Re: Rad Road show

[SAFarberMSPH@CS.COM]

Radsafe:


Some years ago, I noticed a large pallet of KCl ice melt buckets [about 50 pounds each as I recall] stacked near the checkout line of a BJ's Wholesale Club warehouse store in MA.


I went back and took some photos of young mothers with children in their carriages standing in line at BJ's Club next to the KCl bucket pallet [perhaps 5 to 6 tons of pure KCl in 240 containers] and also had my lab RSO take along a micro-R meter to get a gamma reading. If memory serves me right we measured a gamma dose rate of several tenths of an mR/hr. A later calculation of the gamma flux and dose at the center of an infinite sized pile of KCl yielded a dose rate of I think about 0.4 mR/hr.


 I also submitted a sample of this KCl ice melt for blind gamma spec analysis to the environmental radiation monitoring lab where I was QA Officer at the time,  and the K-40 content was  measured right about 450,000 pCi/kg of salt which is what one would calculate based on it being pure dry KCl [about 527 g stable K per kg of KCl which at 852 pCi of K-40 per kg of stable K equates to an expected 449,000 pCi K-40 per kg of pure dry KCl.


Not too shabby a gamma [or beta considering 89% of decay transitions for K-40 are by beta] source for a "natural" gamma spec energy calibration or long-lived non-liquid check standard that costs about $10.00 for 50 pounds at any discount warehouse store. No need for decay corrections as long as you don't plan on using it for more than a few hundred million years. Just be sure you don't buy NaCl by mistake.


Stewart Farber

email: SAFarberMSPH@cs.com

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In a message dated 1/15/02 1:01:57 PM Pacific Standard Time, Susanne.Ziegler@PSEG.COM writes:



> Subj:RE: Rad Road show
>
> Date:1/15/02 1:01:57 PM Pacific Standard Time
>
>
> You might try some of the salts sold to melt ice.  Some are high in natural
>
> radioactive elements.  I have measured some brands 3-10 mRem/hr.