2 ms·

> Huge amounts of energy for a tiny bit of fuel. Zero carbon emission from operation. No venting of waste into atmosphere. This isn't even really true if you l

> Huge amounts of energy for a tiny bit of fuel. Zero carbon emission from operation. No venting of waste into atmosphere. This isn't even really true if you look at the whole supply chain for a PWR. The energy density of the low grade ore that is becoming typical is no more than fossil fuels, and it requires vast amounts of sulfuric acid underground and in tailings pools that contaiminates the ground water even worse than fracking. It's significantly better than fossil fuels over all but still quite destructive. Breeders would solve this if they existed.

credit_guy 4y ago
> It's significantly better than fossil fuels but still quite destructive. There was recently this info-graphic circulating here on Hacker News [1]. It shows all the metals we mined in 2021. There's a huge cube representing Iron, of which more than 2 billion tones were mined. Then there are progressively smaller piles. Aluminum, the next most mined metal comes at a paltry 68 million tons, Chromium at 41 million, and copper at 21 million. Uranium is there, but it's not that easy to find. It comes at 48.3 kilo-tons, about 50 times less than nickel and 200 times less than Titanium. Of course, coal is not in this infographic. People would get a bit spooked if they realized we mined 3 times more coal than iron ore. And we promptly burned it. [1] https://www.visualcapitalist.com/all-the-metals-we-mined-in-2021-visualized/ https://www.visualcapitalist.com/all-the-metals-we-mined-in-...
- Schroedingersat 4y ago
  The thing to remember is the enriched reactor grade Uranium is only about 140ppm in low grade ore. In a mine like Husab you're digging up and processing 7 tonnes or so for that 1kg of fuel (and 7kg of DU). Iron and Al ore concentration is measured in 2 digit percent -- often over 50%. Coal ore is coal (with half water and ash in the real dirty stuff). As such the scale of Uranium mining is not really less, there's just less end product. ISL is less energy intensive but limited in scope and remediation has never been as successful as claimed. The millions of tonnes of sulfuric acid involved are also a problem. The most destructive items on your list are copper and chromium. The former is used in about the same quantities in renewables (offshore wind presently uses several times more, other methods can use less and an increasing share of the marketis using Al for cabling and coils) and the latter is used more in nuclear. A combined mine like olympic dam can create several times more net electricity and net power in the form of PV from copper and silver than the Uranium that comes out (and that's even after taking most of the silver for control rods). That said, the subject here is high burnup and breeder reactors. In principle they actually live up to this dream (especially if the beryllium can be eliminated). It would be foolish to pin all our hopes on something that hasn't been put into practise though. In general they're in the same category as quad junction 50% efficient perovskites, cheap TEG based 24hr CSP, or NaS batteries with the same energy density as chemical fuels -- worth pursuing but not available soon.
DennisP 4y ago
Russia has a couple fast uranium reactors in commercial operation right now. The US probably would too, if the Clinton administration hadn't shut down the Integral Fast Reactor project a couple years before they were done, after thirty years of development.
- Schroedingersat 4y ago
  Commercial is a long stretch for the BN600. It caught fire constantly and would make even Vogtle look like good value for money. I'd love to be optimistic about the BN800, but as it is currently operated it's more of a demonstration project that also happens to get rid of plutonium and produce some power. As I understand this is due to political proliferation reasons more than technical. Neither actually achieve the orders of magnitude increase in burnup that the FNR concept is supposed to enable. They are about on par with a CANDU in terms of energy produced per kg of fissile material. Hopefully China's program isn't vaporware and they decide to share and the USA lets them be built without triggering an express delivery of democracy. Alternatively batteries/electrolysers will keep getting cheaper and the whole thing will become irrelevant because a red hot pool of molten sodium (or Fluorene and Beryllium salts) isn't a particularly cheap, fun, or safe thing to interact with even without the nuclear issues.

credit_guy 4y ago

> It's significantly better than fossil fuels but still quite destructive. There was recently this info-graphic circulating here on Hacker News [1]. It shows all the metals we mined in 2021. There's a huge cube representing Iron, of which more than 2 billion tones were mined. Then there are progressively smaller piles. Aluminum, the next most mined metal comes at a paltry 68 million tons, Chromium at 41 million, and copper at 21 million. Uranium is there, but it's not that easy to find. It comes at 48.3 kilo-tons, about 50 times less than nickel and 200 times less than Titanium. Of course, coal is not in this infographic. People would get a bit spooked if they realized we mined 3 times more coal than iron ore. And we promptly burned it. [1] https://www.visualcapitalist.com/all-the-metals-we-mined-in-2021-visualized/ https://www.visualcapitalist.com/all-the-metals-we-mined-in-...

Schroedingersat 4y ago
The thing to remember is the enriched reactor grade Uranium is only about 140ppm in low grade ore. In a mine like Husab you're digging up and processing 7 tonnes or so for that 1kg of fuel (and 7kg of DU). Iron and Al ore concentration is measured in 2 digit percent -- often over 50%. Coal ore is coal (with half water and ash in the real dirty stuff). As such the scale of Uranium mining is not really less, there's just less end product. ISL is less energy intensive but limited in scope and remediation has never been as successful as claimed. The millions of tonnes of sulfuric acid involved are also a problem. The most destructive items on your list are copper and chromium. The former is used in about the same quantities in renewables (offshore wind presently uses several times more, other methods can use less and an increasing share of the marketis using Al for cabling and coils) and the latter is used more in nuclear. A combined mine like olympic dam can create several times more net electricity and net power in the form of PV from copper and silver than the Uranium that comes out (and that's even after taking most of the silver for control rods). That said, the subject here is high burnup and breeder reactors. In principle they actually live up to this dream (especially if the beryllium can be eliminated). It would be foolish to pin all our hopes on something that hasn't been put into practise though. In general they're in the same category as quad junction 50% efficient perovskites, cheap TEG based 24hr CSP, or NaS batteries with the same energy density as chemical fuels -- worth pursuing but not available soon.

DennisP 4y ago

Russia has a couple fast uranium reactors in commercial operation right now. The US probably would too, if the Clinton administration hadn't shut down the Integral Fast Reactor project a couple years before they were done, after thirty years of development.

Schroedingersat 4y ago
Commercial is a long stretch for the BN600. It caught fire constantly and would make even Vogtle look like good value for money. I'd love to be optimistic about the BN800, but as it is currently operated it's more of a demonstration project that also happens to get rid of plutonium and produce some power. As I understand this is due to political proliferation reasons more than technical. Neither actually achieve the orders of magnitude increase in burnup that the FNR concept is supposed to enable. They are about on par with a CANDU in terms of energy produced per kg of fissile material. Hopefully China's program isn't vaporware and they decide to share and the USA lets them be built without triggering an express delivery of democracy. Alternatively batteries/electrolysers will keep getting cheaper and the whole thing will become irrelevant because a red hot pool of molten sodium (or Fluorene and Beryllium salts) isn't a particularly cheap, fun, or safe thing to interact with even without the nuclear issues.