5 ms·

What happens if the swimming pool leaks ?

rwcarlsen 8y ago
The pool only needs to function for a few days during/after an accident until heat energy from fission product decay reduces to lower levels. The pool's function is as an accident mitigation measure - and when any accident occurs the reactor enters a "shut down" state. The decay heat energy that needs to be dissipated is much lower than normal reactor operational power output.
CodeCube 8y ago
I mean ... millions of people who barely maintain their homes avoid pool leaks, and when it does leak, it tends to be slow enough that they can call in a professional to fix the problem. Imagine a fastidiously maintained facility ... I think they can probably work it out
- 781 8y ago
  You have to consider stuff like terrorist attack and so on. Nobody is so incentivized in making your backyard pool leak.
  - jcranmer 8y ago
    What if a dam explodes? More people have died due to dam failures (both intentional and accidental) than have died to nuclear power, but there is nowhere near the freaking out over the safety of dams compared to nuclear power. For comparison, the Banqiao Dam failure (the largest dam failure in history) killed as many people as the sum total of every nuclear power plant failure and every atomic bomb ever used, combined.
    - petschge 8y ago
      While dam break cost lives, there is crucial differences that are never mentioned by the pro-nuclear crowd on HN. 1.) Dam breaks devastate much smaller areas. So even if the human toll is the same, the amount of infrastructure lost is smaller. 2.) The area is unlivable (or even inaccessible) for a much smaller duration of month instead of millenia. Maybe land lost "forever" (on the timescale of individual human lives) is not a big problem in some part of the world, but in densely populated areas (any they need the most power, so would have MORE reactors per area) you can not simply block off an area the size of Belgium because a reactor exploded. This makes nuclear power a lot less attractive in India, Europe or (coastal) China.
      - jcranmer 8y ago
        Chernobyl's exclusion zone was ~1000 mi^2, consisting of ~120,000 people. The Oroville dam evacuation zone is ~250mi^2 encompassing ~180,000 people. Floods are no laughing matters; the Chinese decision to break the levees of the Yellow River during the Second Sino-Japanese War is credited with killing 400,000 people or so and rendering millions homeless, and the land was unusable for the better part of a decade, not "a month." > 2.) The area is unlivable (or even inaccessible) for a much smaller duration of month instead of millenia. Millennia of uninhabitability is anti-nuclear propaganda. Most of the zone will be reinhabitable within a century of the accident, and much of it is already inhabitable again but still excluded out of safety margin concerns.
        acidburnNSA 8y ago
        Strengthening your point on the persistent anti-nuclear "uninhabitable for millennia" myth, check this recent article out [1]. The wildlife at Chernobyl is thriving. There are far worse energy accidents in other industries that cause far more and widespread damage. [1] https://thoughtscapism.com/2019/05/08/worlds-worst-energy-accidents-in-environmental-perspective/ https://thoughtscapism.com/2019/05/08/worlds-worst-energy-ac...
        uterus-liner 8y ago
        I wonder how many people are as tolerant of miscarriages and birth defects and tap water contamination as wildlife seems to be?
        v_lisivka 8y ago
        Chornobyl's exclusion zone covered small part of contaminated area only. My parent's home is in contaminated area, but nobody was evacuated. Cancer rate is 2.5x larger at average in four regions of Ukraine, which are near to Chornobyl. I saw 6m (20 foot) wide circle of dead grass at about 800m from my parents home, where a hot particle landed. Both my neighbors are died because of cancer. I live in clear region, but my lungs was very radioactive for few years, because of my visits to parents.
