TRANSURANIUM RADIONUCLIDES IN COMPONENTS OF THE BENTHIC
catastrophic events,
little alteration in the present distribution of
transuranics in the sediment is anticipated during the next few decades,
ENVIRONMENT OF ENEWETAK ATOLL
The Atoll seems to have reached a chemical steady state in the
V.E.
partitioning of 23942405, between soluble and insoluble phases of the
Noshkin
environment.
Lawrence Livermore Laboratory
the
concentrations in the sediment agrees well with recently measured
Environmental Sciences Division
California
Ob
23942405
amount of dissolved radionuclides predicted to be in equilibrium with
University of California
Livermore,
Using an experimentally determined Ka for
average concentrations in the water at both Fnewetak and Pikini Atolls.
94550
The remobilized
2394240
Pu has solute-like characteristics.
1t passes
readily and rapidly through dialysis membranes and can be traced ag a
solute for considerable distances in the water.
the present inventory of
We estimate that 50” of
2394240, in sediment wil] be remobilized in
solution and discharged to the North Equatorial Paeific aver the next
ABSTRACT
Data on the concentrations and distributions of transuranium
250 yr.
radionuclides in the marine environment of Enewetak Atoll are reviewed,
INTRODUCTION
The distributions of the transuranics in the lagoon are very
heterogeneous.
The quantities of transuranics generated during the
Nuclear test years at the Atoll and now associated with various sediment
components are discussed.
Whenever possible, concentrations of Alan
and 23942405, are compared.
The lagoon is the largest reservoir of
tranguranics at the Atoll and radionuclides are remobilized continuously
to the hydrosphere from the solid source terms and are cycled with
components of the biosphere.
Although 2394240, is associated with
filterable material in the water column,
the amount that is relocated
and redeposited to different areas in the lagoon is small.
Barring
Large inventories of several transuranium radionuclides (Ne73)
persist in the marine environment of Enewetak Atoll].
Forty-three
nuclear weapons tests were con acted by the United States at Enewetak
between 1948 and 1958.
‘he testing produced close~in fallout debris
that was contaminated with transuranics and that entered the aquatic
environment of the Atoll.
More transuranics were transported westward
to Enewetak in airborne debris and water contaminated from nuclear
testing at Bikini Atol],
Global fallout deposited a small] additional
amount of transuranics to the Atoll.
Presently the largest inventory of
E
CHI
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