14C content in vegetation in the vicinities of Brazilian nuclear power reactors.
(14)C specific activities were measured in grass samples collected around Brazilian nuclear power reactors. The specific activity values varied between 227 and 299 Bq/kg C. Except for two samples which showed (14)C specific activities 22% above background values, half of the samples showed background specific activities, and the other half had a (14)C excess of 1-18%. The highest specific activities were found close to the nuclear power plants and along the main wind directions (NE and NNE). The activity values were found to decrease with increasing distance from the reactors. The unexpectedly high (14)C excess values found in two samples were related to the local topography, which favors (14)C accumulation and limits the dispersion of the plume. The results indicate a clear (14)C anthropogenic signal within 5 km around the nuclear power plants which is most prominent along northeastwards, the prevailing wind direction.
Dias
Cíntia Melazo
CM
National Commission of Nuclear Energy, Brasilia, Federal District, Brazil. cintia@cnen.gov.br <cintia@cnen.gov.br>
Santos
Roberto Ventura
RV
Stenström
Kristina
K
Nícoli
Iêda Gomes
IG
Skog
Göran
G
da Silveira Corrêa
Rosangela
R
D000396:Air Pollutants, Radioactive / Q000032:analysis*; D001938:Brazil; D002250:Carbon Radioisotopes / Q000032:analysis; D005843:Geography; D055848:Nuclear Power Plants; D009688:Nuclear Reactors
D000396:Air Pollutants, Radioactive; D002250:Carbon Radioisotopes