ETUDE DE LA SORPTION DES ELEMENTS DANS LES SEDIMENTS MARINS DES GRANDS FONDS DE L'ATLANTIQUE NORD
We have studied the retention of actinide elements (Np, Pu, Am) and of Cs in the sediments of the ocean deeps around Cap-Vert. Plutonium: retention increases with temperatures of 4 to 30 degrees C, then stays constant from 30 to 80 degrees C. Desorption is slow. Americium: absorption is very strong at any temperature. Measurements of a wide variety of sediments show that retention is not affected by facies (including carbonated sediments). Neptunium: retention is more or less constant between 4 and 15 degrees C, and distinctly higher at 30 - 50 degrees C. It is reversible. Caesium: absorption decreases slightly from 4 to 30 degrees C, but increases rapidly at 50 to 80 degrees C. At the lowest temperatures it is reversible, but it appears to be irreversible at 50 degrees. Cs absorption is subject to ponderal concentration. With equal amounts of activity, retention of 135-Cs is weaker than that of 137-Cs: likewise the addition of the stable isotope causes a decrease in the amounts of Kd in Cs-137. Finally, this paper presents preliminary results showing the natural metallic element content of the sediments.
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Numéro d'enregistrement: 1989123090100 / Dernière mise à jour le: 1987-01-01
Langues disponibles: fr