Accession Number : ADA330410

Title :   Transport and Fate of Anthropogenic Radionuclide Contaminants in the Ob River Estuarine System.

Corporate Author : STATE UNIV OF NEW YORK AT STONY BROOK MARINE SCIENCES RESEARCH CENTER

Personal Author(s) : Cochran, J. K. ; Fisher, N. S. ; Moran, S. E.

PDF Url : ADA330410

Report Date : SEP 1997

Pagination or Media Count : 29

Abstract : This report describes results of field and laboratory studies focusing on the Ob River system. Analyses of suspended particles collected in 1994 and 1995 show that the 240Pu/239Pu atom ratio is lower than global fallout throughout the system (except in the Taz River). Low values of the ratio in the Ob River before it joins the Irtysh suggest that Tomsk-7 is an important source of reprocessing Pu to the system. As much as 39% of the Pu in this part of the river could be derived from reprocessing. 239,240Pu/137Cs activity ratios are depressed relative to global fallout in the Irtysh and Tobal Rivers suggesting that releases from Mayak are also occurring and labelling particles in the system. Mayak is also the apparent source of elevated 12% to the Ob. Decreases in 129I from the Tobal to the Ob at confluence points of the Tobal with the Irtysh and Irtysh with the Ob are evident, probably due to dilution. Laboratory mixing experiments of filtered Ob River water and sea water were performed to determine radionuclide removal in the estuary of the Ob. Removal varied in the order Am>>>Co=I>Cs. Am displayed significant removal (tilde 38%) at 5 ppt salinity, with most of the uptake onto particles in the 0.2 - 1 micrometer size range. Cs and I were most reactive at 0 ppt salinity and uptake decreased with increasing salinity. Irradiation of Ob River water with UV to photooxidize dissolved organic matter caused an increase in uptake of Am onto particles.

Descriptors :   *RADIOACTIVE ISOTOPES, *NEUTRON IRRADIATION, *ESTUARIES, LABORATORY TESTS, ORGANIC MATERIALS, CONTAMINANTS, RIVERS, SALINITY, SEA WATER, ANTHROPOLOGY.

Subject Categories : Hydrology, Limnology and Potamology
      Radioactiv, Radioactive Wastes & Fission Prod

Distribution Statement : APPROVED FOR PUBLIC RELEASE