RE: Uranium Analysis

["Robert Loesch" <loesch@list.eh.doe.gov>]

There are multiple methods for measuring uranium.  KPA is often
used to measure total uranium whereas alpha spec is typically
used to gain isotopic concentrations. Not knowing what the licensee
is (ore extraction, fuel fabrication, D&D, etc.), it is hard to
guess at the forms of uranium in question.  If high fired oxides
of uranium are present, then special procedures are typically
needed to ensure complete dissolution of the uranium. All analyses
of uranium require "some" chemical processing of the sample prior
to the quantification. Prior to analyzing a sample, it is best to
know the chemical forms potentially involved to ensure accurate
results.

Bob Loesch
US Department of Energy
EH-52, GTN, 270CC
19901 Germantown Road
Germantown, MD  20874
(301) 903-4443
(301) 903-7773 fax
robert.loesch@eh.doe.gov


> -----Original Message-----
> From: radsafe@romulus.ehs.uiuc.edu
> [mailto:radsafe@romulus.ehs.uiuc.edu]On Behalf Of Clement, Christopher
> Sent: Monday, July 20, 1998 10:25 AM
> To: Multiple recipients of list
> Subject: RE: Uranium Analysis
>
>
> 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
> >
>