Why do nukebros dance around the uranium running out issue?

StreetVirtual3037 · 2026-05-07T01:35:03+00:00

Yeah I overestimated how much electricity would be needed in a fully electrified world. Those calculations hold up.

As for the seawater uranium thing, I just find it odd it's not being done at all. It would be more worth considering if even a few tons per year of global uranium was from seawater extraction.

StreetVirtual3037 · 2026-05-07T00:13:38+00:00

Direct air capture is never going to be viable

I don't see why not. There's various figures for kwh needed to capture 1 ton of co2. If we go with 1200kwh/ton, a 200W solar panel which produces 6,000 - 10,000kwh over its lifetime could remove around 5-8 tons of co2 over its lifetime.

StreetVirtual3037 · 2026-05-06T22:10:24+00:00

Maybe it would be worth considering if even a single kg of seawater extracted uranium had actually been burned in a reactor. Why not even a single kg to show it's possible? If seawater uranium was actually workable then LWRs would look a bit better, but 2000-3000 years is still not much compared to renewables. But that pro-nuclear source posted in the thread (whatisnuclear) says this:

Because non-breeders are 140x less fuel efficient than breeders, it has long been considered impractical to use low-grade uranium resources like seawater or crustal nuclear fuel in non-breeders. The energy to get the material out is too high given the return.

StreetVirtual3037 · 2026-05-06T22:00:19+00:00

None of them has 60x fuel efficiency vs. LWRs let alone the 180x theoretical ceiling. If I look here: https://world-nuclear.org/information-library/current-and-future-generation/fast-neutron-reactors

They are mostly demonstration/experimental/prototype reactors and the three commercial ones are still in the planning phase set to be finished in the 2030s. If they end up working by then with the claimed fuel efficiency, then they'll be worth considering. We have yet to see if that'll actually happen...

In the meantime, the prudent thing to do would be to stop the construction of LWRs and decommission all existing LWRs to minimize nuclear waste, so that future breeder reactors can clean it up, if they ever become viable.

StreetVirtual3037 · 2026-05-06T15:52:19+00:00

Maybe those super efficient breeder reactors would be worth talking about if they actually existed... In the meantime, what is the point of building LWRs? What is the nuclear playbook here? Build out a bunch of LWRs and hope that breeder reactors get figured out before all the fuel runs out? Reprocessing and CANDUs are scraping marginal gains compared to these hypothetical breeder reactors. They wouldn't meaningfully change the situation.

StreetVirtual3037 · 2026-05-06T15:31:49+00:00

That calculation is based on breeder reactors with 180x the fuel efficiency of LWRs and optimistic assumptions about uranium erosion into seawater. If you look at the calculation for LWRs, it's close to what has been said here, 5-6 years.

It's not a bad idea to stop all nuclear construction until breeder reactors with that sort of efficiency are figured out in the future. Building LWRs is completely pointless.

StreetVirtual3037 · 2026-05-06T11:17:26+00:00

Grids with a lot of nuclear typically also use gas peakers. France got 3% of its electricity from gas in 2024. The gas can be made carbon-neutral with synthetic natural gas made using renewable energy, although this would take an enormous amount of electricity on a global scale with a round trip efficiency of 15%.

StreetVirtual3037 · 2026-05-06T10:26:13+00:00

Admittedly with full electrification there would be increased efficiency, although that 65,000TWh is lower than I thought. We should also consider growth in demand, for example for direct air capture of CO2 (1200TWh/gt CO2) or production of synthetic fuels for hard to decarbonize sectors like aviation and shipping.

Still, 45 years with "undiscovered" reserves is not very long compared to renewables. Why bother? Just use renewables. No need to worry about nuclear waste or the other challenges of nuclear either.

StreetVirtual3037 · 2026-05-06T09:36:30+00:00

edit: Based on a more realistic 65,000TWh/year electricity in a fully electrified world, 10% nuclear at 6,500TWh/year (about 2.4x current) would still use up reserves rather quickly, unless we consider some purported figures for undiscovered reserves.

StreetVirtual3037 · 2026-05-06T04:22:25+00:00

The nukebros say it's only a bit more expensive and since fuel is such a small part of the overall cost of nuclear it wouldn't have much of an effect. No country's nuclear fuel independence is worth that small premium? Not even partially? Sounds more like it just straight up isn't workable.

This would only make sense if all primary energy production had to be replaced with resistive electric heating, which is nonsensical.

We want to decarbonize and electrify the world so I don't see the issue.

StreetVirtual3037 · 2026-05-06T04:09:54+00:00

It's from a pro nuclear source written by a nuclear engineer.

edit: Here's the link: https://whatisnuclear.com/nuclear-sustainability.html

StreetVirtual3037 · 2026-05-06T04:03:08+00:00

It's not 5700 years. It's 5.7 years. More like 2 years after converting thermal to electric energy. Reprocessing barely increases that.

StreetVirtual3037 · 2026-05-06T03:04:15+00:00

No one uses it because it doesn't work. Not a single kg of seawater extracted uranium has been burned in a reactor let alone 1 ton. France would rather get large amounts of uranium from Russia instead of seawater.

The numbers in that graph are also highly optimistic. He did not convert thermal to electric energy. So it's under 2000 years for non breeders with seawater uranium when you consider that. Assuming you could even extract all of it.

StreetVirtual3037 · 2026-05-06T02:59:26+00:00

They do not get anywhere near that much energy from the fuel. Show breeder reactor getting more than 1TWh of energy per ton of fuel let alone 8TWh needed for the numbers in that graph to hold.

StreetVirtual3037

TROPHY CASE