.
+e MEN
ro Ey eowr
rere:
used. FRC states that the operational mechanism described
for application of criteria to limit the whole body dose for
individuals to 0.5 rer per year and to limit exposure of a
suitable sample of the population to 0.17 rem per year is
likely to assure that the gonadal exposure guide will not be
exceeded.
The child, infant, and unborn infant are identified as being more
sensitive to radiation than the adult. Exposures to be compared
with the guidance are to be derived for the most sensitive members
in the population. The guide for the individual applies when in-
dividual exposures are known; otherwise, the guide for a suitable
sample (one-third the guide for the individual) is to be used.
This operational technique may be modified to meet special
situations.
:
The FRC primary numerical guides, expressed in rem, are
provided in two reports, FRC Nos. 1] and 2, summarized in
Table 1 Secondary numerical guides developed by FRC are
expressed in terms of daily intake of specific radionuclides
corresponding to the annual RPG's. Consideration is given
to all radionuclides through all pathways to derive a total
annual exposure for comparison with FRC guides. However, for
many practical situations,
relatively few radionuclides yield the
major contribution to total exposure; by comparison, exposures
from others are very small.
TABLE I
.
FRC RADIATION PROTECTION GUIDES i/
INDIVIDUAL
POPULATION GROUP
Whele body
0.5 rem/yr
0.17 rem/yr
Thyroid 2/
1.5 rems/yr
0.5 rem/yr
1.5 rems/yr
0.5 rem/yr
Gonads
Bone marrow
Bone
-
3/
Bone (aiternate —
guide)
0.5 rem/yr
0. 003 pg of
5 rems/30 yrs
0.17 rem/yr
226... in adult 0.001 pg of
skeleton
226
Ra
in adult skeleton
1/ For conditions and qualifications see FRC Report Nos. } and 2.
2/ Based unon child's thyroid, 2 gms in weight and other factors
listed in paragraphs 2.10-2.14 cf FRC Report No. 2.
3/ Or the biological equivalents of these amounts of
226,
ae