SREL Reprint #0462
Radiocaesium
Dynamics In a Contaminated Floodplain Ecosystem in the
C. T. Garten Jr., J. B. Gentry, J. E. Pinder III,
Rebecca R. Sharitz, and M. H. Smith
Abstract
Radiocaesium Dynamics in a Contaminated Floodplain
Ecosystem in the Southeastern United States.
The fate of radiocaesium (primarily Cs-137) released
into a small stream, Steel Creek, during the operation of nuclear production
reactors has been studied. Releases
from fuel element disassembly basins occurred concurrently with releases of
heat-exchanger cooling water. Cessation
of reactor operations reduced stream flow and temperature and permitted
colonization of a radiocaesium-contaminated floodplain by plants and animals.
Subsequent studies have showed (1) mean radiocaesium concentrations in
the soil of approximately 100 pCi/g, (2) considerable spatial variability in
sediment radiocaesium concentrations, (3) significant radiocaesium uptake by
plants with soil-plant concentration factors usually greater than unity, and (4)
appreciable radiocaesium concentrations in animals.
Significant uptake by plants occurs because kaolinite, the principal clay
mineral in the sediments, does not fit radiocaesium into unavailable forms.
Radiocaesium uptake by plants exhibits considerable spatial heterogeneity
with radiocaesium concentrations in animals being proportional to plant
concentrations. Plant and soil
concentrations are not correlated, and the factors causing spatial heterogeneity
in plant uptake are currently being investigated.
Variability in radiocaesium concentrations between individuals of animals
species is less than that observed for plant species.
This reduction in variations in concentrations probably occurs because
animals are mobile and feed over a large area, hereby integrating widely varying
concentrations in vegetation.
SREL Reprint #0462
Garten, C.T., Jr., J.B. Gentry, J.E. Pinder III, R.R.
Sharitz, and M.H. Smith. 1975. Radiocaesium dynamics in a
contaminated floodplain ecosystem in the southeastern United
States. In Impacts of Nuclear Releases into the Aquatic
Environment, p. 331-347. Vol. SM 198/41. International
Atomic Energy Agency. Vienna, Austria.
