend on economies of scale.
epistasis 2y ago
That's astounding, I've never heard anybody claim that the reactors would be simpler before! Do you have any estimates of anybody working on the problem that thinks that? Every schemer I have ever seen is quite a bit more complex than a fission reactor. Often, designs will depend on materials that do not yet exist. That said there is a tremendous variety of techniques that fit under the umbrella term of "fusion," so I'm hoping to learn something more.
- elcritch 2y ago
  Not simpler in terms of technology, but simpler in terms of deployment, regulation, and security. Those are the majority of costs in fission power plants.
  - epistasis 2y ago
    The majority of the cost in fission is in the massive construction build, change orders, logistics, massive concrete pours, welding, etc. I've looked a lot into this in terms of how to get a project like Georgia's Vogtle to have cost less, or Olkioluoto in Finland, or Flamanville 3 in France. Big complex construction projects are expensive, and it's not clear at all to me that fusion would be simpler or smaller, or escape the rest of Baumol's cost disease that has been plaguing fission in highly developed economies.
    - elcritch 2y ago
      That’d be interesting to learn more about. What I’ve seen always leans toward regulation driving costs. Though I guess some of that infrastructure could be overbuilt due to excessive regulation. Also much of the concrete and steel is needed for the containment domes. Fusion power likely wouldn’t require nearly as much protection. Perhaps just a fairly standard industrial building.
      - bluGill 2y ago
        Regulation generally drives costs by making us build more. Generally safety systems and other redundancy.
    - SecretDreams 2y ago
      I would guess the preventative maintenance over the lifetime of a fission reactor exceeds the initial build costs.
    - gpm 2y ago
      The more plausible looking modern fusion companies tend to be designing very small reactors compared to those projects. Vogtle is 5000 MWs. Olkioluoto is 1600. Helion is promising reactors that are 50 and can be shipped via trains by 2028 (or 2030 depending on how you read some statements/interpret what I just said). They still need some neutron shielding to actually operate them safely (boronated concrete, probably not shipped by train), but nothing on the scale of what you need for a fission plant. (and other than that I echo elcritch's comments)
      - myrmidon 2y ago
        Helion also promised 50MW prototypes by 2021. It's 2025 and they have no 50MW prototype still. Fusion power roadmaps are generally exercises in wishful thinking, while fusion power startup roadmaps are basically gaslighting-as-a-serivce. I still think its worth researching and we'll get there at some point, but I'm not holding my breath-- the whole industry has overpromised in the past, continues to overpromise now and will be probably be irrelevant for de-carbonizing the grid by the time the technology is actually ready at an industrial scale. Mass media reporting on the whole sector is admittedly even worse; especially for uninformed readers without an engineering background.
00N8 2y ago
Modern fission designs mitigate meltdown concerns well enough that I'm not sure the safety & security around a fusion plant would actually be any better/cheaper, although public sentiment may be enough of an advantage. Tritium & neutron activated metals are dangerous enough to require keeping the traditional nuclear plant safeguards IMO. As far as proliferation concerns go, I don't see any reason you couldn't breed plutonium in the neutron flux of a fusion reactor, & the tritium is clearly viable for boosted warheads.
- gpm 2y ago
  Modern fission designs plausibly mitigate meltdown concerns well enough... To move that "plausibly" into "actually" you have to have very careful design review by regulators. Very careful review of construction to make sure what is constructed is what was designed. And so on and so forth. It's a lot of friction that skyrockets costs. Legitimately. People inevitably attempt to cut corners, and there's no way to make sure they aren't on the safety parts without checking. Actual currently regulatory costs seem to bear out the difference between these, with SMR people spending large amounts of money to convince regulators they didn't screw up, vs Helion fusion being "regulated like a hospital". I'm not saying fusion has no proliferation concerns. But it's the difference between "low grade nuclear waste, or a very high tech very advanced program to weaponize a working reactor" and "even a broken reactor can be strapped to some explosives to make a dirty bomb". I can't say I'm very aware of how much proliferation concerns drive costs. Public sentiment also helps.
  - 00N8 2y ago
    A lot depends on the actual reactor design. I was thinking more of large scale D-T fusion, e.g. the tokamak design, which requires breeding tritium & is expected to create a lot of neutron activated waste. The tritium is especially concerning, as it's roughly as deadly as polonium-210 & highly bioavailable in the form of super heavy water. You're probably right for smaller aneutronic designs like Helion's. If they can actually be made to work, they'll be much safer.

