Senet ee

302

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TRANSURANIUM ELEMENTS IN SAMPLES COLLECTED NEAR BIKINI ATOLL

the alpha-acuvity ralto of these nuclides tn

The position where the “Sth Fukuryu-Maru”™

is shown as a daughter nuclide of 7 Pu.

analyzed in this study were collected in 1973

selssa show the weight of a sample required
to detect Idis/min of other nuclides in the
sample which contains 10 dis/min/mg of ?’Pu.

of Tokai University. Accurate latitudes and
longitudes of these locations are given tn

the debris, as shown in Fig. Ib. For mass
number 241, the calculated activity of “'Am

Furthermore, the values on the upper ab-

MATERIALS

A 6me sample of “Bikini Ash” was
obtained from the 70-mg sample stored in the
Institute of Physical and Chemical Research,
Japan. In this present study, made in 1974 ~
1975, 2meg of the sample was submitted for
analysis of 7?"pu and “Am, and 4 mz of
the sample was used for tow energy photon
spectroscopy. I was found by its spectrum,

shown in Fig. 2, that 7°**"pu, “Am, '? Eu,
MCs and Sb were contained in this sample.

was exposed to this explosion debris in 1954
is plotted in Fiz. 3. Marine sediment samples

hy a marine research vessel, the “Tokai 1”

Table 1] together with water depths, topographies of sea bottom, and the characteris-

tics of the sediments. All sediment sumples
were collected with a dredger. The samples

are

identified

as

73105, 73108, 73109 and

73113 as shown in Table 1. One gram of cach

sample was dried at 110°C and used for
plutonium and americium analyses. Sample
No. 73113 contained manganese nodules,
which were removed before analysis.
METHODS

An aliquot of “Pu and '“Gd. solution was
added to the samples as yield tracers for
a Ray-activity

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