34 ms·

Thanks for including the specific model number. While these may address the cement issue (unless they are further encased) I don’t think they addressed any of

by natch 7y ago

Thanks for including the specific model number. While these may address the cement issue (unless they are further encased) I don’t think they addressed any of the other issues I mentioned, such as perceived risks or decentralized control. Having a high energy device bathed in molten lead and under someone else’s control is not what I would consider an ideal situation.

allovernow 7y ago
What do you think is the risk of such a reactor? They are physically incapable of runaway criticality and molten lead sounds scary but really isn't anything particularly dangerous with respect to industrial chemicals. Depending on fuel choice there also is no risk of proliferation - so worst case a well funded actor could disassemble such a reactor to extract the fuel for a dirty bomb; which is a manageable, worthwhile risk, IMO.
- natch 7y ago
  Perceived risk is a real issue. You are not addressing that at all. You are pretending I only mentioned risk. I don’t know enough about the tech to say whether the molten lead could be exposed to the environment due to unforeseen conditions, or what would happen at that point. But I’ve seen false assertions of safety before, plenty of times.
p_l 7y ago
They are designed to be controlled in whatever manner the client chooses, unlike certain US proposals that put a shutoff switch in hands of US government, and are explicitly designed to have little to no proliferation risks. The idea is that you would have local technicians running small sets of modular reactors feeding steam for power and heat generation, with the design directed towards distributed, locally controlled deployment. For minimal proliferation risk, they can run in closed fuel cycle, meaning the whole unit is shipped back to plant for refueling - there's no encasing in cement, as the whole module is designed to be loaded on a flatcar even in open (refueling in-situ) variant. In fact, the lead-bismuth coolant, coupled with passive heat removal systems, mean that the coolant "self-seals" the system. This can lead to somewhat funny observations, for example that leaks of radioactive polonium (from irradiated lead) are less dangerous than high-temperature water in BWR (which turns into mix of hydrogen and oxygen, which risks explosions). The radioactive polonium has short half-life and experience shows it to be of little danger even when coolant leaked from predecessor of the SVBR reactor. They are also fast reactors, meaning they burn down much more of the radioactive material, and as such they eliminate most of the waste problems.

by natch 7y ago

allovernow 7y ago

What do you think is the risk of such a reactor? They are physically incapable of runaway criticality and molten lead sounds scary but really isn't anything particularly dangerous with respect to industrial chemicals. Depending on fuel choice there also is no risk of proliferation - so worst case a well funded actor could disassemble such a reactor to extract the fuel for a dirty bomb; which is a manageable, worthwhile risk, IMO.

natch 7y ago
Perceived risk is a real issue. You are not addressing that at all. You are pretending I only mentioned risk. I don’t know enough about the tech to say whether the molten lead could be exposed to the environment due to unforeseen conditions, or what would happen at that point. But I’ve seen false assertions of safety before, plenty of times.

p_l 7y ago

They are designed to be controlled in whatever manner the client chooses, unlike certain US proposals that put a shutoff switch in hands of US government, and are explicitly designed to have little to no proliferation risks. The idea is that you would have local technicians running small sets of modular reactors feeding steam for power and heat generation, with the design directed towards distributed, locally controlled deployment. For minimal proliferation risk, they can run in closed fuel cycle, meaning the whole unit is shipped back to plant for refueling - there's no encasing in cement, as the whole module is designed to be loaded on a flatcar even in open (refueling in-situ) variant. In fact, the lead-bismuth coolant, coupled with passive heat removal systems, mean that the coolant "self-seals" the system. This can lead to somewhat funny observations, for example that leaks of radioactive polonium (from irradiated lead) are less dangerous than high-temperature water in BWR (which turns into mix of hydrogen and oxygen, which risks explosions). The radioactive polonium has short half-life and experience shows it to be of little danger even when coolant leaked from predecessor of the SVBR reactor. They are also fast reactors, meaning they burn down much more of the radioactive material, and as such they eliminate most of the waste problems.