Use of the radiation environmental monitoring results for control of the atmospheric releases of iodine-131 by the facility

Abstract

The analysis was performed, whether the following characteristics correspond with each other: data on the annual release of the radionuclide by the enterprise, the calculation model used for establishing the annual permissible release levels of radionuclides, and the annual average volume activity of the radionuclide, determined using the data of routine radiation monitoring of the surface air. Such analysis was carried out for the release of 131I from the L.Ya. Karpov Scientific Research Institute of Physics and Chemistry (Obninsk) in 2013–2022. It is shown that for the enterprise release in 2013–2022, the results of environmental radiation monitoring confirm both the data of radiation control of the 131I release source and the correctness of the radionuclide air transfer calculation model. The average annual meteorological dilution factor of the 131I for the enterprise release in the surface layer of the atmosphere, estimated from monitoring data, does not exceed the model calculated value. Strong correlation was revealed between the average annual volume activity of 131I in the surface air, obtained using measurement results, and data on annual air releases of the enterprise. No correlation was found for the variability of the dilution factor estimated by the transfer model and monitoring data. It may be caused by the heterogeneity of the 131I releases by the enterprise during the year.