4 ms·

> the depleted Uranium(10-100x mass) can be converted into Plutonium as drop in replacement. This needs breeder technology which is a different kettle of fish.

by jnxx 6y ago

> the depleted Uranium(10-100x mass) can be converted into Plutonium as drop in replacement. This needs breeder technology which is a different kettle of fish. The only existing plant was the Japanese Monju plant which was closed due to numerous problems and accidents, including a dangerous liquid sodium fire. You can read about it here: https://en.wikipedia.org/wiki/Monju_Nuclear_Power_Plant https://en.wikipedia.org/wiki/Monju_Nuclear_Power_Plant

titzer 6y ago
OP is correct. You don't need breeder technology to produce plutonium. In fact, the US produced enough in 1945 to build and detonate two plutonium-based atomic bombs. There are hundreds of tons of plutonium that have been produced and stockpiled worldwide, not including the thousands of nuclear warheads in existence and the thousands that can/could be decomissioned.
- pfdietz 6y ago
  However, you DO need breeder technology to treat all the 238U as a fuel. With burner reactors, the 239Pu produced is less than the fissionable material consumed, and most of the 238U ends up not being usable. I'll add that with current technology, you can't reprocess MOX fuel another time (too many higher isotopes of Pu and transuranics beyond Pu are produced), so any Pu in it after it's consumed must be disposed of.
- jnxx 6y ago
  > You don't need breeder technology to produce plutonium. In fact, the US produced enough in 1945 to build and detonate two plutonium-based atomic bombs. You can extract plutonium from spent fuel, I agree to that. This is what makes spent fuel processing expensive and this is what was used in 1945 and also turns any fuel waste into a proliferation issue. But converting depleted uranium (U-238) from spent fuel into fissile plutonium or whatever isotope, like GP suggested, is a different thing which would necessarily need some nuclear reaction. https://en.wikipedia.org/wiki/Uranium https://en.wikipedia.org/wiki/Uranium
numpad0 6y ago
There’s nothing complicated in breeder technology, it’s just that it allows constant supply of nuclear material at desired concentrations, aka serial production of nuclear weapons, so politics and regional security needs to be sorted out first.
- jnxx 6y ago
  I have, perhaps, the privilege, to have grown up in Germany in the 80s and at that time there was a really big societal discussion around nuclear energy in general and breeder technology in particular. A focus point was the breeder project in Kalkar, the SNR-300and many physicists and technicians chimed in into that discussion. I say privilege because it was a discussion unlike anything I've seen in this decade, people went very much into the details how such a technology works and what as a society we want from it. https://en.wikipedia.org/wiki/SNR-300 https://en.wikipedia.org/wiki/SNR-300 One main point of the discussion was that such a breeder reactor uses fast neutrons and this has the effect that it is far less controllable. Normal fission power plants use slow neutrons, that is neutrons which come from a nuclear reaction, and are slowed down by a moderator, which is water. Breeder reactors do use fast neutrons and need a far higher energy density. One consequence this has is that they need really exotic and difficult to handle coolants, such as liquid sodium. I therefore call bullshit in that there is nothing complicated in them. Also, such reactors have a different safety behavior. A key task of any nuclear technology is to keep the chain reaction of atoms and neutrons under control. This happens at the microsecond scale, and some chain reaction needs to be going for the reactor to not fizzle out, so it is anything but trivial. If the reaction in a normal pressured-water fission reactor becomes too strong, this has the effect that immediately the water heats up. This makes the water less dense, and this reduces the effect of its moderation, which makes the neutrons faster, which reduces their potential to react with uranium atoms, and therefore it slows down the reaction. This achieves self-control. What happens when this self-control is lost, is perhaps best illustrated by the Chernobyl accident. A fast breeder reactor does not have such an inherent control via the moderator and coolant. It was therefore judged by the public to be more complicated, and more dangerous. A funny thing is that during that discussion, the proponents of nuclear energy said again and again that nuclear power plant's are safe and that they in particular can't explode. I still remember the twitter post with these pictures: https://www.youtube.com/watch?v=7lrJCqNpeZ8 https://www.youtube.com/watch?v=7lrJCqNpeZ8

by jnxx 6y ago

titzer 6y ago

OP is correct. You don't need breeder technology to produce plutonium. In fact, the US produced enough in 1945 to build and detonate two plutonium-based atomic bombs. There are hundreds of tons of plutonium that have been produced and stockpiled worldwide, not including the thousands of nuclear warheads in existence and the thousands that can/could be decomissioned.

pfdietz 6y ago
However, you DO need breeder technology to treat all the 238U as a fuel. With burner reactors, the 239Pu produced is less than the fissionable material consumed, and most of the 238U ends up not being usable. I'll add that with current technology, you can't reprocess MOX fuel another time (too many higher isotopes of Pu and transuranics beyond Pu are produced), so any Pu in it after it's consumed must be disposed of.
jnxx 6y ago
> You don't need breeder technology to produce plutonium. In fact, the US produced enough in 1945 to build and detonate two plutonium-based atomic bombs. You can extract plutonium from spent fuel, I agree to that. This is what makes spent fuel processing expensive and this is what was used in 1945 and also turns any fuel waste into a proliferation issue. But converting depleted uranium (U-238) from spent fuel into fissile plutonium or whatever isotope, like GP suggested, is a different thing which would necessarily need some nuclear reaction. https://en.wikipedia.org/wiki/Uranium https://en.wikipedia.org/wiki/Uranium

numpad0 6y ago

There’s nothing complicated in breeder technology, it’s just that it allows constant supply of nuclear material at desired concentrations, aka serial production of nuclear weapons, so politics and regional security needs to be sorted out first.

jnxx 6y ago
I have, perhaps, the privilege, to have grown up in Germany in the 80s and at that time there was a really big societal discussion around nuclear energy in general and breeder technology in particular. A focus point was the breeder project in Kalkar, the SNR-300and many physicists and technicians chimed in into that discussion. I say privilege because it was a discussion unlike anything I've seen in this decade, people went very much into the details how such a technology works and what as a society we want from it. https://en.wikipedia.org/wiki/SNR-300 https://en.wikipedia.org/wiki/SNR-300 One main point of the discussion was that such a breeder reactor uses fast neutrons and this has the effect that it is far less controllable. Normal fission power plants use slow neutrons, that is neutrons which come from a nuclear reaction, and are slowed down by a moderator, which is water. Breeder reactors do use fast neutrons and need a far higher energy density. One consequence this has is that they need really exotic and difficult to handle coolants, such as liquid sodium. I therefore call bullshit in that there is nothing complicated in them. Also, such reactors have a different safety behavior. A key task of any nuclear technology is to keep the chain reaction of atoms and neutrons under control. This happens at the microsecond scale, and some chain reaction needs to be going for the reactor to not fizzle out, so it is anything but trivial. If the reaction in a normal pressured-water fission reactor becomes too strong, this has the effect that immediately the water heats up. This makes the water less dense, and this reduces the effect of its moderation, which makes the neutrons faster, which reduces their potential to react with uranium atoms, and therefore it slows down the reaction. This achieves self-control. What happens when this self-control is lost, is perhaps best illustrated by the Chernobyl accident. A fast breeder reactor does not have such an inherent control via the moderator and coolant. It was therefore judged by the public to be more complicated, and more dangerous. A funny thing is that during that discussion, the proponents of nuclear energy said again and again that nuclear power plant's are safe and that they in particular can't explode. I still remember the twitter post with these pictures: https://www.youtube.com/watch?v=7lrJCqNpeZ8 https://www.youtube.com/watch?v=7lrJCqNpeZ8