Nuclear fusion has encountered a shortage of tritium • Hacker News Board

Re: Nuclear fusion has encountered a shortage of tritium

#141

Post by ncmncm » Sat, May 21, 2022, 5:23 PM UTC

Manuel_D wrote: post #128

ncmncm wrote: post #124

Earlier quoted context omitted.

And yet, not competitive . So, there is something missing in your model. It is for you to figure out what is wrong.

It's not competitive with a power source containing fossil fuels. And there's no feasible way to run a grid composed of wind and solar without fossil fuels. Ignoring the fact that wind and solar generation is really wind, solar, and fossil fuels , to offset the intermittency is naive. In areas without hydroelectric and geothermal potential, nuclear is the most competitive carbon-free and non+intermittent option. Beca…

See, you got the wrong answer again.

Renewables plus local storage, transmission line, and/or ability to burn imported ammonia or hydrogen suffices, and at radically less cost, with no risk of rendering large areas uninhabitable.

Re: Nuclear fusion has encountered a shortage of tritium

#142

Post by ncmncm » Sat, May 21, 2022, 5:38 PM UTC

tlb wrote: post #119

ncmncm wrote: post #116

Earlier quoted context omitted.

Thorium turns out not to be the solution to any problem.

One problem it solves is making reactors that can't produce material for nuclear weapons. That's pretty important if we want to deploy reactors outside the few countries that already have them.

I live near Indian Point, recently shut down. They tried thorium back when it was new. It cost too much then. Nukes of any stripe are not competitive now, and get less so every year. Thorium cannot save them.

Solutions that rely on a steam turbine generally lose to those that do not. A need to fool with fuel and security cost even more. Account for the disaster insurance subsidy and decommissioning cost, and they come out a marked drag on society.

That is, if you manage to complete one before it gets cancelled because renewables are already doing the job more cheaply than it can. We do better not to spend the initial $billions on what will never produce any marketable power. No such money is ever returned.

A nuke that runs only at night costs almost twice as much per kWh.

Re: Nuclear fusion has encountered a shortage of tritium

#143

Post by ncmncm » Sat, May 21, 2022, 5:41 PM UTC

Filligree wrote: post #130

ncmncm wrote: post #115

Earlier quoted context omitted.

Yes, conventional fission would be much cheaper to operate. But it, also, is no longer economically competitive.

So long as carbon-emitting sources are allowed to be used in the mix. That’s the real problem here.

Carbon sources will have been long since priced out of the market before you could finish building a nuke.

Re: Nuclear fusion has encountered a shortage of tritium

#144

Post by john567 » Sat, May 21, 2022, 5:45 PM UTC

pfdietz wrote: post #132

john567 wrote: post #122

Earlier quoted context omitted.

??? Fission is incredible profitable. It's the only source of reliable electricity we have (with a negligible CO2 impact). The only reason fission isn't more profitable is politics. Politics are making investment and research into fission needlessly costly.

Fission is grossly uncompetitive. That's why there's never been a single merchant fission power plant built anywhere in the world.

What county are we talking about here?

Re: Nuclear fusion has encountered a shortage of tritium

#145

Post by ncmncm » Sat, May 21, 2022, 5:52 PM UTC

ASalazarMX wrote: post #140

ncmncm wrote: post #109

Earlier quoted context omitted.

You could absorb neutron flux in a thousand tons of molten 6Li/7Li, and then try to separate grams of tritium from that thousand tons of molten, extremely inflammable metal, on a continuous basis. Good luck with that. Renewables do not incur such operating expenses. Put renewables and a fusion reactor on the grid, and fusion would never, ever win a bid. "Fusion .. will generate ... less ... than fission"? The whole d…

I dug more about this because it's an interesting topic. Basically we don't know how long a fusion generator will last before radioactivity forces its decommissioning because none exist yet, but fortunately it's short-life isotopes, about 50-120 years before they become safe. Orders of magnitude better than fission waste. I don't know about fusion vs renewables, because renewables are better, but they need a lot of n…

The reactor would need to be replaced frequently as the chamber walls and molten-lithium pipes weaken from neutron bombardment, every two years, maybe as long as five. By the time they could build one, there might be some way to make it last ten?

It needs even bigger containment than a regular nuke because reactive molten lithium bursts into flame on contact with air. The oxidized product is an exploding cloud of vaporized radioactive drain cleaner. A thousand tons of lithium make a lot of drain cleaner.

And again, by that time all our power will be cheaply supplied by renewables with no disastrous failure modes, and maintained just by taking bits down and putting up new bits, in shirtsleeves when weather favors it.

Re: Nuclear fusion has encountered a shortage of tritium

#146

Post by ncmncm » Sat, May 21, 2022, 6:01 PM UTC

john567 wrote: post #144

pfdietz wrote: post #132

Earlier quoted context omitted.

Fission is grossly uncompetitive. That's why there's never been a single merchant fission power plant built anywhere in the world.

What county are we talking about here?

