EXPOSURE RATES CALCULATED FROM SOIL SAMPLE DATA
87 Gs
°°Co
+25 sb
Clearing Experiment Area
Total activity per em”
4200 pec
90 pe
600 pe
Calculated from concentration in soil sample
Inferred from field spectrum
240 uwr/hr
19 pr/hr
24 ur/hr
52 ur/hr
6 ur/hr
9 ur/hr
Percentage of total exposure
84%
8%
6%
77%
9%
14%
rate based on soil
analysis (see p. 11)
Percentage of total exposure
rate from field spectrom-~
eter and ionization chamber
data
74
251
OO
10 feet north of center
30 feet north of center
WA
Core activity (pc/gm)
74
26
The percentages of the total exposure rate due to each isotope
were calculated as discussed in Section II (p. 11) and agree
reasonably well with the field spectrometric data in contrast
to the calculated exposure rates which are quite high, much
higher than could be explained by the excess activity from
3 - 5 inches.
The core data also given in the table illustrate
the large local variation in the total activity which is
probably the main reason for the high values for the calculated exposure rates.
This cleared area was resurveyed two weeks later upon
return to Bikini Island.
The exposure rate measured at the
center of the area was essentially the same as before (59.6
ux/hr).
Additional measurements were made around the edges