PLUTONIUM AND AMERICIUM - UPTAKE FROM CONTAMINATED SEDIMENTS BY POLYCHAETE NEREIS-DIVERSICOLOR

The polychaete N. diversicolor O.F. Mueller was exposed to marine sediments contaminated with Pu and Am either through the testing of nuclear devices or by the release of liquid waste effluent from a nuclear fuel reprocessing plant. The uptake of both Pu and Am was small, about 0.5% of the concentration of these transuranics in the sediments. The degree of relative uptake of Pu from both sediments was comparable; relative uptake of Am from sediments contaminated by waste effluent was greater than that from nuclear test debris sediments. Applying the measured Pu concentration factors from sediment and those previously determined from water-uptake experiments to environmentally determined Pu concentrations in sediments and overlying waters leads to the tentative conclusion that water may be the predominant pathway for Pu accumulation by deposit-feeding worms like N. diversicolor.