then attributable not to soil migration but rather to plant uptake anc
other losses.
To develop this pseudo dose rate, the following equation
was used:
:
“,
A(Ci/m) = p x efZaye:
0
where a is the activity density in pCi/g, z is the depth in cm, 6 is
the soil density (1.89/er?) and the factor of 1078 provides the con-
version from pCi to Ci and from em”? to me
The dose rate for Cs! 2”
is given by
D(R/HR) = 6.21 A(Ci/m)
Table 3 sumerizes the comparison between the estimated and measured
cs29? dose rate and the-pseudo dose rate as well.
As can be seen, the
estimate is a factor of about 20 higher than the measurec value and
~
that roughly half of this difference can be accounted for by mechanisms
_ Other than soil migration.
This comparison indicates that simple
estimates can be used to provide bounding upper limits and that it
might be possible to refine these estimates to within an order of
magnitude by correcting for soil migration.
The conditions for this
refinement would be:
a.)
b.)
that for the location of interest, there had
been no cleanup or major earth moving prior
to the survey and
that the soil profiles would be similar to that
found on undisturbed Enewetak tslands receiving
fallout (such as Fig. 1409 of "Summary of Findings”
chapter of NVO0-140).
Having compared dose rate estimates with survey results for
' Enewetak, we can now turn to those islands in the northern Marshalls
that were contaminated by fallout from shots at Bikini.
DOE ARCHIVES
one-hour
the
requires
used
being
scheme
g
estimatin
the
Because
dose rate as input, it is important to first establish that off-site
measurements were made in all cases where there was fallout on the
fslands of interest. If these data are incomplete, estimations cannot
“so