beta and gamma.
The above equation permits estimating the long term
gamma activity, provided there are one-hour dose rate measurements at
.
the locations of interest.
IJ.
RESULTS
The first step in the analysis was to compare the dose-rete
estimates developed as prescribed above with recent surveys performec
for the Enewetak atoll.
This comparison would indicate the magnitude
of the difference due to neglecting the migration of the isotopes into
the soil and plant uptake.
Figure 1 is a map of the Enewetak atoll
showing the location of 3 islands chosen for the comparison--Alice,
Janet, and Yvonne. Table 1 Jists the measured dose rate from the 1951-58
operations for these three islands as well as the 1972 estimates for
the e537 component.
—
The 1972 survey (reported in NVOD-149) provides average exposure
rates separately for cst3? and C08,
(This latter isotope is not a
fission product but results from weepon debris activation).
In addition,
average profiles are provided of cs}3? concentration (pCi/g) versus
soii depth for Alice and Janet. It is important to note that there
evidently have been no cleanup activities (which would invalidate the
comparisons discussed here) on Alice and Janet.
Yvonne is a different
Situation because of construction and earth moving activities during
the testing period.
Large variations in exposure rates occur on Yvonne;
thus, mean levels are misleading. For this reason, Yvonne will be dropped
from the comparison.
:
DOE ARCHIVES
Table 2 provides the cs}9? survey data for Alice and Janet.
The dose rates can be compared directly with the estimates of Table J.
As expected, the estimates are high since among other reasons it was
assumed that the activity was all on the surface.
The soil profiles
of activity concentration versus depth can be used to develop a pseudo
dose rate by relocating the activity back to the surface.
A comparison
of this value with the estimate is useful in that the difference is
L6G