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Writing: Input Wanted Nuclear Plants -- In the event of a 50% population collapse

  1. Feb 11, 2016 #1
    Hi all,

    I'm a science-fiction/fantasy writer who is in the midst of outlining a distant-future (10,000+ years) story. The main parts of it I can handle (humans on Earth have gone through a cycle of Intellectual --> Dark ages with the current era being a kind of pinnacle never again achieved).

    Supposing that, for various reasons, about 50% of the planet decided to part ways with the Earth and go live elsewhere and that 50% contained the vast majority of scientists and engineers, is there any kind of "Dummies Guide" for nuclear power plants that would let the remaining 50% at least shut them down without having a meltdown? I know that the fuel rods get really hot and take years to cool down so they have to be put in cold water that continually cycles so it won't boil off. That, however, is about the extent of my practical knowledge. In a pinch, could the average high-school student (or rather, a group of them) maintain the spent fuel rods well enough so as not to cause the kind of disaster that Aftermath: Population Zero says would happen if suddenly no one were around to take care of them?

    Also, how long would it take for the satellites (the artificial ones we've sent up) to suffer orbital decay and get pulled down into Earth's atmosphere? What kind of danger would their wreckage pose to people on the ground (if any) other than "insta-death" if one were to land slap on top of someone? ;)

    The rest of the stuff I can handle because it's straight-forward enough for even a history major to piece together. It's the "what would happen to the nuclear plants (and, by extension, the nuclear stockpiles and subs)?" and "what would happen to the satellites?" that has me stumped.

    Thanks!

    -- G.K. Masterson
     
  2. jcsd
  3. Feb 11, 2016 #2
    Well, it would unrealistic to say that 100% of technically capable people would opt to leave planet Earth as part of that exodus, so it would seem likely that there will be people available.

    Human nature is very much saddled to capitalism, too. So as long as there is a need, there will be people willing to compensate other people for their unique skills.

    I think your story needs to look deeper into human nature. People do things for various complex reasons, so your scenario is probably self correcting. That also applies to the schism you proposed where all the intellectuals take off like the dolphins in the Hitch Hiker's Guide to the Galaxy. I just don't see that as being reasonable and I suspect your readers may have a hard time swallowing it, too. You will have to work very hard to make a compelling case for that. Even if you do you will not likely get 100% voluntary compliance. All of that ignores the unbelievable expense required to move 50% of the Earth's population off-planet.

    As for satellites to deorbit it will depend on the type of orbit they occupy. Most low orbiting satellites would probably remain aloft for a few decades to a few hundred years. While we think of low Earth orbits as being in space, there is a small component of atmospheric drag that will cause them to deorbit. The lower the orbit the quicker that is likely to happen.

    Satellites in geosynchronous orbits may remain aloft for many millennia. Altitudes of 36,000 miles have not atmospheric drag to contend with, so the only way to impact those orbits are with bodies like the Moon and other planets over very long stretches of time.

    Lastly, damage from falling satellites is about nill. there will be very few vehicles that are large enough to survive planet-fall. Even the Space Shuttle disintegrated into such fine debris that it posed no statistical risk to anyone on the planet. Odds are most of the debris will end up in the ocean since 2/3 of the planet is water.
     
  4. Feb 11, 2016 #3
    It's not 100% of all the technically inclined, no, but it is a significant section of them and, for story reasons, those who opt to remain behind find themselves in a situation much like scientists in the former USSR lived in and some areas begin to stagnate entirely (like biology and microbiology did). Increasingly, as hard degrees in sciences, math, and engineering earn less bang-for-the-buck that comes into achieving them (and as the Earth-bound populace becomes more war-torn, stricken by resurgent diseases, and subject to the whims of Mother Nature), the subjects are studied less and less and you wind up with the situation that existed in the Dark Ages -- what knowledge is left is inscrutable to the average person whose biggest concerns are getting enough to eat that day.

