Re: Pipes & ducts, surveys of

[Daniel Montgomery <danmon@mindspring.com>]

At 02:50 PM 8/11/95 -0500, you wrote:
>>Whew, its been a long week. But, its Friday!
>>
>>Esteemed Radsafers, a few questions regarding surveys of the
>>interiors, not exterior, of pipes and ducts:
>>
>>1. What instruments, commercially available or otherwise, have you
>>used? Any comments, good or bad?
>>
>>2. If it was done quantitatively, how did you determine the
>>efficiencies?
>>
>>3. Any general thoughts on this subject e.g. problems, good
>>references etc?
>>
>>Thanks
>>
>>Paul Frame
>>
>
>We've done alot of duct remediation at RFETS, but I'm not sure if we ever
>performed surveys internally. I know that I was consulted regarding detector
>types for that purpose, but don't recall any feedback. As I recall the
>detectors were to be mounted on a pipe crawler (robot). I'll check into it
>and get back to you. It would help to know what you are trying to detect. We
>were hunting for alpha emitters.
>
>I do know that our D&D technology group developed some nifty pipe crawlers,
>including the 'robohemien' which was able to shift it's center of gravity
>such that it was able to climb over the butterfly-valve seats in the ductwork
>while still fitting between the seat and gate of an 8" butterfly-valve. We
>showed video of it at the SRS ALARA week a couple years ago.
>
>
>>Bonus question. Does anyone know anything about a navy(?)
>>radiation(?) symbol that takes the form of a trident with a wavy line
>>(gamma ray?) heading off at right angles from one of the prongs?
>>
>
>This sounds alot like the Navy rating symbol for an Ocean Systems Technician.
>I believe the "wavy line" represented a sound wave traveling through the water.
>Basically they were 'ocean snoopers'.
>
>Gary Masters
>gmasters@csn.net
>
>
>Our company, Analytics Inc., has made numerous radionuclide standard
sources for calibrating instruments used for checking contamination levels
of gamma-ray emitters in piping.  The source are rectangular planar sources
with one side equal to the inside circumference of the pipe and the other
side adjusted depending on the field of view of the instrument used.  These
sources can then be inserted in a pipe of the same dimensions to be
monitored and measured with the instrument of choice to determine the
detection efficiency. The radionuclide(s) can be specified depending on
expected contamination.  The sources can also be made at activities
corresponding to or slightly greater that required sensitivity levels. This
allows you to demonstrate that required sensitivities are met.

If you desire more info, get in touch with me at danmon@mindspring.com

Dan Montgomery (Dr. Doom)