for the calculation of wet-chemistry-
tions.
equivalent
2395.)
tam concentrations.
Although the average 24d an:
and 241 23a 240
Pu dpm ratios
Comparisons of the Bikini soil, Eneu
of 1.11 + 8.1% and 0.512 + 7.9% are
soil, and Bikini vegetation are
different than those in the Bikini
presented in Tables 11, 12, and 13,
soils when compared on an atsolute
respectively.
basis,
Only those samples
the deviations associeted
giving positive 241 and 239,240,
with the individual determinations
signals have been included.
indicate that the soil and vegetation
_
From Table 11 it is apparent
ratios
are
the
Same.
that the Bikini soils exhibit quite
PLUTONIUM-ISOTOPE RESULTS
consistent 241ns Pu Yatios regardless of the profile depth.
fact,
In
Mean isotopic atom ratios of
the agreement among the mean
24054 and 241oy to 2395 have been
ratios for the various profiles
calculated from the individual mass
is rather remarkable.
Spectrometric results.
Results indi-
cate that the average dpm ratios of
244ni py and 24dye 239 t2 40, on
These ratios
from the various sample types and
sampling locations are presented in
the island are quite specific and are
Table 14.
1.17 + 8.1% and 0.550 + 8.1%,
activity ratios as determined from
respectively.
the mean atom ratios and half-lives
Table 12,
As evidenced in
Also included are the
listed in Table 4.
there is also excellent
Soil results from
agreement among the Eneu soil samples.
the two islands are indistinguishable.
Although the total number of samples
Statistically, the soil and vegetation
is considerably less, there is no
results are in agreement... The absolute
appreciable variation with profile
differences between the 240 pu
depth.
For Eneu Island soil samples,
the 241.2395, and 2412394240, |
soil and vegetation results show the
difficulties associated with the
dpm ratios are 1.08 + 3.0% and
measurement of minor isotope in
0.512 + 3.6%, respectively.
samples with low concentrations.
Statisti-
cally, there is no difference between
Extensive experience in mass spectro-~
the 241 to Pu concentration ratios
metry has shown that for low level
of these two islands.
samples such as vegetation, measure-—
Bikini vegeta-
tion ratios in Table 13 are in
ment of minor isotopes wil] be biased
reasonable statistical agreement as
higher than
indicated by the fact that the average
To construe that the differences in
dpm ratios exhibit lower deviations
soil and vegetation are an indication
than any of the individual determina-
of fractionation would be erroneous.
~20-
WD 50 0052
the actual concentrations.