Re: I-125

[steven t hand <hand@wam.umd.edu>]

If you have a copy of Reg Guide 8.23 January 1981 Radiation Safety
Surveys at Medical Institutions there is a table, Table 3, for 
Acceptable Surface Contamination levels for uncontrolled release of
equipment.  I-125, Th-228 and a few others are listed at 300 dpm/cmxcm.

If you would like a fax copy please email me at shand@wam.umd.edu.  This
table references Reg Guide 1.86 Termination of Operating Licences for
Nuclear Reactors June 1974.  I do not have a copy of this guide.

I hope this helps.  If not then at least this piece of information can
be dismissed from your search.

steve at umcp
shand@wam.umd.edu

On Wed, 29 Jan 1997, David W Lee wrote:

> At 07:30 PM 28-01-97 -0600, you wrote:
> >     On 1/28/97 Larry R. Sanders wrote, in part:
> >      
> >     >Can anyone tell me where the 300 dpm limit for releasing of I-125 
> >     >contaminated material came from, or the basis for this limit? It 
> >     seems I-125 and I-129 require the same release limit as Ra-226, 
> >     >Ra-228, Th-230, Th-228, Pa231, and Ac-227. Other isotopes from Iodine 
> >     >have a significantly higher release limit.  
> >          
> >     
> >     Larry, you've opened up an old can of worms with this one.  Every 
> >     release limit table I've ever seen, from USNRC, USDOE, or agreement 
> >     state, has the same limit for I-125.  Yet no one seems to know why.
> >     
> >     Carl Bergsagel
> >     Fred Hutchinson Cancer Research Center
> >     cbergsag@fhcrc.org
> >     
> >     
> >     
> > I second Carl's remarks and credit Larry for asking about the technical
> basis of the release limit for I-125.  I also would sincerely appreciate any
> Radsafer trying to answer this question.  Within the DOE, Table 2-2 of the
> DOE Radiological Control Manual (RCM), in terms of removable/total/fixed
> contamination release limits lumps transuranics and the nuclides specified
> by Larry above under the SAME release limit.  Also, I-126,  I-131, I-133
> have the same release limit as natural Th, Th-232, Sr-90, Ra-223/224, U-232.
> Even though I am supposed to be an HP who ought to be capable of explaining
> such things, I have never been able to intuitively understand why the
> release limits for radioiodines (which decay via beta/EC and which typically
> are more volatile) have the same release limit as transuranics (alpha
> emitters).  What radiological and hazard characteristics do the radioiodines
> have in common with transuranics and other alpha emitters that logically
> merits assigning to them all the same release limit?  In the case of the
> DOE, the many problems that DOE HQ has had with the DOE RCM stem largely
> from that fact that DOE HQ never developed a 'technical basis' -type
> document for the RCM, itself, prior to publishing the RCM as holy writ.
> Thus DOE, itself, cannot even explain technically why it specified the
> release limits that it did.  Please help.  Thanks
> 
> As usual, just my opinion.  REGARDS  David
> 
>     
> >         
> >      
> >
> >
> David W. Lee
> Radiation Protection Policy
> & Programs Analysis Group (ESH-12)
> Los Alamos National Laboratory
> PO Box 1663, MS K483
> Los Alamos, NM  87545
> Ph:  (505) 667-8085
> FAX: (505) 667-9726
> 
>