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Comment by vermilingua | Hacker News Reader

OpEx > CapEx

Yes, fusion is considerably more capital intensive than fission power, but the fuel is just water. You don’t need to worry about digging the fuel out of the earth, maintaining a costly disposal scheme for hazardous waste, etc.

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Nuclear byproducts storage (let's not call it waste since MOX fuel is the future for humanity) do not cost much, it's not a point that is salient enough to male fusion relevant in any way.

Thanks, but is the fuel cost a significant factor in fission plants? And the waste disposal? There's already lots of radioactive material in the ground, after all, for example in uranium mines.

Building one power plant is incredibly expensive. Building it again costs less. Building it 1000 times costs much less per plant. We're not building thousands of fission plants because of politics. Fusion might be an easier sell.

This isn't really true. Yes first of a kind is expensive and there is learning curve, but learning is serial and iteration cycle is long. You can't build 1000 plants in parallel and learn 1000x. Solar power cost is falling fast because iteration cycle is short.

South Korea built 28 reactors over 36 years and cost fell 1.5% per year, totalling 40% reduction. Even with this South Korean nuclear power is only about as half cheap as solar power locally (as of 2020), and South Korea is a very poor country for solar power considering its latitude and weather.

Fuel cost is not significant, waste disposal even less so. (In fact, usual accounting of nuclear fuel cost includes waste disposal cost. People argue cost is not accounted in full, but as accounted, waste disposal typically costs 1/6 of fuel cost.)

In terms of cost, 80% of nuclear power is CAPEX. Among OPEX, about 1/3 is fuel, rest is operation and maintenance. So from total cost, about 6% is fuel, and about 1% is waste disposal.

Still, fission operational expense is very, very large when compared to solar and wind, which also have radically lower capital cost. Operational expense of neutron-emission fusion would be radically more than for fission: not for the fuel, but for everything else.

Where does tritium come from?

Li6 fission in between the first wall and confinement coils.

If you want some details: check out section 3.2 of the ITER research plan.

https://www.iter.org/doc/www/content/com/Lists/ITER%20Techni...

This is where tritium will come from, but not where it does now.

Oh. I'm pretty sure it will be the same place most of the current tritium gas comes from: CANDU.

ITER plans to test breeding tritium from lithium. It should work in theory, but there is no practical experience yet. Current tritium used in fusion research is entirely produced from fission reactor moderated by heavy water, and there is only one production facility in the world at Canada.

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