Assessment of the input of particulate 239,240Pu and 137Cs from the Neman River into the Curonian Lagoon

The Curonian Lagoon is a unique system that temporary reservoir of water, accumulating about 62% the suspended solids in river runoff. average activity plutonium particulate matter water Neris River was 0.26±0.02 Bq/kg, and 137Cs ranged from 23±8 to 49±12 Bq/kg. flux dissolved species estimated be (78±61) × 109 Bq/year. Preliminary estimates indicate annual input 239,240Pu Neman into 0.9 GBq, which 0.56 GBq accumulates sediment lagoon.