by gpm 2y ago

beeflet 2y ago

I think that it will depend on economies of scale.

epistasis 2y ago

That's astounding, I've never heard anybody claim that the reactors would be simpler before! Do you have any estimates of anybody working on the problem that thinks that? Every schemer I have ever seen is quite a bit more complex than a fission reactor. Often, designs will depend on materials that do not yet exist. That said there is a tremendous variety of techniques that fit under the umbrella term of "fusion," so I'm hoping to learn something more.

elcritch 2y ago
Not simpler in terms of technology, but simpler in terms of deployment, regulation, and security. Those are the majority of costs in fission power plants.
- epistasis 2y ago
  The majority of the cost in fission is in the massive construction build, change orders, logistics, massive concrete pours, welding, etc. I've looked a lot into this in terms of how to get a project like Georgia's Vogtle to have cost less, or Olkioluoto in Finland, or Flamanville 3 in France. Big complex construction projects are expensive, and it's not clear at all to me that fusion would be simpler or smaller, or escape the rest of Baumol's cost disease that has been plaguing fission in highly developed economies.
  - elcritch 2y ago
    That’d be interesting to learn more about. What I’ve seen always leans toward regulation driving costs. Though I guess some of that infrastructure could be overbuilt due to excessive regulation. Also much of the concrete and steel is needed for the containment domes. Fusion power likely wouldn’t require nearly as much protection. Perhaps just a fairly standard industrial building.
    - bluGill 2y ago
      Regulation generally drives costs by making us build more. Generally safety systems and other redundancy.
  - SecretDreams 2y ago
    I would guess the preventative maintenance over the lifetime of a fission reactor exceeds the initial build costs.
  - gpm 2y ago
    The more plausible looking modern fusion companies tend to be designing very small reactors compared to those projects. Vogtle is 5000 MWs. Olkioluoto is 1600. Helion is promising reactors that are 50 and can be shipped via trains by 2028 (or 2030 depending on how you read some statements/interpret what I just said). They still need some neutron shielding to actually operate them safely (boronated concrete, probably not shipped by train), but nothing on the scale of what you need for a fission plant. (and other than that I echo elcritch's comments)
    - myrmidon 2y ago
      Helion also promised 50MW prototypes by 2021. It's 2025 and they have no 50MW prototype still. Fusion power roadmaps are generally exercises in wishful thinking, while fusion power startup roadmaps are basically gaslighting-as-a-serivce. I still think its worth researching and we'll get there at some point, but I'm not holding my breath-- the whole industry has overpromised in the past, continues to overpromise now and will be probably be irrelevant for de-carbonizing the grid by the time the technology is actually ready at an industrial scale. Mass media reporting on the whole sector is admittedly even worse; especially for uninformed readers without an engineering background.

00N8 2y ago

Modern fission designs mitigate meltdown concerns well enough that I'm not sure the safety & security around a fusion plant would actually be any better/cheaper, although public sentiment may be enough of an advantage. Tritium & neutron activated metals are dangerous enough to require keeping the traditional nuclear plant safeguards IMO. As far as proliferation concerns go, I don't see any reason you couldn't breed plutonium in the neutron flux of a fusion reactor, & the tritium is clearly viable for boosted warheads.

gpm 2y ago
Modern fission designs plausibly mitigate meltdown concerns well enough... To move that "plausibly" into "actually" you have to have very careful design review by regulators. Very careful review of construction to make sure what is constructed is what was designed. And so on and so forth. It's a lot of friction that skyrockets costs. Legitimately. People inevitably attempt to cut corners, and there's no way to make sure they aren't on the safety parts without checking. Actual currently regulatory costs seem to bear out the difference between these, with SMR people spending large amounts of money to convince regulators they didn't screw up, vs Helion fusion being "regulated like a hospital". I'm not saying fusion has no proliferation concerns. But it's the difference between "low grade nuclear waste, or a very high tech very advanced program to weaponize a working reactor" and "even a broken reactor can be strapped to some explosives to make a dirty bomb". I can't say I'm very aware of how much proliferation concerns drive costs. Public sentiment also helps.
- 00N8 2y ago
  A lot depends on the actual reactor design. I was thinking more of large scale D-T fusion, e.g. the tokamak design, which requires breeding tritium & is expected to create a lot of neutron activated waste. The tritium is especially concerning, as it's roughly as deadly as polonium-210 & highly bioavailable in the form of super heavy water. You're probably right for smaller aneutronic designs like Helion's. If they can actually be made to work, they'll be much safer.