    I'm with Heinlein here:
    I just don't want to have a situation where I have to calculate every single nuclear plant going critical within a few decades of each other. Sure, a few probably would here and there -- but not all of them. A more graceful shutdown where they go offline -- never to come up again -- is what I'm hoping would be possible in the event of a great brain-drain sometime in the next 200 years.

    In my back-story (set in the current era to 2500), the only surviving democracies are in Switzerland and a handful of Britons, Aussies, and exiled Americans living in the South Pacific. After a pandemic (which we're more than due for) that is somewhere between the Black Plague and the Spanish Influenza, there's a series of wars and breakdowns that leads to the end of the modern era and a quick regression back to the early days of the Industrial Revolution (with a few odd spots remaining -- things like hydro electric dams, a few nuclear power plants run by people who don't understand *how* they work -- just enough to keep them from going KABOOM! -- the odd solar power array or wind farm).

    Thanks!

    -- G.K. Masterson
     
  5. Feb 12, 2016 #4
    How much population did East Germany, and regions of East Europe, lose when emigration suddenly became possible?
     
  6. Feb 12, 2016 #5
    Some places lost upwards of 40% to voluntary migration which is a bit different than what's happening in my story. Some of mine is voluntary but a lot of it is involuntary -- the scientists, engineers, and a lot of the intellectuals aren't given the choice as to whether or not they're going. For them it's "go or get shot."

    Thanks!

    -- G.K.
     
  7. Mar 7, 2016 #6
    I would think it would depend on how advanced the satellites were and how much fuel they have. It also has a lot to do with how high they are. GPS sats would probably never come back to earth in the anything short of a geological time period. ISS on the other hand, loses about a hundred meters of altitude per day and requires a new burn every few weeks.
    2014-05-17-ISSaltitude.png
     
  8. Mar 7, 2016 #7

    mheslep

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    Gold Member

    All depends on the time scale of the exodus you envision. There are two factors driving the outcome amount of heat produced by the radioactive decay, and the level of radioactivity dangerous to life.

    The moment the reactor is shut off, i.e. stops nuclear fission, the heat output of the reactor drops to 7% of its full power maximum, driven only by the radioactive decay of the fuel which can not be stopped. Within a couple hours the heat output (power) drops to 1%, within a day to 0.5% and so on. As long as the cooling system of the reactor continues to function for some many days or weeks after shutdown, depending on the design of the reactor, the radioactive heat will decay to a point where the fuel can't melt. Some new reactors have designs such that, even in the event of the failure of the normal cooling system (Fukushima), the reactor fuel can't melt from heat, though it remains dangerously radioactive should it escape into the environment.

    Spent fuel is stored first in pools typically close to the reactor, in water deep enough to block harmful radiation. In the US per the NRC, after fuel has been stored in the pool for at least three years it can be placed into dry concrete caskets for semi-permanent storage. The industry standard is 10 years. The fuel should be safe in those caskets, if they were built correctly, for the life of the concrete, and the caskets are designed to resist "natural phenomenon, such as seismic events, tornados, and flooding." Some human or geological catastrophic event might interfere with safe storage. Once in the caskets, most of the very dangerous radiation decays away on the order of a hundred years, though the weaker radioactive elements remain for thousands of years from the current reactor designs. Reactor designs have been proposed that would eliminate the long-lived waste (thousands of years).

    If your left-behind crowd has help for a couple years to shutter the reactors and store the fuel, then all the fuel should be ~safe in caskets. Otherwise?
     
  9. Mar 8, 2016 #8
    "Going Critical" is sci-fi for imminent dangerous explosion.

    Nuclear power plants tend to operate somewhat near to being at critical, where simply put, the chain reaction will be controlled so that neutron production = neutron absorption reaction is self sustaining, and is considered safe.

    Did you read the wiki.
    It explains generally, and may give some more insight into nuclear power.
     
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