I
-
However, a group of film badge readings was obtained covering a
range of values which varied with exposure conditions (Reference 3).
These readings are summarized in Table 2.3. Several badges were worn
both outdoors and indoors. One badge which remained outdoors over the
28.5-hour exposure reached the upper limit of 98 r given in the table,
Several other badges kept inside a refrigerator indoors gave the lowest
value of 38 r., Skin contamination in the Rongerik group appeared to
have been much reduced by the protective measures taken and the resulting beta doses appeared clinically to hava been clearly lower than in
the other groups,
TABLE 2,3 = Film Badge Readings on Rongerik
Location of Badges
Calculated Dose to Badges (r)
Indoors and Out
lk to 52
Outdoors only
98
Inside Refrigerator Indoors
2.3
|
38
LATER SURVEYS
During the period 8 to 11 March, more extended surveys of each of
the islands were made by a monitoring team equipped with five AN/PDR-39
instruments (Reference ),
of the survey
80~-curie Co
Twenty-four hours previous to the departure
party, three of the instruments were calibrated on an
source and cross checked at 0.320 r/hr, where they were
found to be in close agreement,
Using these instruments, measurements
were made in the inhabited areas of all four islands at waist height
(approximately 3 feet above ground},
Table 2.4: is a summary of these
data, Since these later readings were made under better controlled
conditions than the emergency surveys at the times of evacuation given
in Table 2.2, the data of Table 2.) were taken to be the best measure-
ment at a given time of the gamma dose rates in air and were used in
the calculation of the total external gamma dose,
No information existed on the quantity of beta contamination on
the skin of any of the exposed individuals, Further, no experimental
data allowed any reliable calculation of the beta dose rate to an
individual from fission products on the ground. Thus the only basis
for any estimate of external beta dosage was data from other field
tests and fallout measurements, This question is discussed further in
Chapter 8, and a rough estimate for possible beta dose from the ground
is made there,
: