University of Washington
Abstract
CONCENTRATIONS AND REDISTRIBUTION OF PLUTONIUM, ANERICIUM
ANO OTHER RADIONUCLIDES ON SEDIMENTS AT BIKINI ATOLL LAGOON
by Robert Paul Marshatl
The concentrations and distributions of
23942405 2385
Uy
24)
Am,
207
Bi
Sey, 1376, and 60 Co in the sediments of Bikini atoll lagoon were investigated by radiochemical and radiometric analyses of 33 surface sediment
samples and 9 sediment cores collected in 1972.
An initial survey of the
concentrations of the alpha emitting radionuclides in crater and lagoon
sediments was made using a thin source counting technique for measuring total
alpha radioactivity.
The total alpha values obtained for a Bravo crater
sediment were greater (ca. 13%) than the sum of
23942405, 2385, 24la, and
the natural radionuclide concentrations measured or estimated, indicating the
possibility of other alpha emitting radionuclides which were bomb produced.
Sediments collected from a large area of the northern quadrant of the
lagoon, from two of the three detonation craters sampled, and from a region
southeast of the site of the underwater Baker detonation, typically contained
only finely pulverized sediments.
Although these sediments contained the
highest concentrations of al] radionuclides measured, the areal distribution
patterns of each of the radionuclides, except 23942405 and eat a, were
dissimilar,
and
137
Whereas the highest concentrations of 23942405, 24T an, 155 Eu
Cs were measured in surface sediments collected from lagoon stations,
60
the highest concentrations of 238 Pu (19 pCi/g), 207,.
Bi (432 pCi/g) and
“Co
(306 pCi/g) were measured in below surface crater sediment samples.
The shape of the major distribution of
2394240 Pu and 241 Am concentra-
tions in the lagoon may be described as roughly elliptical.
The highest