[ RadSafe ] " Technology to detect radiation has progressed "

Jim Hardeman Jim_Hardeman at dnr.state.ga.us
Fri Aug 24 09:42:42 CDT 2007


Bob --
 
The problem you raise is even more fundamental than that. Many of these devices, even some gauges containing hundreds of mCi, are still generally licensed, requiring minimal paperwork or knowledge on the part of the user -- and thus they are more easily forgotten, fall into disuse and get discarded. And yes, in the midst of all the NORM-contaminated scrap metal incidents that we respond to, we do turn up the occasional gauge -- often enough to warrant the steel industry's concern and ours as well.
 
I wish I had a nickel for every thickness gauge that had been painted over so that the radiation label was no longer visible ... <sigh>
 
Jim

>>> "Robert D Gallagher" <rdgallagher at nssihouston.com> 8/24/2007 07:46 >>>
The real problem is that there are thousands of gauge devices that have been
installed at manufacturing plants and have been in place for years. The
plants were sold this equipment by companies that aided the plant management
in obtaining licensure or who arranged to have their devices generally
licensed. Over the years of use, the job of leak testing fell to the safety
group that had other important jobs to do. As the plant aged, the
responsible safety guy retired, a more profitable plant was built in some
low labor cost country, and the plant closed. Another 10 years passes and
the manufacturer decides to build a new plant. IF, someone happens to note a
radiation label or IF, there is a license, MAYBE someone arranges for the
gauge units to be disposed. For this type of licensee, inspections may be on
a 3 or 5 year frequency IF the agency doesn't have some other crisis to
respond to.

What is lacking is a self flagging record at the regulatory agency and at
the manufacturing plant. People are very mobile these days and radiation
gauges in a plant are just another piece of equipment that has to be leak
tested every 6 months or every 3 years.

NSSI receives probably 1-2 calls each week relative to radioactivity in
scrap metal or oil field tubulars. Within the last 6 months, we have been
involved with at least two major source contamination projects.

There is a need for awareness and all of mobile personnel radiation devices
are focusing knowledgable persons on how extensive the problem is.

We have metal detectors in every travel site we pass through and every
public building we enter and while we don't like the delays these units
involve, we see the need. I feel sure these same devices may have or soon
will have radiation sensors contained.

The ball park incident is just the leading edge of big brothers nose.

Bob Gallagher
NSSI
713 641-0391

-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl]On 
Behalf Of Jim Hardeman
Sent: Friday, August 24, 2007 5:54 AM
To: RADSAFE Mailing List
Subject: Re: [ RadSafe ] " Technology to detect radiation has progressed
"


Steven --

Good point. Even the best gamma spectroscopy algorithm is going to make an
erroneous identification, and if the user has only enough training to
blindly assume that the nuclide ID is correct, you can get yourself into a
world of trouble. As an example, we were evaluating one of the new (I'm not
going to use any brand names) rad-pager / nuclide ID combination units a
while back -- in addition to the standard NaI probe used to DETECT elevated
radiation, the unit also uses a small CZT detector to IDENTIFY the
radionuclide(s) present.

One of my standard acceptance tests is to look at a red / orange FiestaWare
platter -- makes a great check source w/ a contact radiation level of ~50
uR/hr. I placed this unit on top of the platter and set it to count -- it
took 10 minutes to acquire a spectrum (vs. 1 for more of the handheld units
we use) and then only identified U-235 -- where most other units I've used
would either return U-Nat or both U-238 and U-235 in roughly the correct
proportions w/ a 1-minute count.

This instrument is being marketed to law enforcement folks -- folks who
would normally wear only a rad pager, and then would have to call someone
else to back them up w/ nuclide identification. I'm not sure, however, that
at slightly elevated radiation levels even the most qualified gamma
spectroscopist could make an accurate assessment. The only thing preventing
these things from hanging on every street cop is the COST. I shudder to
think what would happen should a similar mis-identification occur in the
field ...

What hasn't been said yet in this chain is how these nuisance radiation
alarms affect state radiation control programs. In most states, the state
radiation control program is responsible for investigating findings of
elevated radiation in the environment -- whether it's a trash truck at the
gate of a landfill, a load of scrap metal that set off the detector at a
steel mill, or (if we ever find out about it) a hit during a security sweep.
Radiation is one of those things where "the more you look, the more you're
going to find" -- and if you have a small, static group of folks equipped
and trained to go in after detection to assess what you've actually
detected -- and then you increase detection capability w/o also increasing
the capability to assess and identify, you're going to run those folks
ragged "chasing gnats" -- not that I would know anything about that <sigh>

Of course, all this is my $0.02 only ...

Jim Hardeman
Jim_Hardeman at dnr.state.ga.us 

>>> Steven Dapra <sjd at swcp.com> 8/23/2007 21:17 >>>
Aug. 23


At 09:12 AM 8/23/07 -0500, Geo>K0FF wrote:

>----- Original Message ----- From: <nssihou at aol.com>
>To: <idias at interchange.ubc.ca>; <neildm at id.doe.gov>; <sjd at swcp.com>;
><brent.rogers at ansto.gov.au>; <radsafe at radlab.nl>
>Sent: Thursday, August 23, 2007 6:17 AM
>Subject: Re: [ RadSafe ] " Technology to detect radiation has progressed "
>
>>
>>Most scrap yards now have radiation monitors and check metal as it enters
>>the site. Unfortunately, the radioactive material is not always seen if
>>shielded by a lot of other steel scarp. Texas has had several source?
>>melts over the last few years. Before radiation monitors, I'm sure lots
>>of radioactive incidents went undetected.

[edit]

>>The bigger problem is that we have larger and larger numbers of radiation
>>monitoring devices and fewer and fewer qualified persons operating them.
>
>**(Geo) Correct, this is part of a learning curve issue, and will be
>addressed by smarter equipment, not by better trained personnel. And so it
>goes.
>Check Radsafe Archives for comment by J. Marshall Reber on this subject.

         Smarter equipment can not take the place of better trained
operators.  Operators are needed who can interpret what they see (detect)
and --- we hope --- apply some reasoning power to it.  Arbitrarily relying
on equipment may cause more problems than it will solve.  Can a machine
tell when it has a false positive?  Can it distinguish between NORM and the
dreaded "dirty bomb"?  What happens when a car carrying a cancer patient
who has undergone rad therapy goes past the detector?  (That's how this
thread got started.  Remember?)

Steven Dapra
sjd at swcp.com 


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