    - redwall_hp 8y ago
      Nuclear has the lowest deaths per petawatt-hour of any generation method: https://en.wikipedia.org/wiki/Energy_accidents https://en.wikipedia.org/wiki/Energy_accidents Lower than wind and solar.
    - v_lisivka 8y ago
      Dams also protects people from floods, so they are net positive.
  - nine_k 8y ago
    The pool, as far as I can tell, is built pretty sturdy. Breaking this amount of concrete takes a lot of high explosives, and breaking it underwater is an order of magnitude harder. The Allies at WWII had to go to a great length to damage German dams, while using multiple heavy bombers. If terrorists were in possession of such amounts of powerful explosives, and a capacity to place them inside a highly guarded area, they could use that to blow up a city center to a much greater destructive effect.
    - Balgair 8y ago
      It's not human action that would worry me, it's nature. Freezing cycles could easily erode a pool in a few decades and make micro-cracks that fester unnoticed for years. Rust is an ever present issue for re-inforced concrete and is the cause of countless civil engineering disasters. Practical Engineering on Youtube is a great overview of the issues we humans have with water: https://www.youtube.com/user/gradyhillhouse/playlists https://www.youtube.com/user/gradyhillhouse/playlists Of interest here are these videos: https://www.youtube.com/watch?v=eImtYyuQCZ8&list=PLTZM4MrZKfW_XJht-K7a9_egIsFqze0nQ&index=8 https://www.youtube.com/watch?v=eImtYyuQCZ8&list=PLTZM4MrZKf... https://www.youtube.com/watch?v=0EzoHXEzdwY&list=PLTZM4MrZKfW_XJht-K7a9_egIsFqze0nQ&index=16 https://www.youtube.com/watch?v=0EzoHXEzdwY&list=PLTZM4MrZKf... https://www.youtube.com/watch?v=EACkiMRT0pc&list=PLTZM4MrZKfW_XJht-K7a9_egIsFqze0nQ&index=15 https://www.youtube.com/watch?v=EACkiMRT0pc&list=PLTZM4MrZKf...
      - CodeCube 7y ago
        I hear what you're saying, but I think the point I tried to make in my OP is getting lost here ... in a (well run) facility such as this, nothing would fester unnoticed for years. Actually, I love that you posted some of Grady's videos ... it shows just how much knowledge we have around these problems. And yes, they're not easy, and they're not necessarily cheap to deal with ... but we can deal with them. It's a known problem.
- Balgair 8y ago
  Yes, but the expected value of harm from my backyard pool leaking is, well, I can't swim and I need to resurface the pool liner. Multiply this issue by the probablity that it'll happen at all, and you get, well, a filled pool to swim in. But the expected harm from a SNR like this having a leak is decidely not the same. Yes, the leaks may be rare, but the outcomes from such a leak occuring have Chernobyl-like outcomes in their failure trees. The probability calculus still may return that this design is quite fine, given the risk tables, but you MUST run the numbers. Hand waving is not ok here.
antris 8y ago
What happens if a windmill explodes?
- Teever 8y ago
  I'm not too sure but I can say for certain that it doesn't spew radioactive material into the environment.
  - i_am_proteus 8y ago
    There would be some trace amounts of radioactivity in the materials used. Probably not enough to harm the public. Similarly, most fission reactor failure modes don't release harmful amounts of contamination to the public.
- C1sc0cat 8y ago
  Some exotic runaway condition - not sure if generators can do that - electric motors if wired incorrectly self destruct in amusing ways. More likely you have an over speed failure and the it runs out of control and self destructs flinging the blades and other heavy objects about.
- mcguire 8y ago
  https://www.youtube.com/watch?v=Q5COAi6KM8o https://www.youtube.com/watch?v=Q5COAi6KM8o
DuskStar 8y ago
The pool won't normally be radioactive if I'm reading things right, so... nothing will happen. It's the backup for if the pods fail, not a primary line of defence.

