8 ms·

"we're in a land where probability says we shouldn't be." You, sir, need better advisors.

by nazgulnarsil 16y ago

Ratfish 16y ago
Go easy... "it was the earthquake and tsunami." they didn't go together in any of the scenarios they ran.
- makmanalp 16y ago
  Are you shitting me? This is Japan. Earthquakes happen very often and it's well known even by common people that they are closely followed by tsunamis. The fact that they didn't go together in any of the scenarios is mindblowing.
  - barrkel 16y ago
    Fairly sure Ratfish was being sarcastic.
- user9756 16y ago
  Your comment broke my sarcasm detector. According to Wikipedia: http://en.wikipedia.org/wiki/Tsunami#Generation_mechanisms http://en.wikipedia.org/wiki/Tsunami#Generation_mechanisms "The principal generation mechanism (or cause) of a tsunami is the displacement of a substantial volume of water or perturbation of the sea. This displacement of water is usually attributed to either earthquakes, landslides, volcanic eruptions, or more rarely by meteorites and nuclear tests." Like the previous gentleman stated. Better advisers? EDIT: spelling
- wtn 16y ago
  Yes, this part of the article was incredibly hilarious.
- starpilot 16y ago
  To be fair, the plant has operated through thirteen [1] previous earthquakes in Japan since its first reactor reached criticality in 1970 [2]. [1] http://en.wikipedia.org/wiki/List_of_earthquakes_in_Japan http://en.wikipedia.org/wiki/List_of_earthquakes_in_Japan [2] http://en.wikipedia.org/wiki/Fukushima_I_Nuclear_Power_Plant#Reactors http://en.wikipedia.org/wiki/Fukushima_I_Nuclear_Power_Plant...
- mbreese 16y ago
  The earthquake and tsunami weren't the coupled failures they were talking about. It was the loss of external power and backup generators. This is what they didn't expect, because it is hard to predict the probability of an event big enough to trigger these two things failing at the same time.
  - moe 16y ago
    Yes, it's indeed hard to predict an earthquake to take out the external power and the subsequent tsunami to take out the backup generators on a coastline facility. (Note: This was sarcasm)
    - mbreese 16y ago
      How big of a tsunami was required? How big of a earthquake would be required to generate such a wave? How much water would be needed to reach the facility? How much to damage it? What about damaging backups? Sarcasm aside, it is easy to predict that the facility would be at risk for an earthquake/tsunami combo. The hard part is to predict how much of one to prepapre for. Remember, even in this neck of the woods, the was a quake of historic proportions.
    - superkarn 16y ago
      Isn't that partly why they have a secondary backup?
btmorex 16y ago
It's interesting. I've been reading the science subreddit and a lot of people are holding this up and some kind of engineering triumph, but to me it's an absolute engineering failure. Even if nothing bad happens from this point forward, two reactors were almost certainly destroyed and they'll have to sit dormant for a long while before they can be properly cleaned up. And as far as I can tell, there's still a very real risk of meltdown/containment vessel breach. From my perspective, the root cause of what happened is that no one anticipated an event that would simultaneously cause failures in multiple systems (power loss, and destroy probably multiple redundant generators). It's easy to say after the fact that of course someone should have thought about that, in your words they should have had "better advisors", but I'm not sure how useful it is. All nuclear accidents that I'm familiar with were unanticipated. Can anyone really argue that they all just had bad advisors or engineers? To me, this is the real argument against nuclear power and I say this as someone who still thinks that overall it's a good idea. How can we say something is truly safe when the accidents that did happen were not anticipated?
- wtallis 16y ago
  I think it's too soon to say that this failure mode was never considered or even conceived of in the contingency planning for the power plant. If you have a source that says otherwise, please provide a link. Keep in mind that this is currently estimated to be the biggest earthquake in the recorded history of Japan. It's completely unreasonable to expect stuff to totally not break when the big one hits. If some reactors are damaged beyond repair, that's understandable, as long as the radiation is contained well enough to keep the public safe. After all, good safety plans will always be willing to sacrifice expensive infrastructure in order to save lives.
  - erikpukinskis 16y ago
    Using "biggest in recorded history" as an approximation for "biggest possible" seems weak to me. Proper engineering will look at the numbers and account for events outside of the historically observed range, but within the probability distribution. The "biggest event we see in 1,000,000 simulations of the lifetime of the plant" is likely much larger than the "biggest we've seen in history." Which isn't to say that it was bad engineering. Just that this being the biggest quake in history is not an excuse.
blue1 16y ago
In other words, it's a magnificent example of Black Swan. Nassim Taleb will be happy.
squidsoup 16y ago
Building a nuclear power plant on the coastline of a subduction zone in a country with a long history of earthquakes and tsunamis does seem like a questionable idea.
- JonoW 16y ago
  Yeah I don't understand why these plants weren't built on the West coast, and why they weren't built on higher ground to mitigate against tsunamis.
  - cstross 16y ago
    You can't build reactors on high ground because they need a very high coolant flow. The (elderly) Fukushima BWRs pumped 480Mw into the grid while they were running -- but that's at the far end of a lossy thermodynamic chain (steam is used to spin turbines which drive dynamos); the thermal power output is probably something like three times that. So you need a heat sink into which you can continuously dump about 1.5Gw of heat. Water fits the bill, but you need a lot of it -- either a big river, or an ocean. Which is why civil nuclear reactors are almost always built close to the coastline.
    - superkarn 16y ago
      Is it feasible/economical to have a secondary power plant to convert all that heat into electricity?
      - cstross 16y ago
        Not unless you repeal the second law of thermodynamics -- the 1.5Gw of heat was already used to generate 0.5Gw of electricity. In general, no thermal power plant can convert much more than about 40% of the input heat into useful work. See also: https://secure.wikimedia.org/wikipedia/en/wiki/Rankine_cycle https://secure.wikimedia.org/wikipedia/en/wiki/Rankine_cycle

