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Comment by joshvm | Hacker News Reader

A common argument used to be that at least the amount of uranium is finite, so we can simply plan where to put it. Another interesting aspect is that we only have a few centuries of nuclear power left at current reserve and consumption rates. Uranium is absolutely a non renewable fuel.

This could change with breeder reactors or the various fancy things being researched, but I think there is a public perception that uranium is unlimited.

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TerraPower claims that their Traveling Wave Reactor could "sustain 80% of the world's population at U.S. per capita energy usages for over a millennium" by using the global stockpiles of depleted uranium [1]. The other upside would be that the new nuclear waste would be dangerously radioactive for a much shorter time.

[1] https://en.wikipedia.org/wiki/Traveling_wave_reactor

Uranium mined on earth is a finite quantity - but I think the carve-outs you included in your statement are quite wide. We may find a way to artificially produce a high energy substance to use in place of Uranium, and other high number elements may provide alternatives for the primary fuel - additionally space may be an option to find new sources of Uranium if we really want to stick with it.

"Peak oil" has been a vague concern for a great many years, with the deadline around the corner but that goalpost was repeatedly moved back as previously uneconomic sources became viable - like tar sand extraction. Similarly the available volume of natural gas was increased drastically with refined fracking techniques. All of these things are finite in quantity, but, if we're reliant on it, then efficiency of extraction and conversion will go up - it's actually an interesting contrast to fission, there really isn't that much research going on since the economic investment of each plant is so heavy.

there are other fission fuel sources, thorium for example is a relatively abundant possible fuel

And actually, to this point, molten salt reactors[1] are one of the reactor search paths that looks pretty promising for better safety outcomes. Especially when compared against boiling water reactors[2].

1. https://en.wikipedia.org/wiki/Molten_salt_reactor

2. https://en.wikipedia.org/wiki/Boiling_water_reactor

Absolutely, the key phrase is "current usage and reserves". There will almost certainly be ways developed to stretch or augment or displace uranium as a nuclear fuel.

Thorium salt reactors look promising. But unfortunately there has been lack of political will to fund research and it's only recently that its being investigated seriously again. And this is a common story with virtually all the interesting nuclear technologies. Sounds great, but who's paying for the fundamental research?

My point is that people often compare nuclear and coal as if radioactive ore - which today does mean uranium - is some infinite resource, just because it isn't made of fossils.

The idea of "oh well, we'll just mine more as it gets economic to do so" isn't a sustainable solution to clean energy.

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