RE: Lower limit for SCO 1 classification

[Glen.Vickers@ucm.com]

Response to this statement:

Look at the definition of Radioactive material in 173.403 again. 70 Bq is
the limit by law. This equal 1.89 nCi.


Just how many significant figures is 70 Bq/g good for?  One significant
figure would generate 2 nCi, not 1.89 nCi.  I wonder how many significant
figures are applicable?  Look at the DAC values in 10CFR20.  They clearly
display only one significant figure of precision.  The degree of precision
is not entirely clear here.  

Look at RQ values, the TBq values are clearly the conversion of the standard
Ci.  The contamination limit standard appears to be 1E-5 and 1E-6 uCi/cm2
and the conversion would be the 0.4 and 0.04 Bq/cm2 or the 22 or 2.2
dpm/cm2.  If the Bq were the standard, surely the would have chosen
something like 0.5 Bq/cm2.  When they write 0.04 they are definitely not
trying to imply anything more than 1 significant figure.

I don't know of anyone ever being audited to 1.89 nCi/g vs 2 nCi/g.  Any
thoughts out there?


Sincerely,
Glen Vickers
glen.vickers@ucm.com

	

	 
	At 02:36 PM 11/4/98 -0600, you wrote:
	>I believe NUREG 1608 explicitly states that the contamination
limits are
	>those on the equipment and your smears can only be a tenth of that
limit
	>because of the 10% smear efficiency.
	>
	>As far as lower limits go, NUREG 1608, 3.1.2. says that if your
material is
	><2 nCi/g, 2200 dpm/100 cm^2 beta/gamma, and 220 dpm/100 cm^2 alpha
then it
	>is below DOT concern.  This is where the free-release policy for
your
	>facility comes in.
	> 
	>NUREG 1608 3.1.3. says that if you have a "limited quantity", then
you may
	>ship as a limited quantity and not SCO.
	>
	>Sincerely,
	>Glen Vickers
	>glen.vickers@ucm.com
	> 
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