"we're in a land where probability says we shouldn't be." You, sir, need better advisors.

Ratfish 16y ago

Go easy... "it was the earthquake and tsunami." they didn't go together in any of the scenarios they ran.

makmanalp 16y ago
Are you shitting me? This is Japan. Earthquakes happen very often and it's well known even by common people that they are closely followed by tsunamis. The fact that they didn't go together in any of the scenarios is mindblowing.
- barrkel 16y ago
  Fairly sure Ratfish was being sarcastic.
user9756 16y ago
Your comment broke my sarcasm detector. According to Wikipedia: http://en.wikipedia.org/wiki/Tsunami#Generation_mechanisms http://en.wikipedia.org/wiki/Tsunami#Generation_mechanisms "The principal generation mechanism (or cause) of a tsunami is the displacement of a substantial volume of water or perturbation of the sea. This displacement of water is usually attributed to either earthquakes, landslides, volcanic eruptions, or more rarely by meteorites and nuclear tests." Like the previous gentleman stated. Better advisers? EDIT: spelling
wtn 16y ago
Yes, this part of the article was incredibly hilarious.
starpilot 16y ago
To be fair, the plant has operated through thirteen [1] previous earthquakes in Japan since its first reactor reached criticality in 1970 [2]. [1] http://en.wikipedia.org/wiki/List_of_earthquakes_in_Japan http://en.wikipedia.org/wiki/List_of_earthquakes_in_Japan [2] http://en.wikipedia.org/wiki/Fukushima_I_Nuclear_Power_Plant#Reactors http://en.wikipedia.org/wiki/Fukushima_I_Nuclear_Power_Plant...
mbreese 16y ago
The earthquake and tsunami weren't the coupled failures they were talking about. It was the loss of external power and backup generators. This is what they didn't expect, because it is hard to predict the probability of an event big enough to trigger these two things failing at the same time.
- moe 16y ago
  Yes, it's indeed hard to predict an earthquake to take out the external power and the subsequent tsunami to take out the backup generators on a coastline facility. (Note: This was sarcasm)
  - mbreese 16y ago
    How big of a tsunami was required? How big of a earthquake would be required to generate such a wave? How much water would be needed to reach the facility? How much to damage it? What about damaging backups? Sarcasm aside, it is easy to predict that the facility would be at risk for an earthquake/tsunami combo. The hard part is to predict how much of one to prepapre for. Remember, even in this neck of the woods, the was a quake of historic proportions.
  - superkarn 16y ago
    Isn't that partly why they have a secondary backup?

