Radioactive Aerosols in Sub-Reactor Rooms of the Shelter Object within Conditions of the New Safe Confinement

V. Ye. Khan, O. S. Lagunenko, V. O. Krasnov, O. O. Odintsov, O. K. Kalynovskyi, V. M. Bezmylov,
V. O. Kashpur, P. V. Sabenin, O. A. Svirid, A. V. Tkach, V. P. Kovalchuk

Institute for Safety Problems of Nuclear Power Plants, NAS of Ukraine, 36a, Kirova st., Chornobyl, 07270, Ukraine

DOI: doi.org/10.31717/2311-8253.23.1.4

Abstract

Radionuclide composition, volumetric activities, radionuclide deposition densities and dispersity of aerosols sampled in 2019–2022 in rooms 012/7, 012/15, 210/7, and in 2017–2022 in room 304/3 of the Shelter object are presented, where lava-like fuel-containing materials (LFCM) penetrated after the accident. It was stated that activity median aerodynamic diameter of carriers of radioactive products of accident in rooms 012/7, 012/15 and 210/7 increased significantly over the past 8–10 years and reached 10 µm. It evidences their dispersion origin. The availability of transuranium elements in radionuclide composition of aerosols in all rooms in the ratios that are close to similar ones in the LFCM shows that the aerosols arose as a result of lava degradation. Substantial enrichment of aerosols in rooms 304/3 by 137Cs as well as 137Cs and 90Sr – in rooms 012/7, 012/15, and 210/7 relatively to lava compositions indicate the presence of two sources more influencing radionuclide composition of aerosols. It is confirmed by the values of parameters of disperse composition of aerosols.

Keywords: New Safe Confinement, Shelter object, lava-like fuel-containing materials, aerosols, volumetric activity, density of radionuclide deposition, activity median aerodynamic diameter, dispersity

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