Proceedings of the International scientific and practical conference ―Advances in Science and Humanity‖ (March 29-31, 2026) / Publisher website: www.naukainfo.com. – Vienna, Austria, 2026. - 176 p.

35 The radionuclide composition of Zaporizhstal dump waste blast furnace slag . Slags accumulate NR. The gamma-ray spectrometric method determines the specific activity of NR ( Ci ) and the effective specific activity ( Сef ) of slag granulometric fractions. The results are in fig. 1. The natural radionuclides discovered are as follows: 40К, 226Ra and 232Th. A major contribution to Сef is made by radionuclide 226Ra, the second сontributor is 232Th. In the work [28] it was shown that heterovalent isomorphic replacement in the structures of minerals of blast-furnace slags that are in crystalline or amorphous state are the most probable mechanism of NR accumulation. A major contributor to the total activity of Zaporizhstal dump waste blast furnace slag is isotope 40К, the second contributor is 226Ra which contribution exceeds 20 % and is hazardous because of radon release. Slag fractions have different specific activation. The exceeding of specific activation is marked for fractions 1.25–2.5 mm and 2.5–5 mm. The most radiation- free fractions have the particles of a size more than 10 mm and less than 0.63 mm. The least value of С эфф and the low content of 226Ra are for the fraction of a particle size more than 20 mm (74.3 Bq/kg). According to С эфф, slag and its separate fractions, which are related to the first class of a radioactive hazard ( С эфф ≤ 370 Bq/kg [29]), can be used in construction engineering without restrictions.