All. Even nominally commercial ones get a whopping disaster liability subsidy, and decommissioning cost is omitted from the price, but charged to ratepayers on top of whatever actual power they are also paying for.

It will cost at least a $billion to take apart and dispose of Indian Point, shut down recently because it was leaking radioactive stuff into the Hudson.

Re: Nuclear fusion has encountered a shortage of tritium

#147

Post by marcosdumay » Sat, May 21, 2022, 6:21 PM UTC

ncmncm wrote: post #109

adrian_b wrote: post #78

Earlier quoted context omitted.

The kinds of fusion generators that are considered for the near future produce most of their energy as kinetic energy of neutrons. The energy of the neutrons is transformed into heat by adsorbing them into some shielding walls. The materials for those walls will be chosen to minimize the quantity of radioactive waste that is produced by the extremely intense neutron irradiation, but it is impossible to avoid complete…

You could absorb neutron flux in a thousand tons of molten 6Li/7Li, and then try to separate grams of tritium from that thousand tons of molten, extremely inflammable metal, on a continuous basis. Good luck with that. Renewables do not incur such operating expenses. Put renewables and a fusion reactor on the grid, and fusion would never, ever win a bid. "Fusion .. will generate ... less ... than fission"? The whole d…

Hydrogen does not seem to dissolve very well in molten lithium. It is quite easy to separate on the lab, but yeah, the practical consequences of convection currents and putting it through a heat exchanger may change this.

Anyway, I imagine the people studying fusion have an answer to this, since it only requires normal centuries-old chemical knowledge.

I also do not believe fusion will ever be a competitive power source for stationary applications on Earth.

Re: Nuclear fusion has encountered a shortage of tritium

#148

Post by marcosdumay » Sat, May 21, 2022, 7:26 PM UTC

ASalazarMX wrote: post #140

ncmncm wrote: post #109

Earlier quoted context omitted.

You could absorb neutron flux in a thousand tons of molten 6Li/7Li, and then try to separate grams of tritium from that thousand tons of molten, extremely inflammable metal, on a continuous basis. Good luck with that. Renewables do not incur such operating expenses. Put renewables and a fusion reactor on the grid, and fusion would never, ever win a bid. "Fusion .. will generate ... less ... than fission"? The whole d…

I dug more about this because it's an interesting topic. Basically we don't know how long a fusion generator will last before radioactivity forces its decommissioning because none exist yet, but fortunately it's short-life isotopes, about 50-120 years before they become safe. Orders of magnitude better than fission waste. I don't know about fusion vs renewables, because renewables are better, but they need a lot of n…

> Basically we don't know how long a fusion generator will last before radioactivity forces its decommissioning

That was one of the main questions the ITER was supposed to answer, wasn't it? AFAIK earlier designs were quite short-lived, but some small changes fixed it. We will know how long they last as soon as we don't have an ITER anymore.

Re: Nuclear fusion has encountered a shortage of tritium

#149

Post by pfdietz » Sat, May 21, 2022, 7:59 PM UTC

DennisP wrote: post #139

pfdietz wrote: post #138

Earlier quoted context omitted.

And as I told you last week, the numbers are actually optimistic compared to US (or actual EPR) numbers. In particular, it assumed the reactor cost 6000 euro per kW, which is considerably less than what EPR ended up costing.

And I linked you a paper surveying global nuclear costs, showing much lower costs in many areas and no overall trend of increasing costs. Here's the paper again: https://www.sciencedirect.com/science/article/pii/S030142151... Skip down to Figure 12 for a quick summary.

Most of those points that were low were either France or Korea. France with EPR has lost whatever mojo they claim to have had (those earlier cost figures are not verifiable) and Korea turned out to achieve low costs by corruption and omitting safety features.

Re: Nuclear fusion has encountered a shortage of tritium

#150

Post by Manuel_D » Sat, May 21, 2022, 8:04 PM UTC

ncmncm wrote: post #141

Manuel_D wrote: post #128

Earlier quoted context omitted.

It's not competitive with a power source containing fossil fuels. And there's no feasible way to run a grid composed of wind and solar without fossil fuels. Ignoring the fact that wind and solar generation is really wind, solar, and fossil fuels , to offset the intermittency is naive. In areas without hydroelectric and geothermal potential, nuclear is the most competitive carbon-free and non+intermittent option. Beca…

See, you got the wrong answer again. Renewables plus local storage, transmission line, and/or ability to burn imported ammonia or hydrogen suffices, and at radically less cost, with no risk of rendering large areas uninhabitable.

Storage at anywhere near significant levels does not yet exist, and might not be achieved in the time necessary to curb the worst effects of climate change. Ammonia and hydrogen storage has been proposed, for decades, yet remains out of reach at the scales necessary to make renewables viable.

Wind and solar is really wind, solar, and fossil fuels. Assuming that we'll be able to replace the last item with energy storage is betting the future of our climate on an engineering breakthrough. No such gamble exists with nuclear, countries like France have successfully produced nearly all their electricity with nuclear power for decades.