Specific Activity Exemption in U.S. NRC Transport Regulations

["Leo M. Lowe" <llowe@senes.ca>]

Hello,



This question may have been asked previously on Radsafe, but I can't find 

the answer right now.



In the U.S., radioactive materials are exempt from the present transport 

regulations when they have a specific activity not greater than 70 Bq/g 

(0.002 uCi/g). (The regs are in the process of being updated to the most 

recent IAEA regulations.)  When estimating the specific activity of natural 

uranium or thorium-bearing materials, do all the radionuclides (14 in U-238 

series, 10 in Th-232 series) need to be considered?  Where is this defined 

in the regulations?  The definition of "specific activity" in the 

regulations would seem to indicate that all radionuclides are considered.



The reason I ask this is that there are some cases in the IAEA regulations 

where radionuclides with half-lives less than 10 days are not specifically 

counted i.e. the daughters and the parent are considered as one 

radionuclide in terms of radioactivity.  Where is this specified in the 

U.S. regulations?



Regards,

Leo M. Lowe, Ph.D.



SENES Consultants Limited

llowe@senes.ca

www.senes.ca

Tel: (905) 764-9380

Fax:(905) 764-9386



This transmission is intended only for the addressee and may contain 

PRIVILEGED or CONFIDENTIAL information.  Any unauthorized disclosure, use 

or retention is strictly prohibited.  SENES does not accept liability for 

any errors, omissions, corruption or virus in contents or 

attachments.  Information is provided for use "as is" by the 

addressee.  Revised documents must not be represented as SENES work 

product, without express, written permission of a SENES Director.





************************************************************************

You are currently subscribed to the Radsafe mailing list. To unsubscribe,

send an e-mail to Majordomo@list.vanderbilt.edu  Put the text "unsubscribe

radsafe" (no quote marks) in the body of the e-mail, with no subject line.

You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/