Re: Decay-In-Storage

[Paul Lavely <lavelyp@uclink4.berkeley.edu>]

>  > If what Sandy say's is true than why are the regulatory folks
>>  requiring 10 half-lives AND non-detectable?  It's a license
>  > condition I must adhere to and document.




We asked this question. "I survey an item of waste contaminated with 
P-32. It reads three times background. My license says I can not 
dispose of any item that is greater than twice background. If I enter 
this item into the decay program I have to store it for 10 half 
lives. However, in about 2 weeks it will have decayed to the point 
that it would be hard to tell if it is greater than background. Can I 
dispose it before the 10 half lives by resurvey and verification that 
it is less than twice background?"

The inspector is in a bind. The inspector looks to the license and it 
says words to the effect that items in the decay program MUST be 
stored for ten half lives and then surveyed. If less than twice 
background the item can THEN be disposed of as non-rad. Therefore, 
once in the decay program it must stay for 10 half lives. We made the 
case that we can survey an item at any time to determine if it is in 
fact no different than background. The issue remains as stated "once 
in the decay program it must be stored for 10 half lives."

In fairness to our regulators, we have not made this an issues that 
required a resolution.

Paul Lavely <lavelyp@uclink4.berkeley.edu>
UC Berkeley
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