2
Significantly removed by physical decay.
Many of these longer-lived by-
products decay by alpha particle emission and cannot be measured by simple
survey techniques.
Tn Yoc2] areas if Bikini Atol’, a notential health hazard to the returning Marshallese people may exist from long-lived radionuclides.
The
increasing potential for release of transuranics to other marine environments
is suggested by the planned increased use of pluton{fum in power reactors by
more than a thousand between 1971 and 2000 (Shapley, 1971).
In the marine environment, the dissemination of transuranium elements
occurs through biogeochemical processes which affect a transfer of materials
between the sediments, waters and biota of the ecosystem.
In the contaminated
environment of Bikini Atoll, there has been little data published on the dissemination of radioactivity between the sediments and waters of the lagoon.
This has been partly due to the primary significance placed on biological and
other studies related to the prediction of radfation exposure to inhabitants
of the atolls.
In addition, the sediments at Bikini were significantly dis-
turbed at some of the nuclear detonation sites and a significant period was
required to achieve a quasi-steady state condition of sediment and radionuclides.
Recent studies on the concentration of long-lived radionuclides
remaining in the lagoon environment indicate that nearly steady state conditions may now exist.
Although the problems of data interpretation presented
by the complex multisource introduction of radioactivity to the lagoon still
remain, the present condition offers unique opportunities and advantages for
the study of the physical and biogeochemical processes which govern and wil]
continue to govern the fate of radionuclides in this marine ecosystem.
Without extensive previous investigations of Bikini sediments, elucidation of the concentrations of long-lived radionuclides, and the processes