4 ms·

Does that mean you cannot use robots, nor can you use humans, to clean up this mess? What do you do then?

Pica_soO 10y ago
It means, that the robots have to be very "custom" build ones. With the intelligent parts beeing deposited outside of the dangerous area, communicating with the muscle via e.g. fibreoptics. The robot consists ideally of some die-hard sensors positioned as far away as possible and as close as necessary - which are retractable mechanically in case of software failure by left behind elements. Then there is the actual tooling, which is basically just a remote controlled shell. A complicated setup, to say the least. Imagine a Anemone with some little remote camera fishes on a tentacle, controlling a robotic crab on the longest tentacle of them all.
- JumpCrisscross 10y ago
  > the intelligent parts beeing [sic] deposited outside of the dangerous area Is there a material that is transparent at optical frequencies but opaque at higher energies?
  - baq 10y ago
    Glass, but nothing stops neutrons.
    - rdtsc 10y ago
      You can stop them by slowing them down. Usually you'd use ellastic collisions with light atoms like hydrogen. Water works which is what reactors use. For shipping polyethylene is often used. Then some materials simply have a higher cross section for absorbing the slow ones. Had to look this up I saw boron and cadmium. (Married to person who used to ship Californium-252)
  - throwanem 10y ago
    Ideally you'd want it to be gamma-transparent as well; otherwise, those gamma photons which hit it are going to deposit their energy into it. This is how glass viewing windows in nuclear materials processing facilities, for example, gradually cloud and embrittle over time, and have to be replaced. I'm not sure how well a relatively thin optical fiber would stand up, especially under the kind of bombardment we're talking about here.
varjag 10y ago
You can use humans to clean the mess, whose massively redundant computational model is much more robust to radiation damage. They will however suffer or die from radiation exposure long term. This is what was done at Chernobyl in admittedly much more dire situation. A quantity of Japanese remote-controlled robots were urgently imported back then as well, and failed in the same manner.
- throwanem 10y ago
  > You can use humans to clean the mess Not this mess, or even that one, really. The "bio-robots", so called by their masters, were mainly collecting debris from the reactor explosion for containment; they were not trying to deal with the core slag sunk into the basement of the building, which at that time was still thermally very hot as well as being ferociously active. Even to approach that would have been immediately lethal. Given the cited dose rate, the same is true at Fukushima - an acute dose of 10Sv is very likely lethal on its own, and at 650Sv/h you get more than that every minute. Anyone you send into that is going to be unable to work within seconds, and dead inside a couple of minutes tops.
  - varjag 10y ago
    The 'Elephant Foot' is 93Sv/h, and there is numerous footage of it filmed by human operators during containment efforts.
    - throwanem 10y ago
      That's good to know, thanks. On the other hand, I find sources calling that dose rate lethal within minutes, and at least some of the Fukushima corium is roughly seven times as active. Even if you're willing to write off as many lives as it takes to reduce what is essentially solidified lava by means of hand tools into a containable form, I doubt it's likely to succeed simply because it'll kill off your workers so fast that, after a little while, no further progress is possible because of all the corpses blocking the way.
      - 10y ago
alphonsegaston 10y ago
Realize that the ostensible safety of nuclear energy is based on believing that black swan environmental and political events are impossible. Walk away from it and move heavily/quickly toward renewables.

It means, that the robots have to be very "custom" build ones. With the intelligent parts beeing deposited outside of the dangerous area, communicating with the muscle via e.g. fibreoptics. The robot consists ideally of some die-hard sensors positioned as far away as possible and as close as necessary - which are retractable mechanically in case of software failure by left behind elements. Then there is the actual tooling, which is basically just a remote controlled shell. A complicated setup, to say the least. Imagine a Anemone with some little remote camera fishes on a tentacle, controlling a robotic crab on the longest tentacle of them all.

JumpCrisscross 10y ago
> the intelligent parts beeing [sic] deposited outside of the dangerous area Is there a material that is transparent at optical frequencies but opaque at higher energies?
- baq 10y ago
  Glass, but nothing stops neutrons.
  - rdtsc 10y ago
    You can stop them by slowing them down. Usually you'd use ellastic collisions with light atoms like hydrogen. Water works which is what reactors use. For shipping polyethylene is often used. Then some materials simply have a higher cross section for absorbing the slow ones. Had to look this up I saw boron and cadmium. (Married to person who used to ship Californium-252)
- throwanem 10y ago
  Ideally you'd want it to be gamma-transparent as well; otherwise, those gamma photons which hit it are going to deposit their energy into it. This is how glass viewing windows in nuclear materials processing facilities, for example, gradually cloud and embrittle over time, and have to be replaced. I'm not sure how well a relatively thin optical fiber would stand up, especially under the kind of bombardment we're talking about here.

varjag 10y ago

You can use humans to clean the mess, whose massively redundant computational model is much more robust to radiation damage. They will however suffer or die from radiation exposure long term. This is what was done at Chernobyl in admittedly much more dire situation. A quantity of Japanese remote-controlled robots were urgently imported back then as well, and failed in the same manner.

throwanem 10y ago
> You can use humans to clean the mess Not this mess, or even that one, really. The "bio-robots", so called by their masters, were mainly collecting debris from the reactor explosion for containment; they were not trying to deal with the core slag sunk into the basement of the building, which at that time was still thermally very hot as well as being ferociously active. Even to approach that would have been immediately lethal. Given the cited dose rate, the same is true at Fukushima - an acute dose of 10Sv is very likely lethal on its own, and at 650Sv/h you get more than that every minute. Anyone you send into that is going to be unable to work within seconds, and dead inside a couple of minutes tops.
- varjag 10y ago
  The 'Elephant Foot' is 93Sv/h, and there is numerous footage of it filmed by human operators during containment efforts.
  - throwanem 10y ago
    That's good to know, thanks. On the other hand, I find sources calling that dose rate lethal within minutes, and at least some of the Fukushima corium is roughly seven times as active. Even if you're willing to write off as many lives as it takes to reduce what is essentially solidified lava by means of hand tools into a containable form, I doubt it's likely to succeed simply because it'll kill off your workers so fast that, after a little while, no further progress is possible because of all the corpses blocking the way.
    - 10y ago

alphonsegaston 10y ago

Realize that the ostensible safety of nuclear energy is based on believing that black swan environmental and political events are impossible. Walk away from it and move heavily/quickly toward renewables.