RE: error propagation for % enrichment

["Bradshaw, Keith" <Keith.Bradshaw@nnc.co.uk>]

> -----Original Message-----
> From:	Hans Honerlah [SMTP:hansbh1@yahoo.com]
> Sent:	Wednesday, January 05, 2000 12:40 PM
> To:	Multiple recipients of list
> Subject:	error propagation for % enrichment
> 
> I am attempting to locate a reference that will
> provide a method to propagate the error associated
> with analytical results from isotopic uranium analysis
> and determining percent enrichment.  To be a little
> more specific; each uranium (U234/U235/U238)
> analytical result has an associated error.  How do
> account for this error in determining enrichment?  At
> low U235 activity any error associated with the
> analytical result significantly changes the percent
> enrichment.
> 
	A can of worms.  There's a geochemistry textbook with a section
stating that the usual method of error propagation does not apply when the
constituents are constrained to total some predetermined value.  In this
case, %234U + %235U + %238U is constrained to total 100%.

	These things are further complicated by references seemingly
equating weight% to atom% etc.  Also it depends on precisely what you are
after and what measurements you have.

> I have went through some old chemistry and statistic
> books to develop an equation, just wondering if
> something specific to this has already been utilized
> or published.
> 
	Perhaps not precisely what you're after, but have you seen

	'Relationship between isotopic uranium activities and total uranium
at various uranium enrichments', by Rucker and Johnson Jr, J. of
Radioanalytical and Nuclear Chemistry, Vol 235 1-2 (1998) pp47-52 ?

> Hans Honerlah
> Health Physicist
> USACE 
> 
	If you want to correspond off list about this, I'd be interested.

	Regards

	keith.bradshaw@nnc.co.uk

	END





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