[ RadSafe ] Re: 49 cfr 173.435 specific activity values

[Cary Renquist]

Thanks for the tips.

I should have been more specific...
I was looking for the basis (or assumed isotopic
ratios) for the 49 cfr 173.435:
Th(nat)
U(dep)
etc.

I just found the info in 173.434.

The question came from a colleague.  He received a
data-sheet that used the DOT Specific Activity
numbers, but when he calculated the SA based on the
datasheet's isotopic data he got very different
numbers.  The fact that the DOT number for Th(nat)
includes Th-228 in equilibrium was once reason for his
observed discrepancy.

Once again, thanks,
Cary

--- Cary Renquist <cary_rdsfe at pacbell.net> wrote:

> 
> What is the origin for the specific activity values
> listed in 49 cfr 173.435?  I don't see any
> references
> cited. 
> 
>
http://www.myregs.com/dotrspa/goto.asp?ref=CFR49.173.435
> 
> Thanks for any information,
> Cary
> 
>