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Fic. 2. Low-energy gamma- and X-ray spectrum on “Bikini Ash”,
;
.
“A
.
plutonium isotopes and *“'Am, respectively.
Cenmpte
4a
One of these tracers, "Gd,
a 3.18-MeV al-
PAP 2am
ayy
pha-emitter, was prepared by the reaction of
Pup. 4ny "Gd, and it was confirmed that
the Gd/Am ratio did not change during the
same radiochemical procedure as used in the
present work. Details of the carrier-free "Gd
preparation (Ko76) and the usefulness of “Gd
as tracer were previously reported elsewhere
;
“Np ——> Pu (1569). The concentration of
'
the **Pu tracer was calibrated with a stan-
Pu
solution
supplied
from
monia to the supernatant, the coprecipitation
of
plutonium
and
other
clements
with
hydroxide precipitates (iron hydroxide, etc.)
was carricd out. When only a little amount of
precipitate was obtained, it was spiked with
Ata
about 5mg Fe* carrier. The precipitate was
ft
i
+ 9.709 | [ba
mip ey"
.
1 BIKINI
tO MOL. +9
my
the
Radioactivity Centre, Amersham, England.
Each sample was treated with 8m hot
hydrochloric acid. By adding aqueous am-
je
yy
.
0
uw.
ey
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50
thm
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we
Go
.
FIG. 3. Analytical resulls for
:
t
om =f;
di
{-
t
'
ir
senting
'
“f
(Sa72). The other tracer nuclide, ?“Pu, was
produced by the reaction of 7”Nply #)
dard
|
'
:
1
.
.
1
_—
-
Pekew asbhtFuk ur pus morul
‘9
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;
RONGELAP
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ne
2199240
°
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167
16
zi
Pu and
.
Am in
“Bikini Ash’ and marine sediment samples. The
open circles indicate sampling points and the
exposure point of the “Sth FPukuryu-Maro.” The
bold fine, set by the U.S. Navy, was the boundary
of the area prohibited for navigation at the time of
the nuclear bomhtest in (984.