survey instruments w/ fixed contamination

["Mario Iannaccone" <miannacc@dhhs.state.nh.us>]

     I recently received an inquiry that concerned instrument calibration
of survey equipment w/ fixed contamination.  It was referred to as an
industry standard (common practice) for the nuclear power industry (not
clear if it is in-house calibration).  The criteria for removable (loose
surface) contamination detection limits was established in NRC IE Circular
No. 81-07 "Control of Radioactively Contaminated Material" and NRC Health
Physics Position Paper HPPOS-072 "How Hard Do You Have To Look" as being
1000 dpm/100 cm2 beta-gamma and 20 dpm/100 cm2 alpha.
     I did a small sampling of some of the larger inst. manufactures and
came up with repossess ranging from 'no contamination, LS or fixed, allowed
and very rarely seen' to 'it's equivalent to a check source and quite
common (with reject limits of >100 ccpm gamma and 3 ccpm alpha)'.
     My background dictates that contamination of survey instruments is
strictly taboo,  a  indication of sloppy survey techniques and potential
loss of control.  Some questions that arise are:  is this a common
situation, are the LS detection limits appropriate to define LS vs fixed
contamination, should fixed contamination be identified (labeled) when
found.  I'd like to call on your collective expertise and open this topic
for discussion and peer review.


M. Iannaccone,
Health Physicist
miannaccone@dhhs.state.nh.us

"Chi nasce tunno nun more quatro"

This material has neither been reviewed nor approved by my management, but
rather represents an individual though process. Any and all similarities to
reality are fictitious, you get the idea, etc.


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