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> and there it was being driven by military needs (submarines) and not civilian. I'm surprised that support for fusion isn't part of US DoD policy; abundant, c

> and there it was being driven by military needs (submarines) and not civilian. I'm surprised that support for fusion isn't part of US DoD policy; abundant, cheap, clean energy would be a huge military asset. Those explosives zooming back and forth in Ukraine are really just energy balls.

ncmncm 4y ago
The necessarily super-expensive fusion would be a strict liability. It will, in consequence, not be built. All work toward that is pure waste. The DoD does spend a great deal of our tax money on fusion, but not for "abundant cheap clean energy". It is, rather, for uses like what is occurring in Ukraine: death and destruction; and for vaporizing cities and ports, distributing radioactive fallout over wide areas.
tsimionescu 4y ago
Fusion would in no possible world be cheap. Whatever else they would be, fusion reactors will be the most expensive structures per unit of volume built by man.
- denton-scratch 4y ago
  Well, I guess I was talking about running costs. Pardon me if I'm talking out of my ass, but this is what I tought: * The main input to a fusion reactor is electrical power. * The main output of a fusion reactor is even more power. So that seems to me to mean that once you've incurred the capital cost, the machine produces free energy. My reasoning sounds naive and simplistic, because I don't know what I'm talking about. But what's wrong with my reasoning?
  - ncmncm 4y ago
    1. A fusion plant would be extremely expensive to build. The most optimistic estimates are 10x per GW vs. fission. But we really don't know how to build one; nobody has identified a material that would work. 2. It is extremely expensive to operate. The most optimistic estimates are >10x fission. A thousand tons of lithium "blanket" would have to be sifted daily to get a few grams of tritium for the next day's operation. Nobody knows how this could be done. 3. It destroys itself with neutron irradiation in only a few years. At best, major parts of the structure would have to be replaced using robots because of the extreme radiation in the parts being replaced. Similarly, for repairs. Nobody has built such robots, so they are custom one-offs. The fuel cost of fission is a negligible part of its cost. The fuel cost of a fusion plant would be negligible, assuming enough tritium could be obtained at all. The ITER project expects to run out and does not know where they will get enough for future experimentation. Nothing about fusion is free, or even affordable.

ncmncm 4y ago

The necessarily super-expensive fusion would be a strict liability. It will, in consequence, not be built. All work toward that is pure waste. The DoD does spend a great deal of our tax money on fusion, but not for "abundant cheap clean energy". It is, rather, for uses like what is occurring in Ukraine: death and destruction; and for vaporizing cities and ports, distributing radioactive fallout over wide areas.

tsimionescu 4y ago

Fusion would in no possible world be cheap. Whatever else they would be, fusion reactors will be the most expensive structures per unit of volume built by man.

denton-scratch 4y ago
Well, I guess I was talking about running costs. Pardon me if I'm talking out of my ass, but this is what I tought: * The main input to a fusion reactor is electrical power. * The main output of a fusion reactor is even more power. So that seems to me to mean that once you've incurred the capital cost, the machine produces free energy. My reasoning sounds naive and simplistic, because I don't know what I'm talking about. But what's wrong with my reasoning?
- ncmncm 4y ago
  1. A fusion plant would be extremely expensive to build. The most optimistic estimates are 10x per GW vs. fission. But we really don't know how to build one; nobody has identified a material that would work. 2. It is extremely expensive to operate. The most optimistic estimates are >10x fission. A thousand tons of lithium "blanket" would have to be sifted daily to get a few grams of tritium for the next day's operation. Nobody knows how this could be done. 3. It destroys itself with neutron irradiation in only a few years. At best, major parts of the structure would have to be replaced using robots because of the extreme radiation in the parts being replaced. Similarly, for repairs. Nobody has built such robots, so they are custom one-offs. The fuel cost of fission is a negligible part of its cost. The fuel cost of a fusion plant would be negligible, assuming enough tritium could be obtained at all. The ITER project expects to run out and does not know where they will get enough for future experimentation. Nothing about fusion is free, or even affordable.