Re: Kr-85

[Schoenhofer <schoenho@via.at>]

At 10:04 04.12.1996 -0600, you wrote:
>
>     Joe,
>     
>     When I add up all the natural abundances of all the grey boxes on the 
>     Kr part of the chart of nuclides, I get 100%.  Kr-85 has a short half 
>     life to stay around for any period of time (~4 1/2 hrs).  I could not 
>     imagine Kr-85 being a rad problem, unless it was being produced by 
>     nuclear methods and not cryogenic-from the atmosphere methods.  
>     
>     Robert A. Jones
>-------------------------------------------------------------------------

No, Kr-85 has a half life of approximately 11 years. Some years ago the
yearly rise of its concentration in air was approximately 5% per year. Its
"production method" is fission of uranium and plutonium and it is released
during reprocessing.

Franz
Schoenhofer
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