AW: [ RadSafe ] Orphan Radioactive Materials

[Franz Schönhofer]

Al,

Thank you for your post, which does not mention global warming, LNT, US
politics and the like, but poses a challenge to radiation protection
scientists!!!! I accept this challenge by putting my 2 Euro-cent of worth
(which equals approximately 2.601 US cents...) into the thread.

I have forwarded your request to the norm-tenorm group and to the list
moderator Phil Egidi from where you might receive helpful information.
William Kolb is a very knowledgable person on such devices and uses, but
unfortunately his e-mail address is no longer in my address list, which
might be due to a recent hard-disk crash. He used to participate in RADSAFE,
so if he reads this message he might comment as well. (This my first
Euro-cent...)

Without going to much into detail I wonder about several of your data:

I do not know the instrument you used, but you obviously described some kind
of beta-measurements. However I do not know, what "window open" and "window
closed" implies - does it refer to an absorber? If "yes", what kind of, what
thickness? The mrem/h are even when recalculated to the world-wide used
mSv/h almost frightening. Remember that the EU has a value of 0.1 mSv/y
(yes, per year!) as a maximum dose rate due to ingestion of drinking water.
More suspicious is the mentioning of an activity concentration of Ra-226 -
you cannot measure this by some beta-measurements. 

My advice to the company involved and especially the authorities would be to
consult a good laboratory, which can identify the radionuclide(s) involved,
both by gamma-spectrometry (which would identify Co-60 in seconds) and
radiochemical analysis. I know a lot of substances which might be present as
NORM, but I do not expect that any of them would give these readings.
Fortunately for us radioanalytics it is not possible to determine the nature
of a radiation source by looking at it.   

I forward to the norm-tenorm group and Phil the pictures of the items
separately. 

This was my second Euro-cents worth.

Best regards.

Franz
 

Franz Schoenhofer, PhD
MinRat i.R.
Habicherg. 31/7
A-1160 Wien/Vienna
AUSTRIA


-----Ursprüngliche Nachricht-----
Von: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] Im Auftrag
von Conklin, Al (DOH)
Gesendet: Freitag, 09. Februar 2007 16:02
An: radsafe at radlab.nl
Cc: Dix, Victoria (DOH)
Betreff: [ RadSafe ] Orphan Radioactive Materials


> Our Radioactive Materials inspectors found some items at a local metal
> recycling facility that they would like help with identifying. If
> anyone could offer some suggestions, please contact me offline, and
> I'll forward it to them. Thanks for the help.
> 
> Their request:
> 
> Does anyone have any ideas where large layers of asbestos & pressboard
> & heavy metal & acoustical tiles would be sandwiched together, that
> would have radioactive sources inside the layers?
> 
> These are photos of some unknown orphan RAM sources that recently
> appeared at a local metal recycling facility.  Any help in identifying
> these sources, or in identifying where these building materials could
> be used is appreciated.
> 
> ~ black coiled plastic wire? (at close to surface (not contact) on
> Eberline RO-2, ~ 80 millirem / hr beta window open, ~ 40 millirem / hr
> beta window closed, background ~ / < 0.2 millirem / hr); activity ~ 40
> microcuries radium-226.
> 
> ~ large piece of red/brown wood & insulation? board, source
> inaccessible inside at approximately center (at close to surface (not
> contact) on Eberline RO-2, ~ 0.4 millirem / hr beta window open, ~ 0.2
> millirem / hr beta window closed, background ~ / < 0.2 millirem / hr);
> activity ~ 5 microcuries radium-226.
> 
> ~ large folded steel plate & sieve? screen, source inaccessible in
> plate folds (at close to surface (not contact) on Eberline RO-2, ~ 0.6
> millirem / hr beta window open, < 0.4 millirem / hr beta window
> closed, background ~ / < 0.2 millirem / hr); activity ~ 1 microcurie
> radium-226.
> 
> ~ hook & 4 markers & small metal cylinder all on one cable (at close
> to surface (not contact) on Eberline RO-2, ~ 3 millirem / hr beta
> window open, ~ 0.6 millirem / hr beta window closed, background ~ / <
> 0.2 millirem / hr); activity ~ 4 microcuries radium-226.
> 
> 
>  <<orphans f.JPG>>  <<orphans a.JPG>>  <<orphans b.JPG>>  <<orphans
> c.JPG>>  <<orphans d.JPG>>  <<orphans e.JPG>> 
> 
> 
> Also, we found this on the Radsafe web site.  Does this ring any bells
> re possible use for radium?
> 
> >Cobalt-60 is used as a wear detector in blast furnace applications.
> Small Co-60 sources are embeded in the firebrick furnace lining at a
> known distance from the hotface. These are readily detectable from the
> outside of the furnace. When the liner has worn to a certain point the
> source disappears into the melt and is no longer detectable from the
> outside. A typical furnace might have 50 sources in the 1-5 mCi range
> embeded at various distances from the hotface, and a quick survey will
> tell you whether they're still in place or not. This technology has
> been used since the isotope became available for industrial
> applications, at least since the '50s.
> >  
> >
> http://lists.radlab.nl/pipermail/radsafe/2006-June/003406.html
> 
> Any help is appreciated.  Thanks for your time.
>