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Why do some nuclear power plants have smoke stacks?

  1. Jun 24, 2015 #1
    There are alot of nuclear power plants around the world that have smoke stacks, the kind you'd usually see at a coal fired power plant. Are they to release steam in an emergency, or are they some kind of exhaust system the plant uses, or something else? Most nuclear power plants in America have them, and mostly all of them in Russia have them aswell. What are they for? Picture below No=311130064&Ref=AR&MaxW=640&Border=0&NRC-reviews-Lacey-s-Oyster-Creek-nuclear-plant-after-Sandy.jpg
     
    Last edited: Jun 24, 2015
  2. jcsd
  3. Jun 24, 2015 #2
    I'm pretty sure that their only purpose is to release unwanted heat from the coolent system after the superheated steam coming from the reactor has done it's job of spinning the generators.
    Note that the steam being released is not coming from the reactor coolent directly, but from a secondary heat exchange system.
     
  4. Jun 24, 2015 #3
    But isin't that the condensors job of cooling it down? Or is there alot of leftover heat that needs to be vented?
     
  5. Jun 24, 2015 #4
    Well I guess it's fair enough to say that the steam which comes out of the stacks is the end product of the condensing process.
    The job of the condensor is to remove heat from the reactor coolent before it is recycled.
    That heat has to go somewhere and the steam coming out of the stack is where it goes.
     
  6. Jun 24, 2015 #5
    But the nuclear cooling towers take the heat away from the condensor, the smoke stacks however are rarely used, I've never seen any gasses at all come from one of these smoke stacks, so what do they do.
     
  7. Jun 24, 2015 #6
    Maybe those stacks are for a different purpose which I don't know of.
    However I did at one time live nearby to a nuclear station and that one had cooling towers which look very similar to the cooling towers you would see at a coal fired station, and assumed their purpose was much the same.
    They were not permanently emitting steam, I guess something like 10% of the time
     
  8. Jun 24, 2015 #7
    So they could either be an emergency release for steam or just for dealing with the heat and steam. But if cooling towers are so huge at the base and have room for all the water cooling, do these smoke stacks do the same thing as cooling towers in a different way, or do they just take steam from the generators and thats it?
     
  9. Jun 24, 2015 #8

    QuantumPion

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    I think those are for releasing non-condensable noble gasses. I believe the reason why some plants have them but not others may be due to the proximity to populated areas although it may be just a difference in design of different plants.
     
    Last edited: Jun 24, 2015
  10. Jun 24, 2015 #9
    The cooling tower should be the rectangular building to the rear.
     
  11. Jun 24, 2015 #10
    But indian point nuclear power plant, which is very very VERY close to New york, has one of these smoke stacks aswell. But if true, where do these noble gasses come from?
     
  12. Jun 24, 2015 #11
    Any chance that is not the building housing the diesel emergency generator system for the nuclear plant.
     
  13. Jun 24, 2015 #12

    QuantumPion

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    Plants which are near populated areas need stacks to release the gasses high up so they spread out quickly and don't come back down over people. Plants in remote areas don't have that concern since there is no large population center to worry about. Note Indian Point is 40 miles away from NYC.

    The gasses come from radioactive byproducts in the reactor coolant system. The gasses are stored temporarily in a tank until they decay into non-radioactive gasses, and then are released.
     
  14. Jun 24, 2015 #13
    So what do rural area Nuclear power plants use to vent the gas? Also, Indian point is 40 miles away, but any gas released from the plant could easily travel the 40 miles downwind to the city, And if a decent amount of radiation was released from Indian point, it could easily travel the 50 mile radius around the plant to new york.
     
  15. Jun 24, 2015 #14

    russ_watters

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    That is my interpretation as well.
     
  16. Jun 24, 2015 #15

    russ_watters

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    Do you have any references to any of that? I live a few miles from Limerick nuclear plant, which is only 20 miles from Philadelphia and it has no such stacks. Beyond that, I don't think I've ever heard that nuclear plants release anything potentially radioactive.
     
  17. Jun 24, 2015 #16

    QuantumPion

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    Well I'm not a weather scientist but I'm guessing you aren't either and you are just making wild assumptions. You'll need to provide a link to a reputable source detailing such as unsubstantiated claims are frowned upon around here.
     
  18. Jun 24, 2015 #17

    QuantumPion

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    I do not know why some plants have tall stacks and others do not, it may just be differences in plant designs. Gas emissions are filtered and monitored for radioactivity and are shut off if radiation is detected. That is for normal operation, they might use the stack in case of a severe accident situation to vent noble gases like TMI to prevent contamination at ground level although I'm not sure if that is what that's for.
     
  19. Jun 24, 2015 #18
    Every nuclear power plant in the US has a 50 mile radius around the plant, every single one. Most emergency plans in the US only call for a 10 mile radius around the plant to be evacuated during a nuclear disaster. However, in a normal radiation release due to emergency, far more than 10 miles around the plant would be affected. Wind would easily carry it 10, or 20 miles away from the plant. Where would this noble gas come from, and how is it filtered from the regular nuclear system to keep from being recycle with the other water or steam?
     
  20. Jun 24, 2015 #19
    Also, found the reason. Thank you plantmap.jpg
     
  21. Jun 25, 2015 #20
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