Re: Emergency Doses Allowed

[David W Lee <lee_david_w@lanl.gov>]

Rey:

	As long as Steve Hand has reopened this issue of dose guidelines for
"emergency situations," you may recall that about a year ago, Joyce Davis
of the DOE Defense Board posted a message to RADSAFE wherein she
essentially asked if the emergency dose guidelines included internal as
well as external dose.  I don't have a copy of her original post in front
of me, but as I recall, her rationale was something like this:

	(1)  Prior to 1991, when the NRC adopted ICRP 26/30 methodology, the
occupational dose limits were dose limits for EXTERNAL radiation only.  Any
internal dose was considered separately; pre-1991 10 CFR 20 did not track
CEDE and TEDE.  Under the pre-1991 10 CFR 20 dose accountability/limit
regime, any doses sustained in any sort of emergency clearly were numerical
limits that pertained to EXTERNAL whole-body (WB) radiation only.  Thus,
whatever the doses were that were recommended as "guidelines" or specified
as "limits" were whole-body doses incurred as a result of external ionizing
radiation exposure.

	(2) Post 1991 10 CFR 20, however, included any internal CEDE with any
external effective dose equivalent (DE) under the total allowed dose
limits, i.e., CEDE + effective DE external = TEDE.  But it does not appear
that the NRC clearly indicated whether the doses permitted for planned
special exposures were TEDE doses or just WB external doses as before
(pre-1991 10 CFR 20).

	(3)  As I recall, Joyce pointed out that IF the dose limit recommended for
an "accident" or some sort of "emergency" includes the internal dose, i.e.,
CEDE, then for long-lived radionuclides, e.g., Pu-239, it just takes little
more than atom amounts of such nuclides to impart a CEDE of 25 rem, 50 rem,
etc., and that the accidental intake of such a few number of atoms
basically can happen at some nuclear facilities that routinely handle
long-lived alpha emitters at a frequency that many would consider to be far
higher than just a once in a blue moon "accident/emergency."  Therefore,
paraphrasing her statements, if the 10 CFR 20 emergency dose guidelines and
similar 10 CFR 835.1302 guidelines are TEDE doses rather than just external
effective DE doses, then we as a Radiation Safety community need to come up
with a much higher, more realistic CEDE dose guideline for "emergency"
situations, particularly in the case of long-lived alpha emitters.

	So perhaps having crudely paraphrased Joyce's original message of about a
year ago, what is your interpretation of the emergency exposure dose limits
specified in 10 CFR 835-1302?  Are the dose limits ranging from 5 to
greater than 25 rem for "emergency exposure situations" TEDE limits or mere
external WB limits?  It seems to me that these dose limits are external
limits/guidelines, but I can't seem to find anything in the text of 10 CFR
835 that clearly says so.

	Perhaps many RADSAFERS replied to Joyce's original post of a year ago to
her private e-mail address, but I don't recall any RADSAFER ever offering a
response back to her over the RADSAFE net such that we all could read it.

Best regards  David 




At 04:15 PM 6/3/1998 -0500, you wrote:
>Steve, et. al.
>
>The U.S. Department of Energy currently has dose guidelines for 
>accidents and emergencies in the regulations (10 CFR 835.1302)  The dose 
>limits run from 5 rem for all emergencies to >25 rem for lifesaving of 
>large populations.  25 rem is the dose limit for "lifesaving or 
>protection of large populations."  There are other caveates too numerous 
>to mention here.
>
>58 FR 65483 makes it very clear that these values are only guidelines 
>and they have been removed from the proposed revision to 10 CFR 835 --- 
>I'm not exactly sure why.
>
>
>Rey Bocanegra
>Sr Tech Advisor on Rad protection
>DOE
>
>Don't usually add disclaimers to what I say, but .....
>The facts I mentioned above are not mine ... just the facts.
>
>>From server@romulus.ehs.uiuc.edu Wed Jun  3 12:34:31 1998
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>>Date: Wed, 3 Jun 1998 14:35:25 -0500 (CDT)
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>>From: steve hand <hand@wam.umd.edu>
>>To: Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
>>Subject: Emergency Doses Allowed
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>>Dear Radsafers:
>>
>>    Please advise on the limits allowed in an emergency with references
>>to literature if possible.  I have NCRP REPORT No. 91 and 116.  In 116
>>chapter 14 page 44 says
>>"for life saving or equivalent purposes the equivalent dose may 
>approach
>>or exceed 0.5 Sv to a large portion of the body in a short time.."  The
>>highest limit I can find in 10 CFR 20 for allowed doses is .25 Sv or 5
>>times the annual for a planned special exposure.
>>
>>1.    In the case of an emergency that is life threatening to an
>>individual, can someone get up to .5 Sv to try and save them, or up to
>>.25 Sv to try and save them ?
>>
>>2.   Rather than use one person in question 1 above, should several
>>people be used for a total of .5 or .25 Sv for life saving?  I seem to
>>remember reading something about not spreading the dose out anymore to
>>several individuals.
>>
>> Thanks
>>
>>
>>steve hand
>>university of maryland
>>radiation safety
>>hand@wam.umd.edu
>>
>>
>>
>
>
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DAVID W. LEE
Los Alamos National Laboratory
PO Box 1663, MS K483
Los Alamos, NM  87545
PH:  (505) 667-8085
FAX: (505) 667-9726
lee_david_w@lanl.gov