[ RadSafe ] > 300 mrems/month = "no significant exposure"?

William Lipton doctorbill34 at gmail.com
Mon Sep 9 11:49:08 CDT 2013

I'm concerned about this NRC event report from a radiography provider:


The RSO for the licensee called to report a potential overexposure of a
radiographer. This event occurred while the radiographer was checking welds
at a refinery in Wyoming. While moving the camera to another location, the
radiographer's dosimeter alarmed. It is suspected that the camera's source
was not fully retracted into the safe position. The source was subsequently
retracted back into the fully shielded position.

The RSO calculates an estimated dose to the radiographer of 5 rem. The
licensee will send the radiographer's dosimetry for expedited reading as
soon as possible.

The licensee will update this report with additional details as they become


The RSO has received the radiographer's dosimetry badge readings. The
radiographer was still wearing his August dosimetry when the event
occurred. His badge readings was 328 mrem for the entire month of August
including the exposure from this event.

Since there was no significant exposure from the event, the licensee has
retracted this event notification. *
While I'm glad that there was no overexposure, there are 2 important issues
that need to be addressed:

1.  Why did the source fail to retract:  mechanical failure?, less than
adequate training?  under time pressure? ...  This has to be determined and

2.  328 mrems in one month is considered routine and acceptable.  This
means that it's acceptable for the company's radiographers  to receive 3 -
5 rems/year.  This is NOT "As Low As Reasonably Achievable."  Again, the
NRC has a double standard.  Power reactors have a de facto limit of 1
rem/year for a rad worker.  My experience is that this is rarely
approached, and this is under much more difficult circumstances than found
in most radiography jobs.

*B*ill Lipton
It's not about dose, it's about trust.

More information about the RadSafe mailing list