Radiation accidents associated with violation of rules of gathering and recycling of ferrous and non-ferrous metal scrap in the Russian Federation in 2010-2023

The study presents summary, analysis, and hygienic assessment of data on the radiation accidents related to violations of the rules of gathering and recycling of ferrous and non-ferrous metal scrap within the Russian, based on data from the Radiation Accidents and Incidents Database of the Information and Analytical Center of Rospotrebnadzor on Radiation Safety. The aim of the study was to analyze information on radiation accidents associated with violations in the collection and handling of scrap metal occurring in the Russian Federation over period from 2010 to 2023. A total of 971 radiation accidents related to improper handling of scrap metal were recorded across 41 regions in Russia during the study period. The largest number of the accidents occurred in Vologda (206), Sverdlovsk (178), Khabarovsk (150), Saint Petersburg (116), and Orenburg (52) regions. A negative trend in the accident frequency was observed, with an average annual decline rate of 12%, indicating a steady decrease in occurrences over the last 14 years. The primary sources of radioactive contamination in scrap metal included fragments of various radiation-related equipment, pipes, and technological equipment from the oil and gas industry contaminated with natural radionuclides during use (primarily 226 Ra and its salts), as well as devices containing permanent luminescent substances based on 226 Ra salts. The identified sources were most commonly associated with the radionuclides 226 Ra (63%), 137 Cs (12%), 60 Co (9%), 238 U (9%), with occasional cases involving 241 Am, 232 Th, and 90 Sr. In 66% of cases, the ambient gamma dose equivalent rate on the source surface exceeded 1 μSv/h; in 27% it exceeded 10 μSv/h, in 7% it exceeded 100 μSv/h, and in five cases were in range from 1 to 8.8 mSv/h. It was found that sources of ionizing radiation posing potential health risks to the public have been detected throughout the study period. In 14 cases, radioactive contamination was identified in scrap, indicating accidents of melting down radiation sources without investigation into the circumstances or assessment of potential adverse effects. In most (64%) of the registered radiation accidents, the batches of scrap metal were accompanied by radiation control certificates from accredited laboratories, confirming compliance with sanitary standards and regulations. The analysis of radiation accidents related to violations in the collection and handling of scrap metal revealed that the current domestic system for ensuring radiation safety during the procurement and sale of scrap metal remains effective and relevant. Recommendations for improving emergency response during investigations of such radiation accidents have been provided to the Rospotrebnadzor organizations.