Re: Cs-137 event

[Doug Aitken <daitken@sugar-land.oilfield.slb.com>]

I'm going to leave this topic, as I am also a 3rd party not in possession 

of all the facts. I am unwilling to speculate on the dose received by the 

individual, the correctness of any initial dose estimates. I already 

clarified that the source was partially shielded and that would appear to 

me to be an "extenuating circumstance"



I would certainly agree with your statement that a biologically significant 

dose would warrant medical follow-up. I just believe, in this case, that 

this is not the case. Also, in every radiation incident of this kind, 

training and conformance to standard procedures is always an area that is 

subject to scrutiny during the investigation process. I feel confident that 

the company involved and the California regulators will complete their 

investigation in a responsible fashion and I think it is best to review the 

final reports for further details of this incident.



For Sid's benefit: the company involved was stated in the original post.



Again, these opinions are my own, and are not official comments of the 

company involved in this incident.



Regards



Doug



At 10:41 AM 1/21/2004 -0500, William V Lipton wrote:

>Thanx for clarifying the source geometry questions.  BTW, I don't have a 

>hypothesis on this.

>

>I like to evaluate incident reports to derive lessons learned.  (There are 

>2 ways of learning:  1.  the easy way - It happens to someone 

>else.  2.  the hard way - It happens to me.  I try to learn as much as 

>possible the easy way.)  I can only derive lessons learned if the report 

>makes sense.

>

>Is your lack of response on the issue of whole body distance an indication 

>that you agree that 2.5 feet is unreasonable?

>

>I have to take issue with your statement, " To make estimates of dose and 

>suggest that medical follow-up is required, without knowing all the facts, 

>is somewhat akin to the scare-mongering on dirty bombs recently discussed 

>on this forum."

>

>1.  I am not performing a dose estimate, only doing a sanity check on the 

>one presented in the incident report.  To touch a 1.3 Ci Cs-137 source and 

>pick up only 20 mR extremity dose is not credible unless there are 

>extenuating circumstances.  The licensee should either revise the dose 

>estimate or explain those circumstances.

>

>2.  Medical followup is definitely indicated in a situation where there is 

>the potential for a biologically significant dose, especially since the 

>dose estimate seems to depend entirely on statements from the worker and 

>his coworkers. (It's  odd that  no dosimetry results seem to be 

>available.  As a minimum, the workers should have had whole body 

>dosimetry, including secondary dosimetry which would have given an 

>immediate dose reading.  It would be easy to calculate the forearm dose 

>from the dose at the dosimeter location. This illustrates a basic 

>principle of incident investigations:  "One peek is worth 1000 

>finesses.")  If you consider good health physics practices to be "scare 

>mongering," we'll just have to agree to disagree.

>

>There are also the issue of whether the workers were properly trained.

>

>The opinions expressed are strictly mine.

>It's not about dose, it's about trust.

>Curies forever.



Khiem Aitken			Phone (home)	(713) 797-1757

The Spires #2304		Phone (cell)	(712) 503-5663

2001 Holcombe Blvd

Houston, TX 77030



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