The status and trends in radioactive contamination of groundwater at a LLW-ILW storage facility site near Sosnovy Bor (Leningrad region, Russia).

The article presents results of field studies at a site of radioactive waste storage and disposal facilities (the so-called LD RosRAO site, Sosnovy Bor, Leningrad region, Russia). The objective of the study is to overview the history and occurrence of groundwater contamination to answer the question whether the radioactive plume is historical (formed due to accidents, which happened at the beginning of the operations with the radioactive waste) or the release of radioactive solutions to groundwater is still occurring. The main method used to study the evolution of radioactive contamination is to analyze long-term observations of tritium, total alpha, and total beta activities in groundwater samples.

Sorption of Cs, Sr, Se, Tc, Eu, Pu on fractured rocks of the Yeniseysky site (Nizhne-Kansky massif, Krasnoyarsk region, Russia).

The study demonstrates the effect of sorption properties of fractured host rocks from the Yeniseysky site (Nizhne-Kansky rock massif, Krasnoyarsk region) on the migration of dissolved radioactive components (Cs, Sr, Se, Tc, Eu, Pu) in the deep geological conditions of a high-level radioactive waste repository. Estimates of radionuclide distribution coefficients between the aqueous solution and fractured rocks obtained from sorption experiments were used to study the influence of various petrographic types and fracture-filling substances on the retardation of radioactive components by different fractured rock units of Nizhne-Kansky rock massif. Based on the results of sorption experiments, we concluded that the type and attributes of rock discontinuities, as well as the mineral composition of the material in fractures, are crucial for the immobilization of radionuclides during their migration through a geological environment.

Geological and physicochemical controls of the spatial distribution of partition coefficients for radionuclides (Sr-90, Cs-137, Co-60, Pu-239,240 and Am-241) at a site of nuclear reactors and radioactive waste disposal (St. Petersburg region, Russian Federation).

The paper presents a study of the sorption properties of sediments of different geological ages and lithological types, governing radionuclide retention in the subsurface (up to 160 m beneath the surface) within the area of potential influence of the Northwestern Center of Atomic Energy (NWCAE), St. Petersburg region, RF. The focus of this work is mostly on the sedimentary rocks of two types, i.