The cycling of radionuclides through the macroflora of White Oak Lake

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:7207197

Mohrbacher, D A

This research considers the role of aquatic macrophytes as one process influencing the transport and cycling of [sup 137]Cs and [sup 60]Co in White Oak Lake and the weir pools of its two tributaries. White Oak Creek and Melton Branch by examining the mechanisms of plant uptake and decomposition. The source of radionuclides, the sediment or the water, to the rooted, submerged macrophytes Myriophyllum spicatum L. and Elodea canadensis L., was determined to evaluate their potential for remobilizing sedimented contaminants to the overlying water column. These plants accumulated approximately 30-50% of their [sup 137]Cs content, and up to 67% of their [sup 60]Co content from the sediments. Approximately 68% of the total [sup 137]Cs and 35% of the total [sup 60]Co contained in Myriophyllum was released in a dissolved state to the water column during the course of senescence. The release was constant and linear over time. This is in contrast to litter bag studies also conducted using air-dried plants, where the radionuclides were released exponentially. Assessing the role macrophytes play in the transport and cycling of radionuclides in White Oak Lake is considered in relation to the total radioecology of the system. The macrophyte populations in the three systems were characterized by examining species composition, abundance, distribution and biomass dynamics in relation to their radionuclide content. This information, along with the data gathered from the uptake and decomposition studies, and measurements of various abiotic and physicochemical parameters were used to develop a dynamic compartmental box model of White Oak Lake to understand how macrophytes influence [sup 137]Cs transport and cycling. Model simulations showed that if the discharge of [sup 137]Cs to the lake were to cease, the rooted, submerged plants would continue to contribute [sup 137]Cs to the water column as a result of sediment remobilization.

• Research Organization: Tennessee Univ., Knoxville, TN (United States)
• OSTI ID: 7207197
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540330* -- Environment
Aquatic-- Radioactive Materials Monitoring & Transport-- (1990-)
ALKALI METAL ISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CESIUM 137
CESIUM ISOTOPES
COBALT 60
COBALT ISOTOPES
ECOLOGICAL CONCENTRATION
ENVIRONMENTAL TRANSPORT
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LAKES
MASS TRANSFER
MATERIALS
MINUTES LIVING RADIOISOTOPES
NATIONAL ORGANIZATIONS
NUCLEI
OAK RIDGE RESERVATION
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
PLANTS
RADIOACTIVE MATERIALS
RADIOACTIVE WASTES
RADIOECOLOGICAL CONCENTRATION
RADIOISOTOPES
RADIONUCLIDE MIGRATION
SEDIMENTS
SURFACE WATERS
US DOE
US ERDA
US ORGANIZATIONS
WASTES
YEARS LIVING RADIOISOT
YEARS LIVING RADIOISOTOPES