Re: Emergency Doses Allowed -Reply

[MICHAEL S FORD <MFORD@pantex.com>]

I hate to muddy the waters, but since Scott brought up Protective
Action Guides (for public exposures), I will point out that they refer
to both internal and external exposures:

"The EPA PAGs are intended to apply only to projected doses from
exposures from an airborne release of radioactive materials during
the early phase of an accident.  The pathways considered include
external gamma and beta dose from direct exposure to airborne
materials and from deposited material and the committed dose to
internal organs from inhalation of radioactive material."  (local
document)

I also came across the following letter at 

http://www.nrc.gov/ACRS/rrs1/Trans_Let/index_top/ACRS_letters/3191225

Honorable Lando W. Zech, Jr.
Chairman
U.S. Nuclear Regulatory Commission
Washington, D.C.  20555

Dear Mr. Zech:

SUBJECT:  PROTECTIVE ACTION GUIDES FOR NUCLEAR
EMERGENCY PLANNING

Included among the factors used by the NRC Staff in its evaluation
of the required sizes of the Emergency Planning Zones around
nuclear power plants are the Protective Action Guides (PAGs)
recommended by the U.S. Environmental Protection Agency (EPA).

During the time period since these guides were prepared, the
concept of the effective dose equivalent has been developed by the
International Commission on Radiological Protection, and
substantial changes have been made in the thyroid dose
considered to be equivalent to a given dose to the whole body.  
For these reasons, we believe that an updating of these guides
would be useful.  We understand that EPA is working on such an
updating as part of its preparation of a broader set of PAGs.  We
suggest that the NRC encourage the EPA to proceed with the
development of the new Guides in a timely manner and that the
results be made available promptly for use in emergency planning 
evaluations.
  
                                    Sincerely,

                                    David A. Ward
                                    Chairman

(Sorry, no date.)

My point is that it is difficult to understand how "Emergency
Exposure" limits would apply to only external exposures while
PAGS are expressed in TEDE, conceivably for the same event. 
Perhaps EPA could chime in here and clear this whole thing up.
Eh?

'Sorry to further confuse things.....
Michael
*************************
Michael S. Ford, CHP
Texas Radiation Advisory Board
Address:
Radiation Safety Department
Battelle Pantex
Amarillo, TX
806.477.5727 phone
806.477.4198 fax
mford@pantex.com
*************************