18
the greatest likelihood of the presence of plutonium.
The
values given in Table 14, therefore, probably are maximum values
for each type of sample.
The ratios of 239,240), to 238,,,
approach 2:1 at Eniman I. and are about 15:1 in Bravo Crater.
Bikini I.
soils contained no detectable 23854,
contained the highest concentration of
analyzed.
although they
239,240,
u of the samples
The presence of 239,240), and 20755 in goatfish viscera
is consistent and probably results from direct ingestion of fine
‘
.
ro
‘
particles of sediment during feeding.
The absence of
238
.
—§ Pu in
goatfish viscera as compared with the sediment merely reflects
a low concentration of this radionuclide,
below the Limits of
detection.
Although none of the 1969 samples were analyzed for the
X-ray emitter 63N4,
this radionuclide was found in concentrations
of 80 d/m/g dry weight in Bravo Crater sediment collected in
1967
(Beasley and Held,
1969).
Nickel-63 is of particular interest
as a tracer since it has a half-life of 92 years.
.
the clam kidney accumulates
63__,
Ni,
.
as it does
60
Co,
In addition,
.
and is there-
fore an indicator organism for the presence of Oni,
:
.
‘
Another long-lived radionuclide,
108m
Ag,
:
L,
with a half-life
of approximately 100 years, has been identified for the first
time among the radionuclides at Bikini.
This radionuclide was
detected from the gamma-ray spectrum of the hepatopancreas of