Re: Emergency Doses Allowed

["Sorensen, Scott" <ssorensen@doeal.gov>]

Greetings,

Regarding the use of TEDE for emergency dose guidelines...  It's
interesting to keep in mind what the 25 rem emergency dose guideline was
based on.  My guess is that the 25 rem level was selected to prevent the
observation of deterministic effects (i.e., one of the basic principles
of radiation protection) from prompt, whole-body irradiation.  A 25 rem
TEDE exposure from a plutonium intake (or any radionuclide delivering
long-term, organ-specific irradiation) would almost certainly not result
in a detectable deterministic effect.  

Using the ICRP 60 guideline of a 50 rem/y  (over successive years)
deterministic effects threshold for internal organs, the dose
potentially causing a deterministic effect from a plutonium intake could
be on the order of 200 rem TEDE.  With this perspective, stating
emergency dose guidelines (or Protective Action Guidelines for that
matter) in terms of TEDE results in apples being compared with
oranges...  Considering the rarity of events requiring their use, maybe
it would be better to express emergency guidelines (or PAGs) in terms of
equivalent dose?

-Scott Sorensen
ssorensen@doeal.gov