Re: TFP update article, E Magazine; replies to all

[Kai Kaletsch <info@eic.nu>]

Richard:



> .... However, is 70 curies a large amount of radiation to

> be released and spread across a wide area?



There is about 1 Ci of radium in one square mile of soil to a depth of 6

inches. This produces 1 Ci of Radon every 5.5 days, or 66 Ci per year. Not

all of that would be released into the air. 10% release gives you about 6.6

Ci Rn released per square mile. There are 4 short lived radon progeny which

will be in equilibrium with the Rn, so that makes it 33 Ci per year. Most of

the short lived progeny are alpha emitters so they carry more dose than beta

and gamma emitters if they get inhaled.



If the soil is dry and/or loosened by farming etc., more Rn is released

because a deeper layer of soil contributes.



Using total release of activity as a proxy for dose has some (big!)

problems, because each isotope has different uptake, metabolism, 1/2 life

and dose characteristics, but those are the numbers.



Best Regards,

Kai

http://www.eic.nu



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