Re: When does "rem" no longer apply? -Reply -Reply

[FRAMEP@ORAU.GOV]

Bob Flood wrote in part

>However, there is a precedent in the way doses are reported by NIST
>and DOE
>for accrediting dosimetry programs. The protection range doses are
>shown in
>the test reports as rem for values up to 10, and the accident range data
>are reported as 10-500 rad. 

One problem  with this is that there are all sorts of precedents. For
example,   in 10 CFR 835 (and we are talking regulations here, not
dosimetry accreditation protocols)  DOE indicates that dose guidelines
greater than 25 rems (not rads) might be acceptable in emergency
situations. NCRP 39, the ancestor of NRCP 116, actually listed values of
100 rem whole body and 300 rems to the arms as emergency response
guidelines

Another issue that no number of precedents will solve is the issue of
dose rate.  Is the sum of ten separate 10 rem exposures 100 rad or 100
rem if they are  taken 1 second apart, one minute apart, one hour apart,
one day apart, one month apart and one year apart.

There is no clear answer.  The dose equivalent is a quantity conceived
for the purpose of radiation protection. It is an administrative concept
subject to the whims of the regulatory agencies (or anyone else for that
matter). Unlike every other quantity in the SI system with which I am
familiar, It has no physical basis.

Paul Frame
Professional Training Programs
ORISE
framep@orau.gov