[ RadSafe ] SCBA and beta dose connection?

Tue Apr 17 14:06:30 CDT 2012

John Rich,

An SCBA face piece has a density thickness of 332.6 mg/cm2 (in most cases). This is quite effective for most beta particles encountered in the nuclear industry. When dealing with higher energies (such as Y-90 ; 2.28 Mev beta), the shield thickness becomes less effective. If you consider the lens of the eye, then the effective density thickness for the "face" of an emergency responder in SCBA protective gear would be 632.6 mg/cm2 when considering the lens of the eye. 

I am sure there are named studies out there which cover this dosimetry topic. Ground breaking studies were done during the TMI response. Beta protection for the skin was pioneered out there. That's where health physicists came up with wearing Navy steam suits for beta protection. Perhaps this could be found if you Google it?

Regards, 

John E. Dixon, CHP
Centers for Disease Control and Prevention
4770 Buford Highway, Chamblee Campus,, Bldg 106
Mail Stop F-58
Atlanta, GA 30341

Office: 770-488-1554
Cell: 404-406-7378

e-mail: GYF7 at cdc.gov

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Perle, Sandy
Sent: Friday, April 13, 2012 10:29 AM
To: The International Radiation Protection (Health Physics) Mailing List
Subject: Re: [ RadSafe ] SCBA and beta dose connection?

Rob, yes, a facility can take credit for any shielding over the eye. We have clients that we provide for the correction based o9n their evaluation and input, or, the facility applies the factor after they receive their dose report and/or electronic file and make the adjustment on their system, using the data we provide. This is perfectly acceptable. Not different than a medical professional wearing a leaded apron. The dose assigned can come from an actual dosimeter reading or applied by the facility to the un-attenuated dose reported.

Regards,

Sandy

-----------------------------------
Sander C. Perle
President
Mirion Technologies
Dosimetry Services Division
2652 McGaw Avenue
Irvine, CA 92614

+1 (949) 296-2306 (Office)
+1 (949) 296-1130 (Fax)

Mirion Technologies: http://www.mirion.com/ "Protecting people, property and the environment"

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Robert J Gunter
Sent: Friday, April 13, 2012 7:24 AM
To: 'The International Radiation Protection (Health Physics) Mailing List'
Subject: Re: [ RadSafe ] SCBA and beta dose connection?

Dose to the lens of the eye is measured at 300 mg/cm^2, so if there is shielding, you may be able to account for its effect on lens of the eye dose, expecially if you have a study to back up your reasoning.  I don't know if Lens dose is limiting in your situation but if so, you may be able to extend your times by accounting for shielding.

Robert J. Gunter, MSc, CHP
CHP Consultants/CHP Dosimetry
www.chpconsultants.com
www.chpdosimetry.com
Toll Free: (888) 766-4833
Fax:  (866) 491-9913
Cel:  (865) 387-0028
rjgunter at chpconsultants.com

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of JOHN.RICH at sargentlundy.com
Sent: Thursday, April 12, 2012 3:12 PM
To: radsafe at health.phys.iit.edu
Subject: [ RadSafe ] SCBA and beta dose connection?

I have a document in front of me that states, " IF SCBAs are used, the beta dose rates may be neglected."  The context is in a post -accident mission dose determination where the effect of SCBAs is discussed. I'll admit my ignorance on this one.  Does anybody know where this came from or what would support it?

thx in advance  - -jmr

John Rich
312-269-3768
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