RE: Uranium Analysis

["Clement, Christopher" <clementc@AECL.CA>]

One problem we've seen is that some types of analyses only assess the "acid
extractable" amount of an element, while others assess the total amount.  It
is possible that only the chemically extractable amount of uranium was
measured using chemical methods, and that all the uranium was counted by
alpha spec.  We've seen these kinds of differences when comparing neutron
activation vs. ICP mass spec.  Neutron activation uses the entire sample,
while ICP mass spec. might only get some of the element in question due to
chemical preparation methods of the sample.


------------------------------------------------------------
Christopher H. Clement
Scientific Specialist / Radiation Protection Program Manager
Low-Level Radioactive Waste Management Office
Atomic Energy of Canada Limited
clementc@aecl.ca


> ----------
> From: 	Joelle Key[SMTP:jkey@mail.state.tn.us]
> Sent: 	July 20, 1998 10:15 AM
> To: 	Multiple recipients of list
> Subject: 	Uranium Analysis
> 
> Dear Radsafers:
> 
> I was recently reviewing a licensee request that delt with Uranium.  In
> the
> original request, the U content was determined chemically.  We asked
> them to take more samples, and these were analyzed with alpha spec. 
> The second samples showed about twice as much Uranium than the first
> samples.  I called the company to ask them if they had any theories as to
> why this was so.  They said that they had the same question and asked
> their HP consultant.  The consultant told them that it was because of the
> different type of analysis.  The HP said he trusted the alpha spec more
> but that this may just be his HP bias.
> 
> What do you people out in HP land know about this?  Is there a reason to
> think that one analysis is more reliable than the other?  Has anyone
> studied this question?
> 
> I appreciate any help ya'll can give me.
> 
> Joelle Key
> TN-DRH
> jkey@mail.state.tn.us
>