pCi/g were found at any depth are
Analysis of the sediment and core
samples indicates the presence of 40K
60
90
101
102m
106
Co,
Sr,
Rh,
Rh,
Ru,
enclosed in cross-hatched areas in
Fig. 152.
1275)
Thus it seems likely that soil bearing
13% og
1525)
1545)
ate
20735, 235). 2385. 239, 2405, and
high concentrations of plutonium — as
opposed to pieces of plutonium — is largely
241
Am in some, but not necessarily all
limited to a band roughly 350 m wide
of the samples.
across the island,
uniformly distributed over the lagoon
centered on the visible
plutonium soil layer,
Each nuclide is non-
floor, with the highest levels generally
Within this band,
plutonium concentrations are greatest on
found in the northwest part of the lagoon,
the ocean side, less on the lagoon side,
2-3 km southeast of the islands ALICE
and least in the island center — a finding
through IRENE; the next highest levels are
consistent with historical data which in-
found in the area southwest of YVONNE;
dicate that debris was bulldozed away
and the lowest levels are found south of a
from the shot point toward both shore-
line extending across the lagoon from the
lines after the event which produced these
Southwest Passage to TOM.
plutonium particles,
for example, shows the distribution pat-
Except for this band across the island,
tern for 95.
Figure 158,
Similar figures have been
there is no evidence which indicates that
prepared for each of the predominant
plutonium particles on or near the ground
species found.
surface in the larger area shown in
Many of the radionuclides found in the
Fig. 152 are also found at any significant
marine sediment and core samples were
depth below the surface.
not detected in the water samples, in102mpy, 106R 1256) 1525)
cluding
and 235
Because of the
discrete nature and random distribution
of these particles, of course, the only way
that their distribution could be further
U.
In only 15 samples from the
northern part of the lagoon were
80 G6,
established would be by analysis of very
1555),
large volumes of soil,
13765 and 239, 24054 were positively
20755 and 241 am detected.
identified in all samples.
Radioactivity Levels in Enewetak
Table 217 gives
the mean surface water concentration of
Lagoon
13765 and 239, 2405, in the four quadrants
of the lagoon, in the ocean close to the
Approximately 858 samples taken from
the Enewetak lagoon environment were
east side of the lagoon,
analyzed by germanium gamma-
areas in other parts of the world for
spectroscopic (GeLi) and wet-chemistry
comparative purposes.
and for several
In the plankton samples, the most
techniques to determine the distribution
of radioactive species in the lagoon, in-
abundant isotopes observed were 90,
cluding 345 sediment and bottom cores,
(av 0.86 pCi/g, wet wt) and 207 Bi
82 seawater and seawater filters, 21 algae,
(0.83 pCi/g), followed in decreasing order
plankton, or coral, and 410 fish samples.
Figure 157 shows the major sampling
of abundance by ©°Co (0.68 pCi/g),
239, 2405, (9.39 pCi/g), 1° Eu (0.24
pCi/g), 744am (0.23 pCi/g), and !3’cs
locations for this marine program.
II-8