"
| |
The other option evaluated is that of chemical competition.
We have
established a series of experiments showing that K (potassium) added to the
K-deficient coral soil is very effective in preventing the uptake of 137Cs
into food crops, including coconuts (BARC,
1988;
Robison et al.,
1988). —
Through the addition of K, the !37Cs concentration can be reduced by more than
90%,
so estimated doses at Bikini Island from al] exposure pathways, including
the terrestrial food chain, would be below the current Federal
guidelines.
radiation
In addition, the added K increases the quality, growth rate, and
productivity of the vegetation. |
The major advantage of the chemical-competition alternative is that it
eliminates the tremendous environmental
option.
insult inherent in the excavation
The mature coconut trees and all other vegetation can be left in
place.
In addition, all the surface soil with organic matter is
left in
place.
A perceived disadvantage is that although the 137¢s can be reduced in
food crops by adding K so that the total estimated doses are below 170 mrem/y,
the '37cs and the 905r, 239+240py, and 241Am, are still present in the soi}.
The !37cs and 90Sr will disappear due to radiological decay and environmental
loss in about 90 y.
very
Jong
periods
The 239+240py and 24am will of course be present for
of
time.
However, the
estimated
doses
from
these
radionuclides are very low, and the radionuclides will become less available
as they move deeper in the soil column.
ACKNOWLEDGMENTS
We
appreciate very much
John Rehder,
the excellent support of James
William Phillips,
and
Bobby Lynn Smith
Johnson,
in the field and
laboratory phases of the project.
Carol Stoker and Steve Kehl have been of
great
reduction, and evaluation of the data
help
in
the organization,
resulting from the analysis of samples collected at Bikini Atoll.
Mark Mount
has played a key role in the quality-control phases of our analytical effort.
The processing of thousands of samples, the data retrieval and reduction was
completed through the superb efforts of the following people:
Jeff Brazelton,
Nina Brown,
Karen Davis,
Mike
Granillo,
Liena Boone,
Steve
Hall,
Richard Herbert, Henry Jones, Ben Kuhn, Joe Silveria, Stan Thompson, and all
the people who worked on the 1978 NMIRS project.
72
(The latter group of people