Modeling the potential radionuclide transport by the Ob and Yenisey Rivers to the Kara Sea

A major portion of the former Soviet Union (FSU) nuclear program is located in the West Siberian Basin. Among the many nuclear facilities are three production reactors and the spent nuclear fuel reprocessing sites, Mayak, Tomsk-7, and Krasnoyarsk-26, which together are probably responsible for the majority of the radioactive contamination found in the Ob and Yenisey River systems that feed into the Arctic Ocean through the Kara Sea. This manuscript describes ongoing research to estimate radionuclide fluxes to the Kara Sea from these river systems. Our approach is to apply a hierarchy of simple models that use existing and forthcoming data to quantify the transport and fate of radionuclide contaminants via various environmental pathways. We present an initial quantification of the contaminant inventory, hydrology, meteorology, and sedimentology of the Ob River system and preliminary conclusions from portions of the Ob River model.