[scottshamus]

I was curious about your point that we only have ~20 years supply. The article you linked doesn’t really defend that estimate, I think it’s actually pointing out that’s the absolute floor of our supply.

It mentions estimates of undiscovered uranium and also multiple pathways to extend that estimate if there was demand to improve the technology or increase our supply. It sounds like realistically we could find the material for powering all of our energy using fission if we had the demand to do so.

[dredmorbius]

The resource size is one I've seen many times in many places, and it seems widely accepted. The linked article isn't the best source, but it's characteristics of others I've encountered over the years.

The general point is that uranium ore is not especially abundant, and tends to be highly localised, which suggests a reprise of petroleum-induced geopolitics.

(Uranium in seawater is far more prevalent, but quite difficult and expensive to access.)

I'm also familiar with the long and tedious discussion of just what "resources" and "reserves" constitute. I'd suggest briefly that much of that discussion fails to reflect that the true benefit of energy resources is the surplus EROEI (energy return on energy input) which results from their use, and that whilst it's often possible to increase the total resource quantity that comes with a corresponding decrease in resource quality in the sense of a far lower EROEI.

Early petroleum finds featured EROEI of 200:1 or greater. That is, 1 unit of energy invested returned 200 units returned. Present finds are closer to 10:1 to 20:1. I'm not as versed on uranium, though I'm finding indications that current ore-based finds are ~10:1 to 60:1. Seawater extraction is all but certainly far lower than that. Generally I'm somewhat suspicious of casual claims that we could vastly increase our uranium supply.

Thorium's a somewhat different animal (or mineral, definitely not vegetable) in that it's 3--4 times more abundant than uranium, and if I recall correctly can be "bred" into fissionable forms more readily. Non-thorium breeder reactors rely on a plutonium cycle, which introduces numerous other concerns (weapons, terrorism, etc.).

Moreover, liquid hydrocarbon is fantastically useful stuff and can be stored, transported, and utilised with immense flexibility and (comparative) safety. Nuclear energy must be converted to other forms, at considerable loss, to be utilised. Grid mains current is useful, but nuclear power plant output isn't especially flexible, and transition to storable forms comes at high costs, limited capacity, or high conversion losses (e.g., synfuel production). Hydrocarbon-powered automobiles, lorries, aircraft, construction equipment, hand tools, portable generators, etc., are all readily produced and utilised. Their nuclear variants not so much.

(I'm specifying hydrocarbons rather than petroleum to note that it's the chemical constitution rather than the origin or creation process which is significant here. I'm something of a fan of hydrocarbon fuels, somewhat less so of fossil fuels, despite their past utility.)

[wokwokwok]

If you want to speculate wildly on maybes then it’s also hard to argue that hydrogen is fundamentally one of the most common elements in the entire universe and it’s not particularly controversial to say that a high tech future society would probably want to use that rather than the vastly less abundant heavier elements.

> It sounds like realistically we could find the material for powering all of our energy using fission

For a while

> if we had the demand to do so.

Maybe two decades isn’t spot on, but come on, you’re really grasping at straws.

It’s fundamentally less abundant.

20 years? 50 years? 100 years.

Sooner or later you’re going to run out, and not on geological timescales.

Tell me it ain’t so?

There are reasons to prefer fission, but “we have plenty of uranium” isn’t one of them.