Re: Industrial Radiography Accidents

[Ted de Castro <tdc@XRAYTED.COM>]

You are of course right and this is of course a very good idea!  Even I

thought of it - so it MUST be good!!! <grin>



BUT - what you will hear back from the field is that this equipment is

usually un powered!  Made to be used in ANY field conditions.  Also -

the equipment is treated VERY badly - thus why sources so often stick in

the guide tubes (kind of like portable x-ray machines are treated in

hospitals!).



There is a great resistance to change in the industry!  For the very

occasional need for flexibility of free operation - they want the

cameras ALWAYS unencumbered by any sort of safety "accessories".  IF

they were put on - they would be quickly be "accidentally" broken off.



I am on the ANSI writing committee for the OPERATIONAL standard for

industrial radiography and it is VERY frustrating.  The controls are ALL

administrative because the equipment is SO primitive!



Realize - if a phosphor were put in the shield right up next the the

parked source and the light were light piped out through twists and

turns in the shield - there would be enough light for a very clear and

non powered (or self powered if you will) indication that the source was

indeed parked.



Even that would meet with resistance.



Like I said - its frustrating.  I don't even bother to offer suggestions

any more!



I'm glad we don't do that here - and seldom have radiographers in.



I think the solution MAY be in making some regulatory tradeoffs -

instead of the "pile it on" method currently used.



For instance.  For standard equipment - shorter license periods, more

inspections, more record keeping, more training and more often.  BUT -

IF they have an indication device such as you suggest - or the phosphor

method I mentioned - BACK OFF on the above.



Unfortunately in today's regulatory atmosphere - the rules put in place

by lawyers stay in force - no matter what more advanced and secure

methods you use.



I look at it this way:



Under current regs an operation using ONLY administrative controls is

permitted - while recognizing that engineered controls are better and

suggested.  THUS stating that administrative in lieu of engineered

control is acceptable.



YET - an operation with total engineered controls is NOT acceptable -

thus engineered controls in lieu of administrative controls is NOT

accepted.



So - why bother to spend the money on and suffer the limitations of

engineered controls!



"Richard, Mack L" wrote:

> 

> Radsafers:

> 

> First, please understand that I have limited knowledge/experience with

> industrial radiography.  I've seen the sources/shields (as I recall the

> radiographers referred to these as "cameras") and have a basic understanding

> of how they function.  With that disclaimer out of the way, I wonder if some

> modifications to these cameras might help prevent some of these overexposure

> problems.

> 

> It seems that in a number of overexposure cases I've read about, the

> radiographer fails to perform a radiation survey after the source has

> supposedly but unsuccessfully been retracted into the shield.  Whether the

> failure is forgetfulness, negligence, pending tee time, etc., the result is

> the same.  Someone stated that these devices have some type of indicator to

> advise the radiographer of the source position.  While not explicitly

> stated, I assume that to mean either a mechanical or electro-mechanical

> device (i.e., it doesn't actually measure radiation).

> 

> Here's a thought on a solution to this problem.  Would it not be possible to

> place some type of detector on the side of the shield where the source exits

> the shield that would be connected to a flashing light to indicate the

> presence of elevated levels of radiation?  One could even configure the

> "on-off" switch so that when the source guide tube is connected, it

> automatically turns the detector on (that prevents the radiographer from

> forgetting to turn on the detector).  Of course, a "threshold" level would

> have to be set to prevent the detector from activating the flashing light

> due to radiation shining through the shield.  Since this would have to be a

> battery powered detector, one would also like to see some type of audible or

> visual warning if the batteries are low.

> 

> Granted, as the source is extended away from the shield through the guide

> tube, the detector may quit flashing due to a reduction in radiation

> intensity.  Thus, if the source became detached in the guide tube at some

> distance from the shield, there would be no indication of a problem.

> However, the radiographer would know something was amiss if the light didn't

> begin flashing as he retracted the source back into the shield.  Given this

> drawback, such a device shouldn't replace the post irradiation survey.

> 

> This idea is similar to what we utilize when we perform "high dose rate

> (HDR)" brachytherapy.  HDR brachytherapy involves remotely threading a 10 Ci

> Ir-192 source through a catheter (thin plastic "guide" tube for you

> non-medical types) into a specific area of a patient's body (e.g., tumor).

> This is necessarily performed in a shielded room.  Although the HDR console

> indicates the status of the source position, we are required to have a

> separate monitoring system that monitors the radiation in the room to

> independently indicate the presence/absence of radiation in the room.  At

> the end of the treatment, we perform a survey with a portable survey

> instrument before we take the patient out of the treatment room.

> 

> It seems that such a system might help to prevent these overexposures

> (unfortunately, nothing is 100%).  Perhaps such a system would be cost

> prohibitive or not compatible for the various camera configurations.  As I

> said, my knowledge of industrial radiography is limited and sometimes

> ignorance is bliss.  I won't be offended if someone comes up with a laundry

> list of reasons why this won't work.

> 

> Just my 2 cents worth (see, you may have gotten what you paid for).

> 

> Regards,

> Mack R.

> 

> Mack L. Richard, M.S., C.H.P.

> Radiation Safety Officer - IUPUI/Indiana Univ. Med. Cntr.

> Phone #: (317) 274-0330   Fax #: (317) 274-2332

> E-Mail Address:  mrichar@iupui.edu

> 

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