Job coverage for contaminated filters

[welch@CEBAF.GOV (welch)]

OK experts, please provide any nifty ideas and solutions to the following
hypothetical problem.

Provide contamination control for changing filters on an air handling system
which tends to build up Be-7 in the filters.  These are regular 24"x24"
'boulder catcher' pleated paper filters.  There is a bank of about 16 of
them.  The air handler just recirculates the air through the filters, a
cooling coil, and back out into the space.

Now for the fun part - the air handler is ~ 60' up in the air at the top of
a dome shaped "hall".  There is no catwalk.  An aerial "manlift" is used to
access the area (it sways a lot).

What's the cheapest, easiest way to deal with this?  Anyone familiar with
rolling prefilters, special containments, or anything we could adapt to the
device itself?  Is there a reasonable substitute for a catwalk? (the main
hazard of the job is the aerial lift)

Lastly, how do I check people and items for Be-7 contamination at the
rediculously low limit of 1000dpm/100cm^2  IN THE FIELD.  (a pancake GM sees
this nuclide at around 100 cpm per 15,000 dpm)

Did I mention, this is just a hypothetical case?


My employer did not review or approve this.
Keith Welch
CEBAF
welch@cebaf.gov
KW