Host phase of Pu-239,Pu-240 and Am-241 in deep-sea sediment

Host phases of fallout Pu-239,Pu-240 and Am-241 were studied in the surface sediments obtained in 1994 from abyssal basins of relatively small area of the western North Pacific. An analytical procedure involving sequential ch emical extraction was employed for partitioning the host phases of the nucl ides in sediment into five fractions: (1) exchangeable, (2) bound to carbon ate, (3) bound to hydrous Fe-Mn oxides, (4) bound to organic matter and (5) residual. Decrease of total Pu-239,Pu-240 concentration with decreasing as sociation of Pu-239,Pu-240 with organic matter, high Am-241/Pu-239,Pu-240 a ctivity ratio in carbonate phase and somewhat high proportion of oxidized P u-239,Pu-240 in leachable phases suggest a possibility of post-depositional diagenetic remobilization of Pu from sediment to water column.