RE: release of material

["Sherman, Conrad" <ShermaC@ttemi.com>]

I wish the people who wrote such guidance had practical experience, then
they would realize that all they were doing was copying someone else's old
inadequate guidance.

This problem has been around forever, at least as long as I have been a
health physicist.  When I started, DOE sites were using criteria and survey
techniques that they couldn't possibly justify to support measurement at the
concentration of surface activity they were claiming, but nobody questioned
it.  Now we do better quality surveys, but the problem of porosity and
cracks remain.

I know some sites have taken to release objects using a mil-std sampling
approach.  If you have gamma emissions, you may be able to develop an
equivalent activity, based on some surface area assumed to be present and
contaminated.  You then can figure out your sensitivity to find this spot,
using microshield to attenuate the source.  Then, will you flip it over and
count from both sides, cut up the ties, etc.  MARSSIM explains how to derive
a scan sensitivity for a spot of contaminated soil.  You can extend the
technique for a buried spot as well.  You can do the same thing for a
railroad tie.

You can also cut cores, and have them analyzed, using a statistical
approach.

I like common sense and professional judgement, the problem is that some one
else always has a different judgement or a better idea.

  you wrote

Trying to locate guidance documents, procedures, regs, notices, site 
  positions pertaining to monitoring and release of porous materials, such
as 
  wood, and items with inaccessible surfaces, such as railroad ties with
deep 
  cracks.  The DOE RADCON Manual uses language such as "disassemble to the 
  extent required to perform an adequate survey" and similar language can be

  found in other documents.  Have you established a percentage of the limit,

  e.g., 25%, that you use to separate questionable items from others?  Of 
  course, one can never rule out the most important aspects of a survey - 
  history of the item, common sense, and professional judgement. 
************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html