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> Seawater extraction of uranium is renewable since geological processes replenish that circulating uranium as it is extracted, too. No, it's not. Uranium once

> Seawater extraction of uranium is renewable since geological processes replenish that circulating uranium as it is extracted, too. No, it's not. Uranium once used in reactor is literally changed to other elements. And the radioactive waste is sealed in container safe for 100s of 1000s of years.

gotstad 5y ago
But the discussion of whether something is renewable is also a complex topic that is only true to some extent. Renewable energy sources (Wind and Solar) are technically not renewable - the production of the equipment uses raw resources that we (today) cannot renew indefinitely. However, for both Nuclear and Solar/Wind energy we do know, that the energy sources are sufficiently abundant to sustain us almost indefinitely without us upsetting other ecological balances.
DennisP 5y ago
GP's claim is that seawater uranium is replenished from natural processes, not from reactor waste. That claim is true, and their link describes why. Here's another article: https://cna.ca/2016/07/27/theres-uranium-seawater-renewable/ https://cna.ca/2016/07/27/theres-uranium-seawater-renewable/ There is of course a finite amount of uranium on the planet. But there's also a finite amount of fusion fuel in the sun. Neither will run out before the sun boils the oceans. If we keep using fission long-term, it will likely be in the form of fast reactors, which get a hundred times as much energy from natural uranium because they don't just fission U235, but also U238 and transuranics. (Because of that, the waste from fast reactors only has to be securely stored for 300 years.)
Symmetry 5y ago
If you look closely enough the sunlight that powers solar panels also comes from the fusion of hydrogen that will be literally changed to another element. But I think it's still fair to call solar renewable because the sunlight hitting the Earth is continually renewed. And while the amount of Uranium on Earth is fixed the amount of uranium in the seas is renewed from that much larger stock, so I think calling extraction of sea uranium is fair.
lazyier 5y ago
> No, it's not. Uranium once used in reactor is literally changed to other elements. And the radioactive waste is sealed in container safe for 100s of 1000s of years. Sort of. What you are talking about is a technical problem and it has a solution. (and as others pointed out is not directly related to the subject at hand) Conventional nuclear reactors require a certain level of purity in the uranium to provide stable operation. As the uranium breaks down the fuel becomes less stable. After a while they remove the fuel and then place it into storage. However that uranium is not used up in that process. Most of it is still there. Which is one of the reasons why it's so difficult and expensive to store safely. Theoretically you can recover that fuel in breeder reactors. Essentially recycling it. So it can be re-used in conventional reactors. The breeder reactors will still produce usable electricity as well. And this can be done multiple times. Up to the point were most of the fissionable material is used up and it is much less radioactive and safe to handle. At that point you would combine the waste with clay and bake it into ceramic vessels that can be safely transported and stored indefinitely. The reason why this technology hasn't moved forward is mostly to do with a couple facts. The first one being that nobody is allowed to do anything with the 'waste' as it is Federally controlled and not owned by the power company. So the operators can't do anything with it even if they wanted to. And the second one being that during the cold war USA and other countries created vast amounts of purified uranium as part of their nuclear programs. And they have no place to put it and no use for it other than being put through nuclear reactors. The amount of potentially unlimited power left laying on the table because of politics, paranoia, and fear is mind boggling. If recycling is implemented we currently have many multiple generations worth of fuel stockpiled. It could put a end to the use of fossil fuels used for energy generation within our lifetime. Which is something that is not possible with wind or solar.
- Retric 5y ago
  That’s basically abusing the word uranium as U235 is used up while U238 is largely not in current designs. Reprocess spent fuel lets you extract the leftover U235, but it’s a small percentage of the original amount. What you want is something like the CANDU design which is far less dependent on U235. https://en.wikipedia.org/wiki/CANDU_reactor https://en.wikipedia.org/wiki/CANDU_reactor

gotstad 5y ago

But the discussion of whether something is renewable is also a complex topic that is only true to some extent. Renewable energy sources (Wind and Solar) are technically not renewable - the production of the equipment uses raw resources that we (today) cannot renew indefinitely. However, for both Nuclear and Solar/Wind energy we do know, that the energy sources are sufficiently abundant to sustain us almost indefinitely without us upsetting other ecological balances.

DennisP 5y ago

GP's claim is that seawater uranium is replenished from natural processes, not from reactor waste. That claim is true, and their link describes why. Here's another article: https://cna.ca/2016/07/27/theres-uranium-seawater-renewable/ https://cna.ca/2016/07/27/theres-uranium-seawater-renewable/ There is of course a finite amount of uranium on the planet. But there's also a finite amount of fusion fuel in the sun. Neither will run out before the sun boils the oceans. If we keep using fission long-term, it will likely be in the form of fast reactors, which get a hundred times as much energy from natural uranium because they don't just fission U235, but also U238 and transuranics. (Because of that, the waste from fast reactors only has to be securely stored for 300 years.)

Symmetry 5y ago

If you look closely enough the sunlight that powers solar panels also comes from the fusion of hydrogen that will be literally changed to another element. But I think it's still fair to call solar renewable because the sunlight hitting the Earth is continually renewed. And while the amount of Uranium on Earth is fixed the amount of uranium in the seas is renewed from that much larger stock, so I think calling extraction of sea uranium is fair.

lazyier 5y ago

> No, it's not. Uranium once used in reactor is literally changed to other elements. And the radioactive waste is sealed in container safe for 100s of 1000s of years. Sort of. What you are talking about is a technical problem and it has a solution. (and as others pointed out is not directly related to the subject at hand) Conventional nuclear reactors require a certain level of purity in the uranium to provide stable operation. As the uranium breaks down the fuel becomes less stable. After a while they remove the fuel and then place it into storage. However that uranium is not used up in that process. Most of it is still there. Which is one of the reasons why it's so difficult and expensive to store safely. Theoretically you can recover that fuel in breeder reactors. Essentially recycling it. So it can be re-used in conventional reactors. The breeder reactors will still produce usable electricity as well. And this can be done multiple times. Up to the point were most of the fissionable material is used up and it is much less radioactive and safe to handle. At that point you would combine the waste with clay and bake it into ceramic vessels that can be safely transported and stored indefinitely. The reason why this technology hasn't moved forward is mostly to do with a couple facts. The first one being that nobody is allowed to do anything with the 'waste' as it is Federally controlled and not owned by the power company. So the operators can't do anything with it even if they wanted to. And the second one being that during the cold war USA and other countries created vast amounts of purified uranium as part of their nuclear programs. And they have no place to put it and no use for it other than being put through nuclear reactors. The amount of potentially unlimited power left laying on the table because of politics, paranoia, and fear is mind boggling. If recycling is implemented we currently have many multiple generations worth of fuel stockpiled. It could put a end to the use of fossil fuels used for energy generation within our lifetime. Which is something that is not possible with wind or solar.

Retric 5y ago
That’s basically abusing the word uranium as U235 is used up while U238 is largely not in current designs. Reprocess spent fuel lets you extract the leftover U235, but it’s a small percentage of the original amount. What you want is something like the CANDU design which is far less dependent on U235. https://en.wikipedia.org/wiki/CANDU_reactor https://en.wikipedia.org/wiki/CANDU_reactor