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APPENDIX II 51
TABLE V. CRITICAL PATHWAY APPROACH TO DISPOSAL
ASSESSMENT FOR AQUEOUS RADIOACTIVE WASTE
Estim ated a c tiv ity le v e l in w ater a t equ ilib riu m from one cu rie per day
&
C o n cen tratio n factors for c r itic a l m a te ria ls
A ctiv ity le v e ls in c r itic a l m a te ria ls
&
L o cal survey data
♦
D a ily in ta k e /d a ily exposure
&
ICRP m axim u m perm issible d a ily in tak e/exp o su re
I
M axim um p erm issible d aily discharge rate
These concentrations are used, together with suitable concentration
factors, to derive concentrations for the material or materials
likely to provide the greatest degree of human radiation exposure;
then, from the known utilization of these m aterials, the perm issible
concentrations of radioactivity are ascertained and, in consequence,
the perm issible water concentrations and discharge rates. The
vitally important aspect of such an exercise is the habits survey,
because it is necessary at an early stage to establish the working,
eating and recreational habits of the loca l population, and in certain
instances those of populations at some distance from the contaminated
area, in order to make quantitative estimates of food intake, or of
hours exposed to external radiation. In this way rates of introduction
compatible with acceptable dose limits for m em bers of the public
may be established, or estimates of the dose resulting from uncontrolled
contamination, e. g. weapon-test fall-out, may be made.
The early results of monitoring in relation to potentially
exposed groups allow the classification of situations into three
principal types:
(a) those where contamination of critical materials leads to
a significant fraction of the ICRP dose lim it for m em bers
of the public;