The geochemistry of fallout plutonium in the North Atlantic: II. sup 240 Pu/ sup 239 Pu ratios and their significance

Journal Article · Thu Oct 01 00:00:00 EDT 1987 · Geochimica et Cosmochimica Acta; (USA)

DOI:https://doi.org/10.1016/0016-7037(87)90144-X· OSTI ID:7147512

Buesseler, K O; Sholkovitz, E R ^[1]

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1. Woods Hole Oceanographic Institution, MA (USA)

A systematic decrease in the {sup 240}Pu/{sup 239}Pu ratios in marine sediments is found with increasing water depth along a transect of cores between Woods Hole and Bermuda. The {sup 240}Pu/{sup 239}Pu atom ratios range from similarly ordered 0.18 on the shelf to similarly ordered 0.10 at 5000 m but do not change with depth in individual cores. A model is presented which can account for the range of {sup 240}Pu/{sup 239}Pu ratios found in this and other similar studies. The authors propose that there have been at least two distinct sources of fallout Pu to this region. The major source of Pu is global stratospheric fallout, characterized by a {sup 240}Pu/{sup 239}Pu ratio of 0.18 and a relatively long residence time in seawater. The second source is characterized by a much lower {sup 240}Pu/{sup 239}Pu ratio, and relative to global fallout it must have been much more efficiently removed from the water column to deep-sea sediments. They suggest that surface-based low yield testing at the Nevada Test Site is the only source of low ratio fallout Pu which could account for the timing, inventories, and refractory characteristics of this second component of fallout Pu inputs to the North Atlantic.

• DOE Contract Number: FG02-85ER60358
• OSTI ID: 7147512
• Journal Information: Geochimica et Cosmochimica Acta; (USA), Journal Name: Geochimica et Cosmochimica Acta; (USA) Vol. 51:10; ISSN GCACA; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540330* -- Environment
Aquatic-- Radioactive Materials Monitoring & Transport-- (1990-)
ACTINIDES
ATLANTIC OCEAN
CHEMICAL ANALYSIS
CHEMICAL COMPOSITION
CHEMISTRY
ELEMENTS
ENVIRONMENTAL TRANSPORT
EXPLOSIONS
FALLOUT
FALLOUT DEPOSITS
GEOCHEMISTRY
HYDROGEN COMPOUNDS
INTERFACES
MASS TRANSFER
METALS
NUCLEAR EXPLOSIONS
ORIGIN
OXYGEN COMPOUNDS
PLUTONIUM
POROSITY
QUANTITATIVE CHEMICAL ANALYSIS
RADIONUCLIDE MIGRATION
SEAS
SEAWATER
SEDIMENT-WATER INTERFACES
SEDIMENTATION
SEDIMENTS
SURFACE WATERS
TRANSURANIUM ELEMENTS
WATER
WATER CHEMISTRY