[ RadSafe ] NCRP Report 95

Charlie Simmons csimmons at athompsonlaw.com
Thu Sep 25 12:23:50 CDT 2008


While I agree that NUREG 1717 is a useful catalog of the commercial uses of "unimportant quantities" of uranium and thorium and other materials exempt from regulation under 10 CFR 40.13, the estimated doses arising from such uses should be approached with caution.  NRC has published the following disclaimer for NUREG 1717 on its web site http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1717/:

Subsequent to the publication of NUREG-1717, the zirconium industry provided additional data on particle size and occupancy times. They stated that facilities which handle and process zircon flours are rather dusty environments with a distribution of particle sizes which are typically 5 µm or greater. Although this was acknowledged in the text of the NUREG, the original calculations in NUREG-1717 were done using a particle size of 1µm (which is consistent with the ICRP recommendations on which 10 CFR Part 20 and Federal Guidance Report 11 are based) and occupancy times of 2000 hours, essentially full time. Increasing the particle size to 5 µm or higher decreases the dose and using a typical worker occupancy time of 20% would further decrease the dose. The NRC realizes that a typical average worker dose would be much lower than the worst case most conserative high dose presented in the NUREG. The agency will not use the results presented in NUREG-1717 as a sole basis for any regulatory decisions or future rulemaking without additional analysis.


Charlie Simmons

-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On Behalf Of Eric.Goldin at sce.com
Sent: Thursday, September 25, 2008 1:01 PM
To: Maury Siskel
Cc: radsafe at radlab.nl
Subject: Re: [ RadSafe ] NCRP Report 95

If you're interested in some of the more arcane uses of radioactive 
material, check out NUREG-1717, Systematic Radiological Assessment of 
Exemptions for Source and Byproduct Materials.  There are some really 
weird application of radioactive materials.  Uranium in dentures was only 
one.  Eric

Eric M. Goldin, CHP
<Eric.Goldin at sce.com>

Maury Siskel <maurysis at peoplepc.com> 
09/25/2008 09:24 AM

bill <iocbr at aol.com>
Eric.Goldin at sce.com, radsafe at radlab.nl
Re: [ RadSafe ] NCRP Report 95

Thanks for posting this interesting bit of background information. Was 
not previously aware of these practices.
Maury&Dog  (maurysis at peoplepc.com)

bill wrote:

>Eric,  Attached are pages 41 and 42 of NCRP Report 95.
>Sandi Nemecek
>Retired, Global Dosimetry Services
>-----Original Message-----
>From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On 
>Of Eric.Goldin at sce.com

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