Measurements of the paniculate distribution of plutonium and americium in Spanish Mediterranean coastal waters have been carried out. Plutonium-239, 340 and 241Am concentrations have been measured in suspended particulate matter by filtering (< 0.22 μm) large volume (200-300 litres) sea water samples. Results indicate that paniculate plutonium constitutes on average 11 ± 4% of the total concentration in sea water. In the case of americium, this percentage rises to 45 ± 14%. From the 241Am 239, 240Pu activity ratios it is clear that suspended particulate matter is enriched in 241Am relative to 239,240Pu by a factor 8 ± 4. Plutonium and americium in surface Mediterranean coastal waters appear to be fractionated as they present a different transfer rate to the particles. Our measurements allowed us to estimate sediment-water distribution coefficients (Kd), which are a key parameter to interpret differences observed between the behaviour of plutonium and americium in sea water. Distribution coefficients Kd have been estimated to be (1.4 ± 0.5) × 105 litres kg-1 for plutonium and (0.9 ± 0.5) × 106 litres kg-1 for americium in surface Mediterranean coastal waters. © 1995.
|Journal||Journal of Environmental Radioactivity|
|Publication status||Published - 1 Jan 1995|