Forecast assessment of the radiation impact of ionizing radiation sources on the environment after decommissioning of nuclear facilities

Forecast assessment of the radiation impact of ionizing radiation sources on the environment after decommissioning of nuclear facilities.

Plotnikov D. A., Mishagina A. S., Schadilov A. E.

Radiation safety of the environment is one of the high-priority challenges both for operation of the existing nuclear facilities, and for planning of future activities in the field of atomic energy use. This paper presents the results of analysis of the current Russian legislative and normative documents regulating safety in the field of atomic energy use in terms of ensuring radiation safety of the environment (biota) elements during operation and decommissioning of nuclear facilities. Methodological recommendations on assessment of radiation exposure on biota elements, suggested by the Russian and international organizations involved in ensuring nuclear and radiation safety, were analyzed. Based on this analysis, the authors have chosen an approach allowing for conservative assessment of the adverse radiation impact on the representative (reference) elements of water and land biota using dose conversion factors, which allow you to switch from the measured characteristics of radioactive contamination of the environment to the exposure dose for plants and animals. In order to demonstrate application of the chosen approach, the forecast assessment was carried out for the absorbed dose rate received by the reference elements of water and land biota on the territory covered by radiation impact from the production uranium-graphite reactor EI-2 that was decommissioned using the option “entombment in-situ”, and the obtained values were compared with the criteria of environmentally safe exposure and permissible radiation impact on the environment. The obtained results demonstrate the possible approaches to considering of radiation impact on the environment while carrying out forecast calculations for nuclear facilities’ safety.

Keywords: decommissioning, radiation safety, environment, biota, exposure dose.

Article language: Russian. Pp. 39–50. [in Russian]. DOI: 10.26277/SECNRS.2023.107.1.004.