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by ncmncm 1542 days ago
Cynicism is well justified, given history and the present landscape.

Suppose they get this working, and able to produce, what, 300 MW worth of hot neutrons. They have to capture the neutrons and turn them into heat to boil water to drive a turbine to get out 150 MW. Thus, handle the, what, 1000 tons? 10,000 tons? of lithium needed to capture all those neutrons. And, I guess, sieve it for tritium? Maybe chemically separate micrograms of Li-3H from the thousand tons of pure, molten, radioactive lithium? And, every year replace all the pipes the lithium runs in, weakened by neutron bombardment. By remote control, because strongly radioactive.

This is clearly a bigger job than what needs to be done for a fission plant, where all you need to handle is water and fuel rods. (If you think a 1000 tons of molten radioactive lithium won't need containment, allow me to disabuse you.) But fission is already not competitive with solar/wind + storage. In 10 years, fission will be even less competitive than today. There is no scenario where this ends up economically useful.

2 comments

> Cynicism is well justified, given history and the present landscape.

The history, measured by the fusion triple product, is exponential progress on par with Moore's law [1], despite abysmal funding [2].

[1] Figure 1, https://www.scipedia.com/public/Sanchez_2014a

[2] https://hardware.slashdot.org/story/12/04/11/0435231/mit-fus...

If only achieving a high triple product were enough to achieve practical fusion. It's not -- there are serious obstacles, especially for DT fusion, that have nothing to do with plasma physics.
The history is of radical overpromising, and continual announcement of "breakthroughs" that do not bring plausible competitive viability any nearer.

The current funding level, given the abysmal prospects for any return, is too high. It was even higher before. We'll never get any of that back.

> The history is of radical overpromising, and continual announcement of "breakthroughs" that do not bring plausible competitive viability any nearer.

It sounds like your issue is with the PR, not the technology. Is there something faulty or misleading with the progress made in the triple-product score?

> The current funding level, given the abysmal prospects for any return, is too high. It was even higher before. We'll never get any of that back.

30 years of fusion research is what a single Nimitz aircraft carrier costs. The "even higher" level was one Nimitz carrier per decade. And it only lasted one decade. Eyeballing the funding graph, the US has spent a total of 3 aircraft carrier's worth of funding for fusion in total, since research began.

3 aircraft carriers in, 0 kWh out.
"But fission is already not competitive with solar/wind + storage." Any source about that ? It just sounds like an arbitrary anti-nuclear opinion without any evidence backing it. But I'm still cursious if you have anything serious to prove this claim.
I could go google that for you. But, why?

Innumerable commercial entities are building out solar and wind farms as fast as they can scare up capital. Literally not a single purely commercially-backed nuke plant has ever been built in 70+ years. Not one. Capital did build and operate coal plants, at a profit. But nobody is building new coal plants, anymore. Even operating an existing coal plant is not competitive any more; coal plants are being shut down with no plan ever to re-open, exactly as fast as solar and wind come on line.

Nukes are made out of steel, concrete, plumbing, and pumps. None of those are getting cheaper. They produce power by blasting steam through enormous turbines, that need regular expensive maintenance, not getting cheaper. Mining and refining uranium is expensive and not getting cheaper. Solar and wind generation cost have been declining at an exponential rate for two decades, and are still falling. Can you even conceive of an exponentially declining cost not crossing any given constant cost?

Suppose you figured out a way to get power from nukes at half the cost, and that was less than renewables just now. How long would it be before they undercut that, again? Would you be able to finish building one, in that amount of time?

There is no future for fission, and even less for fusion.

"Literally not a single purely commercially-backed nuke plant has ever been built in 70+ years. Not one."

Sure, let's check wikipedia to see how this is not true : https://en.wikipedia.org/wiki/List_of_commercial_nuclear_rea...

Also, after googling it: yes indeed, in some countries renewable energies are more competitive than fission. But that's not the case everywhere : https://www.iea.org/reports/projected-costs-of-generating-el... Or maybe you were just talking about the US, in this case your statement might be true.

I hope renewable energies cost will keep decreasing as much as it did those last ten years but I'm not as optimistic as you are.

Supposed purely commercial plants are always, it turns out, massively subsidized. At minimum, they are absolutely protected against liability, so do not need to try to find an insurer, never mind pay premiums to one.

And, mining and refining fuel has been massively subsidized.