The pool only needs to function for a few days during/after an accident until heat energy from fission product decay reduces to lower levels. The pool's function is as an accident mitigation measure - and when any accident occurs the reactor enters a "shut down" state. The decay heat energy that needs to be dissipated is much lower than normal reactor operational power output.

CodeCube 8y ago

I mean ... millions of people who barely maintain their homes avoid pool leaks, and when it does leak, it tends to be slow enough that they can call in a professional to fix the problem. Imagine a fastidiously maintained facility ... I think they can probably work it out

781 8y ago
You have to consider stuff like terrorist attack and so on. Nobody is so incentivized in making your backyard pool leak.
- jcranmer 8y ago
  What if a dam explodes? More people have died due to dam failures (both intentional and accidental) than have died to nuclear power, but there is nowhere near the freaking out over the safety of dams compared to nuclear power. For comparison, the Banqiao Dam failure (the largest dam failure in history) killed as many people as the sum total of every nuclear power plant failure and every atomic bomb ever used, combined.
  - petschge 8y ago
    While dam break cost lives, there is crucial differences that are never mentioned by the pro-nuclear crowd on HN. 1.) Dam breaks devastate much smaller areas. So even if the human toll is the same, the amount of infrastructure lost is smaller. 2.) The area is unlivable (or even inaccessible) for a much smaller duration of month instead of millenia. Maybe land lost "forever" (on the timescale of individual human lives) is not a big problem in some part of the world, but in densely populated areas (any they need the most power, so would have MORE reactors per area) you can not simply block off an area the size of Belgium because a reactor exploded. This makes nuclear power a lot less attractive in India, Europe or (coastal) China.
    - jcranmer 8y ago
      Chernobyl's exclusion zone was ~1000 mi^2, consisting of ~120,000 people. The Oroville dam evacuation zone is ~250mi^2 encompassing ~180,000 people. Floods are no laughing matters; the Chinese decision to break the levees of the Yellow River during the Second Sino-Japanese War is credited with killing 400,000 people or so and rendering millions homeless, and the land was unusable for the better part of a decade, not "a month." > 2.) The area is unlivable (or even inaccessible) for a much smaller duration of month instead of millenia. Millennia of uninhabitability is anti-nuclear propaganda. Most of the zone will be reinhabitable within a century of the accident, and much of it is already inhabitable again but still excluded out of safety margin concerns.
      - acidburnNSA 8y ago
        Strengthening your point on the persistent anti-nuclear "uninhabitable for millennia" myth, check this recent article out [1]. The wildlife at Chernobyl is thriving. There are far worse energy accidents in other industries that cause far more and widespread damage. [1] https://thoughtscapism.com/2019/05/08/worlds-worst-energy-accidents-in-environmental-perspective/ https://thoughtscapism.com/2019/05/08/worlds-worst-energy-ac...
        uterus-liner 8y ago
        I wonder how many people are as tolerant of miscarriages and birth defects and tap water contamination as wildlife seems to be?
      - v_lisivka 8y ago
        Chornobyl's exclusion zone covered small part of contaminated area only. My parent's home is in contaminated area, but nobody was evacuated. Cancer rate is 2.5x larger at average in four regions of Ukraine, which are near to Chornobyl. I saw 6m (20 foot) wide circle of dead grass at about 800m from my parents home, where a hot particle landed. Both my neighbors are died because of cancer. I live in clear region, but my lungs was very radioactive for few years, because of my visits to parents.
  - redwall_hp 8y ago
    Nuclear has the lowest deaths per petawatt-hour of any generation method: https://en.wikipedia.org/wiki/Energy_accidents https://en.wikipedia.org/wiki/Energy_accidents Lower than wind and solar.
  - v_lisivka 8y ago
    Dams also protects people from floods, so they are net positive.
- nine_k 8y ago
  The pool, as far as I can tell, is built pretty sturdy. Breaking this amount of concrete takes a lot of high explosives, and breaking it underwater is an order of magnitude harder. The Allies at WWII had to go to a great length to damage German dams, while using multiple heavy bombers. If terrorists were in possession of such amounts of powerful explosives, and a capacity to place them inside a highly guarded area, they could use that to blow up a city center to a much greater destructive effect.
  - Balgair 8y ago
    It's not human action that would worry me, it's nature. Freezing cycles could easily erode a pool in a few decades and make micro-cracks that fester unnoticed for years. Rust is an ever present issue for re-inforced concrete and is the cause of countless civil engineering disasters. Practical Engineering on Youtube is a great overview of the issues we humans have with water: https://www.youtube.com/user/gradyhillhouse/playlists https://www.youtube.com/user/gradyhillhouse/playlists Of interest here are these videos: https://www.youtube.com/watch?v=eImtYyuQCZ8&list=PLTZM4MrZKfW_XJht-K7a9_egIsFqze0nQ&index=8 https://www.youtube.com/watch?v=eImtYyuQCZ8&list=PLTZM4MrZKf... https://www.youtube.com/watch?v=0EzoHXEzdwY&list=PLTZM4MrZKfW_XJht-K7a9_egIsFqze0nQ&index=16 https://www.youtube.com/watch?v=0EzoHXEzdwY&list=PLTZM4MrZKf... https://www.youtube.com/watch?v=EACkiMRT0pc&list=PLTZM4MrZKfW_XJht-K7a9_egIsFqze0nQ&index=15 https://www.youtube.com/watch?v=EACkiMRT0pc&list=PLTZM4MrZKf...
    - CodeCube 7y ago
      I hear what you're saying, but I think the point I tried to make in my OP is getting lost here ... in a (well run) facility such as this, nothing would fester unnoticed for years. Actually, I love that you posted some of Grady's videos ... it shows just how much knowledge we have around these problems. And yes, they're not easy, and they're not necessarily cheap to deal with ... but we can deal with them. It's a known problem.
Balgair 8y ago
Yes, but the expected value of harm from my backyard pool leaking is, well, I can't swim and I need to resurface the pool liner. Multiply this issue by the probablity that it'll happen at all, and you get, well, a filled pool to swim in. But the expected harm from a SNR like this having a leak is decidely not the same. Yes, the leaks may be rare, but the outcomes from such a leak occuring have Chernobyl-like outcomes in their failure trees. The probability calculus still may return that this design is quite fine, given the risk tables, but you MUST run the numbers. Hand waving is not ok here.

antris 8y ago

What happens if a windmill explodes?

Teever 8y ago
I'm not too sure but I can say for certain that it doesn't spew radioactive material into the environment.
- i_am_proteus 8y ago
  There would be some trace amounts of radioactivity in the materials used. Probably not enough to harm the public. Similarly, most fission reactor failure modes don't release harmful amounts of contamination to the public.
C1sc0cat 8y ago
Some exotic runaway condition - not sure if generators can do that - electric motors if wired incorrectly self destruct in amusing ways. More likely you have an over speed failure and the it runs out of control and self destructs flinging the blades and other heavy objects about.
mcguire 8y ago
https://www.youtube.com/watch?v=Q5COAi6KM8o https://www.youtube.com/watch?v=Q5COAi6KM8o

DuskStar 8y ago

The pool won't normally be radioactive if I'm reading things right, so... nothing will happen. It's the backup for if the pods fail, not a primary line of defence.