btmorex 16y ago

It's interesting. I've been reading the science subreddit and a lot of people are holding this up and some kind of engineering triumph, but to me it's an absolute engineering failure. Even if nothing bad happens from this point forward, two reactors were almost certainly destroyed and they'll have to sit dormant for a long while before they can be properly cleaned up. And as far as I can tell, there's still a very real risk of meltdown/containment vessel breach. From my perspective, the root cause of what happened is that no one anticipated an event that would simultaneously cause failures in multiple systems (power loss, and destroy probably multiple redundant generators). It's easy to say after the fact that of course someone should have thought about that, in your words they should have had "better advisors", but I'm not sure how useful it is. All nuclear accidents that I'm familiar with were unanticipated. Can anyone really argue that they all just had bad advisors or engineers? To me, this is the real argument against nuclear power and I say this as someone who still thinks that overall it's a good idea. How can we say something is truly safe when the accidents that did happen were not anticipated?

wtallis 16y ago
I think it's too soon to say that this failure mode was never considered or even conceived of in the contingency planning for the power plant. If you have a source that says otherwise, please provide a link. Keep in mind that this is currently estimated to be the biggest earthquake in the recorded history of Japan. It's completely unreasonable to expect stuff to totally not break when the big one hits. If some reactors are damaged beyond repair, that's understandable, as long as the radiation is contained well enough to keep the public safe. After all, good safety plans will always be willing to sacrifice expensive infrastructure in order to save lives.
- erikpukinskis 16y ago
  Using "biggest in recorded history" as an approximation for "biggest possible" seems weak to me. Proper engineering will look at the numbers and account for events outside of the historically observed range, but within the probability distribution. The "biggest event we see in 1,000,000 simulations of the lifetime of the plant" is likely much larger than the "biggest we've seen in history." Which isn't to say that it was bad engineering. Just that this being the biggest quake in history is not an excuse.

blue1 16y ago

In other words, it's a magnificent example of Black Swan. Nassim Taleb will be happy.

squidsoup 16y ago

Building a nuclear power plant on the coastline of a subduction zone in a country with a long history of earthquakes and tsunamis does seem like a questionable idea.

JonoW 16y ago
Yeah I don't understand why these plants weren't built on the West coast, and why they weren't built on higher ground to mitigate against tsunamis.
- cstross 16y ago
  You can't build reactors on high ground because they need a very high coolant flow. The (elderly) Fukushima BWRs pumped 480Mw into the grid while they were running -- but that's at the far end of a lossy thermodynamic chain (steam is used to spin turbines which drive dynamos); the thermal power output is probably something like three times that. So you need a heat sink into which you can continuously dump about 1.5Gw of heat. Water fits the bill, but you need a lot of it -- either a big river, or an ocean. Which is why civil nuclear reactors are almost always built close to the coastline.
  - superkarn 16y ago
    Is it feasible/economical to have a secondary power plant to convert all that heat into electricity?
    - cstross 16y ago
      Not unless you repeal the second law of thermodynamics -- the 1.5Gw of heat was already used to generate 0.5Gw of electricity. In general, no thermal power plant can convert much more than about 40% of the input heat into useful work. See also: https://secure.wikimedia.org/wikipedia/en/wiki/Rankine_cycle https://secure.wikimedia.org/wikipedia/en/wiki/Rankine_cycle