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Sr-90 Dirty Bomb

  1. Jul 16, 2008 #1
    For a conference I am running, I have concocted the following scenario.

    Evil terrorists have 11 lbs of Strontium-90
    Good guys drop 4 bombs on the building housing the Sr-90, collapsing it and distributing the material

    I know this will require rough numbers, just please help as you can

    what would the likely radiation levels be at ground Zero?
    How about at a given range (1 km)?
    Would anyone die of radiation poisoning in the immediate area, if so, within what radius
    what lasting health effects would be observed in the local population?

    Thanks for any help you can give,

  2. jcsd
  3. Jul 16, 2008 #2

    Vanadium 50

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    Eleven pounds? Holy smokes! If I did the math right, eleven pounds in a sphere will have an equilibrium temperature of over 1500K - well above the melting point. It's well over a megacurie.
  4. Jul 16, 2008 #3
    i'm looking for a reasonable amount for a dirty bomb, something that will make maybe a km radius around the site be unsafe for a while, and cause some radiation illness/deaths

    any suggestions as to a more reasonable amount for "terrorist possession"?
  5. Jul 17, 2008 #4

    Vanadium 50

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    Bump? After 12-1/2 hours (including night in Europe and the Americas) and only two other messages in the section?

    I'm sorry we're not doing your work for you fast enough to suit you.
  6. Jul 17, 2008 #5


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    Most studies on the physiological effects of dirty bombs show that they aren't very dangerous at all, with one study I remember saying it was "comparable to smoking several packs of cigerettes" or eating lots of ice cream.

    If the building collapsed, wouldn't that mean dispersal would be pretty minimal? Thousands of pounds of rubble would cover the isotope grains that are probably already in a container.

    Sorry not to offer help towards what you're looking to know.
  7. Jul 17, 2008 #6
    I am thinking the radiation source will be the SR-90 from a RTG reactor used in russian nuclear lighthouses-the reactors are fueled by SR-90, contain "5kg of radioactive material", which is why I assumed it was 5kg of SR90. The other information given on the RTG is as follows

    Concentration of strontium 90 1,500 TBq, or 40,000 curies
    Temperature on the surface, centigrade 300-400 degrees
    Exposition dose rate at the distance of 0,02 to 0,5 metres 2,800-1,000 R/h

    Does this sound accurate given a mass of 5kg? If not, is there any way I could backtrack (with no nuclear physics experience) to find the actual mass of SR90 in the RTG's?

    Thanks again for all your help...
  8. Oct 20, 2009 #7
    Let me get this straight - you're running a conference on this topic yet have no nuclear physics experience? Who are the attendees? Do they know?
  9. Oct 20, 2009 #8
    Ehh, he's running a gaming "conference" i bet...or he was.
  10. Oct 20, 2009 #9


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    Sr90 theoretical max is about 2.3Watts/g, typically say about 0.8W/g
    specific activity of Sr90 is 140Ci/g
    A 40,000Ci RTG would be about 200W = 300g of Sr90.
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