40
of the transuranic inventory in the water column of the lagoon.
237
The
Np concentrations in the lagoon and crater water samples were less
+.
to 1.42 and averaged
in 56 soil samples from 7 islands ranged from 0.066
water and biota
0,84 + 0.37 (Ga75), while the average ratio in 7 marine
Neither average value determined in the
than 0.2% of the measured 239 2405, concentrations in those samples.
samples was 0,66 + 0.40.
Plutonium
0.65 + 0.05
environmental samples differed preatly from the average of
Many types of samples from the Atoll contain 2385 239, 240, Pu,
and 244 Pu.
Most reported values are the sum
activities determined by alpha spectrometry.
o ¢ 239 Pu
and
240p,,
distributed widely throughout the Atol] and were detected in nearly
Atoll
ed
tissues of organisms in the Atol] if feeding and living are restrict
to specific regions of the Atoll.
The average 24051 .239py ratio in the yearly wrowth sections
water samples, sedimentary components (including fine unidentifiable
live sample of Favites virens coral
carbonate sands, coral fragments, Halimeda debris, foraminifera, and
Bikini Lagoon was 0.77 + 0.07
mollusk shells),
isotopic ratio in Enewetak samples.
living algae, benthic invertebrate tissues, planktonic
species, and marine vertebrate tissue all contain 23942405.)
The distribution of 2385, is ag wide among components in the marine
environment as is 23942405 u, but at lower concentrations.
238,
The similar isotople ratio in
isotopes by
mackeral tissue shows no obvious discrimination in uptake of
These radionuclides are
every type of marine and terrestrial sample analyzed to date.
for global fallout debris (Kr 76).
The
23H 240 Pu ratio determined in a variety of aquatic samples from
ws
collected from the western basin in
(No 75).
This value is similar to the
However,
the mean isotopic
and Eneu Islands is
concentration ratio in soil and vegetation of Bikini
1.15 (Mo76),
somewhat higher than the average in the Bikini coral
sample.
samples
Since the 2405, 239py activity ratio in sowe environmental
,
;
different regions of the lagoon ranges from less than 0.04 to greater
exceeds 1, it seems inappropriate to use the shorthand notation,
than 0.50,
when referring to the sum of
A few activity ratios of 2405, 239Pu was determined by mass
spectrometry,
The ratios in two water samples collected from the lagoon
during 1972 were 0.432 and 0.289 (No74).
Samples of mackeral bone and
viscera collected in 1972 near the island of Glenn had 2405,,239p,
activity ratios of 1.15 + 0.25 and 1,27 + 0.26,
respectively, while
been done in the literature,
239
Pu and
240
239 Pu,
Pu activities as has so often
Throughout this report,
2394240
iL
Pu wi
as
239
Pu
while
refer to the sum of the activities of the two radionuclides,
will refer to only that isotope.
197?
In two Enewetuk lagoon water samples collected during
2415, was measured by mass spectrometry.
(No 74),
ceauity
2394240 Pu activit
24h Pu:’*
y
The
In the 197? growth
goatfish viscera and tridacna tissue from nearby David had ratios of
ratios as of December 1972 were 1.24 and 2.56,
0.68 + 0.07 and 0.66 + 0,19 (Ga 75), respectively,
section of the previously mentioned live coral frav Hilini,
The activity ratios
cf a
the
pon ARCBEE