THE CONTENT OF NATURAL RADIONUCLIDES IN TECHNOLOGICAL RESIDUES OF UKRAINIAN INDUSTRIES

to assess the naturally occurring radioactive materials (NORM) content in industrial waste in Ukraine and assess which industries should be a subject for the regulatory oversight.

Sampling and analysis followed the same procedure in all cases. 250 samples were taken in total. High- resolution gamma spectrometry system ORTEK (US) with the high-purity germanium semiconductor detector (HPGe) were used for sample measurements. AMERSHAM (Germany) standard source was used for calibration of the gamma spectrometer. The estimated minimum detected activity for the measurement time of 3600 s was 0.5 Bq/kg for Thorium-232, and Radium-226 and 1.5 Bq/kg for Potassium-40.

Industries with the potential NORM content in their waste were approached in this research. 32 enterpris- es were the subject for investigation. It has been established average content of NORM in waste iron ore enterpris- es varies from 210 to 100 Bq/kg, 226Ra - from 14 to 45 Bq/kg, 40K - from 21 to 350 Bq/kg, 232Th - from 5 to 26 Bq/kg and 238U - from 19 to 48 Bq/kg. It was determined the content of NORM in waste is lower than the exemption lev- els. The average concentration of individual radionuclides does not exceed 10-20 Bq/kg. The assessment of the NORM average activity concentration in sludge and waste samples from different spots of the industrial site esti- mated that values may differ as much as 3 times, with average activity of 8,440 Bq/kg for 226Ra, 28,600 Bq/kg for 232Th, 11,000 Bq/kg for 210Pb. The NORM level in pipe sediments and silts of oil exceed the established exemption lev- els and range as follows: 210Pb 3-11 kBq/kg, 226Ra 2.9-8.4 kBq/kg, 232Th 0.8-2.8 kBq/kg, 226U 0.18-6.9 kBq/kg.

Monitoring of the NORM levels in wastes has identified the need to establish regulatory control and oversight of the oil industry in the country.