Plutonium Bioassay

["Carbaugh, Eugene H" <gene.carbaugh@pnl.gov>]

Guidance on bioassay program design for plutonium can be found in Chapter 5 of
DOE-STD-1128-98, Guide of Good Practices for Occupational Radiological
Protection in Plutonium Facilitiies.  It's available online at 

http://tis.eh.doe.gov/whs/rhmwp/pluton.pdf

At Hanford, our typical Pu bioassay program is an annual large volume urine
sample (equivalent to 24-hours collection) analyzed with a minimum detectable
activity for Pu239 (or Pu238) of 0.02 dpm...that's about 0.3 mBq for those of
you who don't want to do the conversion to SI.  This is supplemented by an
annual chest count using planar germanium detectors (MDA of about 0.2 nCi [7.4
Bq] for Am241).  These levels are pretty darn good state-of-the-commercial-art
but don't necessarily make for a class Y monitoring program you want to brag
about.  Make sure you have really good workplace surveillance to catch potential
intakes at the time they occur to initiate special fecal and urine sampling.
Personally, I'd like to supplement with personal air samling (i.e., lapel
samplers) as a supplemental indicator of potential intake to use for initiating
special bioassay - but so far we've only had partial success at getting that
technique accepted by facilities.  Urine sampling does work well for class W
monitoring.

I'd be happy to talk with whoever is seeking the info.

Gene Carbaugh, CHP
Internal Dosimetry
Pacific Northwest National Laboratory
Richland, WA 

gene.carbaugh@pnl.gov
(509) 376-6632
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