into an area that might produce an "effective biological dose" (the
Fee ee eee
term given to the radiation exposure according to the above assumptions)
of one roentgen.~0
This graph may be extrapolated to other readings.
For example, if fallout begins three hours after detonation and the ~
dose rate at that time is 10 r per hour, about 67 r (effective
biological dose) will be accumulated provided personnel continuesto
live normally in the contaminated area.
This is computed asfollows:
10 = 67
0.15
It is frankiy recognized that in any single curve, such as
that shown in Figure 6, there are inherent a number of uncertainties.
Criteria based on deliberate analyses of the relevant data, however,
may be more valid than those determined under the duress of an emergency situation.
Such a simplified graph might provide radiological
monitors with a quick, even if rough, estimate of the potential hazards
and thus assist in making decisions on questions such as evacuation.
Using Figure 6, the idealized fallout diagram on page
was constructed to illustrate a possibie pattern from a single high
yield surface burst.
The two innermost isodose lines shown were selected to
suggest regions where (a) a significant percentage of personnel
might be expected to die (400 r) and (b) a few percent to become ill
(100 r), assuming continued occupancy of these areas with no special
protective measures.
the encompassed areas.
These percentages would, of course, rise within
The 50 r effective biological isodose line
has no unique significance but suggeststhe magnitude of dose which _
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=