Aerial Deposition of Plutonium in Mixed Forest Stands from Nuclear Fuel Reprocessing

Autor: D. C. Adriano, J. E. Pinder
Rok vydání: 1977
Předmět:
Zdroj: Journal of Environmental Quality. 6:303-307
ISSN: 1537-2537
0047-2425
DOI: 10.2134/jeq1977.00472425000600030015x
Popis: Concentrations of /sup 238/Pu and /sup 239/,/sup 240/Pu were determined in bark, organic matter, and soil samples collected in the summer of 1975 from pine (Pinus taeda) and hardwood (Quercus falcata; Carya tormentosa) stands near a nuclear fuel reprocessing plant at the U.S. Energy Res. and Dev. Admin.'s Savannah River Plant near Aiken, S.C. The results indicated that tree crowns intercepted fallout Pu (Pu-bearing particles) and produced higher Pu concentrations in the organic matter and soil under tree crowns. Higher /sup 239/,/sup 240/Pu concentrations were found under pines than under hardwoods. Plutonium concentrations in the O1 (litter, A/sub 00/) and O2 (organic matter, A/sub 0/) layers were higher than those in mineral soil, but most of the Pu was contained in the mineral soil. Higher contents of /sup 239/,/sup 240/Pu were observed near the tree stems than in locations outside of the tree crowns. In pines these values were 163 and 80 nCi /sup 239/,/sup 240/Pu/m/sub 2/, and in hardwoods, 122 and 80 nCi /sup 239/,/sup 240/Pu/m/sub 2/, for the respective locations, from the litter to the 15-cm depth. The proportion of /sup 238/Pu contained in foliage, litter, and organic matter was greater than for /sup 239/,/sup 240/Pu. However, themore » latter radionuclides had a greater proportion contained in the mineral soil. This observation is consistent with the more recent releases containing a higher percentage of /sup 238/Pu from reprocessing operation. Plutonium concentrations in the 5 to 15 cm depth indicated limited Pu mobility in soil, but /sup 238/,/sup 240/Pu concentrations at this depth were higher near tree stems, suggesting greater mobility perhaps as a result of stem flow.« less
Databáze: OpenAIRE
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