> 200 years of uranium

As other people have mentioned, that's known 235U.

We have enough domestic 232Th to satisfy our energy needs for a very long time. If we use breeder reactors that can utilize 238U, we also have sufficient availability for well-beyond any reasonably foreseeable future ("many millenia").

Besides, that gives us plenty of time to actually develop other methods of providing energy. Right now every day we fail to deploy nuclear is another day of coal/gas. Even if we used your silly figure of 200 years, it shouldn't take that long to develop a proper solar+batteries replacement (heck, we should have fusion before the 200 years is up).

> mining

There are rare earth mines that we aren't operating right now because it's too expensive to dispose of the Th. In any serious nuclear deployment, the fuel itself would be free (or nearly free).

> far fewer

Comparing U or Th mining to coal mining is silly when you only need to do over 2,000,000x more coal mining.

With breeder reactors, the Uranium should last much longer. I read somewhere that you get approximately 100 times as much energy out of the same amount of Uranium when you use a breeder reactor, and don't throw the fission byproducts.

So assuming we have 20 years of (currently discovered) Uranium, breeder reactors should make that last a theoretical 2000 years at current energy consumption levels.

Pick a problem, you cant solve them all at once.

- mining is pretty much a necessity of life at this point.

- 200 years to come up with solutions to energy production while not turning the planet into an oven sounds pretty good.

There aren't a lot of problems though, there is just one: We rely on fossil fuels. Switching to nuclear fission won't change that in the slightest.

Also even if you could get sufficient agreement on the need for more nuclear power plants - which you won't - it would still take way to long to build enough of them to have an impact.

It makes much more sense to invest in renewable energy, the energy grid and research into nuclear fusion.

You've misunderstood my comment.

We have 200 years of uranium left at current rates of consumption. But if we replaced all fossil fuels with nuclear, we'd consume 10 times more per year and we'd only have about 20 years of energy available before needing to move on to a new energy source.

Okay, it is wikipedia, but:

https://en.wikipedia.org/wiki/Breeder_reactor

"Adherents claim that with seawater uranium extraction, there would be enough fuel for breeder reactors to satisfy our energy needs for 5 billion years at 1983's total energy consumption rate, thus making nuclear energy effectively a renewable energy."

There are only four breeder reactors in operation, we'd need a lot more rather quickly for them to be useful.

Also as with all things nuclear there are an awful lot of claims and not a lot of known things here. Nuclear somehow always looks much better in theory than it does in practice.

Yeah, breeder reactors are even mentioned in the sciam article that nostromo posted. He's cherry-picking his info.

Uranium exploration is pretty much non existent these days, I would'nt be comfortable saying how much there actually is. Peak oil has been coming for decades but they keep finding it.

This is the same argument that the proponents of peak oil put forth. Discovered uranium deposits != all uranium deposits on earth. When price pressure is put on uranium, we'll have more speculators looking for it. (Which the article addresses.)

Also, Economically unaccessible today != economically unaccessible tomorrow. Our mining technology gets better all the time, especially if there's price pressure on it. We're accessing deep-sea oil deposits that we weren't able to twenty years ago. (Which the article addresses, but you omitted the key point!!! We have a 60,000 year supply of uranium in the oceans!)

The chief problem with coal isn't pitmining, it's the pollution from burning the stuff.

I think in your link "economical extraction" means "economical extraction at current or similar prices". At suitably high prices, even extraction from seawater becomes reasonable (google gave me http://www.technologyreview.com/news/514751/novel-material-s... with an estimate of $1e3–2e3/kg). I assume this would have a limited effect on electricity prices because uranium prices are probably a minor component of nuclear power costs.

Don't fall for the mistake of taking known reserves to be the actual amount in the earths crust.

'Oil is about to run out' predictions have been falling for this for a century now, and continue to make the same error.

There is no economic reason to find resources out beyond a set timeline. So they aren't looking for them, and so the reserves always look like they are going to run out in 30 years.

The actual environmental impact of mines is negligible over the long term, provided the mining is done in a country with good environmental protection in place.

> Currently we have about 200 years of uranium available for economical extraction.

I responded to your claim previously[0]:

> In that 200 years a whole lot more uranium will become available for economical extraction, exactly the same as what happened with oil and natural gas.

Do you have reason to believe this will not happen?

[0]https://news.ycombinator.com/item?id=10623187

I'm no expert here. I'm simply parroting what the scientists at the Nuclear Energy Agency have reported.

OK, but remember that the experts said the same thing about oil and natural gas, and were wrong in that case. Here the estimate of ~10 megatonnes assumes that seawater extraction will never be economically viable, one possible source of error.

If you're interested in the history of "peak resources" here is a good book about Paul Ehrlich's famous bet with Julian L. Simon:

http://www.amazon.com/The-Bet-Ehrlich-Julian-Earth%C2%92s/dp...

> Do you have reason to believe this will not happen?

What's kind of amazing is that people don't believe that we will develop a solar powered technique to extract carbon the from the atmosphere and create liquid fuels.

Like an artificial plant? If it is possible to engineer something that works better (and there is no reason to believe it is impossible) that would be a huge event.

You may be interest in:

"A New Dawn for Industrial Photosynthesis"

http://link.springer.com/content/pdf/10.1007%2Fs11120-011-96...

By 200 years we will probably have fusion working anyway. Problem mostly solved.