Data/hora: 16/06/2024 00:09:48

Provedor de dados: 	5	
País: 	France	
Título: 	Comportement biogéochimique d'antimoine (Sb) et de tellure (Te) dans le milieu côtier : vers des scénarios de dispersion des radionucléides de Sb et de Te en cas de rejets accidentels de centrales nucléaires

Coastal biogeochemical behaviour of antimony (Sb) and tellurium (Te) : an approach to Sb and Te radionuclide dispersal scenarios in case of accidental nuclear power plant releases	
Autores: 	Gil-diaz, Teba.	
Data: 	2019-01-11	
Ano: 	2019	
Palavras-chave: 	Antimoine; Tellure; Estuaire de la Gironde; Partition solide/liquide (Kd); Extractions sélectives; Antimony; Tellurium; Gironde Estuary; Solid/liquid partitioning (Kd); Selective extractions.	
Resumo: 	Antimony (Sb) and tellurium (Te) are relatively uncommon contaminants (stable isotopes) and may form short-lived fission products (radionuclides) released into the environment during nuclear power plants accidents. Little is known about their respective biogeochemical behaviours, necessary for general contamination studies and post-accidental radiological risk assessment.This work provides original knowledge on Sb and Te biogeochemical behaviour in highly dynamic continent-ocean transition systems: the Gironde Estuary and the Rhône River. Concentrations, spatial/temporal variations, solid/liquid partitioning (Kd), and fluxes are studied from long-term records at the watershed scale. Four estuarine sampling campaigns during contrasting hydrological conditions show higher Sb solubility and Te particle affinity in the estuary than in the upstream fluvial reaches. Historical records (1984-2017) in wild oysters from the estuary mouth do not show clear trends of past or recent contamination, but measurable bioaccumulation suggests that potential uptake of radionuclides is likely to occur. Combined adsorption experiments using isotopically-labelled (spiked) Sb and Te, and subsequent selective extractions of carrier phases from suspended particulate matter (SPM) suggest that spiked Sb and Te are more mobile and potentially bioaccessible than their environmental (inherited) equivalents. Radiotracer adsorption experiments using environmentally representative concentrations of both Gironde and Rhône systems underpin that highly soluble elements may show contrasting reactivity between inherited and spiked forms.Radionuclide dispersion will greatly depend on (i) the geographical position of the source (Rhône) and/or the maximum turbidity zone (MTZ; Gironde fluvial-estuarine system), (ii) the succession of hydrological situations during and after the accident, and (iii) the biogeochemical reactivity and half-lives of the radionuclides. First scenarios on hypothetical dissolved radionuclide dispersion in the Gironde Estuary suggest (i) low sorption of Sb to the SPM, implying a transport of radionuclides in dissolved phase towards the coast, and (ii) high retention of Te within the MTZ, especially for accidental releases during flood conditions, linking the fate of radioactive Te to long estuarine SPM residence times (1-2 years). Potential upstream migration of Te radionuclides in the MTZ towards the city of Bordeaux during the following summer season and Te decay into radioactive iodine warrants further evaluation of the associated potential radiotoxicity.	
Tipo: 	Text	
Idioma: 	Francês	
Identificador: 	https://archimer.ifremer.fr/doc/00607/71891/70592.pdf

https://archimer.ifremer.fr/doc/00607/71891/	
Editor: 	Université de Bordeaux	
Relação: 	info:eu-repo/grantAgreement/EC/FP7/614002/EU//SCHeMA	
Formato: 	application/pdf	
Fonte: 	info:eu-repo/semantics/openAccess

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