Re: mrad readings

[Eli Port <port@northwestern.edu>]

Kevin:



The Health Physics Instruments Model 1010 is a portable instrument that 

measures absorbed dose in tissue equivalent material.  The chamber wall is 

greater than 7 mg/sq cm and it will not respond correctly to low energies 

betas or photons below 70 KeV.  Both beta dose and photon dose can be 

calculated from areal contamination survey data.  This may be preferable to 

direct measurement of dose.  Communicate with me privately if you wish to 

discuss this further.



Eli

++++++++++++++++

At 11:20 AM 2/3/04, KOSKOKD@AOL.COM wrote:

>Radsafers,

>

>I am working at an NRC licensed facility that references the Guidelines 

>for Decontamination of Facilities and Equipment Prior to Release for 

>Unrestricted Use or Termination of Licenses for Byproduct, Source, or 

>Special Nuclear Material (April 1993)in their License.

>My question is in regard to Table 1 of the referenced document. The 

>typical release limits are promulgated for maximum and average 

>contamination levels, however reference [f] (in fine print at the bottom) 

>states, " The average and maximum radiation levels associated with surface 

>contamination resulting from beta-gamma emitters should not exceed 0.2 

>mrad/hr at 1 cm and 1.0 mrad/hr at 1 cm, respectively, measured through 

>not more than 7 milligrams per square centimeter of total absorber".

>I am not aware of any portable instrumentation that meets the requirements 

>of this statement.

>I would be interested in methodology used by others to meet this 

>requirement. I am aware that certain conclusions could be drawn based on 

>surface contamination, isotopic energies and relative abundance and this 

>is only a "guidance document". However, we are in a very strict verbatim 

>compliance work atmosphere where my customer expects direct measurements 

>that comply with the above referenced document. Due to the fact the April 

>1993 document is referenced in the License, it becomes by default, a 

>License requirement.

>Additionally, does anyone know why statement [f] is included in this 

>document and not in Reg Guide 1.86?

>

>Kevin D. Kosko RRPT

>President

>K2 Environmental Services LLC.

>Phone:(937) 470-2655

>Fax: (937) 743-1036

>e-mail:KOSKOKD@aol.com

>************************************************************************

>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/