17
.
And, at the same time, the difference in
60
Co content between
the goatfish from near the crater and those at Bikini I. is
by a factor of about ten.
.
.
207...
It appears that the physical redistribution of
Bi is
similar to that of 6000,
but since the levels of 207535 are
lower than those of 60K by a factor of about 20, we are at the
‘limits of detection, with the method used,
from the crater.
for samples distant
The use of larger samples,
chemical separation
and more sensitive counting methods would make it possible to
determine 6005 77s ratios in sediments,
lagoon water and
organisms in different parts of the lagoon.
These ratios would
indicate whether transported radionuclides were primarily in
solution or on particles.
If the ratios remained constant, that
would be a strong indication of transport on particles.
The
results of analyses of selected samples for 20754 by gamma-ray
spectrometry and by chemical separation are compared in Table
t3.
Bismuth-207 will be a useful tracer in the future because
it has a long half-life,
30 years compared to 5.2 years for
6000.
Plutonium-239, with a half-life in excess of 24,000 years,
is another potentially useful tracer.
The sample analyzed for
plutonium were selected on the bases of collection location
and content of gamma-emitting radionuclides, which indicate