Investigation of Radionuclide Migration at Sites Adjacent to the 30-km Exclusion Zone of the Chernobyl Nuclear Power Plant.

ABSTRACT: This paper reports the study of the vertical migration of radionuclides in soils at test sites adjacent to the 30-km Chernobyl Exclusion Zone. The results of this effort demonstrate that the migration processes for studied pollution occur similarly to the fuel fallout behavior at the vicinity of the Chernobyl Nuclear Power Plant (ChNPP) Unit 4. It was also observed that the main fallout component, 137Cs, originated from aerosol fallout and was bound in the surface layer. The authors determined a significant increase of 60Co, 94Nb, and 241Am radionuclide concentrations in soils near the ChNPP Unit 4 and suggested their appearance due to the installation of the New Safe Confinement. Niobium-94 activity is proposed as a marker for monitoring the "fresh" fallout in the Chernobyl Exclusion Zone.

Spectroscopy of Radiostrontium in Fuel Materials Retrieved from the Chernobyl Nuclear Power Plant.

ABSTRACT: Some basic methods of measuring radiostrontium activity by spectroscopic methods are considered in this study. These methods of assessing beta spectra and the characteristic radiation that accompanies the breakdown of radiostrontium are described. The sensitivity of these methods based on the assessments of beta spectra both after radiochemical procedures and without radiochemistry is presented. The objective of this paper is to review the spectroscopic procedures that have been developed and used to determine radiostrontium in various matrices; they are focused on modern methods. Samples of fuel particles of different origins, obtained from the Chernobyl Nuclear Power Plant Unit 4, were analyzed using the methods presented in this study.

Environmental problems associated with decommissioning the Chernobyl Nuclear Power Plant Cooling Pond.

Decommissioning of nuclear power plants and other nuclear fuel cycle facilities associated with residual radioactive contamination of their territories is an imperative issue. Significant problems may result from decommissioning of cooling ponds with residual radioactive contamination. The Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond is one of the largest self-contained water reservoirs in the Chernobyl region and Ukrainian and Belorussian Polesye region. The 1986 ChNPP Reactor Unit Number Four significantly contaminated the ChNPP Cooling Pond. The total radionuclide inventory in the ChNPP Cooling Pond bottom deposits are as follows: ¹³7Cs: 16.28 ± 2.59 TBq; 9°Sr: 2.4 ± 0.48 TBq; and ²³9+²4°Pu: 0.00518 ± 0.00148 TBq. The ChNPP Cooling Pond is inhabited by over 500 algae species and subspecies, over 200 invertebrate species, and 36 fish species. The total mass of the living organisms in the ChNPP Cooling Pond is estimated to range from about 60,000 to 100,000 tons. The territory adjacent to the ChNPP Cooling Pond attracts many birds and mammals (178 bird species and 47 mammal species were recorded in the Chernobyl Exclusion Zone). This article describes several options for the ChNPP Cooling Pond decommissioning and environmental problems associated with its decommissioning. The article also provides assessments of the existing and potential exposure doses for the shoreline biota. For the 2008 conditions, the estimated total dose rate values were 11.4 40 µGy h⁻¹ for amphibians, 6.3 µGy h⁻¹ for birds, 15.1 µGy h⁻¹ for mammals, and 10.3 µGy h⁻¹ for reptiles, with the recommended maximum dose rate being equal to 40 µGy h⁻¹. However, drying the ChNPP Cooling Pond may increase the exposure doses to 94.5 µGy h⁻¹ for amphibians, 95.2 µGy h⁻¹ for birds, 284.0 µGy h⁻¹ for mammals, and 847.0 µGy h⁻¹ for reptiles. All of these anticipated dose rates exceed the recommended values.