Safety_Series_041_1975 - gnssn - International Atomic Energy ...

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72 APPENDIX IV
2. D e riv e d W ork in g L im its . M eth od ology
The Derived Working Limits for routine environmental monitoring
at Atucha were determined by the methods indicated below,
which will be described in greater detail in another document.
2.1. DWL for the contamination of foodstuffs by one
radionuclide
In the case of a standard man, not exposed to external radiation,
and consuming only one type of contaminated foodstuff, the DWL=IL/g,
where IL is the uptake limit and g the annual amount of the foodstuff
consumed. Obviously, the dose resulting from consumption of a
foodstuff with a concentration C over a period of one year will give
a dose commitment of (C/DWL) XDL, where Dl is the corresponding
dose limit.
2.2. DWL for the case of irradiation due to contamination of
various foodstuffs and to external radiation, in both
cases by one radionuclide
Let the concentration of the radionuclide in each foodstuff be
termed Q and the external radiation dose to the organ R. The
dose limits are not exceeded if
If the concentrations and external dose are equal to their respective
DWL values, the expression is equal to one. The equation can
be solved for a given DWL if the relations between the concentrations
(and the external dose) are known. This is the case when all
exposure pathways have a common precursor compartment in the
'exposure model1. If the concentration in this precursor is Ca,
Fai is the transfer parameter to the foodstuff i, and FaR is the
transfer parameter to the external dose, then we have