random comments

["Les Slaback, Health Physics" <SLABACK@micf.nist.gov>]

Collected responses to various items (having just gone thru a
month of messages):

Pb equivalence of cinderblock:  Based on some transmission
measurements I made some time ago of well filtered 200 kV xrays
from a LINAC klystron I consider CB's 'air equivalent'.  We saw
about 4% reduction.  If you have very low energy photons they
will be of some value.  Otherwise all they are is support.

NRC 'time-to-pulse': We have used several of their survey
instruments for about 8 years.  Good reliability, great dynamic
range, fast response to a stable reading.  Expensive.  In doing
the initial calibration I was impressed with its linearity over
6 orders of magnitude of dose rate, and with the almost
immediate stable reading after opening the source, e.g., about 2
seconds.

ABHP: Having reviewed renewal paperwork for one year, my
personal observation is that the vast majority of CHP's are
excessively overqualified, Type A, overachievers; of which Ron K
is a prime example.  But of course my past involvements might
reflect a slight bias on my part.

Solubility:  The original purpose for deleting 'dispersable'
from the rule was to solve the problem of a few licensees
dumping chunks of metal into the sewer.  Now we are dancing on
the head of a pin over minutiae, e.g., doing freshman chemistry
experiments for each sewer release.  But the die is cast, and
the rule is not likely to change before most of us retire.
So....
   1. The NRC Info notice is only one suggested solution.  Some
licensees have characterized their waste and justified the use
of larger filters for routine releases.
   2. NRC has, and will, authorize alternative practices.  The
vast majority of sewer releases are at concentrations that could
be released to the environment.  Clearly the sewer pathway is
preferable, and of lesser impact to the public.  An ALARA
argument for what could otherwise be an environmental release
(where solubility is not an issue) might be a successful basis
for such a petition. (Check with your local regulator.)
   3.  There are facilities that have simply cut the pipe, i.e.,
no longer release any RAM to sewer.  They minimize liquid waste
generation, purify what they can, and evaporate the rest.  This
can be very expensive, but it is no more crazy than the
monuments we are building for our solid LLW.  If we HP's do not
convince our public that the world is radioactive this will be
the wave of the future.  Besides, with the large number of
compact LLW sites we will have :), we will need more solids to
keep them busy.  Of course, 0.45 micron filters clog so fast
that they will provide lots of volume too.

SLABACK@MICF.NIST.GOV
   ...a little risk, like a bit of spice, adds flavor to life